激光烧结铜基合金的关键工艺及基础研究
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摘要
作为快速原型制造技术重要分支的直接金属激光烧结可在没有工装夹具或模具的条件下,利用激光束将疏松粉体材料逐层烧结成形复杂形状的三维零件。但目前直接金属激光烧结的研究仍处于起步阶段,对其中涉及的金属粉体材料制备与表征、工艺控制与优化、及烧结过程冶金物理化学理论等都有待深入探讨。本文选取铜基金属粉末作为直接激光烧结研究对象,主要研究内容和结构安排如下。
论文第一部分,研究激光烧结多组分Cu基合金粉末(Cu-Cu10Sn-Cu8.4P)的关键工艺和基础理论,内容包括:
(1)多组分铜基合金粉末设计、制备及材料成形性研究,获取了激光烧结用金属粉末的物性指标、制备技术和表征方法
直接激光烧结因其特殊的成形方式(逐行烧结、逐层叠加)和成形过程(高能激光动态扫描下的瞬态冶金过程),对材料成形性有特殊要求,即粉体化学成分和物理性质须适于逐层铺粉和激光逐层烧结的工艺。作者基于粉末在激光作用下部分熔化的液相烧结机制(Cu充当骨架金属,Cu-10Sn充当粘结金属,Cu-8.4P作为脱氧剂或稀释剂),设计制备了多组分铜基金属粉末Cu-Cu10Sn-Cu8.4P,该粉末体系在液相成形机制下可有效抑制“球化”效应,降低由热应力导致的翘曲变形。铜基金属粉末的组分比例、颗粒形貌、粒度、松装密度等的优化设计结果表明,一方面,适当增加Cu-10Sn比例,可提高烧结致密度;但若超过50 wt.%,则会导致“球化”效应。Cu-8.4P比例以15 wt.%为宜,P元素可充当脱氧剂而防止烧结体系氧化,亦可充当稀释剂而降低熔体表面张力、改善固液润湿性,从而提高激光成形性。另一方面,粗(Cu平均粒径54μm)、细(Cu-10Sn平均粒径28μm)粉末共混形成“双峰”粉体,并使其具有较宽粒度分布(≥70μm);使用球形或近球形细粉,均可提高粉体松装密度及烧结致密度。在粉末制备中,首次提出了“磨球混粉”工艺,并通过合理设置球料比(5:1)、转速(100 rpm)及混粉时间(90 min),在不破坏原始粉末主要特性的前提下,实现了多元系粉体混粉均匀性,为提高烧结致密度和组织均匀性奠定了基础。
(2)多组分铜基合金粉末激光烧结的工艺成形性研究,实现了高致密度复杂形状铜基金属样件激光烧结精密成形
结合金属粉末激光烧结涉及的复杂物理冶金和化学冶金过程,作者从直接金属激光烧结基本成形机制和综合调控激光参数和铺粉参数入手,获得了金属激光烧结中抑制“球化”效应、改善成形精度和控制成形机制、提高烧结致密度的基本规律。提出了将不同激光功率和扫描速率下的粉体激光熔凝特征划分为微熔区、部分熔化区、持续熔化区、球化区、及完全熔化区这一新颖的工艺思路;且以部分熔化区为适宜工艺区间。在保证适宜成形机制条件下,通过合理设定光斑直径(0.3 mm)、适当增加激光功率(>300 W)、减小扫描速率(<0.06 m/s)、减小扫描间距(≤0.15 mm)、或降低铺粉厚度(≤0.30 mm),能改善烧结致密度及组织均匀性。发现并总结了3类激光烧结“球化”机制:“第一线球化”、“收缩球化”和“自球化”;并可通过合理设定粉床预热温度及控制激光功率和扫描速率加以抑制。提出了利用“能量体密度”对激光成形性作精确化和稳定化调控,对于制备的多组分铜基金属粉末在能量体密度为0.23 kJ/mm3条件下,可实现最大外观尺寸210 mm×70 mm×9 mm,相对密度>90%,最大尺寸误差<2%、拉伸强度>140 MPa的复杂形状铜基金属样件的激光烧结成形。
论文第二部分,研究激光烧结制备亚微米WC-Co颗粒增强Cu基块体复合材料的成形工艺、冶金机制及基础理论,内容包括:
(1)激光烧结制备亚微米WC-10Co颗粒增强Cu基复合材料的材料设计与工艺研究,获取了高性能颗粒增强金属基复合材料激光快速成形的关键材料与工艺
激光烧结具有工艺灵活性和取材广泛性,可用于新型材料及零件的制备与成形;同时,因激光作用的高度非平衡性,也有望使成形材料具有特殊的组织及性能。对于陶瓷颗粒增强金属基复合材料,可用包覆金属的金属陶瓷和基体金属制备成复合粉体,在激光烧结过程中易实现金属-金属界面结合。作者设计并制备了包覆Co的亚微米WC(增强体)和Cu(基体)的复合粉末,成功获得了激光烧结制备的WC-10Co颗粒增强Cu基复合材料块体试样。发现高能激光的快速作用机制致使WC颗粒完好保留亚微米尺寸特征,甚至部分细化至纳米级。同时,对工艺条件(激光参数和铺粉参数)作了优化,发现增加激光功率至700 W、在高于0.04 m/s条件下提高扫描速率、或减小铺粉厚度至0.30 mm以下,均能提高烧结致密度,改善增强体分散均匀性以及与基体结合性。在材料界面结构的研究中,发现将增强相WC通过WC-10Co复合粉体加入,可将WC/Cu(陶瓷/金属)界面转变为WC/Co/Cu(陶瓷/中间层金属/金属)界面,也即将粘结相Co作为基体金属Cu与增强相WC的“润湿媒介”,从而改善颗粒/基体界面结合性。同时,通过优化粉末体系中增强体含量,避免了在增强体含量较低时(≤20 wt.%),因复合体系热膨胀系数较高、熔体过热倾向明显而出现的“球化”效应;或在增强体含量较高时(≥40 wt.%),因液相生成量偏少、熔体粘度过高而导致的增强颗粒团聚现象。实验结果表明WC-10Co以30 wt.%为宜。
(2)激光作用下增强颗粒与基体金属推挤/俘获机制的理论研究,提出了提高颗粒/界面俘获效应、改善颗粒分散均匀性及界面结合性的工艺和材料措施
激光快速作用下颗粒与动态凝固界面的交互作用是影响颗粒增强金属基复合材料激光成形性能的又一关键因素。已有的关于颗粒/界面作用的研究,一般将固液界面简化为平界面,而将颗粒假设为置于平界面前沿的单个球形颗粒或少量规则分布的颗粒;此种假设对于复合体系激光成形过程难以成立。一方面,因基体与颗粒热导率和比热的差异,从本质上决定了复合体系的起始平界面存在局部不稳定性;另一方面,因激光束移动扫描,熔体流动具有紊乱性,故凝固过程难以通过平界面方式进行。作者通过引入枝晶形态的凝固界面,建立了用以描述激光快速凝固条件下增强颗粒与动态固液界面交互作用的理论模型;分析结果表明,颗粒俘获的主控因素是激光作用下的熔体临界过冷度。为提高颗粒俘获效应,特别是在增强体质量分数较高的条件下改善其分散均匀性,在工艺方面,可适当提高激光功率和扫描速率,以提高熔体过冷度;在材料方面,可在粉体中适量添加稀土元素来降低熔体表面张力,改善固液润湿性;钉扎晶界/相界,抑制晶粒/颗粒粗化;提高形核率,细化晶粒。实验研究结果表明,在高质量分数(50.0 wt.%)亚微米WC-10Co和Cu复合粉末中添加适量La_2O_3(1.0 wt.%),可实现对增强颗粒的有效俘获,提高颗粒分散均匀性以及颗粒/基体界面结合性,并获取良好的成形致密度。
As an important branch of rapid prototyping (RP) techniques, direct metal laser sintering (DMLS) enables the quick fabrication of complex shaped three-dimensional (3D) components by layerwise fusing loose powder with a scanning laser beam, without the use of fixturing or tooling. However, DMLS is still in its early stage of development. Significant further research and understanding are required in the aspects of materials preparation and characterization, process control and optimization, and theories of physical and chemical metallurgy involved in DMLS. In the present thesis, the direct laser sintering of Cu-based metal powder is carried out, with the main research work listed as follows.
In the first part of this thesis, key processes and basic mechanisms involved in direct laser sintering of multi-component Cu-based alloy powder (i.e., Cu-Cu10Sn-Cu8.4P) are studied, with the main conclusions drawn as follows.
(1) Design, preparation, and laser sintering mechanism of multi-component Cu-based metal powder, obtaining materials properties, preparation technique, and characterization method of metal powder for the use of DMLS
Due to the special forming fashion (i.e., line-by-line sintering followed by layer-by-layer bonding) and sintering process (i.e., transient metallurgical process induced by high-energy laser scanning) of DMLS, the material formability is of special concern, i.e., the chemical compositions and physical properties of powder materials should be feasible for powder deposition and laser sintering. In the present work, a multi-component Cu-based metal powder, which consists of a mixture of Cu, Cu-10Sn, and Cu-8.4P, is developed for DMLS. Laser sintering of this powder system is through the mechanism of liquid phase sintering with partial melting of the powder. The Cu acts as a structural metal, the Cu-8.4P acts as a binder, while the Cu-8.4P is taken as a deoxidizing agent or a fluxing agent. Such a semi-solid sintering mechanism can well alleviate the“balling”effect and decrease the curling deformation induced by thermal stress. The component ratio, particle morphology, particle size distribution, and loose packing density of the powder system are optimized. It shows that a proper increase in the amount of the Cu-10Sn leads to a denser microstructure; however, at a high content larger than 50 wt.%, the“balling”phenomena occur. A suitable weight fraction of the Cu-8.4P in this powder system is 15 wt.%. The additive phosphorus element can act as a deoxidizing agent to prevent the sintering system from oxidation. The phosphorus can also act as a fluxing agent to decrease the surface tension of molten materials, thereby improving the liquid-solid wettability and the resultant sintered densification. On the other hand, using a bimodal mixture with a broad size distribution (≥70μm) produced by mixing coarse Cu powder with a mean particle size of 54μm and fine Cu-10Sn powder with a mean particle size of 28μm, and using spherical or near-spherical fine powders can generally lead to an increase in the loose packing density of the powder and thus the densification of the laser sintered powder. A novel“ball mixing”process is primarily developed to prepare the powder system. With a reasonable setting of the weight ratio of balls to powders (5: 1), the rotation speed of mixer (100 rpm), and the mixing time (90 min), the multi-component system is homogeneously dispersed without destroying the initial characteristics of the starting powder, thereby giving a material basis for improving the sintered density and microstructural homogeneity.
(2) Optimization of processing conditions of multi-component Cu-based metal powder using DMLS, realizing the precise fabrication of complex shaped Cu-based metal parts with high density
With consideration of the complex physical and chemical metallurgical processes during DMLS, the author studies the basic operating mechanism of DMLS and the influence of laser processing conditions and powder depositing parameters, so as to obtain the generic principles for increasing fabricating precision by alleviating“balling”effect and for improving sintered densification by controlling sintering mechanism. At different combinations of laser power and scan speed, the mechanisms of powder melting are divided into slight melting, partial melting, excessive melting, balling, and complete melting, among which the partial melting proves to be a feasible one. With a feasible sintering mechanism permitted, setting a suitable spot size (0.3 mm), increasing laser power (>300 W), decreasing scan speed (<0.06 m/s), narrowing scan line spacing (≤0.15 mm), or lowering layer thickness (≤0.30 mm) generally lead to a higher densification and a more homogeneous microstructure. Three kinds of balling mechanisms under different processing conditions are proposed, i.e.,“first line scan balling”,“shrinkage-induced balling”, and“self-balling”. Setting a suitable preheating temperature of powder bed or controlling laser power and scan speed can well alleviate the balling phenomena. In order to provide a precise and steady control of laser sintering process, an“energy density by volume”is defined. Using the“energy density by volume”of 0.23 kJ/mm3 is able to produce best quality Cu-based metal parts with complex configurations. The maximum dimensions are 210 mm×70 mm×9 mm, the one-step sintered density is large than 90% theoretical density, the maximum dimension error is less than 2%, and the tensile strength is larger than 140 MPa.
In the second part of this thesis, processing conditions, metallurgical mechanisms, and basic theories involved in direct laser sintering of submicron WC-Co particulate reinforced Cu matrix bulk composite materials are studied, with the main conclusions drawn as follows.
(1) Material design and process control in direct laser sintering of submicron WC-10Co particulate reinforced Cu matrix composites, obtaining key materials and processes for laser rapid manufacturing of high quality particulate reinforced metal matrix composites (MMCs)
DMLS, due to its flexibility in feedstock and shapes, exhibits a great potential for developing novel materials and components. Meanwhile, the highly non-equilibrium state induced by a scanning laser beam might lead to the formation of some special structures and properties. As to MMCs reinforced with ceramics particulates, the ceramics phase can be firstly coated with a metal to form a metalloceramics before mixing with the matrix metal, so as to form metal-metal interfaces during laser sintering. In the present work, laser sintering of a composite system consisting of the submicron Co-coated WC powder (i.e., the reinforcement) and the Cu powder (i.e., the matrix) is performed; and the WC-10Co particulate reinforced Cu matrix composites in bulk form are successfully prepared. It is found that with a rapid action of a high-energy laser beam, the WC reinforcing particulates are either well remained the submicron characteristics or further refined to nanometer scales. The processing conditions including laser parameters and layer thickness are optimized. It shows that increasing the laser power to 700 W, increasing the scan speed above 0.04 m/s, and decreasing the powder layer thickness below 0.30 mm generally lead to a higher densification with a uniform particulate dispersion and a coherent particulate/matrix bonding ability. With regard to the interfacial design of such a composite system, the WC reinforcing phase is added in the form of WC-10Co composite powder, so as to change the WC/Cu (ceramics/metal) interface into the WC/Co/Cu (ceramics/interlayer metal/metal) interface. In other words, the Co can act as a wetting intermedium to improve the wetting characteristics between the Cu matrix and the WC particulates, leading to a sound interfacial bonding coherence after sintering. On the other hand, the weight fraction of the WC-10Co reinforcement in the powder system is optimized. It shows that using a low reinforcement content of 20 wt.% results in severe balling phenomena, due to a high average composite coefficient of thermal expansion (CTE) and a superheating of the melt. A severe particulate aggregation occurs at a high reinforcement content of 40 wt.%, because of a limited liquid formation and the resultant high liquid viscosity. An optimal content of WC-10Co reinforcement is found to be 30 wt.%.
(2) Theoretical studies on mechanism of laser-induced pushing/trapping of reinforcing particulates by matrix metal, providing process and material measures to improve particulate/interface trapping effect, homogenize particulate dispersion, and enhance particulate/matrix bonding coherence
The interaction between the reinforcing particulates and the advancing solidification front under the rapid action of a mobile laser beam is another important factor in determining the laser formability of particulate reinforced MMCs. In most studies concerning the particle-interface interaction, the problem is simplified by accounting a single spherical particle or a small amount of well separated particles ahead of a steady state planar solidification front, which is unlikely to be realized in the laser-induced solidification process of a solid-liquid composite system. This is because (i) a local destabilization of an initially planar solid-liquid interface caused by the different thermal conductivities and specific heats of the solidifying matrix and the particulate material is inherent to the solidification process of a composite system; (ii) a significant turbulence in the laser-generated melt pool will easily destroy such a planar solidification interface. In the present work, a theoretical model, which introduces a dendritic solidification front, is developed for describing the behavior of the reinforcing particulates at an advancing solid-liquid interface during the laser-induced rapid solidification process. The substantial governing parameter for particulate engulfment is found to be the laser-induced critical undercooling. In order to favor the particulate trapping effect and improve the particulate dispersion homogeneity under condition of high weight fraction of reinforcement, a proper increase in scan speed and laser power is regarded as feasible, so as to enhance the undercooling degrees of melts. Moreover, adding a suitable amount of rare earth element in the powder system can (i) decrease the surface tension of the melt and improve the liquid-solid wettability, (ii) pin the grain and/or phase boundaries and resist the grain and/or particulate coarsening, and (iii) increase the heterogeneous nucleation rate and refine the sintered structure. The experimental results show that using an optimal La_2O_3 content of 1.0 wt.% in the WC-10Co/Cu composite system possessing a high weight fraction of reinforcement of 50.0 wt.% can effectively enhance the particulate trapping effect, homogenize the dispersion of reinforcing particulates, and improve the particulate/matrix bonding coherence, leading to a higher sintered densification.
论文第一部分,研究激光烧结多组分Cu基合金粉末(Cu-Cu10Sn-Cu8.4P)的关键工艺和基础理论,内容包括:
(1)多组分铜基合金粉末设计、制备及材料成形性研究,获取了激光烧结用金属粉末的物性指标、制备技术和表征方法
直接激光烧结因其特殊的成形方式(逐行烧结、逐层叠加)和成形过程(高能激光动态扫描下的瞬态冶金过程),对材料成形性有特殊要求,即粉体化学成分和物理性质须适于逐层铺粉和激光逐层烧结的工艺。作者基于粉末在激光作用下部分熔化的液相烧结机制(Cu充当骨架金属,Cu-10Sn充当粘结金属,Cu-8.4P作为脱氧剂或稀释剂),设计制备了多组分铜基金属粉末Cu-Cu10Sn-Cu8.4P,该粉末体系在液相成形机制下可有效抑制“球化”效应,降低由热应力导致的翘曲变形。铜基金属粉末的组分比例、颗粒形貌、粒度、松装密度等的优化设计结果表明,一方面,适当增加Cu-10Sn比例,可提高烧结致密度;但若超过50 wt.%,则会导致“球化”效应。Cu-8.4P比例以15 wt.%为宜,P元素可充当脱氧剂而防止烧结体系氧化,亦可充当稀释剂而降低熔体表面张力、改善固液润湿性,从而提高激光成形性。另一方面,粗(Cu平均粒径54μm)、细(Cu-10Sn平均粒径28μm)粉末共混形成“双峰”粉体,并使其具有较宽粒度分布(≥70μm);使用球形或近球形细粉,均可提高粉体松装密度及烧结致密度。在粉末制备中,首次提出了“磨球混粉”工艺,并通过合理设置球料比(5:1)、转速(100 rpm)及混粉时间(90 min),在不破坏原始粉末主要特性的前提下,实现了多元系粉体混粉均匀性,为提高烧结致密度和组织均匀性奠定了基础。
(2)多组分铜基合金粉末激光烧结的工艺成形性研究,实现了高致密度复杂形状铜基金属样件激光烧结精密成形
结合金属粉末激光烧结涉及的复杂物理冶金和化学冶金过程,作者从直接金属激光烧结基本成形机制和综合调控激光参数和铺粉参数入手,获得了金属激光烧结中抑制“球化”效应、改善成形精度和控制成形机制、提高烧结致密度的基本规律。提出了将不同激光功率和扫描速率下的粉体激光熔凝特征划分为微熔区、部分熔化区、持续熔化区、球化区、及完全熔化区这一新颖的工艺思路;且以部分熔化区为适宜工艺区间。在保证适宜成形机制条件下,通过合理设定光斑直径(0.3 mm)、适当增加激光功率(>300 W)、减小扫描速率(<0.06 m/s)、减小扫描间距(≤0.15 mm)、或降低铺粉厚度(≤0.30 mm),能改善烧结致密度及组织均匀性。发现并总结了3类激光烧结“球化”机制:“第一线球化”、“收缩球化”和“自球化”;并可通过合理设定粉床预热温度及控制激光功率和扫描速率加以抑制。提出了利用“能量体密度”对激光成形性作精确化和稳定化调控,对于制备的多组分铜基金属粉末在能量体密度为0.23 kJ/mm3条件下,可实现最大外观尺寸210 mm×70 mm×9 mm,相对密度>90%,最大尺寸误差<2%、拉伸强度>140 MPa的复杂形状铜基金属样件的激光烧结成形。
论文第二部分,研究激光烧结制备亚微米WC-Co颗粒增强Cu基块体复合材料的成形工艺、冶金机制及基础理论,内容包括:
(1)激光烧结制备亚微米WC-10Co颗粒增强Cu基复合材料的材料设计与工艺研究,获取了高性能颗粒增强金属基复合材料激光快速成形的关键材料与工艺
激光烧结具有工艺灵活性和取材广泛性,可用于新型材料及零件的制备与成形;同时,因激光作用的高度非平衡性,也有望使成形材料具有特殊的组织及性能。对于陶瓷颗粒增强金属基复合材料,可用包覆金属的金属陶瓷和基体金属制备成复合粉体,在激光烧结过程中易实现金属-金属界面结合。作者设计并制备了包覆Co的亚微米WC(增强体)和Cu(基体)的复合粉末,成功获得了激光烧结制备的WC-10Co颗粒增强Cu基复合材料块体试样。发现高能激光的快速作用机制致使WC颗粒完好保留亚微米尺寸特征,甚至部分细化至纳米级。同时,对工艺条件(激光参数和铺粉参数)作了优化,发现增加激光功率至700 W、在高于0.04 m/s条件下提高扫描速率、或减小铺粉厚度至0.30 mm以下,均能提高烧结致密度,改善增强体分散均匀性以及与基体结合性。在材料界面结构的研究中,发现将增强相WC通过WC-10Co复合粉体加入,可将WC/Cu(陶瓷/金属)界面转变为WC/Co/Cu(陶瓷/中间层金属/金属)界面,也即将粘结相Co作为基体金属Cu与增强相WC的“润湿媒介”,从而改善颗粒/基体界面结合性。同时,通过优化粉末体系中增强体含量,避免了在增强体含量较低时(≤20 wt.%),因复合体系热膨胀系数较高、熔体过热倾向明显而出现的“球化”效应;或在增强体含量较高时(≥40 wt.%),因液相生成量偏少、熔体粘度过高而导致的增强颗粒团聚现象。实验结果表明WC-10Co以30 wt.%为宜。
(2)激光作用下增强颗粒与基体金属推挤/俘获机制的理论研究,提出了提高颗粒/界面俘获效应、改善颗粒分散均匀性及界面结合性的工艺和材料措施
激光快速作用下颗粒与动态凝固界面的交互作用是影响颗粒增强金属基复合材料激光成形性能的又一关键因素。已有的关于颗粒/界面作用的研究,一般将固液界面简化为平界面,而将颗粒假设为置于平界面前沿的单个球形颗粒或少量规则分布的颗粒;此种假设对于复合体系激光成形过程难以成立。一方面,因基体与颗粒热导率和比热的差异,从本质上决定了复合体系的起始平界面存在局部不稳定性;另一方面,因激光束移动扫描,熔体流动具有紊乱性,故凝固过程难以通过平界面方式进行。作者通过引入枝晶形态的凝固界面,建立了用以描述激光快速凝固条件下增强颗粒与动态固液界面交互作用的理论模型;分析结果表明,颗粒俘获的主控因素是激光作用下的熔体临界过冷度。为提高颗粒俘获效应,特别是在增强体质量分数较高的条件下改善其分散均匀性,在工艺方面,可适当提高激光功率和扫描速率,以提高熔体过冷度;在材料方面,可在粉体中适量添加稀土元素来降低熔体表面张力,改善固液润湿性;钉扎晶界/相界,抑制晶粒/颗粒粗化;提高形核率,细化晶粒。实验研究结果表明,在高质量分数(50.0 wt.%)亚微米WC-10Co和Cu复合粉末中添加适量La_2O_3(1.0 wt.%),可实现对增强颗粒的有效俘获,提高颗粒分散均匀性以及颗粒/基体界面结合性,并获取良好的成形致密度。
As an important branch of rapid prototyping (RP) techniques, direct metal laser sintering (DMLS) enables the quick fabrication of complex shaped three-dimensional (3D) components by layerwise fusing loose powder with a scanning laser beam, without the use of fixturing or tooling. However, DMLS is still in its early stage of development. Significant further research and understanding are required in the aspects of materials preparation and characterization, process control and optimization, and theories of physical and chemical metallurgy involved in DMLS. In the present thesis, the direct laser sintering of Cu-based metal powder is carried out, with the main research work listed as follows.
In the first part of this thesis, key processes and basic mechanisms involved in direct laser sintering of multi-component Cu-based alloy powder (i.e., Cu-Cu10Sn-Cu8.4P) are studied, with the main conclusions drawn as follows.
(1) Design, preparation, and laser sintering mechanism of multi-component Cu-based metal powder, obtaining materials properties, preparation technique, and characterization method of metal powder for the use of DMLS
Due to the special forming fashion (i.e., line-by-line sintering followed by layer-by-layer bonding) and sintering process (i.e., transient metallurgical process induced by high-energy laser scanning) of DMLS, the material formability is of special concern, i.e., the chemical compositions and physical properties of powder materials should be feasible for powder deposition and laser sintering. In the present work, a multi-component Cu-based metal powder, which consists of a mixture of Cu, Cu-10Sn, and Cu-8.4P, is developed for DMLS. Laser sintering of this powder system is through the mechanism of liquid phase sintering with partial melting of the powder. The Cu acts as a structural metal, the Cu-8.4P acts as a binder, while the Cu-8.4P is taken as a deoxidizing agent or a fluxing agent. Such a semi-solid sintering mechanism can well alleviate the“balling”effect and decrease the curling deformation induced by thermal stress. The component ratio, particle morphology, particle size distribution, and loose packing density of the powder system are optimized. It shows that a proper increase in the amount of the Cu-10Sn leads to a denser microstructure; however, at a high content larger than 50 wt.%, the“balling”phenomena occur. A suitable weight fraction of the Cu-8.4P in this powder system is 15 wt.%. The additive phosphorus element can act as a deoxidizing agent to prevent the sintering system from oxidation. The phosphorus can also act as a fluxing agent to decrease the surface tension of molten materials, thereby improving the liquid-solid wettability and the resultant sintered densification. On the other hand, using a bimodal mixture with a broad size distribution (≥70μm) produced by mixing coarse Cu powder with a mean particle size of 54μm and fine Cu-10Sn powder with a mean particle size of 28μm, and using spherical or near-spherical fine powders can generally lead to an increase in the loose packing density of the powder and thus the densification of the laser sintered powder. A novel“ball mixing”process is primarily developed to prepare the powder system. With a reasonable setting of the weight ratio of balls to powders (5: 1), the rotation speed of mixer (100 rpm), and the mixing time (90 min), the multi-component system is homogeneously dispersed without destroying the initial characteristics of the starting powder, thereby giving a material basis for improving the sintered density and microstructural homogeneity.
(2) Optimization of processing conditions of multi-component Cu-based metal powder using DMLS, realizing the precise fabrication of complex shaped Cu-based metal parts with high density
With consideration of the complex physical and chemical metallurgical processes during DMLS, the author studies the basic operating mechanism of DMLS and the influence of laser processing conditions and powder depositing parameters, so as to obtain the generic principles for increasing fabricating precision by alleviating“balling”effect and for improving sintered densification by controlling sintering mechanism. At different combinations of laser power and scan speed, the mechanisms of powder melting are divided into slight melting, partial melting, excessive melting, balling, and complete melting, among which the partial melting proves to be a feasible one. With a feasible sintering mechanism permitted, setting a suitable spot size (0.3 mm), increasing laser power (>300 W), decreasing scan speed (<0.06 m/s), narrowing scan line spacing (≤0.15 mm), or lowering layer thickness (≤0.30 mm) generally lead to a higher densification and a more homogeneous microstructure. Three kinds of balling mechanisms under different processing conditions are proposed, i.e.,“first line scan balling”,“shrinkage-induced balling”, and“self-balling”. Setting a suitable preheating temperature of powder bed or controlling laser power and scan speed can well alleviate the balling phenomena. In order to provide a precise and steady control of laser sintering process, an“energy density by volume”is defined. Using the“energy density by volume”of 0.23 kJ/mm3 is able to produce best quality Cu-based metal parts with complex configurations. The maximum dimensions are 210 mm×70 mm×9 mm, the one-step sintered density is large than 90% theoretical density, the maximum dimension error is less than 2%, and the tensile strength is larger than 140 MPa.
In the second part of this thesis, processing conditions, metallurgical mechanisms, and basic theories involved in direct laser sintering of submicron WC-Co particulate reinforced Cu matrix bulk composite materials are studied, with the main conclusions drawn as follows.
(1) Material design and process control in direct laser sintering of submicron WC-10Co particulate reinforced Cu matrix composites, obtaining key materials and processes for laser rapid manufacturing of high quality particulate reinforced metal matrix composites (MMCs)
DMLS, due to its flexibility in feedstock and shapes, exhibits a great potential for developing novel materials and components. Meanwhile, the highly non-equilibrium state induced by a scanning laser beam might lead to the formation of some special structures and properties. As to MMCs reinforced with ceramics particulates, the ceramics phase can be firstly coated with a metal to form a metalloceramics before mixing with the matrix metal, so as to form metal-metal interfaces during laser sintering. In the present work, laser sintering of a composite system consisting of the submicron Co-coated WC powder (i.e., the reinforcement) and the Cu powder (i.e., the matrix) is performed; and the WC-10Co particulate reinforced Cu matrix composites in bulk form are successfully prepared. It is found that with a rapid action of a high-energy laser beam, the WC reinforcing particulates are either well remained the submicron characteristics or further refined to nanometer scales. The processing conditions including laser parameters and layer thickness are optimized. It shows that increasing the laser power to 700 W, increasing the scan speed above 0.04 m/s, and decreasing the powder layer thickness below 0.30 mm generally lead to a higher densification with a uniform particulate dispersion and a coherent particulate/matrix bonding ability. With regard to the interfacial design of such a composite system, the WC reinforcing phase is added in the form of WC-10Co composite powder, so as to change the WC/Cu (ceramics/metal) interface into the WC/Co/Cu (ceramics/interlayer metal/metal) interface. In other words, the Co can act as a wetting intermedium to improve the wetting characteristics between the Cu matrix and the WC particulates, leading to a sound interfacial bonding coherence after sintering. On the other hand, the weight fraction of the WC-10Co reinforcement in the powder system is optimized. It shows that using a low reinforcement content of 20 wt.% results in severe balling phenomena, due to a high average composite coefficient of thermal expansion (CTE) and a superheating of the melt. A severe particulate aggregation occurs at a high reinforcement content of 40 wt.%, because of a limited liquid formation and the resultant high liquid viscosity. An optimal content of WC-10Co reinforcement is found to be 30 wt.%.
(2) Theoretical studies on mechanism of laser-induced pushing/trapping of reinforcing particulates by matrix metal, providing process and material measures to improve particulate/interface trapping effect, homogenize particulate dispersion, and enhance particulate/matrix bonding coherence
The interaction between the reinforcing particulates and the advancing solidification front under the rapid action of a mobile laser beam is another important factor in determining the laser formability of particulate reinforced MMCs. In most studies concerning the particle-interface interaction, the problem is simplified by accounting a single spherical particle or a small amount of well separated particles ahead of a steady state planar solidification front, which is unlikely to be realized in the laser-induced solidification process of a solid-liquid composite system. This is because (i) a local destabilization of an initially planar solid-liquid interface caused by the different thermal conductivities and specific heats of the solidifying matrix and the particulate material is inherent to the solidification process of a composite system; (ii) a significant turbulence in the laser-generated melt pool will easily destroy such a planar solidification interface. In the present work, a theoretical model, which introduces a dendritic solidification front, is developed for describing the behavior of the reinforcing particulates at an advancing solid-liquid interface during the laser-induced rapid solidification process. The substantial governing parameter for particulate engulfment is found to be the laser-induced critical undercooling. In order to favor the particulate trapping effect and improve the particulate dispersion homogeneity under condition of high weight fraction of reinforcement, a proper increase in scan speed and laser power is regarded as feasible, so as to enhance the undercooling degrees of melts. Moreover, adding a suitable amount of rare earth element in the powder system can (i) decrease the surface tension of the melt and improve the liquid-solid wettability, (ii) pin the grain and/or phase boundaries and resist the grain and/or particulate coarsening, and (iii) increase the heterogeneous nucleation rate and refine the sintered structure. The experimental results show that using an optimal La_2O_3 content of 1.0 wt.% in the WC-10Co/Cu composite system possessing a high weight fraction of reinforcement of 50.0 wt.% can effectively enhance the particulate trapping effect, homogenize the dispersion of reinforcing particulates, and improve the particulate/matrix bonding coherence, leading to a higher sintered densification.
引文
[1] Lu L, Fuh J, Wong Y S. Laser-induced materials and processes for rapid prototyping [M]. Norwell, Kluwer Academic Publishers, 2001: 1-7.
[2] Pham D T, Dimov S S. Rapid manufacturing: the technologies and applications of rapid prototyping and rapid tooling [M]. London, Springer-Verlag, 2001: 19-40.
[3] Chua C K, Leong K F, Lim C S. Rapid prototyping: principles and applications [M]. Singapore, World Scientific Publishing Company, 2003: 11-19.
[4] Das S. Direct selective laser sintering of high performance metals - machine design, process development and process control [D]. Ph.D. Thesis, The University of Texas at Austin, 1998.
[5] Noorani R I. Rapid prototyping: principles and applications [M]. New Jersey, John Wiley & Sons, 2005: 34-44.
[6] Venuvinod P K, Ma W Y. Rapid prototyping: laser-based and other technologies [M]. Norwell, Kluwer Academic Publishers, 2001: 245-275.
[7]沈以赴,陈文华,赵剑峰,等.快速成形技术中材料成形性的研究进展[J].材料科学与工程, 2001, 19(4): 90-96.
[8]王华明.金属材料激光表面改性与高性能金属零件激光快速成形技术研究进展[J].航空学报, 2002, 23(5): 473-478.
[9]张永忠,石力开,章萍芝,等.基于金属粉末的激光快速成型技术新进展[J].稀有金属材料与工程, 2000, 29(6): 361-365.
[10]黄树槐,肖跃加,莫健华,等.快速成形技术的展望[J].中国机械工程, 2000, 11(1-2): 195-200.
[11] Ferreira J C, Mateus A. A numerical and experimental study of fracture in RP stereolithography patterns and ceramic shells for investment casting [J]. Journal of Materials Processing Technology, 2003, 134(1): 135-144.
[12] Harris R A, Hague R J M, Dickens P M. The structure of parts produced by stereolithography injection mould tools and the effect on part shrinkage [J]. International Journal of Machine Tools and Manufacture, 2004, 44(1): 59-64.
[13] Kim H C, Lee S H. Reduction of post-processing for stereolithography systems by fabrication-direction optimization [J]. Computer-Aided Design, 2005, 37(7): 711-725.
[14] Chiu Y Y, Liao Y S, Hou C C. Automatic fabrication for bridged laminated object manufacturing (LOM) process [J]. Journal of Materials Processing Technology, 2003,140(1-3): 179-184.
[15] Yi S P, Liu F, Zhang J, et al. Study of the key technologies of LOM for functional metal parts [J]. Journal of Materials Processing Technology, 2004, 150(1-2): 175-181.
[16] Kechagias J, Maropoulos S, Karagiannis S. Process build-time estimator algorithm for laminated object manufacturing [J]. Rapid Prototyping Journal, 2004, 10(5): 297-304.
[17] Chung H, Das S. Processing and properties of glass bead particulate-filled functionally graded Nylon-11 composites produced by selective laser sintering [J]. Materials Science and Engineering A, 2006, 437(2): 226-234.
[18] Zarringhalam H, Hopkinson N, Kamperman N F, et al. Effects of processing on microstructure and properties of SLS Nylon 12 [J]. Materials Science and Engineering A, 2006, 435-436: 172-180.
[19] Zheng H Z, Zhang J, Lu S Q, et al. Effect of core-shell composite particles on the sintering behavior and properties of nano-Al2O3/polystyrene composite prepared by SLS [J]. Materials Letters, 2006, 60(9-10): 1219-1223.
[20] Ang K C, Leong K F, Chua C K, et al. Investigation of the mechanical properties and porosity relationships in fused deposition modelling-fabricated porous structures [J]. Rapid Prototyping Journal, 2006, 12(2): 100-105.
[21] Zein I, Hutmacher D W, Tan K C, et al. Fused deposition modeling of novel scaffold architectures for tissue engineering applications [J]. Biomaterials, 2002, 23(4): 1169-1185.
[22] Pennington R C, Hoekstra N L, Newcomer J L. Significant factors in the dimensional accuracy of fused deposition modelling [J]. Proceedings of the Institution of Mechanical Engineers, Part E, Journal of Process Mechanical Engineering, 2005, 219(E1): 89-92.
[23] Hull C W. Apparatus for production of three-dimensional objects by stereolithography [P]. United States Patent, 4575330, 1986.
[24] http://www.3dsystems.com/
[25] Hull C, Feygin M, Baron Y, et al. Rapid prototyping: current technology and future potential [J]. Rapid Prototyping Journal, 1995, 1(1): 11-19.
[26] Deckard C. Methods and apparatus for producing parts by selective laser sintering [P]. United States Patent, 4863538, 1989.
[27] http://intl.stratasys.com/
[28] Ho H C H, Gibson I, Cheung W L. Effects of energy density on morphology and properties of selective laser sintered polycarbonate [J]. Journal of Materials Processing Technology, 1999, 89-90: 204-210.
[29] Tang Y, Fuh J Y H, Loh H T, et al. Direct laser sintering of a silica sand [J]. Materials &Design, 2003, 24(8): 623-629.
[30] Shi Y, Li Z, Sun H, et al. Effect of the properties of the polymer materials on the quality of selective laser sintering parts [J]. Proceedings of the Institution of Mechanical Engineers, Part L, Journal of Materials: Design & Applications, 2004, 218(L3): 247-252.
[31] Wiedemann B, Jantzen H A. Strategies and applications for rapid product and process development in Daimler-Benz AG [J]. Computers in Industry, 1999, 39(1): 11-25.
[32] Liu H J, Fan Z T, Huang N Y, et al. A note on rapid manufacturing process of metallic parts based on SLS plastic prototype [J]. Journal of Materials Processing Technology, 2003, 142(3): 710-713.
[33] Karalekas D, Kakoudakis J. Predictive mechanical performance evaluation of consumer food cans using stereo lithography models [J]. Packaging Technology and Science, 2003, 16(1): 37-45.
[34] Hanninen J. Direct metal laser sintering [J]. Advanced Materials & Processes, 2002, 160(5): 33-36.
[35] King D, Tansey T. Rapid tooling: selective laser sintering injection tooling [J]. Journal of Materials Processing Technology, 2003, 132(1-3): 42-48.
[36] Cheah C M, Chua C K, Lee C W, et al. Rapid prototyping and tooling techniques: a review of applications for rapid investment casting [J]. International Journal of Advanced Manufacturing Technology, 2005, 25(3-4): 308-320.
[37] Lino F J, Neto R J L, Paiva R, et al. Rapid prototyping and rapid tooling applied in product development of ceramic components [J]. Materials Science Forum, 2004, 455-456: 835-838.
[38] Evans R S, Bourell D L, Beaman J J, et al. Rapid manufacturing of silicon carbide composites [J]. Rapid Prototyping Journal, 2005, 11(1): 37-40.
[39] Gahler A, Heinrich J G, Gunster J. Direct laser sintering of Al2O3-SiO2 dental ceramic components by layer-wise slurry deposition [J]. Journal of the American Ceramic Society, 2006, 89(10): 3076-3080.
[40]王华明.航空高性能金属结构件激光快速成形研究进展[J].航空制造技术, 2005, 12: 26-28.
[41] Raja V, Zhang S J, Garside J, et al. Rapid and cost-effective manufacturing of high-integrity aerospace components [J]. International Journal of Advanced Manufacturing Technology, 2006, 27(7-8): 759-773.
[42] Zhang J F, Huang Y H, Shen Y F, et al. Study on selective laser sintering of metallic powders [J]. Transactions of Nanjing University of Aeronautics & Astronautics, 2002, 19(1): 77-83.
[43] Vasinonta A, Beuth J L, Griffith M L. A process map for consistent build conditions in thesolid freeform fabrication of thin-walled structures [J]. Journal of Manufacturing Science and Engineering-Transactions of the ASME, 2001, 123(4): 615-622.
[44] Sansoni G, Docchio F. Three-dimensional optical measurements and reverse engineering for automotive applications [J]. Robotics and Computer-Integrated Manufacturing, 2004, 20(5): 359-367.
[45] Hopkinson N, Gao Y, McAfee D J. Design for environment analyses applied to rapid manufacturing [J]. Proceedings of the Institution of Mechanical Engineers, Part D, Journal of Automobile Engineering, 2006, 220(D10): 1363-1372.
[46] Canellidis V, Dedoussis V, Mantzouratos N, et al. Pre-processing methodology for optimizing stereolithography apparatus build performance [J]. Computers in Industry, 2006, 57(5): 424-436.
[47] Ghany K A, Moustafa S F. Comparison between the products of four RPM systems for metals [J]. Rapid Prototyping Journal, 2006, 12(2): 86-94.
[48] Li H L, Zeng X Y. A study on embedded resistor components fabricated by laser micro-cladding and rapid prototype [J]. Materials Science and Engineering B, 2006, 133(1-3): 84-90.
[49] Zeng X Y, Li X Y, Liu J W, et al. Direct fabrication of electric components on insulated boards by laser microcladding electronic pastes [J]. IEEE Transactions on Advanced Packaging, 2006, 29(2): 291-294.
[50] Li X Y, Zeng X Y, Li H L, et al. Laser direct fabrication of silver conductors on glass boards [J]. Thin Solid Films, 2005, 483(1-2): 270-275.
[51] Laoui T, Santos E, Osakada K, et al. Properties of titanium dental implant models made by laser processing [J]. Proceedings of the Institution of Mechanical Engineers, Part C, Journal of Mechanical Engineering Science, 2006, 220(6): 857-863.
[52] Li J P, de Wijn J R, Van Blitterswijk C A, et al. Porous Ti6Al4V scaffold directly fabricating by rapid prototyping: Preparation and in vitro experiment [J]. Biomaterials, 2006, 27(8): 1223-1235.
[53] Hollander D A, von Walter M, Wirtz T, et al. Structural, mechanical and in vitro characterization of individually structured Ti-6Al-4V produced by direct laser forming [J]. Biomaterials, 2006, 27(7): 955-963.
[54]顾冬冬,沈以赴,潘琰峰,等.直接金属粉末激光烧结成形机制的研究[J].材料工程, 2004, 5: 42-48.
[55] Agarwala M, Bourell D, Beaman J, et al. Direct selective laser sintering of metals [J]. Rapid Prototyping Journal, 1995, 1(1): 26-36.
[56] Das S, Beaman J J, Wohlert M, et al. Direct laser freeform fabrication of high performance metal components [J]. Rapid Prototyping Journal, 1998, 4(3): 112-117.
[57]沈以赴,顾冬冬,陈文华,等. CuSn预合金对金属粉末选区激光烧结过程及烧结体质量的影响[J].航空学报, 2005, 26(6): 768-773.
[58]顾冬冬,沈以赴,杨家林,等.多组分铜基金属粉末选区激光烧结致密化机理[J].中国有色金属学报, 2005, 15(4): 596-602.
[59]顾冬冬,沈以赴,杨家林,等.多组分铜基金属粉末选区激光烧结试验研究[J].航空学报, 2005, 26(4): 510-514.
[60] Kruth J P, Froyen L, Van Vaerenbergh J, et al. Selective laser melting of iron-based powder [J]. Journal of Materials Processing Technology, 2004, 149(1-3): 616-622.
[61] Osakada K, Shiomi M. Flexible manufacturing of metallic products by selective laser melting of powder [J]. International Journal of Machine Tools & Manufacture, 2006, 46(11): 1188-1193.
[62] Wright C S, Youseffi M, Akhtar S P, et al. Selective laser melting of prealloyed high alloy steel powder beds [J]. Materials Science Forum, 2006, 514-516: 516-523.
[63] Morgan R, Sutcliffe C J, O’Neill W. Density analysis of direct metal laser re-melted 316L stainless steel cubic primitives [J]. Journal of Materials Science, 2004, 39(4): 1195-1205.
[64] Chen X C, Xie J W, Fox P. Direct laser remelting of iron with addition of boron [J]. Materials Science and Technology, 2004, 20(6): 715-719.
[65] Pogson S R, Fox P, Sutcliffe C J, et al. The production of copper parts using DMLR [J]. Rapid Prototyping Journal, 2003, 9(5): 334-343.
[66] Kelly S M, Kampe S L. Microstructural evolution in laser-deposited multilayer Ti-6Al-4V builds: Part I. Microstructural characterization [J]. Metallurgical and Materials Transactions A, 2004, 35(6): 1861-1867.
[67] Kelly S M, Kampe S L. Microstructural evolution in laser-deposited multilayer Ti-6Al-4V builds: Part II. Thermal modeling [J]. Metallurgical and Materials Transactions A, 2004, 35(6): 1869-1879.
[68] Li P, Yang T P, Li S, et al. Direct laser fabrication of nickel alloy samples [J]. International Journal of Machine Tools & Manufacture, 2005, 45(11): 1288-1294.
[69] Wang L, Felicelli S. Analysis of thermal phenomena in LENSTM deposition [J]. Materials Science and Engineering A, 2006, 435-436: 625-631.
[70] Ye R Q, Smugeresky J E, Zheng B L, et al. Numerical modeling of the thermal behavior during the LENS? process [J]. Materials Science and Engineering A, 2006, 428(1-2): 47-53.
[71] Rangaswamy P, Griffith M L, Prime M B, et al. Residual stresses in LENS? componentsusing neutron diffraction and contour method [J]. Materials Science and Engineering A, 2005, 399(1-2): 72-83.
[72] Santos E C, Shiomi M, Osakada K, et al. Rapid manufacturing of metal components by laser forming [J]. International Journal of Machine Tools & Manufacture, 2006, 46(12-13): 1459-1468.
[73]潘琰峰,沈以赴,顾冬冬,等.选择性激光烧结技术的发展现状[J].工具技术, 2004, 38(6): 3-7.
[74]张剑峰,沈以赴,赵剑峰,等.激光烧结成形金属材料及零件的进展[J].金属热处理, 2001, 26(12): 1-4.
[75]史玉升,孙海宵,樊自田,等.基于选择性激光烧结方法的金属零件快速制造技术研究[J].铸造, 2003, 52(10): 749-752.
[76] Bourell D, Wohlert M, Harlan N, et al. Powder densification maps in selective laser sintering [J]. Advanced Engineering Materials, 2002, 4(9): 663-669.
[77] Simchi A, Petzoldt F, Pohl H. Direct metal laser sintering: Material considerations and mechanisms of particle bonding [J]. International Journal of Powder Metallurgy, 2001, 37(2): 49-61.
[78] Kruth J P, Mercelis P, Van Vaerenbergh J, et al. Binding mechanisms in selective laser sintering and selective laser melting [J]. Rapid Prototyping Journal, 2005, 11(1): 26-36.
[79] Tolochko N K, Arshinov M K, Gusarov A V, et al. Mechanisms of selective laser sintering and heat transfer in Ti powder [J]. Rapid Prototyping Journal, 2003, 9(5): 314-326.
[80] Kathuria Y P. Microstructuring by selective laser sintering of metallic powder [J]. Surface and Coatings Technology, 1999, 116-119: 643-647.
[81] Simchi A, Pohl H. Direct laser sintering of iron-graphite powder mixture [J]. Materials Science and Engineering A, 2004, 383(2): 191-200.
[82] Murali K, Chatterjee A N, Saha P, et al. Direct selective laser sintering of iron-graphite powder mixture [J]. Journal of Materials Processing Technology, 2003, 136(1-3): 179-185.
[83] Simchi A, Petzoldt F, Pohl H. On the development of direct metal laser sintering for rapid tooling [J]. Journal of Materials Processing Technology, 2003, 141(3): 319-328.
[84] Kruth J P, Kumar S, Van Vaerenbergh J. Study of laser-sinterability of ferro-based powders [J]. Rapid Prototyping Journal, 2005, 11(5): 287-292.
[85] Rossi S, Deflorian F, Venturini F. Improvement of surface finishing and corrosion resistance of prototypes produced by direct metal laser sintering [J]. Journal of Materials Processing Technology, 2004, 148(3): 301-309.
[86] Wang Y, Bergstr?m J, Burman C. Four-point bending fatigue behaviour of an iron-basedlaser sintered material [J]. International Journal of Fatigue, 2006, 28(12): 1705-1715.
[87] Wang Y, Bergstr?m J, Burman C. Characterization of an iron-based laser sintered material [J]. Journal of Materials Processing Technology, 2006, 172(1): 77-87.
[88] Zhu H H, Fuh J Y H, Lu L. Formation of Fe-Cu metal parts using direct laser sintering [J]. Proceedings of the Institution of Mechanical Engineers, Part C, Journal of Mechanical Engineering Science, 2003, 217(1): 139-147.
[89]沈以赴,吴鹏,顾冬冬,等. Ni-CuSn混合粉末选区激光烧结试验[J].焊接学报, 2005, 26(2): 73-76.
[90] Tolochko N, Mozzharov S, Laoui T, et al. Selective laser sintering of single- and two-component metal powders [J]. Rapid Prototyping Journal, 2003, 9(2): 68-78.
[91]张剑峰,沈以赴,赵剑峰,等. Ni基金属粉末激光快速制造的研究[J].航空学报, 2002, 23(3): 221-225.
[92] Zhu H H, Lu L, Fuh J Y H. Development and characterisation of direct laser sintering Cu-based metal powder [J]. Journal of Materials Processing Technology, 2003, 140(1-3): 314-317.
[93] Zhu H H, Lu L, Fuh J Y H. Influence of binder’s liquid volume fraction on direct laser sintering of metallic powder [J]. Materials Science and Engineering A, 2004, 371(1-2): 170-177.
[94] Zhu H H, Fuh J Y H, Lu L. Microstructural evolution in direct laser sintering of Cu-based metal powder [J]. Rapid Prototyping Journal, 2005, 11(2): 74-81.
[95] Das S, Wohlert M, Beaman J J, et al. Processing of titanium net shapes by SLS/HIP [J]. Materials & Design, 1999, 20(2-3): 115-121.
[96] Shen Y F, Gu D D, Pan Y F. Balling process in selective laser sintering 316 stainless steel powder [J]. Key Engineering Materials, 2006, 315-316: 357-360.
[97] Childs T H C, Hauser C, Badrossamay M. Selective laser sintering (melting) of stainless and tool steel powders: experiments and modelling [J]. Proceedings of the Institution of Mechanical Engineers, Part B, Journal of Engineering Manufacture, 2005, 219(4): 339-357.
[98] Katz Z, Smith P E S. On process modelling for selective laser sintering of stainless steel [J]. Proceedings of the Institution of Mechanical Engineers, Part B, Journal of Engineering Manufacture, 2001, 215(11): 1497-1504.
[99] Asgharzadeh H, Simchi A. Effect of sintering atmosphere and carbon content on the densification and microstructure of laser-sintered M2 high-speed steel powder [J]. Materials Science and Engineering A, 2005, 403(1-2): 290-298.
[100] Simchi A. Direct laser sintering of metal powders: Mechanism, kinetics and microstructuralfeatures [J]. Materials Science and Engineering A, 2006, 428(1-2): 148-158.
[101] Dewidar M M, Dalgarno K W, Wright C S. Processing conditions and mechanical properties of high-speed steel parts fabricated using direct selective laser sintering [J]. Proceedings of the Institution of Mechanical Engineers, Part B, Journal of Engineering Manufacture, 2003, 217(12): 1651-1663.
[102] Niu H J, Chang I T H. Selective laser sintering of gas atomized M2 high speed steel powder [J]. Journal of Materials Science, 2000, 35(1): 31-38.
[103] Chatterjee A N, Kumar S, Saha P, et al. An experimental design approach to selective laser sintering of low carbon steel [J]. Journal of Materials Processing Technology, 2003, 136(1-3): 151-157.
[104] Su W N, Erasenthiran P, Dickens P M. Investigation of fully dense laser sintering of tool steel powder using a pulsed Nd: YAG (neodymium-doped yttrium aluminium garnet) laser [J]. Proceedings of the Institution of Mechanical Engineers, Part C, Journal of Mechanical Engineering Science, 2003, 217(1): 127-138.
[105] Kovalev A I, Mishina V P, Wainstein D L, et al. Selective laser sintering of single-phase powder Cr-V tool steel [J]. Journal of Materials Engineering and Performance, 2002, 11(5): 492-495.
[106] Tang Y, Loh H T, Wong Y S, et al. Direct laser sintering of a copper-based alloy for creating three-dimensional metal parts [J]. Journal of Materials Processing Technology, 2003, 140(1-3): 368-372.
[107]赵剑峰.基于选区激光烧结快速成形的快速制造技术研究[D].博士学位论文,南京:南京航空航天大学, 1999.
[108]田宗军.激光烧结快速成型计算机控制系统的研究与运用[D].博士学位论文,南京:南京航空航天大学, 2000.
[109]李湘生.选区激光烧结若干关键技术研究[D].博士学位论文,武汉:华中科技大学, 2001.
[110]蔡道生.选择性激光烧结工艺软件关键技术研究[D].博士学位论文,武汉:华中科技大学, 2004.
[111] http://www.eos.info/
[112] http://www.binhurp.com/
[113] http://www.lyafs.com.cn/
[114]杨家林,王洋. 50W激光快速成型设备与2kW CO2激光器的系统集成[J].制造技术与机床, 2003, 9: 28-30.
[115] Morgan R H, Papworth A J, Sutcliffe C, et al. High density net shape components by directlaser re-melting of single-phase powders [J]. Journal of Materials Science, 2002, 37(15): 3093-3100.
[116] Xie J W, Fox P, O’Neill W, et al. Effect of direct laser re-melting processing parameters and scanning strategies on the densification of tool steels [J]. Journal of Materials Processing Technology, 2005, 170(3): 516-523.
[117] Childs T H C, Hauser C. Raster scan selective laser melting of the surface layer of a tool steel powder bed [J]. Proceedings of the Institution of Mechanical Engineers, Part B, Journal of Engineering Manufacture, 2005, 219(4): 379-384.
[118] Mercelis P, Kruth J P. Residual stresses in selective laser sintering and selective laser melting [J]. Rapid Prototyping Journal, 2006, 12(5): 254-265.
[119] Shiomi M, Osakada K, Nakamura K, et al. Residual stress within metallic model made by selective laser melting process [J]. CIRP Annals - Manufacturing Technology, 2004, 53(1): 195-198.
[120] Abe F, Osakada K, Shiomi M, et al. The manufacturing of hard tools from metallic powders by selective laser melting [J]. Journal of Materials Processing Technology, 2001, 111(1-3): 210-213.
[121] Fischer P, Romano V, Weber H P, et al. Sintering of commercially pure titanium powder with a Nd: YAG laser source [J]. Acta Materialia, 2003, 51(6): 1651-1662.
[122] Fischer P, Romano V, Weber H P, et al. Pulsed laser sintering of metallic powders [J]. Thin Solid Films, 2004, 453: 139-144.
[123] Fischer P, Leber H, Romano V, et al. Microstructure of near-infrared pulsed laser sintered titanium samples [J]. Applied Physics A - Materials Science & Processing, 2004, 78(8): 1219-1227.
[124] Fischer P, Romano V, Blatter A, et al. Highly precise pulsed selective laser sintering of metallic powders [J]. Laser Physics Letters, 2005, 2(1): 48-55.
[125] Pogson S, Fox P, O’Neill W, et al. The direct metal laser remelting of copper and tool steel powders [J]. Materials Science and Engineering A, 2004, 386(1-2): 453-459.
[126] Brooks J A, Robino C V, Headley T, et al. Microstructure and property optimization of LENS deposited H13 tool steel [C]. Proceedings of the Solid Freeform Fabrication Symposium, Austin, TX, 1999: 375-382.
[127] Hofmeister W, Griffith M, Ensz M, et al. Solidification in direct metal deposition by LENS processing [J]. JOM, 2001, 53(9): 30-34.
[128] Atwood C, Griffith M, Harwell L, et al. Laser engineered net shaping (LENSTM): a tool for direct fabrication of metal parts [C]. Proceedings of the Laser Materials ProcessingConference ICALEO’98, Orlando, FL, 1998: E1-7.
[129] Griffith M L, Ensz M T, Puskar J D, et al. Understanding the microstructure and properties of components fabricated by laser engineered net shaping (LENS) [C]. Materials Research Society Symposium - Proceedings, San Francisco, CA, 2000: 9-20.
[130] Pinkerton A J, Li L. Rapid prototyping using direct laser deposition - the effect of powder atomization type and flowrate [J]. Proceedings of the Institution of Mechanical Engineers, Part B, Journal of Engineering Manufacture, 2003, 217(6): 741-752.
[131] Wu X H, Liang J, Mei J F, et al. Microstructures of laser-deposited Ti-6Al-4V [J]. Materials & Design, 2004, 25(2): 137-144.
[132] Wu X, Sharman R, Mei J, et al. Microstructure and properties of a laser fabricated burn-resistant Ti alloy [J]. Materials & Design, 2004, 25(2): 103-109.
[133] Srivastava D, Chang I T H, Loretto M H. The effect of process parameters and heat treatment on the microstructure of direct laser fabricated TiAl alloy samples [J]. Intermetallics, 2001, 9(12) 1003-1013.
[134] Pinkerton A J, Li L. Multiple-layer laser deposition of steel components using gas- and water-atomised powders: the differences and the mechanisms leading to them [J]. Applied Surface Science, 2005, 247(1-4): 175-181.
[135] Pinkerton A J, Li L. The effect of laser pulse width on multiple-layer 316L steel clad microstructure and surface finish [J]. Applied Surface Science, 2003, 208-209: 411-416.
[136] Pinkerton A J, Li L. An investigation of the effect of pulse frequency in laser multiple-layer cladding of stainless steel [J]. Applied Surface Science, 2003, 208-209: 405-410.
[137] Pinkerton A J, Li L. Multiple-layer cladding of stainless steel using a high-powered diode laser: an experimental investigation of the process characteristics and material properties [J]. Thin Solid Films, 2004, 453-454: 471-476.
[138] Banerjee R, Collins P C, Bhattacharyya D, et al. Microstructural evolution in laser deposited compositionally gradedα/βtitanium-vanadium alloys [J]. Acta Materialia, 2003, 51(11): 3277-3292.
[139] Banerjee R, Bhattacharyya D, Collins P C, et al. Precipitation of grain boundaryαin a laser deposited compositionally graded Ti-8Al-xV alloy - an orientation microscopy study [J]. Acta Materialia, 2004, 52(2): 377-385.
[140] Unocic R R, DuPont J N. Composition control in the direct laser-deposition process [J]. Metallurgical and Materials Transactions B, 2003, 34(4): 439-445.
[141]陈静,林鑫,王涛,等. 316L不锈钢激光快速成形过程中熔覆层的热裂机理[J].稀有金属材料与工程, 2003, 32(3): 183-186.
[142]林鑫,杨海欧,陈静,等.激光快速成形过程中316L不锈钢显微组织的演变[J].金属学报, 2006, 42(4): 361-368.
[143]张永忠,席明哲,石力开,等.激光快速成形316L不锈钢的组织及性能[J].稀有金属材料与工程, 2002, 31(2): 103-105.
[144]杨海欧,陈静,李延民,等. Rene95高温合金激光快速成形试样的力学性能[J].稀有金属材料与工程, 2003, 32(4): 276-279.
[145]张永忠,石力开,章萍芝,等.激光快速成形镍基高温合金研究[J].航空材料学报, 2002, 22(1): 22-25.
[146] Lin X, Yue T M, Yang H O, et al. Microstructure and phase evolution in laser rapid forming of a functionally graded Ti-Rene88DT alloy [J]. Acta Materialia, 2006, 54(7): 1901-1915.
[147] Lin X, Yue T M, Yang H O, et al. Laser rapid forming of SS316L/Rene88DT graded material [J]. Materials Science and Engineering A, 2005, 391(1-2): 325-336.
[148] Lin X, Yue T M. Phase formation and microstructure evolution in laser rapid forming of graded SS316L/Rene88DT alloy [J]. Materials Science and Engineering A, 2005, 402(1-2): 294-306.
[149]陈静,谭华,杨海欧,等.激光快速成形过程熔池行为的实时观察研究[J].应用激光, 2005, 25(2): 77-80.
[150]石力开,高士友,席明哲,等.金属直薄壁件激光直接沉积过程的有限元模拟I.沉积过程中温度场的模拟[J].金属学报, 2006, 42(5): 449-453.
[151]石力开,高士友,席明哲,等.金属直薄壁件激光直接沉积过程的有限元模拟II.沉积过程中热应力场的模拟[J].金属学报, 2006, 42(5): 454-458.
[152]石力开,高士友,席明哲,等.金属直薄壁件激光直接沉积过程的有限元模拟III.沉积过程中变形的分析[J].金属学报, 2006, 42(5): 459-462.
[153]王华明,张凌云,李安,等.金属材料快速凝固激光加工与成形[J].北京航空航天大学学报, 2004, 30(10): 962-967.
[154] Wang H M, Cao F, Cai L X, et al. Microstructure and tribological properties of laser clad Ti2Ni3Si/NiTi intermetallic coatings [J]. Acta Materialia, 2003, 51(20): 6319-6327.
[155] Wang H M, Luan D Y, Cai L X. Microstructure and sliding-wear behavior of tungsten-reinforced W-Ni-Si metal-silicide in-situ composites [J]. Metallurgical and Materials Transactions A, 2003, 34(9): 2005-2015.
[156] Cai L X, Wang H M. Microstructure and dry-sliding wear resistance of laser clad tungsten reinforced W5Si3/W2Ni3Si intermetallic coatings [J]. Applied Surface Science, 2004, 235(4): 501-506.
[157] Zhong M L, Liu W J, Ning G Q, et al. Laser direct manufacturing of tungsten nickelcollimation component [J]. Journal of Materials Processing Technology, 2004, 147(2): 167-173.
[158]陈静,杨海欧,李延民,等.激光快速成形过程中熔覆层的两种开裂行为及其机理研究[J].应用激光, 2002, 22(3): 300-304.
[159]杨健,黄卫东,杨海欧.激光快速成形316L不锈钢残余应力分布[J].应用激光, 2005, 25(3): 151-154.
[160] Niu H J, Chang I T H. Instability of scan tracks of selective laser sintering of high speed steel powder [J]. Scripta Materialia, 1999, 41(11): 1229-1234.
[161] Niu H J, Chang I T H. Liquid phase sintering of M3/2 high speed steel by selective laser sintering [J]. Scripta Materialia, 1998, 39(1): 67-72.
[162]潘琰峰,沈以赴,顾冬冬,等.工艺参数对316不锈钢粉末激光烧结球化的影响[J].材料工程, 2005, 5: 52-55.
[163]潘琰峰,沈以赴,顾冬冬,等. 316不锈钢粉末直接激光烧结的球化效应[J].中国机械工程, 2005, 16(17): 1573-1576.
[164]顾冬冬,沈以赴.铜基金属粉末直接激光烧结工艺及成形件显微组织研究[J].中国机械工程, 2006, 17(20): 2171-2175.
[165] Simchi A, Pohl H. Effects of laser sintering processing parameters on the microstructure and densification of iron powder [J]. Materials Science and Engineering A, 2003, 359(1-2) 119-128.
[166]顾冬冬,沈以赴,吴鹏,等.铜基金属粉末选区激光烧结的工艺研究[J].中国激光, 2005, 32(11): 1561-1566.
[167]沈以赴,顾冬冬,余承业,等.直接金属粉末激光烧结成形过程温度场模拟[J].中国机械工程, 2005, 16(1): 67-73.
[168] Das S. Physical aspects of process control in selective laser sintering of metals [J]. Advanced Engineering Materials, 2003, 5(10): 701-711.
[169] Gu D D, Shen Y F. Influence of phosphorus element on direct laser sintering of multicomponent Cu-based metal powder [J]. Metallurgical and Materials Transactions B, 2006, 37(6): 967-977.
[170] Niu H J, Chang I T H. Selective laser sintering of gas and water atomized high speed steel powders [J]. Scripta Materialia, 1999, 41(1): 25-30.
[171] Gu D D, Shen Y F, Liu M C, et al. Numerical simulations of temperature field in direct metal laser sintering process [J]. Transactions of Nanjing University of Aeronautics & Astronautics, 2004, 21(3): 225-233.
[172] Wang X C, Laoui T, Bonse J, et al. Direct selective laser sintering of hard metal powders:Experimental study and simulation [J]. International Journal of Advanced Manufacturing Technology, 2002, 19(5): 351-357.
[173] Gu D D, Shen Y F. Development and characterisation of direct laser sintering multicomponent Cu based metal powder [J]. Powder Metallurgy, 2006, 49(3): 258-264.
[174]张剑峰. Ni基金属粉末激光直接烧结成形及关键技术研究[D].博士学位论文,南京:南京航空航天大学, 2002.
[175] Tolochko N K, Laoui T, Khlopkov Y V, et al. Absorptance of powder materials suitable for laser sintering [J]. Rapid Prototyping Journal, 2000, 6(3): 155-160.
[176] Gu D D, Shen Y F. Effects of dispersion technique and component ratio on densification and microstructure of multi-component Cu-based metal powder in direct laser sintering [J]. Journal of Materials Processing Technology, 2007, 182(1-3): 564-573.
[177]邓琦林,方建成.选择性激光烧结粉末的参数分析[J].制造技术与机床, 1997, 10: 26-29.
[178]邓琦林,余承业.金属粉末的选择性激光烧结[J].航空工艺技术, 1996, 2: 19-21.
[179]李湘生,史玉升,黄树槐.激光选区烧结成形机的粉末预热研究[J].机械工程学报, 2002, 38(3): 94-98.
[180]郑明新.工程材料[M].北京,清华大学出版社, 1991: 32-204.
[181] Massalski T B. Binary Alloy Phase Diagrams [M]. Ohio, Materials Park, ASM International, 1996.
[182] Gusarov A V, Laoui T, Froyen L, et al. Contact thermal conductivity of a powder bed in selective laser sintering [J]. International Journal of Heat and Mass Transfer, 2003, 46(6): 1103-1109.
[183] German R M. Supersolidus liquid phase sintering part I: process review [J]. International Journal of Powder Metallurgy, 1990, 26(1): 23-34.
[184] German R M. Supersolidus liquid phase sintering part II: densification theory [J]. International Journal of Powder Metallurgy, 1990, 26(1): 35-43.
[185] Zumelzu E, Cabezas C. Study on welding such dissimilar materials as AISI 304 stainless steel and DHP copper in a sea-water environment. Influence of weld metals on corrosion [J]. Journal of Materials Processing Technology, 1996, 57(3-4): 249-252.
[186] Rupert W D. Copper-phosphorus alloys offer advantages in brazing copper [J]. Welding Journal, 1996, 75(5): 43-45.
[187] Zhu H H, Lu L, Fuh J Y H, et al. Effect of braze flux on direct laser sintering Cu-based metal powder [J]. Materials & Design, 2006, 27(2): 166-170.
[188] Barin I. Thermochemical Data of Pure Substances [M]. New York, VCH, 1993: 602-1263.
[189] Yang X F. Equilibrium contact angle and intrinsic wetting hysteresis [J]. Applied Physics Letters, 1995, 67(15): 2249-2251.
[190] Jin W, Koplik J, Banavar J R. Wetting hysteresis at the molecular scale [J]. Physical Review Letters, 1997, 78(8): 1520-1523.
[191] Matucha K H. Structure and properties of nonferrous alloys [M], in: Cahn R W, Haasen P, Kramer E J. Materials Science and Technology: A Comprehensive Treatment, vol. 8, New York, VCH, 1996: 302-303.
[192] Breval E, Cheng J P, Agrawal D K, et al. Comparison between microwave and conventional sintering of WC/Co composites [J]. Materials Science and Engineering A, 2005, 391(1-2): 285-295.
[193] Jia C C, Tang H, Mei X Z, et al. Spark plasma sintering on nanometer scale WC-Co powder [J]. Materials Letters, 2005, 59(19-20): 2566-2569.
[194] Kim H C, Oh D Y, Shon I J. Sintering of nanophase WC-15vol.%Co hard metals by rapid sintering process [J]. International Journal of Refractory Metals & Hard Materials, 2004, 22(4-5): 197-203.
[195] Gui M C, Han J M, Li P Y. Microstructure and mechanical properties of Mg-Al9Zn/SiCp composite produced by vacuum stir casting process [J]. Materials Science and Technology, 2004, 20(6): 765-771.
[196] Jiménez J A, CarsíM, Frommeyer G, et al. Microstructural and mechanical characterisation of composite materials consisting of M3/2 high speed steel reinforced with niobium carbides [J]. Powder Metallurgy, 2005, 48(4): 371-376.
[197] Maeda K, Childs T H C. Laser sintering (SLS) of hard metal powders for abrasion resistant coatings [J]. Journal of Materials Processing Technology, 2004, 149(1-3): 609-615.
[198] Zhong M L, Liu W J, Zhang Y, et al. Formation of WC/Ni hard alloy coating by laser cladding of W/C/Ni pure element powder blend [J]. International Journal of Refractory Metals and Hard Materials, 2006, 24(6): 453-460.
[199] Chao M J, Niu X, Yuan B, et al. Preparation and characterization of in situ synthesized B4C particulate reinforced nickel composite coatings by laser cladding [J]. Surface and Coatings Technology, 2006, 201(3-4): 1102-1108.
[200] Tobar M J,álvarez C, Amado J M, et al. Morphology and characterization of laser clad composite NiCrBSi-WC coatings on stainless steel [J]. Surface and Coatings Technology, 2006, 200(22-23): 6313-6317.
[201]杨明川.碳化钨-钴(WC-Co)基纳米复合粉体及合金的制备研究[D].博士学位论文,沈阳:中国科学院金属研究所, 2004.
[202] Haglund S, ?gren J. W content in Co binder during sintering of WC-Co [J]. Acta Materialia, 1998, 46(8): 2801-2807.
[203] Gu D D, Shen Y F. Processing and microstructure of submicron WC-Co particulate reinforced Cu matrix composites prepared by direct laser sintering [J]. Materials Science and Engineering A, 2006, 435-436: 54-61.
[204] Wu X L, Chen G N. Microstructure and wear resistance of in situ TiCp composite coating by laser cladding [J]. Journal of Materials Science and Technology, 1999, 15(3): 233-238.
[205] Gu D D, Shen Y F. WC-Co particulate reinforcing Cu matrix composites produced by direct laser sintering [J]. Materials Letters, 2006, 60(29-30): 3664-3668.
[206] Tang D W, Zhou B L, Cao H, et al. Dynamic thermal expansion under transient laser-pulse heating [J]. Applied Physics Letters, 1991, 59(24): 3113-3114.
[207] Tang D W, Zhou B L, Cao H, et al. Thermal stress relaxation behavior in thin films under transient laser-pulse heating [J]. Journal of Applied Physics, 1993, 73(8): 3749-3752.
[208]张伟,隋曼龄,周亦胄,等.高密度电脉冲下材料微观结构的演变[J].金属学报, 2003, 39(10): 1009-1018.
[209] Boccalini M, Goldenstein H. Solidification of high speed steels [J]. International Materials Reviews, 2001, 46(2): 92-115.
[210] Kaynak C, Boylu S. Effects of SiC particulates on the fatigue behaviour of an Al-alloy matrix composite [J]. Materials & Design, 2006, 27(9): 776-782.
[211] Seshan S, Jayamathy M, Kailas S V, et al. The tensile behavior of two magnesium alloys reinforced with silicon carbide particulates [J]. Materials Science and Engineering A, 2003, 363(1-2): 345-351.
[212] Gu J H, Zhang X N, Qiu Y F, et al. Damping behaviors of magnesium matrix composites reinforced with Cu-coated and uncoated SiC particulates [J]. Composites Science and Technology, 2005, 65(11-12): 1736-1742.
[213] Zheng Y, Xiong W H, Lei W, et al. Effect of nano addition on the microstructures and mechanical properties of Ti(C, N)-based cermets [J]. Ceramics International, 2005, 31(1): 165-170.
[214] Zhang K, Chen G N. Effect of SiC particles on crystal growth of Al-Si alloy during laser rapid solidification [J]. Materials Science and Engineering A, 2000, 292(2): 229-231.
[215] Wong W L E, Karthik S, Gupta M. Development of hybrid Mg/Al2O3 composites with improved properties using microwave assisted rapid sintering route [J]. Journal of Materials Science, 2005, 40(13): 3395-3402.
[216] Stefanescu D M, Dhindaw B K, Kacar S A, et al. Behavior of ceramic particles at thesolid-liquid metal interface in metal matrix composites [J]. Metallurgical Transactions A, 1988, 19(11): 2847-2855.
[217] Uhlmann D R, Chalmers B, Jackson K A. Interaction between particles and a solid-liquid interface [J]. Journal of Applied Physics, 1964, 35(10): 2986-2993.
[218] Zubko A M, Lobanov V G, Nikonova V V. Reaction of foreign particles with a crystallization front [J]. Soviet Physics - Crystallography, 1973, 18(2): 239-241.
[219] Surappa M K, Rohatgi P K. Heat Diffusivity criterion for the entrapment of particles by a moving solid-liquid interface [J]. Journal of Materials Science, 1981, 16(2): 562-564.
[220] Omenyi S N, Neumann A W. Thermodynamic aspects of particle engulfment by solidifying melts [J]. Journal of Applied Physics, 1976, 47(9): 3956-3962.
[221] Omenyi S N, Neumann A W, van Oss C J. Attraction and repulsion of solid particles by solidification fronts. I. Thermodynamic effects [J]. Journal of Applied Physics, 1981, 52(2):789-795.
[222] Omenyi S N, Neumann A W, Martin W W, et al. Attraction and repulsion of solid particles by solidification fronts. II. Dimensional analysis [J]. Journal of Applied Physics, 1981, 52(2):796-802.
[223] Wilde G, Perepezko J H. Experimental study of particle incorporation during dendritic solidification [J]. Materials Science and Engineering A, 2000, 283(1-2): 25-37.
[224] Youssef Y M, Dashwood R J, Lee P D. Effect of clustering on particle pushing and solidification behaviour in TiB2 reinforced aluminium PMMCs [J]. Composites Part A, 2005, 36(6): 747-763.
[225] Shangguan D, Ahuja S, Stefanescu D M. An analytical model for the interaction between an insoluble particle and an advancing solid/liquid interface [J]. Metallurgical Transactions A, 1992, 23(2): 669-680.
[226] Chernov A A, Temkin D E, Mel’nikova A M. Theory of the capture of solid inclusions during the growth of crystals from the melt [J]. Soviet Physics - Crystallography, 1976, 21(4): 369-374.
[227] Bolling G F, CisséJ. A theory for the interaction of particles with a solidifying front [J]. Journal of Crystal Growth, 1971, 10(1): 56-66.
[228] CisséJ, Bolling G F. A study of the trapping and rejection of insoluble particles during the freezing of water [J]. Journal of Crystal Growth, 1971, 10(1): 67-76.
[229] Chernov A A, Temkin D E, Mel’nikova A M. The influence of the thermal conductivity of a macroparticle on its capture by a crystal growing from a melt [J]. Soviet Physics - Crystallography, 1977, 22(6): 656-658.
[230] P?tschke J, Rogge V. On the behaviour of foreign particles at an advancing solid-liquid interface [J]. Journal of Crystal Growth, 1989, 94(3): 726-738.
[231]刘江龙,邹至荣,苏宝嫆.高能束热处理[M].北京,机械工业出版社, 1997: 156-167.
[232]潘清跃,李延民,黄卫东,等.不锈钢激光表面熔凝处理的组织特征[J].金属学报, 1996, 32(7): 718-722.
[233]胡赓祥,钱苗根.金属学[M].上海,上海科学技术出版社, 1980: 127-141.
[234]沈以赴,佟百运,冯钟潮,等.稀土在激光熔覆涂层中的分布及其对腐蚀性能的影响[J].材料研究学报, 1998, 12(5): 434-436.
[235]沈以赴,陈继志,冯钟潮,等.稀土在激光熔覆涂层中的分布和行为[J].中国稀土学报, 1997, 15(4): 344-349.
[236]刘秀波,王华明. La2O3对TiAl合金激光熔覆γ/Cr7C3/TiC复合材料涂层组织与性能的影响[J].中国激光, 2005, 32(7): 1011-1016.
[237]赵高敏,王昆林,刘家浚. La2O3对激光熔覆铁基合金层硬度及其分布的影响[J].金属学报, 2004, 40(10): 1115-1120.
[238] Tian Y S, Chen C Z, Chen L X, et al. Effect of RE oxides on the microstructure of the coatings fabricated on titanium alloys by laser alloying technique [J]. Scripta Materialia, 2006, 54(5): 847-852.
[239]袁章福,柯家骏,李晶.金属及合金的表面张力[M].北京,科学出版社, 2006: 29-53.
[240]赵高敏,王昆林,李传刚. La2O3对激光熔覆Fe基合金熔覆层显微组织的影响[J].金属热处理, 2004, 29(4): 9-13.
[241] Zhao G M, Wang K L. Effect of La2O3 on corrosion resistance of laser clad ferrite-based alloy coatings [J]. Corrosion Science, 2006, 48(2): 273-284.
[242]翟启杰,关绍康,商全义.合金热力学理论及其应用[M].北京,冶金工业出版社, 1999: 142-148.
[243] Wu C M L, Yu D Q, Law C M T, et al. Properties of lead-free solder alloys with rare earth element additions [J]. Materials Science and Engineering R, 2004, 44(1): 1-44.
[244]钟华仁.钢的稀土化学热处理.北京:国防工业出版社, 1998: 195-205.
[245] Balluffi R W, Allen S M, Craig Carter W. Kinetics of Materials [M]. New Jersey, John Wiley & Sons, 2005: 460-468.
[2] Pham D T, Dimov S S. Rapid manufacturing: the technologies and applications of rapid prototyping and rapid tooling [M]. London, Springer-Verlag, 2001: 19-40.
[3] Chua C K, Leong K F, Lim C S. Rapid prototyping: principles and applications [M]. Singapore, World Scientific Publishing Company, 2003: 11-19.
[4] Das S. Direct selective laser sintering of high performance metals - machine design, process development and process control [D]. Ph.D. Thesis, The University of Texas at Austin, 1998.
[5] Noorani R I. Rapid prototyping: principles and applications [M]. New Jersey, John Wiley & Sons, 2005: 34-44.
[6] Venuvinod P K, Ma W Y. Rapid prototyping: laser-based and other technologies [M]. Norwell, Kluwer Academic Publishers, 2001: 245-275.
[7]沈以赴,陈文华,赵剑峰,等.快速成形技术中材料成形性的研究进展[J].材料科学与工程, 2001, 19(4): 90-96.
[8]王华明.金属材料激光表面改性与高性能金属零件激光快速成形技术研究进展[J].航空学报, 2002, 23(5): 473-478.
[9]张永忠,石力开,章萍芝,等.基于金属粉末的激光快速成型技术新进展[J].稀有金属材料与工程, 2000, 29(6): 361-365.
[10]黄树槐,肖跃加,莫健华,等.快速成形技术的展望[J].中国机械工程, 2000, 11(1-2): 195-200.
[11] Ferreira J C, Mateus A. A numerical and experimental study of fracture in RP stereolithography patterns and ceramic shells for investment casting [J]. Journal of Materials Processing Technology, 2003, 134(1): 135-144.
[12] Harris R A, Hague R J M, Dickens P M. The structure of parts produced by stereolithography injection mould tools and the effect on part shrinkage [J]. International Journal of Machine Tools and Manufacture, 2004, 44(1): 59-64.
[13] Kim H C, Lee S H. Reduction of post-processing for stereolithography systems by fabrication-direction optimization [J]. Computer-Aided Design, 2005, 37(7): 711-725.
[14] Chiu Y Y, Liao Y S, Hou C C. Automatic fabrication for bridged laminated object manufacturing (LOM) process [J]. Journal of Materials Processing Technology, 2003,140(1-3): 179-184.
[15] Yi S P, Liu F, Zhang J, et al. Study of the key technologies of LOM for functional metal parts [J]. Journal of Materials Processing Technology, 2004, 150(1-2): 175-181.
[16] Kechagias J, Maropoulos S, Karagiannis S. Process build-time estimator algorithm for laminated object manufacturing [J]. Rapid Prototyping Journal, 2004, 10(5): 297-304.
[17] Chung H, Das S. Processing and properties of glass bead particulate-filled functionally graded Nylon-11 composites produced by selective laser sintering [J]. Materials Science and Engineering A, 2006, 437(2): 226-234.
[18] Zarringhalam H, Hopkinson N, Kamperman N F, et al. Effects of processing on microstructure and properties of SLS Nylon 12 [J]. Materials Science and Engineering A, 2006, 435-436: 172-180.
[19] Zheng H Z, Zhang J, Lu S Q, et al. Effect of core-shell composite particles on the sintering behavior and properties of nano-Al2O3/polystyrene composite prepared by SLS [J]. Materials Letters, 2006, 60(9-10): 1219-1223.
[20] Ang K C, Leong K F, Chua C K, et al. Investigation of the mechanical properties and porosity relationships in fused deposition modelling-fabricated porous structures [J]. Rapid Prototyping Journal, 2006, 12(2): 100-105.
[21] Zein I, Hutmacher D W, Tan K C, et al. Fused deposition modeling of novel scaffold architectures for tissue engineering applications [J]. Biomaterials, 2002, 23(4): 1169-1185.
[22] Pennington R C, Hoekstra N L, Newcomer J L. Significant factors in the dimensional accuracy of fused deposition modelling [J]. Proceedings of the Institution of Mechanical Engineers, Part E, Journal of Process Mechanical Engineering, 2005, 219(E1): 89-92.
[23] Hull C W. Apparatus for production of three-dimensional objects by stereolithography [P]. United States Patent, 4575330, 1986.
[24] http://www.3dsystems.com/
[25] Hull C, Feygin M, Baron Y, et al. Rapid prototyping: current technology and future potential [J]. Rapid Prototyping Journal, 1995, 1(1): 11-19.
[26] Deckard C. Methods and apparatus for producing parts by selective laser sintering [P]. United States Patent, 4863538, 1989.
[27] http://intl.stratasys.com/
[28] Ho H C H, Gibson I, Cheung W L. Effects of energy density on morphology and properties of selective laser sintered polycarbonate [J]. Journal of Materials Processing Technology, 1999, 89-90: 204-210.
[29] Tang Y, Fuh J Y H, Loh H T, et al. Direct laser sintering of a silica sand [J]. Materials &Design, 2003, 24(8): 623-629.
[30] Shi Y, Li Z, Sun H, et al. Effect of the properties of the polymer materials on the quality of selective laser sintering parts [J]. Proceedings of the Institution of Mechanical Engineers, Part L, Journal of Materials: Design & Applications, 2004, 218(L3): 247-252.
[31] Wiedemann B, Jantzen H A. Strategies and applications for rapid product and process development in Daimler-Benz AG [J]. Computers in Industry, 1999, 39(1): 11-25.
[32] Liu H J, Fan Z T, Huang N Y, et al. A note on rapid manufacturing process of metallic parts based on SLS plastic prototype [J]. Journal of Materials Processing Technology, 2003, 142(3): 710-713.
[33] Karalekas D, Kakoudakis J. Predictive mechanical performance evaluation of consumer food cans using stereo lithography models [J]. Packaging Technology and Science, 2003, 16(1): 37-45.
[34] Hanninen J. Direct metal laser sintering [J]. Advanced Materials & Processes, 2002, 160(5): 33-36.
[35] King D, Tansey T. Rapid tooling: selective laser sintering injection tooling [J]. Journal of Materials Processing Technology, 2003, 132(1-3): 42-48.
[36] Cheah C M, Chua C K, Lee C W, et al. Rapid prototyping and tooling techniques: a review of applications for rapid investment casting [J]. International Journal of Advanced Manufacturing Technology, 2005, 25(3-4): 308-320.
[37] Lino F J, Neto R J L, Paiva R, et al. Rapid prototyping and rapid tooling applied in product development of ceramic components [J]. Materials Science Forum, 2004, 455-456: 835-838.
[38] Evans R S, Bourell D L, Beaman J J, et al. Rapid manufacturing of silicon carbide composites [J]. Rapid Prototyping Journal, 2005, 11(1): 37-40.
[39] Gahler A, Heinrich J G, Gunster J. Direct laser sintering of Al2O3-SiO2 dental ceramic components by layer-wise slurry deposition [J]. Journal of the American Ceramic Society, 2006, 89(10): 3076-3080.
[40]王华明.航空高性能金属结构件激光快速成形研究进展[J].航空制造技术, 2005, 12: 26-28.
[41] Raja V, Zhang S J, Garside J, et al. Rapid and cost-effective manufacturing of high-integrity aerospace components [J]. International Journal of Advanced Manufacturing Technology, 2006, 27(7-8): 759-773.
[42] Zhang J F, Huang Y H, Shen Y F, et al. Study on selective laser sintering of metallic powders [J]. Transactions of Nanjing University of Aeronautics & Astronautics, 2002, 19(1): 77-83.
[43] Vasinonta A, Beuth J L, Griffith M L. A process map for consistent build conditions in thesolid freeform fabrication of thin-walled structures [J]. Journal of Manufacturing Science and Engineering-Transactions of the ASME, 2001, 123(4): 615-622.
[44] Sansoni G, Docchio F. Three-dimensional optical measurements and reverse engineering for automotive applications [J]. Robotics and Computer-Integrated Manufacturing, 2004, 20(5): 359-367.
[45] Hopkinson N, Gao Y, McAfee D J. Design for environment analyses applied to rapid manufacturing [J]. Proceedings of the Institution of Mechanical Engineers, Part D, Journal of Automobile Engineering, 2006, 220(D10): 1363-1372.
[46] Canellidis V, Dedoussis V, Mantzouratos N, et al. Pre-processing methodology for optimizing stereolithography apparatus build performance [J]. Computers in Industry, 2006, 57(5): 424-436.
[47] Ghany K A, Moustafa S F. Comparison between the products of four RPM systems for metals [J]. Rapid Prototyping Journal, 2006, 12(2): 86-94.
[48] Li H L, Zeng X Y. A study on embedded resistor components fabricated by laser micro-cladding and rapid prototype [J]. Materials Science and Engineering B, 2006, 133(1-3): 84-90.
[49] Zeng X Y, Li X Y, Liu J W, et al. Direct fabrication of electric components on insulated boards by laser microcladding electronic pastes [J]. IEEE Transactions on Advanced Packaging, 2006, 29(2): 291-294.
[50] Li X Y, Zeng X Y, Li H L, et al. Laser direct fabrication of silver conductors on glass boards [J]. Thin Solid Films, 2005, 483(1-2): 270-275.
[51] Laoui T, Santos E, Osakada K, et al. Properties of titanium dental implant models made by laser processing [J]. Proceedings of the Institution of Mechanical Engineers, Part C, Journal of Mechanical Engineering Science, 2006, 220(6): 857-863.
[52] Li J P, de Wijn J R, Van Blitterswijk C A, et al. Porous Ti6Al4V scaffold directly fabricating by rapid prototyping: Preparation and in vitro experiment [J]. Biomaterials, 2006, 27(8): 1223-1235.
[53] Hollander D A, von Walter M, Wirtz T, et al. Structural, mechanical and in vitro characterization of individually structured Ti-6Al-4V produced by direct laser forming [J]. Biomaterials, 2006, 27(7): 955-963.
[54]顾冬冬,沈以赴,潘琰峰,等.直接金属粉末激光烧结成形机制的研究[J].材料工程, 2004, 5: 42-48.
[55] Agarwala M, Bourell D, Beaman J, et al. Direct selective laser sintering of metals [J]. Rapid Prototyping Journal, 1995, 1(1): 26-36.
[56] Das S, Beaman J J, Wohlert M, et al. Direct laser freeform fabrication of high performance metal components [J]. Rapid Prototyping Journal, 1998, 4(3): 112-117.
[57]沈以赴,顾冬冬,陈文华,等. CuSn预合金对金属粉末选区激光烧结过程及烧结体质量的影响[J].航空学报, 2005, 26(6): 768-773.
[58]顾冬冬,沈以赴,杨家林,等.多组分铜基金属粉末选区激光烧结致密化机理[J].中国有色金属学报, 2005, 15(4): 596-602.
[59]顾冬冬,沈以赴,杨家林,等.多组分铜基金属粉末选区激光烧结试验研究[J].航空学报, 2005, 26(4): 510-514.
[60] Kruth J P, Froyen L, Van Vaerenbergh J, et al. Selective laser melting of iron-based powder [J]. Journal of Materials Processing Technology, 2004, 149(1-3): 616-622.
[61] Osakada K, Shiomi M. Flexible manufacturing of metallic products by selective laser melting of powder [J]. International Journal of Machine Tools & Manufacture, 2006, 46(11): 1188-1193.
[62] Wright C S, Youseffi M, Akhtar S P, et al. Selective laser melting of prealloyed high alloy steel powder beds [J]. Materials Science Forum, 2006, 514-516: 516-523.
[63] Morgan R, Sutcliffe C J, O’Neill W. Density analysis of direct metal laser re-melted 316L stainless steel cubic primitives [J]. Journal of Materials Science, 2004, 39(4): 1195-1205.
[64] Chen X C, Xie J W, Fox P. Direct laser remelting of iron with addition of boron [J]. Materials Science and Technology, 2004, 20(6): 715-719.
[65] Pogson S R, Fox P, Sutcliffe C J, et al. The production of copper parts using DMLR [J]. Rapid Prototyping Journal, 2003, 9(5): 334-343.
[66] Kelly S M, Kampe S L. Microstructural evolution in laser-deposited multilayer Ti-6Al-4V builds: Part I. Microstructural characterization [J]. Metallurgical and Materials Transactions A, 2004, 35(6): 1861-1867.
[67] Kelly S M, Kampe S L. Microstructural evolution in laser-deposited multilayer Ti-6Al-4V builds: Part II. Thermal modeling [J]. Metallurgical and Materials Transactions A, 2004, 35(6): 1869-1879.
[68] Li P, Yang T P, Li S, et al. Direct laser fabrication of nickel alloy samples [J]. International Journal of Machine Tools & Manufacture, 2005, 45(11): 1288-1294.
[69] Wang L, Felicelli S. Analysis of thermal phenomena in LENSTM deposition [J]. Materials Science and Engineering A, 2006, 435-436: 625-631.
[70] Ye R Q, Smugeresky J E, Zheng B L, et al. Numerical modeling of the thermal behavior during the LENS? process [J]. Materials Science and Engineering A, 2006, 428(1-2): 47-53.
[71] Rangaswamy P, Griffith M L, Prime M B, et al. Residual stresses in LENS? componentsusing neutron diffraction and contour method [J]. Materials Science and Engineering A, 2005, 399(1-2): 72-83.
[72] Santos E C, Shiomi M, Osakada K, et al. Rapid manufacturing of metal components by laser forming [J]. International Journal of Machine Tools & Manufacture, 2006, 46(12-13): 1459-1468.
[73]潘琰峰,沈以赴,顾冬冬,等.选择性激光烧结技术的发展现状[J].工具技术, 2004, 38(6): 3-7.
[74]张剑峰,沈以赴,赵剑峰,等.激光烧结成形金属材料及零件的进展[J].金属热处理, 2001, 26(12): 1-4.
[75]史玉升,孙海宵,樊自田,等.基于选择性激光烧结方法的金属零件快速制造技术研究[J].铸造, 2003, 52(10): 749-752.
[76] Bourell D, Wohlert M, Harlan N, et al. Powder densification maps in selective laser sintering [J]. Advanced Engineering Materials, 2002, 4(9): 663-669.
[77] Simchi A, Petzoldt F, Pohl H. Direct metal laser sintering: Material considerations and mechanisms of particle bonding [J]. International Journal of Powder Metallurgy, 2001, 37(2): 49-61.
[78] Kruth J P, Mercelis P, Van Vaerenbergh J, et al. Binding mechanisms in selective laser sintering and selective laser melting [J]. Rapid Prototyping Journal, 2005, 11(1): 26-36.
[79] Tolochko N K, Arshinov M K, Gusarov A V, et al. Mechanisms of selective laser sintering and heat transfer in Ti powder [J]. Rapid Prototyping Journal, 2003, 9(5): 314-326.
[80] Kathuria Y P. Microstructuring by selective laser sintering of metallic powder [J]. Surface and Coatings Technology, 1999, 116-119: 643-647.
[81] Simchi A, Pohl H. Direct laser sintering of iron-graphite powder mixture [J]. Materials Science and Engineering A, 2004, 383(2): 191-200.
[82] Murali K, Chatterjee A N, Saha P, et al. Direct selective laser sintering of iron-graphite powder mixture [J]. Journal of Materials Processing Technology, 2003, 136(1-3): 179-185.
[83] Simchi A, Petzoldt F, Pohl H. On the development of direct metal laser sintering for rapid tooling [J]. Journal of Materials Processing Technology, 2003, 141(3): 319-328.
[84] Kruth J P, Kumar S, Van Vaerenbergh J. Study of laser-sinterability of ferro-based powders [J]. Rapid Prototyping Journal, 2005, 11(5): 287-292.
[85] Rossi S, Deflorian F, Venturini F. Improvement of surface finishing and corrosion resistance of prototypes produced by direct metal laser sintering [J]. Journal of Materials Processing Technology, 2004, 148(3): 301-309.
[86] Wang Y, Bergstr?m J, Burman C. Four-point bending fatigue behaviour of an iron-basedlaser sintered material [J]. International Journal of Fatigue, 2006, 28(12): 1705-1715.
[87] Wang Y, Bergstr?m J, Burman C. Characterization of an iron-based laser sintered material [J]. Journal of Materials Processing Technology, 2006, 172(1): 77-87.
[88] Zhu H H, Fuh J Y H, Lu L. Formation of Fe-Cu metal parts using direct laser sintering [J]. Proceedings of the Institution of Mechanical Engineers, Part C, Journal of Mechanical Engineering Science, 2003, 217(1): 139-147.
[89]沈以赴,吴鹏,顾冬冬,等. Ni-CuSn混合粉末选区激光烧结试验[J].焊接学报, 2005, 26(2): 73-76.
[90] Tolochko N, Mozzharov S, Laoui T, et al. Selective laser sintering of single- and two-component metal powders [J]. Rapid Prototyping Journal, 2003, 9(2): 68-78.
[91]张剑峰,沈以赴,赵剑峰,等. Ni基金属粉末激光快速制造的研究[J].航空学报, 2002, 23(3): 221-225.
[92] Zhu H H, Lu L, Fuh J Y H. Development and characterisation of direct laser sintering Cu-based metal powder [J]. Journal of Materials Processing Technology, 2003, 140(1-3): 314-317.
[93] Zhu H H, Lu L, Fuh J Y H. Influence of binder’s liquid volume fraction on direct laser sintering of metallic powder [J]. Materials Science and Engineering A, 2004, 371(1-2): 170-177.
[94] Zhu H H, Fuh J Y H, Lu L. Microstructural evolution in direct laser sintering of Cu-based metal powder [J]. Rapid Prototyping Journal, 2005, 11(2): 74-81.
[95] Das S, Wohlert M, Beaman J J, et al. Processing of titanium net shapes by SLS/HIP [J]. Materials & Design, 1999, 20(2-3): 115-121.
[96] Shen Y F, Gu D D, Pan Y F. Balling process in selective laser sintering 316 stainless steel powder [J]. Key Engineering Materials, 2006, 315-316: 357-360.
[97] Childs T H C, Hauser C, Badrossamay M. Selective laser sintering (melting) of stainless and tool steel powders: experiments and modelling [J]. Proceedings of the Institution of Mechanical Engineers, Part B, Journal of Engineering Manufacture, 2005, 219(4): 339-357.
[98] Katz Z, Smith P E S. On process modelling for selective laser sintering of stainless steel [J]. Proceedings of the Institution of Mechanical Engineers, Part B, Journal of Engineering Manufacture, 2001, 215(11): 1497-1504.
[99] Asgharzadeh H, Simchi A. Effect of sintering atmosphere and carbon content on the densification and microstructure of laser-sintered M2 high-speed steel powder [J]. Materials Science and Engineering A, 2005, 403(1-2): 290-298.
[100] Simchi A. Direct laser sintering of metal powders: Mechanism, kinetics and microstructuralfeatures [J]. Materials Science and Engineering A, 2006, 428(1-2): 148-158.
[101] Dewidar M M, Dalgarno K W, Wright C S. Processing conditions and mechanical properties of high-speed steel parts fabricated using direct selective laser sintering [J]. Proceedings of the Institution of Mechanical Engineers, Part B, Journal of Engineering Manufacture, 2003, 217(12): 1651-1663.
[102] Niu H J, Chang I T H. Selective laser sintering of gas atomized M2 high speed steel powder [J]. Journal of Materials Science, 2000, 35(1): 31-38.
[103] Chatterjee A N, Kumar S, Saha P, et al. An experimental design approach to selective laser sintering of low carbon steel [J]. Journal of Materials Processing Technology, 2003, 136(1-3): 151-157.
[104] Su W N, Erasenthiran P, Dickens P M. Investigation of fully dense laser sintering of tool steel powder using a pulsed Nd: YAG (neodymium-doped yttrium aluminium garnet) laser [J]. Proceedings of the Institution of Mechanical Engineers, Part C, Journal of Mechanical Engineering Science, 2003, 217(1): 127-138.
[105] Kovalev A I, Mishina V P, Wainstein D L, et al. Selective laser sintering of single-phase powder Cr-V tool steel [J]. Journal of Materials Engineering and Performance, 2002, 11(5): 492-495.
[106] Tang Y, Loh H T, Wong Y S, et al. Direct laser sintering of a copper-based alloy for creating three-dimensional metal parts [J]. Journal of Materials Processing Technology, 2003, 140(1-3): 368-372.
[107]赵剑峰.基于选区激光烧结快速成形的快速制造技术研究[D].博士学位论文,南京:南京航空航天大学, 1999.
[108]田宗军.激光烧结快速成型计算机控制系统的研究与运用[D].博士学位论文,南京:南京航空航天大学, 2000.
[109]李湘生.选区激光烧结若干关键技术研究[D].博士学位论文,武汉:华中科技大学, 2001.
[110]蔡道生.选择性激光烧结工艺软件关键技术研究[D].博士学位论文,武汉:华中科技大学, 2004.
[111] http://www.eos.info/
[112] http://www.binhurp.com/
[113] http://www.lyafs.com.cn/
[114]杨家林,王洋. 50W激光快速成型设备与2kW CO2激光器的系统集成[J].制造技术与机床, 2003, 9: 28-30.
[115] Morgan R H, Papworth A J, Sutcliffe C, et al. High density net shape components by directlaser re-melting of single-phase powders [J]. Journal of Materials Science, 2002, 37(15): 3093-3100.
[116] Xie J W, Fox P, O’Neill W, et al. Effect of direct laser re-melting processing parameters and scanning strategies on the densification of tool steels [J]. Journal of Materials Processing Technology, 2005, 170(3): 516-523.
[117] Childs T H C, Hauser C. Raster scan selective laser melting of the surface layer of a tool steel powder bed [J]. Proceedings of the Institution of Mechanical Engineers, Part B, Journal of Engineering Manufacture, 2005, 219(4): 379-384.
[118] Mercelis P, Kruth J P. Residual stresses in selective laser sintering and selective laser melting [J]. Rapid Prototyping Journal, 2006, 12(5): 254-265.
[119] Shiomi M, Osakada K, Nakamura K, et al. Residual stress within metallic model made by selective laser melting process [J]. CIRP Annals - Manufacturing Technology, 2004, 53(1): 195-198.
[120] Abe F, Osakada K, Shiomi M, et al. The manufacturing of hard tools from metallic powders by selective laser melting [J]. Journal of Materials Processing Technology, 2001, 111(1-3): 210-213.
[121] Fischer P, Romano V, Weber H P, et al. Sintering of commercially pure titanium powder with a Nd: YAG laser source [J]. Acta Materialia, 2003, 51(6): 1651-1662.
[122] Fischer P, Romano V, Weber H P, et al. Pulsed laser sintering of metallic powders [J]. Thin Solid Films, 2004, 453: 139-144.
[123] Fischer P, Leber H, Romano V, et al. Microstructure of near-infrared pulsed laser sintered titanium samples [J]. Applied Physics A - Materials Science & Processing, 2004, 78(8): 1219-1227.
[124] Fischer P, Romano V, Blatter A, et al. Highly precise pulsed selective laser sintering of metallic powders [J]. Laser Physics Letters, 2005, 2(1): 48-55.
[125] Pogson S, Fox P, O’Neill W, et al. The direct metal laser remelting of copper and tool steel powders [J]. Materials Science and Engineering A, 2004, 386(1-2): 453-459.
[126] Brooks J A, Robino C V, Headley T, et al. Microstructure and property optimization of LENS deposited H13 tool steel [C]. Proceedings of the Solid Freeform Fabrication Symposium, Austin, TX, 1999: 375-382.
[127] Hofmeister W, Griffith M, Ensz M, et al. Solidification in direct metal deposition by LENS processing [J]. JOM, 2001, 53(9): 30-34.
[128] Atwood C, Griffith M, Harwell L, et al. Laser engineered net shaping (LENSTM): a tool for direct fabrication of metal parts [C]. Proceedings of the Laser Materials ProcessingConference ICALEO’98, Orlando, FL, 1998: E1-7.
[129] Griffith M L, Ensz M T, Puskar J D, et al. Understanding the microstructure and properties of components fabricated by laser engineered net shaping (LENS) [C]. Materials Research Society Symposium - Proceedings, San Francisco, CA, 2000: 9-20.
[130] Pinkerton A J, Li L. Rapid prototyping using direct laser deposition - the effect of powder atomization type and flowrate [J]. Proceedings of the Institution of Mechanical Engineers, Part B, Journal of Engineering Manufacture, 2003, 217(6): 741-752.
[131] Wu X H, Liang J, Mei J F, et al. Microstructures of laser-deposited Ti-6Al-4V [J]. Materials & Design, 2004, 25(2): 137-144.
[132] Wu X, Sharman R, Mei J, et al. Microstructure and properties of a laser fabricated burn-resistant Ti alloy [J]. Materials & Design, 2004, 25(2): 103-109.
[133] Srivastava D, Chang I T H, Loretto M H. The effect of process parameters and heat treatment on the microstructure of direct laser fabricated TiAl alloy samples [J]. Intermetallics, 2001, 9(12) 1003-1013.
[134] Pinkerton A J, Li L. Multiple-layer laser deposition of steel components using gas- and water-atomised powders: the differences and the mechanisms leading to them [J]. Applied Surface Science, 2005, 247(1-4): 175-181.
[135] Pinkerton A J, Li L. The effect of laser pulse width on multiple-layer 316L steel clad microstructure and surface finish [J]. Applied Surface Science, 2003, 208-209: 411-416.
[136] Pinkerton A J, Li L. An investigation of the effect of pulse frequency in laser multiple-layer cladding of stainless steel [J]. Applied Surface Science, 2003, 208-209: 405-410.
[137] Pinkerton A J, Li L. Multiple-layer cladding of stainless steel using a high-powered diode laser: an experimental investigation of the process characteristics and material properties [J]. Thin Solid Films, 2004, 453-454: 471-476.
[138] Banerjee R, Collins P C, Bhattacharyya D, et al. Microstructural evolution in laser deposited compositionally gradedα/βtitanium-vanadium alloys [J]. Acta Materialia, 2003, 51(11): 3277-3292.
[139] Banerjee R, Bhattacharyya D, Collins P C, et al. Precipitation of grain boundaryαin a laser deposited compositionally graded Ti-8Al-xV alloy - an orientation microscopy study [J]. Acta Materialia, 2004, 52(2): 377-385.
[140] Unocic R R, DuPont J N. Composition control in the direct laser-deposition process [J]. Metallurgical and Materials Transactions B, 2003, 34(4): 439-445.
[141]陈静,林鑫,王涛,等. 316L不锈钢激光快速成形过程中熔覆层的热裂机理[J].稀有金属材料与工程, 2003, 32(3): 183-186.
[142]林鑫,杨海欧,陈静,等.激光快速成形过程中316L不锈钢显微组织的演变[J].金属学报, 2006, 42(4): 361-368.
[143]张永忠,席明哲,石力开,等.激光快速成形316L不锈钢的组织及性能[J].稀有金属材料与工程, 2002, 31(2): 103-105.
[144]杨海欧,陈静,李延民,等. Rene95高温合金激光快速成形试样的力学性能[J].稀有金属材料与工程, 2003, 32(4): 276-279.
[145]张永忠,石力开,章萍芝,等.激光快速成形镍基高温合金研究[J].航空材料学报, 2002, 22(1): 22-25.
[146] Lin X, Yue T M, Yang H O, et al. Microstructure and phase evolution in laser rapid forming of a functionally graded Ti-Rene88DT alloy [J]. Acta Materialia, 2006, 54(7): 1901-1915.
[147] Lin X, Yue T M, Yang H O, et al. Laser rapid forming of SS316L/Rene88DT graded material [J]. Materials Science and Engineering A, 2005, 391(1-2): 325-336.
[148] Lin X, Yue T M. Phase formation and microstructure evolution in laser rapid forming of graded SS316L/Rene88DT alloy [J]. Materials Science and Engineering A, 2005, 402(1-2): 294-306.
[149]陈静,谭华,杨海欧,等.激光快速成形过程熔池行为的实时观察研究[J].应用激光, 2005, 25(2): 77-80.
[150]石力开,高士友,席明哲,等.金属直薄壁件激光直接沉积过程的有限元模拟I.沉积过程中温度场的模拟[J].金属学报, 2006, 42(5): 449-453.
[151]石力开,高士友,席明哲,等.金属直薄壁件激光直接沉积过程的有限元模拟II.沉积过程中热应力场的模拟[J].金属学报, 2006, 42(5): 454-458.
[152]石力开,高士友,席明哲,等.金属直薄壁件激光直接沉积过程的有限元模拟III.沉积过程中变形的分析[J].金属学报, 2006, 42(5): 459-462.
[153]王华明,张凌云,李安,等.金属材料快速凝固激光加工与成形[J].北京航空航天大学学报, 2004, 30(10): 962-967.
[154] Wang H M, Cao F, Cai L X, et al. Microstructure and tribological properties of laser clad Ti2Ni3Si/NiTi intermetallic coatings [J]. Acta Materialia, 2003, 51(20): 6319-6327.
[155] Wang H M, Luan D Y, Cai L X. Microstructure and sliding-wear behavior of tungsten-reinforced W-Ni-Si metal-silicide in-situ composites [J]. Metallurgical and Materials Transactions A, 2003, 34(9): 2005-2015.
[156] Cai L X, Wang H M. Microstructure and dry-sliding wear resistance of laser clad tungsten reinforced W5Si3/W2Ni3Si intermetallic coatings [J]. Applied Surface Science, 2004, 235(4): 501-506.
[157] Zhong M L, Liu W J, Ning G Q, et al. Laser direct manufacturing of tungsten nickelcollimation component [J]. Journal of Materials Processing Technology, 2004, 147(2): 167-173.
[158]陈静,杨海欧,李延民,等.激光快速成形过程中熔覆层的两种开裂行为及其机理研究[J].应用激光, 2002, 22(3): 300-304.
[159]杨健,黄卫东,杨海欧.激光快速成形316L不锈钢残余应力分布[J].应用激光, 2005, 25(3): 151-154.
[160] Niu H J, Chang I T H. Instability of scan tracks of selective laser sintering of high speed steel powder [J]. Scripta Materialia, 1999, 41(11): 1229-1234.
[161] Niu H J, Chang I T H. Liquid phase sintering of M3/2 high speed steel by selective laser sintering [J]. Scripta Materialia, 1998, 39(1): 67-72.
[162]潘琰峰,沈以赴,顾冬冬,等.工艺参数对316不锈钢粉末激光烧结球化的影响[J].材料工程, 2005, 5: 52-55.
[163]潘琰峰,沈以赴,顾冬冬,等. 316不锈钢粉末直接激光烧结的球化效应[J].中国机械工程, 2005, 16(17): 1573-1576.
[164]顾冬冬,沈以赴.铜基金属粉末直接激光烧结工艺及成形件显微组织研究[J].中国机械工程, 2006, 17(20): 2171-2175.
[165] Simchi A, Pohl H. Effects of laser sintering processing parameters on the microstructure and densification of iron powder [J]. Materials Science and Engineering A, 2003, 359(1-2) 119-128.
[166]顾冬冬,沈以赴,吴鹏,等.铜基金属粉末选区激光烧结的工艺研究[J].中国激光, 2005, 32(11): 1561-1566.
[167]沈以赴,顾冬冬,余承业,等.直接金属粉末激光烧结成形过程温度场模拟[J].中国机械工程, 2005, 16(1): 67-73.
[168] Das S. Physical aspects of process control in selective laser sintering of metals [J]. Advanced Engineering Materials, 2003, 5(10): 701-711.
[169] Gu D D, Shen Y F. Influence of phosphorus element on direct laser sintering of multicomponent Cu-based metal powder [J]. Metallurgical and Materials Transactions B, 2006, 37(6): 967-977.
[170] Niu H J, Chang I T H. Selective laser sintering of gas and water atomized high speed steel powders [J]. Scripta Materialia, 1999, 41(1): 25-30.
[171] Gu D D, Shen Y F, Liu M C, et al. Numerical simulations of temperature field in direct metal laser sintering process [J]. Transactions of Nanjing University of Aeronautics & Astronautics, 2004, 21(3): 225-233.
[172] Wang X C, Laoui T, Bonse J, et al. Direct selective laser sintering of hard metal powders:Experimental study and simulation [J]. International Journal of Advanced Manufacturing Technology, 2002, 19(5): 351-357.
[173] Gu D D, Shen Y F. Development and characterisation of direct laser sintering multicomponent Cu based metal powder [J]. Powder Metallurgy, 2006, 49(3): 258-264.
[174]张剑峰. Ni基金属粉末激光直接烧结成形及关键技术研究[D].博士学位论文,南京:南京航空航天大学, 2002.
[175] Tolochko N K, Laoui T, Khlopkov Y V, et al. Absorptance of powder materials suitable for laser sintering [J]. Rapid Prototyping Journal, 2000, 6(3): 155-160.
[176] Gu D D, Shen Y F. Effects of dispersion technique and component ratio on densification and microstructure of multi-component Cu-based metal powder in direct laser sintering [J]. Journal of Materials Processing Technology, 2007, 182(1-3): 564-573.
[177]邓琦林,方建成.选择性激光烧结粉末的参数分析[J].制造技术与机床, 1997, 10: 26-29.
[178]邓琦林,余承业.金属粉末的选择性激光烧结[J].航空工艺技术, 1996, 2: 19-21.
[179]李湘生,史玉升,黄树槐.激光选区烧结成形机的粉末预热研究[J].机械工程学报, 2002, 38(3): 94-98.
[180]郑明新.工程材料[M].北京,清华大学出版社, 1991: 32-204.
[181] Massalski T B. Binary Alloy Phase Diagrams [M]. Ohio, Materials Park, ASM International, 1996.
[182] Gusarov A V, Laoui T, Froyen L, et al. Contact thermal conductivity of a powder bed in selective laser sintering [J]. International Journal of Heat and Mass Transfer, 2003, 46(6): 1103-1109.
[183] German R M. Supersolidus liquid phase sintering part I: process review [J]. International Journal of Powder Metallurgy, 1990, 26(1): 23-34.
[184] German R M. Supersolidus liquid phase sintering part II: densification theory [J]. International Journal of Powder Metallurgy, 1990, 26(1): 35-43.
[185] Zumelzu E, Cabezas C. Study on welding such dissimilar materials as AISI 304 stainless steel and DHP copper in a sea-water environment. Influence of weld metals on corrosion [J]. Journal of Materials Processing Technology, 1996, 57(3-4): 249-252.
[186] Rupert W D. Copper-phosphorus alloys offer advantages in brazing copper [J]. Welding Journal, 1996, 75(5): 43-45.
[187] Zhu H H, Lu L, Fuh J Y H, et al. Effect of braze flux on direct laser sintering Cu-based metal powder [J]. Materials & Design, 2006, 27(2): 166-170.
[188] Barin I. Thermochemical Data of Pure Substances [M]. New York, VCH, 1993: 602-1263.
[189] Yang X F. Equilibrium contact angle and intrinsic wetting hysteresis [J]. Applied Physics Letters, 1995, 67(15): 2249-2251.
[190] Jin W, Koplik J, Banavar J R. Wetting hysteresis at the molecular scale [J]. Physical Review Letters, 1997, 78(8): 1520-1523.
[191] Matucha K H. Structure and properties of nonferrous alloys [M], in: Cahn R W, Haasen P, Kramer E J. Materials Science and Technology: A Comprehensive Treatment, vol. 8, New York, VCH, 1996: 302-303.
[192] Breval E, Cheng J P, Agrawal D K, et al. Comparison between microwave and conventional sintering of WC/Co composites [J]. Materials Science and Engineering A, 2005, 391(1-2): 285-295.
[193] Jia C C, Tang H, Mei X Z, et al. Spark plasma sintering on nanometer scale WC-Co powder [J]. Materials Letters, 2005, 59(19-20): 2566-2569.
[194] Kim H C, Oh D Y, Shon I J. Sintering of nanophase WC-15vol.%Co hard metals by rapid sintering process [J]. International Journal of Refractory Metals & Hard Materials, 2004, 22(4-5): 197-203.
[195] Gui M C, Han J M, Li P Y. Microstructure and mechanical properties of Mg-Al9Zn/SiCp composite produced by vacuum stir casting process [J]. Materials Science and Technology, 2004, 20(6): 765-771.
[196] Jiménez J A, CarsíM, Frommeyer G, et al. Microstructural and mechanical characterisation of composite materials consisting of M3/2 high speed steel reinforced with niobium carbides [J]. Powder Metallurgy, 2005, 48(4): 371-376.
[197] Maeda K, Childs T H C. Laser sintering (SLS) of hard metal powders for abrasion resistant coatings [J]. Journal of Materials Processing Technology, 2004, 149(1-3): 609-615.
[198] Zhong M L, Liu W J, Zhang Y, et al. Formation of WC/Ni hard alloy coating by laser cladding of W/C/Ni pure element powder blend [J]. International Journal of Refractory Metals and Hard Materials, 2006, 24(6): 453-460.
[199] Chao M J, Niu X, Yuan B, et al. Preparation and characterization of in situ synthesized B4C particulate reinforced nickel composite coatings by laser cladding [J]. Surface and Coatings Technology, 2006, 201(3-4): 1102-1108.
[200] Tobar M J,álvarez C, Amado J M, et al. Morphology and characterization of laser clad composite NiCrBSi-WC coatings on stainless steel [J]. Surface and Coatings Technology, 2006, 200(22-23): 6313-6317.
[201]杨明川.碳化钨-钴(WC-Co)基纳米复合粉体及合金的制备研究[D].博士学位论文,沈阳:中国科学院金属研究所, 2004.
[202] Haglund S, ?gren J. W content in Co binder during sintering of WC-Co [J]. Acta Materialia, 1998, 46(8): 2801-2807.
[203] Gu D D, Shen Y F. Processing and microstructure of submicron WC-Co particulate reinforced Cu matrix composites prepared by direct laser sintering [J]. Materials Science and Engineering A, 2006, 435-436: 54-61.
[204] Wu X L, Chen G N. Microstructure and wear resistance of in situ TiCp composite coating by laser cladding [J]. Journal of Materials Science and Technology, 1999, 15(3): 233-238.
[205] Gu D D, Shen Y F. WC-Co particulate reinforcing Cu matrix composites produced by direct laser sintering [J]. Materials Letters, 2006, 60(29-30): 3664-3668.
[206] Tang D W, Zhou B L, Cao H, et al. Dynamic thermal expansion under transient laser-pulse heating [J]. Applied Physics Letters, 1991, 59(24): 3113-3114.
[207] Tang D W, Zhou B L, Cao H, et al. Thermal stress relaxation behavior in thin films under transient laser-pulse heating [J]. Journal of Applied Physics, 1993, 73(8): 3749-3752.
[208]张伟,隋曼龄,周亦胄,等.高密度电脉冲下材料微观结构的演变[J].金属学报, 2003, 39(10): 1009-1018.
[209] Boccalini M, Goldenstein H. Solidification of high speed steels [J]. International Materials Reviews, 2001, 46(2): 92-115.
[210] Kaynak C, Boylu S. Effects of SiC particulates on the fatigue behaviour of an Al-alloy matrix composite [J]. Materials & Design, 2006, 27(9): 776-782.
[211] Seshan S, Jayamathy M, Kailas S V, et al. The tensile behavior of two magnesium alloys reinforced with silicon carbide particulates [J]. Materials Science and Engineering A, 2003, 363(1-2): 345-351.
[212] Gu J H, Zhang X N, Qiu Y F, et al. Damping behaviors of magnesium matrix composites reinforced with Cu-coated and uncoated SiC particulates [J]. Composites Science and Technology, 2005, 65(11-12): 1736-1742.
[213] Zheng Y, Xiong W H, Lei W, et al. Effect of nano addition on the microstructures and mechanical properties of Ti(C, N)-based cermets [J]. Ceramics International, 2005, 31(1): 165-170.
[214] Zhang K, Chen G N. Effect of SiC particles on crystal growth of Al-Si alloy during laser rapid solidification [J]. Materials Science and Engineering A, 2000, 292(2): 229-231.
[215] Wong W L E, Karthik S, Gupta M. Development of hybrid Mg/Al2O3 composites with improved properties using microwave assisted rapid sintering route [J]. Journal of Materials Science, 2005, 40(13): 3395-3402.
[216] Stefanescu D M, Dhindaw B K, Kacar S A, et al. Behavior of ceramic particles at thesolid-liquid metal interface in metal matrix composites [J]. Metallurgical Transactions A, 1988, 19(11): 2847-2855.
[217] Uhlmann D R, Chalmers B, Jackson K A. Interaction between particles and a solid-liquid interface [J]. Journal of Applied Physics, 1964, 35(10): 2986-2993.
[218] Zubko A M, Lobanov V G, Nikonova V V. Reaction of foreign particles with a crystallization front [J]. Soviet Physics - Crystallography, 1973, 18(2): 239-241.
[219] Surappa M K, Rohatgi P K. Heat Diffusivity criterion for the entrapment of particles by a moving solid-liquid interface [J]. Journal of Materials Science, 1981, 16(2): 562-564.
[220] Omenyi S N, Neumann A W. Thermodynamic aspects of particle engulfment by solidifying melts [J]. Journal of Applied Physics, 1976, 47(9): 3956-3962.
[221] Omenyi S N, Neumann A W, van Oss C J. Attraction and repulsion of solid particles by solidification fronts. I. Thermodynamic effects [J]. Journal of Applied Physics, 1981, 52(2):789-795.
[222] Omenyi S N, Neumann A W, Martin W W, et al. Attraction and repulsion of solid particles by solidification fronts. II. Dimensional analysis [J]. Journal of Applied Physics, 1981, 52(2):796-802.
[223] Wilde G, Perepezko J H. Experimental study of particle incorporation during dendritic solidification [J]. Materials Science and Engineering A, 2000, 283(1-2): 25-37.
[224] Youssef Y M, Dashwood R J, Lee P D. Effect of clustering on particle pushing and solidification behaviour in TiB2 reinforced aluminium PMMCs [J]. Composites Part A, 2005, 36(6): 747-763.
[225] Shangguan D, Ahuja S, Stefanescu D M. An analytical model for the interaction between an insoluble particle and an advancing solid/liquid interface [J]. Metallurgical Transactions A, 1992, 23(2): 669-680.
[226] Chernov A A, Temkin D E, Mel’nikova A M. Theory of the capture of solid inclusions during the growth of crystals from the melt [J]. Soviet Physics - Crystallography, 1976, 21(4): 369-374.
[227] Bolling G F, CisséJ. A theory for the interaction of particles with a solidifying front [J]. Journal of Crystal Growth, 1971, 10(1): 56-66.
[228] CisséJ, Bolling G F. A study of the trapping and rejection of insoluble particles during the freezing of water [J]. Journal of Crystal Growth, 1971, 10(1): 67-76.
[229] Chernov A A, Temkin D E, Mel’nikova A M. The influence of the thermal conductivity of a macroparticle on its capture by a crystal growing from a melt [J]. Soviet Physics - Crystallography, 1977, 22(6): 656-658.
[230] P?tschke J, Rogge V. On the behaviour of foreign particles at an advancing solid-liquid interface [J]. Journal of Crystal Growth, 1989, 94(3): 726-738.
[231]刘江龙,邹至荣,苏宝嫆.高能束热处理[M].北京,机械工业出版社, 1997: 156-167.
[232]潘清跃,李延民,黄卫东,等.不锈钢激光表面熔凝处理的组织特征[J].金属学报, 1996, 32(7): 718-722.
[233]胡赓祥,钱苗根.金属学[M].上海,上海科学技术出版社, 1980: 127-141.
[234]沈以赴,佟百运,冯钟潮,等.稀土在激光熔覆涂层中的分布及其对腐蚀性能的影响[J].材料研究学报, 1998, 12(5): 434-436.
[235]沈以赴,陈继志,冯钟潮,等.稀土在激光熔覆涂层中的分布和行为[J].中国稀土学报, 1997, 15(4): 344-349.
[236]刘秀波,王华明. La2O3对TiAl合金激光熔覆γ/Cr7C3/TiC复合材料涂层组织与性能的影响[J].中国激光, 2005, 32(7): 1011-1016.
[237]赵高敏,王昆林,刘家浚. La2O3对激光熔覆铁基合金层硬度及其分布的影响[J].金属学报, 2004, 40(10): 1115-1120.
[238] Tian Y S, Chen C Z, Chen L X, et al. Effect of RE oxides on the microstructure of the coatings fabricated on titanium alloys by laser alloying technique [J]. Scripta Materialia, 2006, 54(5): 847-852.
[239]袁章福,柯家骏,李晶.金属及合金的表面张力[M].北京,科学出版社, 2006: 29-53.
[240]赵高敏,王昆林,李传刚. La2O3对激光熔覆Fe基合金熔覆层显微组织的影响[J].金属热处理, 2004, 29(4): 9-13.
[241] Zhao G M, Wang K L. Effect of La2O3 on corrosion resistance of laser clad ferrite-based alloy coatings [J]. Corrosion Science, 2006, 48(2): 273-284.
[242]翟启杰,关绍康,商全义.合金热力学理论及其应用[M].北京,冶金工业出版社, 1999: 142-148.
[243] Wu C M L, Yu D Q, Law C M T, et al. Properties of lead-free solder alloys with rare earth element additions [J]. Materials Science and Engineering R, 2004, 44(1): 1-44.
[244]钟华仁.钢的稀土化学热处理.北京:国防工业出版社, 1998: 195-205.
[245] Balluffi R W, Allen S M, Craig Carter W. Kinetics of Materials [M]. New Jersey, John Wiley & Sons, 2005: 460-468.
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