铝硅合金低温加硅技术的研究及变质处理
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摘要
21世纪是重视资源与能源的世纪,铝在地壳中资源丰富、比强度高、又可以回收利用,日益引起人们的重视。铝已被用到生活日用品、建筑、汽车、飞机、火箭等国民经济生活的各个方面,已成为仅次于铁的第二大金属。铝硅合金是铝合金中用量很大、用途很广的合金。
选择良好制备工艺对铝硅合金稳定质量、节约能源大有裨益。本文阐述了制备铝硅合金的电热还原法、电解法和熔配法,着重对比了熔配法生产铝硅合金的几种工艺。选择低温加硅法熔炼了Al-13 Si共晶合金和Al-2OSi过共晶合金,实验证明该方法生产的铝硅合金质量稳定、环境友好。分析了低温加硅工艺的熔炼温度与微观组织的关系。
Si的熔点为1414℃,而Si却可以在远低于熔点温度的情况下熔化于铝液中。本文用坩埚空冷法观察了硅块不同熔化阶段凝固后的微观组织,发现了硅块在铝液中熔化并在铝液中扩散的规律。
对硅块熔化过程进行热力学分析,计算出硅在铝中的熔化热约为608J/g,这个数值仅为晶体硅熔化热(1808.69J/g)的1/3左右,说明了硅熔化于铝中不同于晶体硅的熔化。结合团簇学理论提出了硅块在铝液中熔化的“硅块上的Si团簇→Al-Si团簇→Si-Si团簇”熔化模式,较好的阐述了硅在铝液中的熔化机理,并分析了铝硅合金液态结构演变的规律及原因。
铝硅合金的硅含量超过6%时,会出现长针状的共晶硅,甚至会出现板块状的初晶硅,严重割裂了铝基体,需要对铝硅合金进行变质细化处理。本文采用磷盐与稀土中间合金对Al-20Si过共晶合金进行了复合变质,成功地将微观组织由未变质时的初晶硅140μm、共晶硅100μm变质细化到初晶硅15μm、共晶硅10μm.用团簇学理论及晶格相似理论分析了两种变质剂的作用机理。
Resource and energy source are attended in 21 century.Aluminum is rich in the earth's crust,has good strength and can be recycled,so people give many attentions to aluminum.Aluminum has been used in many areas of the national economy,for example:daily necessities,architectures,cars, aircraft,rockets and so on.Aluminum consumption has became the second metal compared to iron.Al-Si alloy is an important branch of aluminum. Al-Si alloy is widely used in many areas.
Good preparation is useful to produce good Al-Si alloy and save energy sources.The methods of Electric Reduction Act,Electrolysis and Melting are used to produce Al-Si alloy.This paper compared with several schemes of melting Al-Si alloy.Al-13Si eutectic and Al-20Si hypereutectic alloys are melt with the method of adding Si blocks at low temperature.Practice has proved that the method can keep good quality,economize energy sources and protect environment.The relationship between the melting temperature and the microstructure are analyzed.
The melting point of Si is 1414℃,but Si can be dissolved in liquid aluminum at low temperature.The paper contrasts microstructures in melting processes using the method that crucibles are cooled in the atmosphere and detects the proliferation laws of Si.
The thermodynamic analysis proves that the melting heat which Si is dissolved in liquid aluminum is about 608J/g.The value is only one third of the data(1808.69J/g)which Si melts.The experiment proves that Si melting is different from Si melting in liquid aluminum.With cluster theory we lodge that the mode of Si melting in liquid aluminum complies with the model of "Si cluster on Si block→Al-Si cluster→Si-Si cluster".The model describes the mechanism of Si melting in liquid aluminum and analyses the reason of liquid Al-Si alloy structural changes.
There are many long and massive silicon phases which adversely affect the mechanical properties when Al-Si alloy contains more than 6%Si,so it is necessary to modify silicon phases.This paper modifies Al-20Si hypereutectic alloy with phosphorous salt and rare earth alloy.The primary silicon particles are modified from 140μm to 15μm and the eutectic silicon particles are modified from 100μm to 10μm.Mechanisms of the modifier are analyzed with cluster theory and lattice similarity theory.
选择良好制备工艺对铝硅合金稳定质量、节约能源大有裨益。本文阐述了制备铝硅合金的电热还原法、电解法和熔配法,着重对比了熔配法生产铝硅合金的几种工艺。选择低温加硅法熔炼了Al-13 Si共晶合金和Al-2OSi过共晶合金,实验证明该方法生产的铝硅合金质量稳定、环境友好。分析了低温加硅工艺的熔炼温度与微观组织的关系。
Si的熔点为1414℃,而Si却可以在远低于熔点温度的情况下熔化于铝液中。本文用坩埚空冷法观察了硅块不同熔化阶段凝固后的微观组织,发现了硅块在铝液中熔化并在铝液中扩散的规律。
对硅块熔化过程进行热力学分析,计算出硅在铝中的熔化热约为608J/g,这个数值仅为晶体硅熔化热(1808.69J/g)的1/3左右,说明了硅熔化于铝中不同于晶体硅的熔化。结合团簇学理论提出了硅块在铝液中熔化的“硅块上的Si团簇→Al-Si团簇→Si-Si团簇”熔化模式,较好的阐述了硅在铝液中的熔化机理,并分析了铝硅合金液态结构演变的规律及原因。
铝硅合金的硅含量超过6%时,会出现长针状的共晶硅,甚至会出现板块状的初晶硅,严重割裂了铝基体,需要对铝硅合金进行变质细化处理。本文采用磷盐与稀土中间合金对Al-20Si过共晶合金进行了复合变质,成功地将微观组织由未变质时的初晶硅140μm、共晶硅100μm变质细化到初晶硅15μm、共晶硅10μm.用团簇学理论及晶格相似理论分析了两种变质剂的作用机理。
Resource and energy source are attended in 21 century.Aluminum is rich in the earth's crust,has good strength and can be recycled,so people give many attentions to aluminum.Aluminum has been used in many areas of the national economy,for example:daily necessities,architectures,cars, aircraft,rockets and so on.Aluminum consumption has became the second metal compared to iron.Al-Si alloy is an important branch of aluminum. Al-Si alloy is widely used in many areas.
Good preparation is useful to produce good Al-Si alloy and save energy sources.The methods of Electric Reduction Act,Electrolysis and Melting are used to produce Al-Si alloy.This paper compared with several schemes of melting Al-Si alloy.Al-13Si eutectic and Al-20Si hypereutectic alloys are melt with the method of adding Si blocks at low temperature.Practice has proved that the method can keep good quality,economize energy sources and protect environment.The relationship between the melting temperature and the microstructure are analyzed.
The melting point of Si is 1414℃,but Si can be dissolved in liquid aluminum at low temperature.The paper contrasts microstructures in melting processes using the method that crucibles are cooled in the atmosphere and detects the proliferation laws of Si.
The thermodynamic analysis proves that the melting heat which Si is dissolved in liquid aluminum is about 608J/g.The value is only one third of the data(1808.69J/g)which Si melts.The experiment proves that Si melting is different from Si melting in liquid aluminum.With cluster theory we lodge that the mode of Si melting in liquid aluminum complies with the model of "Si cluster on Si block→Al-Si cluster→Si-Si cluster".The model describes the mechanism of Si melting in liquid aluminum and analyses the reason of liquid Al-Si alloy structural changes.
There are many long and massive silicon phases which adversely affect the mechanical properties when Al-Si alloy contains more than 6%Si,so it is necessary to modify silicon phases.This paper modifies Al-20Si hypereutectic alloy with phosphorous salt and rare earth alloy.The primary silicon particles are modified from 140μm to 15μm and the eutectic silicon particles are modified from 100μm to 10μm.Mechanisms of the modifier are analyzed with cluster theory and lattice similarity theory.
引文
[1]潘复生,张丁非等.铝合金及应用[M].北京:化学工业出版社,2006.
[2]杨冠群,赵劭,杨异.铝硅系合金不同生产工艺的比较[J].有色金属(冶炼部分),2000(4):28-29.
[3]宋基敏,中江秀雄.Al-Si共晶合金共晶Si细化[J].铸造工学1993,(3):148-155.
[4]雄艳才,刘伯操.铸造铝合金现状及未来发展[J].特种铸造及有色合金,1998,(4):1-5.
[5]S.G.Shabestari,J.E.Gruzleski.Modification of Iron Intermetallics by Strontium in 413 Aluminum Alloys.AFS Transaction,1995,(26):285-293.
[6]M.Pekguleryuz,B.Closset,J.E.Gruzleski.The Dissolution of Metallic Strontium in Liquid Aluminum Alloys.AFS Trans,1984(25):109-118.
[7]李隆盛.铸造合金及其熔炼[M].北京:机械工业出版社,1989.
[8]Lu Shu-zu.Micro-structural Transition of Al-Si during eutectic Solidification.An Expanded Abstract submitted in Partial Fulfillment of the Requirement for the Degree of Doctor of Philoshy,USA:Michigan Tech.Univ,1986:26.
[9]赵恒先,陈润辉.过共晶铝硅细化变质的进展[J].轻金属,1992,(3):60-64.
[10]朱志超.GZLSi7MgTi高强度铸造铝合金及复合长效变质[J].造,1991,(3):28-33.
[11]雄艳才,刘伯操.铸造铝合金现状及未来发展[J].特种铸造及有色合金,1998,(4):1-5.
[12]蒋建青,王楠,朱明礼等.高强稀土铸造Al-Si铝硅合金的组织与性能[J].特种铸造及有色合金,1993,(1):22-24.
[13]朱培钺,陈熙琛,贾均等.铝硅合金变质过程的研究[J].哈尔滨工业大学学报,1981,(1):11-29.
[14]Lu Shuzu.Microtrutual Transitions of AI-Si Alloys during Eutectic Solidification.An Expanded Abstract Submitted in Partial Fulfillment of the Degree of Doctor of Philosophy in Metallurgical Engineering,1996.
[15]罗启全.铝合金熔炼与铸造[M].广州:广东科技出版社,2002.
[16]刘伏梅.活塞铝-硅合金一次熔炼工艺的研究与应用[J].内燃机配件,1997,(6):17-21.
[17]阙端麟,陈修治.硅材料科学与技术[M].杭州:浙江大学出版社,2000:3-4.
[18]王祝堂,王殿楹,王真超.铝合金的新型合金元素添加剂及其添加方法[J].轻合金加工技术,2000,28(9):16-19.
[19]Ziman J.M.A theory of the electrical properties of liquid metals,I:monovalent metals,Phil.Mag,1961,(6):10-13.
[20]Ellitt S R.Medium-range structural ordering in covalent amorphous solids.Nature.1991:354-445.
[21]下地光雄著,郭淦钦译.液态金属[M],北京:科学出版社,1987:2.
[22]O.A.易新,II.B格尔德.火法冶金物理化学[M].北京:高等教育出版,1982.
[23]桂满昌.Al-Si合金液态若于物性及其与凝固组织的相关性[D],哈尔滨工业大学,1994.
[24]Bernal J D.A geometrical approach to the structure of liquids.Nature,Lond.1959.
[25]Bernal J D.Geometry of the structure of monatomic liquids.Nature,Lond.1960.
[26]Bernal J D.Proc.Roy.Soc.Ser.A.1964:280-299.
[27]李培杰,曾大本,贾均,李庆春.铝硅合金中的结构遗传及其控制[J].铸造,1999,(6):10-14.
[28]G.D.Stain.Phys.Tech.1979.
[29]S.Bjornholm.Contemporary Phys.1990,31:309..
[30]冯端.凝聚态物理学新论[M].上海:上海科学技术出版利,1994.
[31]Knight,W.D.,Clemenger K.& de Heer W.A.,et al,Electronic Shell Structure and Abundances of Sodium Clusters,Phys.Rev.Lett.1984,52:2141-2143.
[32]Khanna,S.N.& Jena,P.,Atomic clusters:Building blocks for a class of solids,Phys.Rev.1995,B51:13705-13716.
[33]RonsleyC E,Talbot D E J.Zs.Metallkunde.B.1955,46(329).
[34]Iida T,Guthrie R L.The physical properties of liquid metals,Clarendon,Oxford,1993:233.
[35]Waseda Y,Suzuki K.Structure of molten Si and Ge by X-ray diffraction,Z.Physik,1975,B20:319-343.
[36]Waseda Y,Shinoda K,Sugiyama K,Takeda S,Terashima K,Toguri J M.High temperature X-ray diffraction study of melt structure of Si,Jpn.J.Appl.Phys.1995,34:4124-4128.
[37]Gabathuler J P,Steeb S.Z,Naturforsch,1979,34:1314.
[38]王伟民.Al-Si合金熔体的微观结构及Si原子集团的演变行为[D].济南:山东工业大学,1998.
[39]邢俊德.国外铸造铝硅合金变质处理的最新进展[J].全国铝合金精1炼、变质处理学术讨论会论文集,1993,(9):7-9.
[40]蒋玉华.提高铝合金质量的技术途径和方法[J].全国铝合金精炼、变质处理学术讨论会论文集,1993,(9).
[41]Zhou Yongxin,Lu Zhenlin,Zhao Xicheng.The Alterative of Research and Development of Ai-Si alloy.Foundry Technology,2001,25(1):13-15.
[42]王兆昌.铝硅合金的结晶与钠变质机制[J].特种铸造及有色合.金,1990(4):13～17.
[43]L.Lua,K.Nogita b,A.K.Dahle.Combining Sr and Na Additions in Hypoeutectic Al-Si Foundry Alloys.Materials Science and Engineering.2005,399:244-253.
[44]黄良余.铝硅合金变质机理的新发展和新观点[J].特种铸造及有色合金,1995(5):19-22.
[45]L.Clapham,R.W.Smith,Segregation behaviour of strontium in modified and unmodified Al-Si alloys,Journal of Crystal Growth.1988,92:263-270.
[46]L.Lu,K.Nogita,A.K.Dahle.Combining Sr and Na additions in hypoeutectic Al-Si foundry alloys.Materials Science and Engineering.2005,399(1-2):244-253.
[47]鲁薇华,王汝耀.锶变质铝硅合金的组织、性能及其变质工艺[J].铸造.1997,(9):44-49.
[48]K.Nogita,A.Knuutinen,S.D.McDonald,A.K.Dahle,Mechanisms of Eutectic Solidification in Al-Si Alloys modified with Ba,Ca,Y and Yb.Journal of Light Metals.2001,1:219-228.
[49]李伟,盛险峰,戢家齐等.钡对共晶铝硅合余组织和性能的影响[J].热加工工艺,1995,(6):27-29.
[50]刘相法,乔进国.Al-P中间合金的变质特性及变质机理探讨[J].内燃机 配件,2003(5):18-20.
[51]周晓霞,张仁元,刘银峁.稀土元素在铝合金中的作用和应用[J].新技术新工艺·材料与表面处理,2003,4:43-45.
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[53]Tang Duoguang.An Excellent Material for Casting Al Alloy Refinement and Modification Rare-Earth Alloy.Special Casting &Nonferrous Alloys.1999,(5):42-45.
[54]王正军,刘天佐,夏天东等.工艺参数对熔配法制备Al-10Ce中间合金的影响[J].有色金属(冶炼部分),2005,(2):44-46.
[2]杨冠群,赵劭,杨异.铝硅系合金不同生产工艺的比较[J].有色金属(冶炼部分),2000(4):28-29.
[3]宋基敏,中江秀雄.Al-Si共晶合金共晶Si细化[J].铸造工学1993,(3):148-155.
[4]雄艳才,刘伯操.铸造铝合金现状及未来发展[J].特种铸造及有色合金,1998,(4):1-5.
[5]S.G.Shabestari,J.E.Gruzleski.Modification of Iron Intermetallics by Strontium in 413 Aluminum Alloys.AFS Transaction,1995,(26):285-293.
[6]M.Pekguleryuz,B.Closset,J.E.Gruzleski.The Dissolution of Metallic Strontium in Liquid Aluminum Alloys.AFS Trans,1984(25):109-118.
[7]李隆盛.铸造合金及其熔炼[M].北京:机械工业出版社,1989.
[8]Lu Shu-zu.Micro-structural Transition of Al-Si during eutectic Solidification.An Expanded Abstract submitted in Partial Fulfillment of the Requirement for the Degree of Doctor of Philoshy,USA:Michigan Tech.Univ,1986:26.
[9]赵恒先,陈润辉.过共晶铝硅细化变质的进展[J].轻金属,1992,(3):60-64.
[10]朱志超.GZLSi7MgTi高强度铸造铝合金及复合长效变质[J].造,1991,(3):28-33.
[11]雄艳才,刘伯操.铸造铝合金现状及未来发展[J].特种铸造及有色合金,1998,(4):1-5.
[12]蒋建青,王楠,朱明礼等.高强稀土铸造Al-Si铝硅合金的组织与性能[J].特种铸造及有色合金,1993,(1):22-24.
[13]朱培钺,陈熙琛,贾均等.铝硅合金变质过程的研究[J].哈尔滨工业大学学报,1981,(1):11-29.
[14]Lu Shuzu.Microtrutual Transitions of AI-Si Alloys during Eutectic Solidification.An Expanded Abstract Submitted in Partial Fulfillment of the Degree of Doctor of Philosophy in Metallurgical Engineering,1996.
[15]罗启全.铝合金熔炼与铸造[M].广州:广东科技出版社,2002.
[16]刘伏梅.活塞铝-硅合金一次熔炼工艺的研究与应用[J].内燃机配件,1997,(6):17-21.
[17]阙端麟,陈修治.硅材料科学与技术[M].杭州:浙江大学出版社,2000:3-4.
[18]王祝堂,王殿楹,王真超.铝合金的新型合金元素添加剂及其添加方法[J].轻合金加工技术,2000,28(9):16-19.
[19]Ziman J.M.A theory of the electrical properties of liquid metals,I:monovalent metals,Phil.Mag,1961,(6):10-13.
[20]Ellitt S R.Medium-range structural ordering in covalent amorphous solids.Nature.1991:354-445.
[21]下地光雄著,郭淦钦译.液态金属[M],北京:科学出版社,1987:2.
[22]O.A.易新,II.B格尔德.火法冶金物理化学[M].北京:高等教育出版,1982.
[23]桂满昌.Al-Si合金液态若于物性及其与凝固组织的相关性[D],哈尔滨工业大学,1994.
[24]Bernal J D.A geometrical approach to the structure of liquids.Nature,Lond.1959.
[25]Bernal J D.Geometry of the structure of monatomic liquids.Nature,Lond.1960.
[26]Bernal J D.Proc.Roy.Soc.Ser.A.1964:280-299.
[27]李培杰,曾大本,贾均,李庆春.铝硅合金中的结构遗传及其控制[J].铸造,1999,(6):10-14.
[28]G.D.Stain.Phys.Tech.1979.
[29]S.Bjornholm.Contemporary Phys.1990,31:309..
[30]冯端.凝聚态物理学新论[M].上海:上海科学技术出版利,1994.
[31]Knight,W.D.,Clemenger K.& de Heer W.A.,et al,Electronic Shell Structure and Abundances of Sodium Clusters,Phys.Rev.Lett.1984,52:2141-2143.
[32]Khanna,S.N.& Jena,P.,Atomic clusters:Building blocks for a class of solids,Phys.Rev.1995,B51:13705-13716.
[33]RonsleyC E,Talbot D E J.Zs.Metallkunde.B.1955,46(329).
[34]Iida T,Guthrie R L.The physical properties of liquid metals,Clarendon,Oxford,1993:233.
[35]Waseda Y,Suzuki K.Structure of molten Si and Ge by X-ray diffraction,Z.Physik,1975,B20:319-343.
[36]Waseda Y,Shinoda K,Sugiyama K,Takeda S,Terashima K,Toguri J M.High temperature X-ray diffraction study of melt structure of Si,Jpn.J.Appl.Phys.1995,34:4124-4128.
[37]Gabathuler J P,Steeb S.Z,Naturforsch,1979,34:1314.
[38]王伟民.Al-Si合金熔体的微观结构及Si原子集团的演变行为[D].济南:山东工业大学,1998.
[39]邢俊德.国外铸造铝硅合金变质处理的最新进展[J].全国铝合金精1炼、变质处理学术讨论会论文集,1993,(9):7-9.
[40]蒋玉华.提高铝合金质量的技术途径和方法[J].全国铝合金精炼、变质处理学术讨论会论文集,1993,(9).
[41]Zhou Yongxin,Lu Zhenlin,Zhao Xicheng.The Alterative of Research and Development of Ai-Si alloy.Foundry Technology,2001,25(1):13-15.
[42]王兆昌.铝硅合金的结晶与钠变质机制[J].特种铸造及有色合.金,1990(4):13～17.
[43]L.Lua,K.Nogita b,A.K.Dahle.Combining Sr and Na Additions in Hypoeutectic Al-Si Foundry Alloys.Materials Science and Engineering.2005,399:244-253.
[44]黄良余.铝硅合金变质机理的新发展和新观点[J].特种铸造及有色合金,1995(5):19-22.
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