激光增材制造仿真过程分析
|
摘要
针对激光增材制造过程,采用仿真的方式获取加工过程中各参量随时间变化的情况。建立了高斯热源的模型,主要分析了激光扫描过程中材料的温度、不同方向的温度梯度、不同方向的变形量、正应力和屈服应力,最后分析了冷却后的温度、变形和应力分布情况。结果表明:薄壁框由于各方向与空气接触面积大小不同,冷却的温度梯度差别大;各方向刚度不同,会导致变形量不同,从而对应力的分布造成影响;激光对已成形部分的影响主要位于前几个扫描周期,影响程度随熔池与该节点的距离增大而快速减小;最大单向变形约为2. 5 mm,最大残余应力约为560 MPa。
According to the process of laser additive manufacturing,simulation was used to processing parameters at any time. The model of Gaussian heat source was established. The temperature,temperature gradient and deformations in different directions,normal stress and yield stress were analyzed. Finally,the distributions of temperature,deformation and stress after cooling were analyzed. The results shows that the cooling temperature gradients of the thin-walled frame are large different because the contact areas with the air are different. The different stiffness in three directions will lead to the different deformation and distribution of stress. The impact of the laser on the formed part is mainly in the first few scan cycles,and the effect decreases rapidly with the increasing of the distance between the weld pool and the node. The maximum deformation is about 2. 5 mm and the maximum residual stress is about 560 MPa.
According to the process of laser additive manufacturing,simulation was used to processing parameters at any time. The model of Gaussian heat source was established. The temperature,temperature gradient and deformations in different directions,normal stress and yield stress were analyzed. Finally,the distributions of temperature,deformation and stress after cooling were analyzed. The results shows that the cooling temperature gradients of the thin-walled frame are large different because the contact areas with the air are different. The different stiffness in three directions will lead to the different deformation and distribution of stress. The impact of the laser on the formed part is mainly in the first few scan cycles,and the effect decreases rapidly with the increasing of the distance between the weld pool and the node. The maximum deformation is about 2. 5 mm and the maximum residual stress is about 560 MPa.
引文
[1]Lauwers B,Klocke F,Klink A,et al.Hybrid processes in manufacturing[J].CIRP Annals-Manufacturing Technology,2014,63(2):561-583.
[2]Kolleck R,Vollmer R,Veit R.Investigation of a combined microforming and punching process for the realization of tight geometrical tolerances of conically formed hole patterns[J].CIRP Annals-Manufacturing Technology,2011,60(1):331-334.
[3]Zhu Z,Dhokia V G,Nassehi A,et al.A review of hybrid manufacturing processes-state of the art and future perspectives[J].International Journal of Computer Integrated Manufacturing,2013,26(7):596-615.
[4]Ponche R,Kerbrat O,Mognol P,et al.A novel methodology of design for Additive Manufacturing applied to Additive Laser Manufacturing process[J].Robotics and Computer-Integrated Manufacturing,2014,30(4):389-398.
[5]Bontha S,Klingbeil N W,Kobryn P A,et al.Thermal process maps for predicting solidification microstructure in laser fabrication of thin-wall structures[J].Journal of Materials Processing Technology,2006,178(1):135-142.
[6]Bontha S,Klingbeil N W,Kobryn P A,et al.Effects of process variables and size-scale on solidification microstructure in beambased fabrication of bulky 3D structures[J].Materials Science and Engineering:A,2009,513:311-318.
[7]Zhao Z,Chen J,Tan H,et al.Evolution of plastic deformation and its effect on mechanical properties of laser additive repaired Ti64ELI titanium alloy[J].Optics&Laser Technology,2017,92:36-43.
[8]Zhou Y,Chen H,Tang Y,et al.Simulation and optimization framework for additive manufacturing processes[C]//Innovative Design and Manufacturing(ICIDM),Proceedings of the 2014 International Conference on.IEEE,2014:34-40.
[9]Zhu Z,Dhokia V,Nassehi A,et al.Investigation of part distortions as a result of hybrid manufacturing[J].Robotics and Computer-Integrated Manufacturing,2016,37:23-32.
[10]Sonmez F O,Hahn H T.Thermomechanical analysis of the laminated object manufacturing(LOM)process[J].Rapid Prototyping Journal,1998,4(1):26-36.
[11]Vatani M,Barazandeh F,Rahimi A R,et al.Distortion modeling of SLparts by classical lamination theory[J].Rapid Prototyping Journal,2012,18(3):188-193.
[12]Denlinger E R,Heigel J C,Michaleris P.Residual stress and distortion modeling of electron beam direct manufacturing Ti-6Al-4V[J].Proceedings of the Institution of Mechanical Engineers,Part B:Journal of Engineering Manufacture,2015,229(10):1803-1813.
[13]Denlinger E R,Heigel J C,Michaleris P,et al.Effect of inter-layer dwell time on distortion and residual stress in additive manufacturing of titanium and nickel alloys[J].Journal of Materials Processing Technology,2015,215:123-131.
[14]Ding J,Colegrove P,Mehnen J,et al.Thermo-mechanical analysis of wire and arc additive layer manufacturing process on large multi-layer parts[J].Computational Materials Science,2011,50(12):3315-3322.
[15]Zaeh M F,Branner G.Investigations on residual stresses and deformations in selective laser melting[J].Production Engineering,2010,4(1):35-45.
[16]Wang Z,Guan K,Gao M,et al.The microstructure and mechanical properties of deposited-IN718 by selective laser melting[J].Journal of Alloys and Compounds,2012,513:518-523.
[2]Kolleck R,Vollmer R,Veit R.Investigation of a combined microforming and punching process for the realization of tight geometrical tolerances of conically formed hole patterns[J].CIRP Annals-Manufacturing Technology,2011,60(1):331-334.
[3]Zhu Z,Dhokia V G,Nassehi A,et al.A review of hybrid manufacturing processes-state of the art and future perspectives[J].International Journal of Computer Integrated Manufacturing,2013,26(7):596-615.
[4]Ponche R,Kerbrat O,Mognol P,et al.A novel methodology of design for Additive Manufacturing applied to Additive Laser Manufacturing process[J].Robotics and Computer-Integrated Manufacturing,2014,30(4):389-398.
[5]Bontha S,Klingbeil N W,Kobryn P A,et al.Thermal process maps for predicting solidification microstructure in laser fabrication of thin-wall structures[J].Journal of Materials Processing Technology,2006,178(1):135-142.
[6]Bontha S,Klingbeil N W,Kobryn P A,et al.Effects of process variables and size-scale on solidification microstructure in beambased fabrication of bulky 3D structures[J].Materials Science and Engineering:A,2009,513:311-318.
[7]Zhao Z,Chen J,Tan H,et al.Evolution of plastic deformation and its effect on mechanical properties of laser additive repaired Ti64ELI titanium alloy[J].Optics&Laser Technology,2017,92:36-43.
[8]Zhou Y,Chen H,Tang Y,et al.Simulation and optimization framework for additive manufacturing processes[C]//Innovative Design and Manufacturing(ICIDM),Proceedings of the 2014 International Conference on.IEEE,2014:34-40.
[9]Zhu Z,Dhokia V,Nassehi A,et al.Investigation of part distortions as a result of hybrid manufacturing[J].Robotics and Computer-Integrated Manufacturing,2016,37:23-32.
[10]Sonmez F O,Hahn H T.Thermomechanical analysis of the laminated object manufacturing(LOM)process[J].Rapid Prototyping Journal,1998,4(1):26-36.
[11]Vatani M,Barazandeh F,Rahimi A R,et al.Distortion modeling of SLparts by classical lamination theory[J].Rapid Prototyping Journal,2012,18(3):188-193.
[12]Denlinger E R,Heigel J C,Michaleris P.Residual stress and distortion modeling of electron beam direct manufacturing Ti-6Al-4V[J].Proceedings of the Institution of Mechanical Engineers,Part B:Journal of Engineering Manufacture,2015,229(10):1803-1813.
[13]Denlinger E R,Heigel J C,Michaleris P,et al.Effect of inter-layer dwell time on distortion and residual stress in additive manufacturing of titanium and nickel alloys[J].Journal of Materials Processing Technology,2015,215:123-131.
[14]Ding J,Colegrove P,Mehnen J,et al.Thermo-mechanical analysis of wire and arc additive layer manufacturing process on large multi-layer parts[J].Computational Materials Science,2011,50(12):3315-3322.
[15]Zaeh M F,Branner G.Investigations on residual stresses and deformations in selective laser melting[J].Production Engineering,2010,4(1):35-45.
[16]Wang Z,Guan K,Gao M,et al.The microstructure and mechanical properties of deposited-IN718 by selective laser melting[J].Journal of Alloys and Compounds,2012,513:518-523.