金属激光增材制造过程数值模拟

金属激光增材制造过程中,热应力导致零件发生形变;气孔与熔合不良等缺陷降低零件的拉伸以及疲劳性能;熔池内的凝固微观组织,尤其是柱状晶等轴晶转变(Columnar to Equiaxed Transition,CET)是影响零件性能的重要因素。针对上述3个方面,回顾了金属激光增材制造数值模拟的发展历史,对其研究现状和存在问题进行了评述,阐述了金属激光增材制造过程中所采用的数值模型和数值方法,包括热应力分析的有限元(Finite Element Method,FEM)方法、模拟熔池金属液流动的计算流体力学方法(Computational Fluid Dynamics,CFD),以及凝固微观组织模拟的相场法(Phase Field,PF)和元胞自动机方法(Cellular Automaton,CA)。在此基础上对金属激光增材制造过程数值模拟的前景及趋势进行了展望。

Numerical Simulation on Laser Additive Manufacturing Process for Metal Components

During the laser additive manufacturing of metal components,the thermal/mechanical cycles cause the deformation of the part.The pore and unmelted metal powder reduce the tensile and fatigue properties.The solidification microstructure,especially the columnar to equiaxed transition (CET),determines the properties of final products.In view of the above three aspects,this study reviews the developments of the numerical simulating of laser additive manufacturing for metal components.The current researches and exist problems have been reviewed.And the numerical models used in the simulations have been discussed,including the finite element method (FEM) for thermal/mechanical problems,computational fluid dynamics (CFD) for the liquid metal flow in the molten pool and the numerical models (phase field (PF) and cellular automaton (CA)) for the solidification of microstructure.On the basis of this,the prospect and trend of the numerical simulation of the laser additive manufacturing for metal components are discussed.