激光增材制造参数对构件残余应力影响的数值模拟  

Numerical Simulation Study of Laser Additive Manufacturing Process Parameters Influence on Residual Stress

作　　者：何东 汪斌 张龙 吴自越 刘高阳 李佳怡 He Dong;Wang Bin;Zhang Long;Wu Ziyue;Liu Gaoyang;Li Jiayi(School of Mechanical and Material Engineering,North China University of Technology,Beijing 100144,China)

机构地区：[1]北方工业大学机械与材料工程学院,北京100144

出　　处：《应用激光》2024年第11期24-33,共10页Applied Laser

基　　金：国家自然科学基金青年科学基金(51401226);市教委基本科研业务费资助项目(110052971803/030);科技创新服务能力建设-基本科研业务(110052971921/044)。

摘　　要：金属选择性激光熔化(SLM)过程固有的反复热循环、大温度梯度及非均匀微观组织等因素导致的构件残余应力是SLM构件面临的重要问题之一。针对该问题,采用热传递模型以及耦合温度场、组织场的晶体塑性有限元模型,研究了不同工艺参数对316L不锈钢SLM过程中构件温度场以及晶粒尺度残余应力场的影响。结果表明,SLM过程中,激光光斑经过代表区域时,熔池附近出现应力集中区并逐渐向周围扩展。残余应力平均值沿扫描方向和横向方向分量以拉应力为主,沿构建方向的拉、压应力大小相近。随着激光功率的增大或扫描速度的降低,熔池体积和平均残余应力均增大;双道交叉扫描相比于双道平行扫描,第二道扫描时的熔池体积更大,而平均残余应力更小。Residual stress in metal Selective Laser Melting(SLM)components,stemming from the inherent repeated thermal cycles,large temperature gradients,and non-uniform microstructures during additive manufacturing,is a critical issue.This study employs a heat transfer model and a crystal plastic finite element model,coupled with temperature and microstructure fields,to investigate the impact of various process parameters on the temperature field and grain size residual stress field of 316L stainless steel SLM components.The results show that in the SLM process,when the laser spot passes through the representative region,the stress concentration area appears near the molten pool and gradually expands to the surrounding area.The average residual stress is mainly tensile stress along the scanning direction and transverse direction,while tensile stress and compressive stress are similar along the construction direction.With the increase of laser power or the decrease of scanning speed,the molten pool volume and the average residual stress increase.Double track intersect scanning compared to double track parallel scanning,the molten pool volume in the second scanning is larger and the average residual stress is smaller.

关 键 词：选择性激光熔化 残余应力 工艺参数 晶体塑性 

分 类 号：TG665[金属学及工艺—金属切削加工及机床]