基于数值模拟的选区激光熔化成形残余应力演化研究  

Residual Stress Evolution by Selective Laser Melting Based on Numerical Simulation

作　　者：赵仕宇 陈向文 詹艳然[2] ZHAO Shiyu;CHEN Xiangwen;ZHAN Yanran(Department of Mechanical and Electrical Engineering,Fuzhou Polytechnic,Fuzhou 350121,China;School of Mechanical Engineering and Automation,Fuzhou University,Fuzhou 350108,China)

机构地区：[1]福州职业技术学院机电工程系,福州350121 [2]福州大学机械工程及自动化学院,福州350108

出　　处：《精密成形工程》2024年第1期174-180,共7页Journal of Netshape Forming Engineering

基　　金：国家自然科学基金(51774097);福建省教育厅中青年项目(JAT210822)。

摘　　要：目的以选区激光熔化成形(SLM)试件的残余应力为研究对象,研究残余应力对成形质量的影响,为SLM成形的产业化应用提供理论依据。方法以316L不锈钢粉末为原材料,利用AltairInspire软件的Print3D模块分析SLM成形中支撑、成形角对残余应力的影响及残余应力的演化规律,并进行实验验证。结果SLM成形最大残余应力出现在零件与基板结合面,添加支撑可减小残余应力。零件不同位置残余应力的演化规律不同。顶部残余应力呈先增大后减小的趋势,底部两侧残余应力呈缓慢上升的趋势;底部中间残余应力的演化规律较为复杂:起先残余应力随温度的降低而增大,当温度降到最低点时达最大值;随后在热累积作用下,残余应力先减小后增大,当达到去应力退火温度时,残余应力又减小并在一定范围内波动。残余应力随着成形角的增大呈先增大后减小再增大的趋势,当成形角为60°时,残余应力较小。结论在SLM成形时,在零件底部添加支撑可将最大残余应力位置转移到支撑上,从而减小成形件内部的残余应力,提高成形质量。成形零件不同位置残余应力的演化规律不同,成形角对残余应力的影响也不同,成形时应根据零件工况制定合适的打印策略。The work aims to take the residual stress occurring in selective laser melting(SLM)process as the research ob-ject,to study its effect on forming quality,so as to provide a theoretical basis for industrial applications.With 316L stainless steel powder as raw material,a Print3D module of Altair Inspire software was used to analyze the effects of support and forming angle on residual stresses and the corresponding evolution law with experimental verification.During SLM processing,the highest value of residual stress occurred at the part-substrate interface,and could be reduced by adding supports.At different locations of the formed part,the evolution of residual stress was different.At the top area,the residual stresses tended to increase firstly then decrease,but they tended to increase slowly all the time at the sides near bottom area.At the center position near bottom,the evolution law was complex.Firstly,it increased with the decrease of temperature,and when the temperature got to the lowest point,the residual stress reached its maximum value.Subsequently,under the effect of heat accumulation,it de-creased firstly and then increased,and when the de-stressing annealing temperature was reached,the stress began to fluctuate within a certain range.With the increment of forming angle,the value of residual stress fluctuated,which was small with form-ing angle 60°.In SLM processing,adding support at the bottom of the part transfers the location of the largest residual stress to the support to be cut,which reduces the residual stress in the part and improves the forming quality.The evolution of residual stresses at different locations of the part is complex,and the influence of the forming angle on the residual stresses is also dif-ferent,so a suitable printing strategy should be developed based on specific working condition.

关 键 词：数值模拟 选区激光熔化 残余应力 316L不锈钢 成形角 

分 类 号：TG495[金属学及工艺—焊接]