SLM成形AlSi10Mg合金残余应力数值模拟及组织性能分析

通过有限元模拟与试验测试,研究了打印参数对选区激光熔化(SLM)工艺成形AlSi10Mg合金残余应力的影响。结果表明,打印过程存在3个峰值温度;随着基板温度、激光功率、扫描速度和扫描间距的增加,成形件残余应力先减小后增大。当激光功率为450 W、扫描速度为1 100mm/s、扫描间距为70μm、基板温度为200℃时,打印件具有最小的残余应力,成形件抗拉强度为480MPa、屈服强度为310MPa、伸长率为6%。成形件组织中存在粗晶区、细晶区和热影响区3种区域,Si相呈网状结构分布。

Numerical Simulation and Microstructure Analysis of Residual Stress in SLM Formed AlSi10Mg

The influence of printing parameters on the residual stress of AlSi10Mg alloy parts formed by SLM process was explored via the finite element simulation and experimental testing.The results show that there exist three peak temperatures during printing,and with the increase of substrate temperature,laser power,scanning speed and scanning interval,the residual stress of the workpiece is decreased firstly and then increased.With the laser power of 450 W,the scanning speed of 1 100 mm/s,the scanning interval of 70μm,and the substrate temperature of 200℃,the printed parts have the minimum residual stress.Based on the optimized parameters,the tensile strength,yield strength and elongation of the printed parts reach 480 MPa,310 MPa,and 6%,respectively.The microstructure of printing specimen is composed of coarse grained zone,fine grained zone,and heat affected zone,in which the Si phase is distributed in a network structure.