SLM成形Al-Mg-Li-Cu合金残余应力及组织性能

Residual Stress,Microstructure and Properties of SLM-formed Al-Mg-Li-Cu Alloy

通过阿基米德排水法以及试验测试综合分析选区激光熔融成形Al-Mg-Li-Cu合金的致密度、微观形貌和硬度等组织性能特征,探究了打印参数对合金残余应力的影响。结果表明,当粉末层厚(T)、激光功率(P)、舱口间距(H)逐渐增加时,残余应力逐渐减小。当T、P、H一定时,残余应力随扫描速率的增加先减小后增大。在最佳打印参数如下:P为240 W、V为140 mm/s、H为100μm、T为50μm时,成形件的残余应力最小,为56.53 MPa,且致密度高,硬度(HV)为114。

The density,micromorphology and hardness of SLM-formed Al-Mg-Li-Cu alloy were comprehensively investigated by Archimedes drainage method and tests.The influence of printing parameters on the residual stress of alloy was explored.The results indicate that the residual stress of Al-Mg-Li-Cu alloy is gradually reduced with the increase of powder layer thickness(T),laser power(P)and hatch spacing(H).When T、P、H are constant,the residual stress is decreased firstly and then increased as the scanning rate increases.The optimal printing parameters is presented as follows:laser power of 240 W,scanning rate of 140 mm/s,scanning spacing of 100μm,and layer thickness of 50μm,corresponding to the minimum residual stress of 56.53 MPa,where the alloy is highly dense,and the hardness is 114 HV.