层间激光重熔对激光选区熔化成形件内部残余应力的影响  

Influence of Interlayer Laser Remelting on Residual Stress During Forming Using Selective Laser Melting

作　　者：宜亚丽[1] 武红波 贾长治 金贺荣[1] Yi Yali;Wu Hongbo;Jia Changzhi;Jin Herong(School of Mechanical Engineering,Yanshan University,Qinhuangdao 066004,Hebei,China;Artillery Engineering Department,Shijiazhuang Branch,Army Engineering University,Shijiazhuang 050003,Hebei,China)

机构地区：[1]燕山大学机械工程学院,河北秦皇岛066004 [2]陆军工程大学石家庄校区火炮工程系,河北石家庄050003

出　　处：《中国激光》2023年第24期127-139,共13页Chinese Journal of Lasers

基　　金：河北省重点研发计划项目(22351805D)。

摘　　要：激光选区熔化(SLM)成形316L不锈钢的内部残余应力是影响成形件力学性能的关键因素之一。考虑到重熔回火效应对残余应力的影响规律,笔者提出了成形件“层间激光重熔”的成形方式,针对性研究了层间重熔对SLM成形件内部残余应力的影响。利用有限元软件Abaqus建立成形过程的三维瞬态仿真模型,模拟了间隔1~10层重熔与未重熔成形件内部残余应力的变化规律,并通过实验研究了间隔2、5、10层重熔与未重熔成形件的内部残余应力、显微组织、表面形貌、抗拉强度、冲击韧性及显微硬度。结果表明:层间激光重熔在重熔层及其相邻层产生的回火效应有利于降低成形件内部的残余应力,使力学性能得到改善。当重熔间隔为2层时,成形件内部残余应力的测量值和模拟值分别较未重熔样件降低了77.1%和70.6%,同时成形件的抗拉强度达到702.99 MPa,相较于未重熔样件提高了6.2%;冲击吸收功达到209.5 J,相较于未重熔样件提高了11.97%;显微硬度达到391.8 HV,相较于未重熔样件提高了6.35%。分析认为,采用层间激光重熔方式可以显著降低成形件内部的残余应力,提高成形件的力学性能。Objective The internal residual stress generated inside 316L stainless steel parts formed using selective laser melting(SLM) is one of the key factors affecting the mechanical properties of fabricated components.At present,most studies primarily focus on reducing the residual stresses on the surface layer and improving the surface quality.Thus,the internal residual stress level remains high,leading to the fabrication of components with poor mechanical properties that may not meet the specified requirements.With the goal of investigating the reduction of the mechanical properties of components caused by internal residual stresses,the effects of remelting on the residual stresses were studied.An “interlayer laser remelting” forming method was proposed for components,and the effects of interlayer remelting on the internal residual stresses of components fabricated using SLM were studied in a targeted manner.In contrast to the traditional surface laser remelting,remelting was performed at intervals inside the components to eliminate any internal residual stresses and provide references for the optimization of the laser remelting process and improvement in the quality of the fabricated components.Methods The interlayer laser remelting forming method was proposed based on the effects of laser remelting on the residual stresses.The non-remelted layers were formed layer-by-layer using optimized process parameters,with the same process parameters used to form the remelted layers at intervals.The laser remelting was performed after the powder layer was initially pre-melted by laser scanning.This laser remelting operation was performed at evenly spaced layers until the printing of the component was completed.First,a three-dimensional transient simulation model of the forming process was established using Abaqus to simulate the variation law of the internal residual stresses of the components during remelting at intervals of 1-10 layers,along with those of the non-remelted components.Then,the influence of the stress fiel

关 键 词：激光技术 激光选区熔化 层间激光重熔 316L不锈钢 内部残余应力 力学性能 显微组织 

分 类 号：TG142.1[一般工业技术—材料科学与工程] TG13[金属学及工艺—金属材料] V261.8[金属学及工艺—金属学]