激光选区熔化成形18Ni300工艺参数优化及组织性能分析  

Optimization of Process Parameters and Analysis of Microstructure and Properties of 18Ni300 by Laser Selective Melting

作　　者：白晶斐 马亚鑫 陈晓辉[2] 张宏 门正兴[1] 陈诚 岳太文[1] BAI Jing-fei;MA Ya-xin;CHEN Xiao-hui;ZHANG Hong;MEN Zheng-xing;CHEN Cheng;YUE Tai-wen(School of Aeronautical Manufacturing Industry,Chengdu Aeronautic Polytechnic,Chengdu 610021,China;China Aerodynamics Research and Development Center,Sichuan Mianyang 621000,China;Failure Mechanics and Engineering Disaster Prevention and Mitigation Key Laboratory of Sichuan Province,College of Architecture and Environment,Sichuan University,Chengdu 610065,China)

机构地区：[1]成都航空职业技术学院航空装备制造产业学院,成都610021 [2]中国空气动力研究与发展中心,四川绵阳621000 [3]四川大学建筑与环境学院破坏力学与工程防灾减灾四川省重点实验室,成都610065

出　　处：《精密成形工程》2022年第4期162-168,共7页Journal of Netshape Forming Engineering

基　　金：四川省科技厅项目(2019YJ0519);中国博士后基金(2019M653396);四川大学-自贡政府战略合作支持项目(2019CDZG-4);四川大学-宜宾政府战略合作支持项目(2019CDYB-24);四川大学博士后基金(2019SCU12056)。

摘　　要：目的研究工艺参数对18Ni300马氏体时效钢激光选区熔化成形质量的影响。方法采用正交试验方法研究激光功率和扫描速度对18Ni300相对致密度、硬度的影响,得到铺层层厚0.03 mm、扫描间距0.1 mm时为18Ni300最佳工艺参数,并对最佳工艺参数成形的试样进行组织及力学性能表征。结果激光功率为230 W、扫描速度为1100 mm/s时,试样硬度为44.7HRC,相对致密度为99.98%,相对最优;材料鱼鳞状组织均匀致密,气孔较少,部分柱状晶沿熔池边界呈外延生长,熔池边界细小晶粒取向基本随机,熔池内部分粗大柱状晶有一定的择优性。结论最优参数情况下SLM成形的18Ni300主要由体积分数为99.8%的马氏体和0.2%的残余奥氏体组成;试样的力学性能有明显的各向异性,拉伸断口有明显的颈缩,断裂形式为韧性断裂,纤维区可以看到明显的等轴大韧窝、孔洞,并伴有明显的撕裂特征。The work aims to study the effects of process parameters on the quality of laser selective melting of 18Ni300maraging steel.The effects of laser power and scanning speed on the relative density and hardness of 18Ni300 were studied by orthogonal experiment.The optimum process parameters of 18Ni300 were obtained when the layer thickness was 0.03 mm and the scanning spacing was 0.1 mm.The microstructure and mechanical properties of the sample formed by the optimum process parameters were characterized.When the laser power was 230 W and the scanning speed was 1100 mm/s,the hardness of the sample was 44.7HRC and the relative density was 99.98%;The fish scale structure of the material was uniform and dense,with few pores.Some columnar crystals grew vertically along the boundary of the molten pool in an outward direction,the fine grain orientation at the boundary of the molten pool was basically random,and some coarse columnar crystals in the molten pool had certain selectivity.Under the optimal parameters,18Ni300 formed by SLM is mainly composed of 99.8%martensite and 0.2%retained austenite;The mechanical properties of the sample have obvious anisotropy,the tensile fracture has obvious necking,and the fracture form is ductile fracture.There are obvious equiaxed large dimples and holes and tearing characteristics in the fiber area.

关 键 词：激光选区熔化 马氏体时效不锈钢 微观组织 力学性能 

分 类 号：TG316[金属学及工艺—金属压力加工]