激光选区熔化成形TA7 ELI钛合金显微组织及力学性能研究  

Microstructure and Mechanical Properties of TA7 ELI Titanium Alloy Formed by Selective Laser Melting

作　　者：陈帅 汪洋 刘涵 张京京 董鹏 梁晓康 周庆军 严振宇 倪江涛 雷悦 Chen Shuai;Wang Yang;Liu Han;Zhang Jingjing;Dong Peng;Liang Xiaokang;Zhou Qingjun;Yan Zhenyu;Ni Jiangtao;Lei Yue(Country Capital Aerospace Machinery Corporation Ltd.,Beijing 100o76,China)

机构地区：[1]首都航天机械有限公司,北京100076

出　　处：《应用激光》2023年第10期53-60,共8页Applied Laser

摘　　要：针对TA7 ELI钛合金开展激光选区熔化(SLM)成形工艺研究,获得激光功率P、扫描速度V对致密度的影响规律,进一步分析激光能量密度对缺陷的影响,并基于最佳成形工艺参数开展显微组织及力学性能分析。研究表明,SLM成形TA7 ELI致密度随激光功率P的升高先增加后降低,随着激光能量密度增加先增加后降低。当激光功率P为280 W、扫描速度V为1000 mm/s、扫描间距H为120μm、铺粉层厚t为30μm时,成形试样致密度最高为99.89%,此时激光能量密度为78 J/mm^(3)。SLM成形TA7 ELI沿着沉积方向为外延生长柱状晶,垂直沉积方向为等轴晶组织,晶内由平行或交错分布的细小针状α′马氏体组成。TA7 ELI沉积态抗拉强度超过1050 MPa,延伸率达到15%,拉伸断口均匀密集分布等轴韧窝,表现为典型的韧性断裂特征。This work aims to investigate the selective laser melting(SLM)process of TA7 ELI on the density through analyzing the influence of process parameters such as laser power P and scanning speed V.The influence of laser energy density on defects was further analyzed,and the microstructure and mechanical properties were analyzed based on the optimal forming process parameters.Results show that the density of TA7 ELI formed by SLM firstly increases and then decreases with the increase of laser power P and laser energy density.When the laser power P is 280 W,the scanning speed V is 1000 mm/s,the scanning spacing H is 120μm,and the coating thickness t is 30μm,the highest density of the formed sample is 99.89%,and the corresponding laser energy density is 78 J/mm^(3).TA7 ELI formed by SLM shows epitaxial columnar crystal growth along the deposition direction and equiaxed crystal structure along the direction perpendicular to the deposition direction,which is composed of fine needle-like a'martensite with parallel or staggered distribution.The as-deposited tensile strength of material is more than 1050MPa and the elongation rate reaches 15%.The tensile fractures are evenly and densely distributed with equiaxed dimples,showing typical ductile fracture characteristics.

关 键 词：激光选区熔化 TA7 ELI钛合金 致密度 显微组织 力学性能 

分 类 号：TG665[金属学及工艺—金属切削加工及机床]