激光选区熔化成形TA7钛合金各向异性分析  

Anisotropy analysis of laser selective melting formingTA7 titanium alloy

作　　者：杨兴远 魏红伟 张静[2] 王继航 姜沐池 刘意 任德春 蔡雨升 吉海宾[1] YANG Xingyuan;WEI Hongwei;ZHANG Jing;WANG Jihang;JIANG Muchi;LIU Yi;REN Dechun;CAI Yusheng;JI Haibin(Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China;Beijing Aerospace Propulsion Institute,Beijing 100076,China)

机构地区：[1]中国科学院金属研究所,辽宁沈阳110016 [2]北京航天动力研究所,北京100076

出　　处：《火箭推进》2023年第4期99-105,共7页Journal of Rocket Propulsion

基　　金：中国科学院创新交叉团队项目(JCTD-2020-10)。

摘　　要：采用激光选区熔化成形技术(selective laser melting,SLM)制备了不同成形角度的TA7钛合金,分析了成形角度以及热处理对成形合金显微组织、织构及力学性能的影响。结果表明:由于SLM成形技术凝固较快的特点,导致成形TA7钛合金的显微组织受成形角度影响较为显著,为平行于成形方向的柱状β晶粒,晶内均为快速凝固形成的生成α′马氏体;成形合金存在<0001>织构,成形角度为30°时,<0001>织构的取向密度指数达到最高的15.05,Schmid因子为4.35;在显微组织与织构差异的影响下,成形合金的性能具有显著的各向异性,随着成形角度的增加,合金的强度逐渐升高,塑性呈现降低的趋势;经过热处理后,合金的显微组织转变为等轴晶,织构显著弱化,合金的力学性能实现了各向同性。基于上述研究,采用激光选区熔化成形技术可成形具有复杂流道结构的TA7钛合金级间壳体构件。Selective laser melting(SLM)was used to produce TA7 titanium alloy with different forming angles.The effects of forming angles and heat treatment on the microstructure,texture and mechanical properties of the alloy were analyzed.The results show that the microstructure of the formed TA7 titanium alloy was significantly affected by the forming angle due to the fast solidification of SLM forming technology.The columnarβgrains were parallel to the forming direction,and theα′martensite was formed by rapid solidification in the crystals.When the forming angle was 30°,the orientation density index of the<0001>texture reached the highest 15.05 and Schmid factor was 4.35.Under the influence of microstructure and texture differences,the properties of the alloy had significant anisotropy.With the increase of forming angle,the strength of the alloy increased gradually,and the plasticity of the alloy decreased.After heat treatment,the microstructure of the alloy changed to equiaxed crystal,the texture was weakened significantly,and the mechanical properties of the alloy achieved isotropy.Based on the above research,the TA7 titanium alloy interstage shell with complex runner structure was fabricated by laser selective melting forming technology.

关 键 词：激光选区熔化 TA7钛合金 织构 各向异性 热处理 

分 类 号：TG146.23[一般工业技术—材料科学与工程]