电子束选区熔化成形Ti-6Al-4V合金不同沉积高度上的组织与性能  

Microstructure and Properties of Ti-6Al-4V Alloy Formed by Electron Beam Selective Melting at Different Deposition Heights

作　　者：高紫豪 杨尚磊[1,2] 彭曾 王贞涛 GAO Zihao;YANG Shanglei;PENG Zeng;WANG Zhentao(School of Materials Engineering,Shanghai University of Engineering Science,Shanghai 201620.China;Shanghai Collaborative Innovation Center for Laser Advanced Manufacturing Technology,Shanghai 201620,China)

机构地区：[1]上海工程技术大学材料工程学院,上海201620 [2]上海市激光先进制造技术协同创新中心,上海201620

出　　处：《机械工程材料》2022年第6期7-10,20,共5页Materials For Mechanical Engineering

基　　金：国家自然科学基金资助项目(51971129);上海市自然科学基金资助项目(19ZR1421200);克拉玛依市科技重大专项资助项目(2018ZD002B);科技援疆计划资助项目(2019E0235)。

摘　　要：采用电子束选区熔化技术制备了厚度10 mm的Ti-6A1-4V合金板,研究了沿沉积方向合金的显微组织、拉伸性能和显微硬度的变化。结果表明:合金组织以α集束和α片层交织的网篮组织为主,底部由于经历多次热循环作用,α片层较顶部的略粗大,初生β晶的宽度随沉积高度增加而略有增大;合金底部、中部和顶部的屈服强度和抗拉强度呈逐渐升高趋势,但差异不大;不同沉积高度处的拉伸试样均表现为韧性断裂,断口处存在孔洞和未熔化的球形粉末;合金顶部的平均硬度(约315 HV)略高于底部(约295 HV),拉伸后由于应变硬化效应硬度略有提高。Ti-6 A1-4 V alloy sheet with a thickness of 10 mm was prepared by electron beam selective melting.Change of microstructure,tensile properties and microhardness of the alloy along the deposition direction was studied.The results show that the alloy structure was mainly composed ofαclusters and a mesh basket structure with interlacedαsheets.Due to multiple thermal cycles,theαsheets at the bottom were slightly coarser than those at the top.The width of the primaryβcrystals increased slightly with the increase of deposition height.The yield strength and tensile strength of the bottom,middle and top of the alloy showed a gradually increasing trend,but the difference was small.Tensile specimens at different deposition heights all showed ductile fracture.There were voids and unmelted spherical powder at the fracture.The average hardness of the top of the alloy(about 315 HV)was slightly higher than that of the bottom(about 295 HV),and the hardness after tension slightly increased due to the strain hardening effect.

关 键 词：电子束选区熔化 TI-6A1-4V合金 显微组织 拉伸性能 硬度 

分 类 号：TG14[一般工业技术—材料科学与工程]