Ti6Al4V钛合金LBW/SPF/DB夹层结构微观组织研究  

Research on Microstructure of Ti6Al4V Alloy Sandwich Structure Made by LBW/SPF/DB Process

作　　者：盖鹏涛[1] 吴为[1] 王飞[1] 涂刚[2] 

机构地区：[1]中航工业北京航空制造工程研究所 [2]中国人民解放军驻西飞公司军事代表室

出　　处：《航空制造技术》2011年第16期126-129,共4页Aeronautical Manufacturing Technology

摘　　要：采用激光焊接/超塑成形/扩散连接(LBW/SPF/DB)组合工艺制作Ti6Al4V钛合金夹层结构试验件,分析超塑成形/扩散连接前后激光焊接区域及母材显微组织的变化。结果表明:超塑性变形过程中,β晶粒取向逐渐向拉伸方向转变,内部细小的片层状组织能使焊缝强硬度降低、塑性增加,从而能够承受拉伸过程中的弯曲、拉伸应力的联合作用。超塑成形后Ti6Al4V钛合金母材晶粒仍保持等轴状,其晶粒尺寸明显增大,焊缝中心区针状α相变大、变粗,焊缝中心两侧区域为粗大的魏氏组织,在热影响区内的针状马氏体α′相,形成与初生α相形态相似的短小α条。The Ti6Al4V alloy sandwich structure is made by LBW/SPF/DB process.The evolvement of the microstructure in the LBW area is investigate before and after SPF/DB process.The results indicate that,during the SPF process,the orientation of the β grain changeds gradually towards the tension direction and the fine lamellar structure formed which enables the hardness of the welded joint to be reduced but the plasticity increased can bear the combination of the bending and the tension stresses.The crystal grain of the as-received Ti6Al4V alloy remains equiaxed but larger after SPF/DB process and the needle-like α phase is coarser in the central area of the welded joint and the coarse Widmanstaten structure exists in bilateral areas of the welded joint centre and in the heat-affected zone the needle-like α' phase transforms into short and small α banding.

关 键 词：TI6AL4V钛合金 夹层结构 LBW/SPF/DB 激光焊接 超塑成形 

分 类 号：V214.6[航空宇航科学与技术—航空宇航推进理论与工程]