Ti-6Al-4V钛合金激光焊接的超塑性与组织研究(英文)  

Superplastic Tensile Behavior and Microstructure Evolution of Laser Welded Ti-6Al-4V Alloy

作　　者：郭伟[1] 李瑞婷[1] 朱颖[1] 刘钦[1] 曲平[1] 康慧[1] 

机构地区：[1]北京航空航天大学,北京100191

出　　处：《稀有金属材料与工程》2013年第S2期74-77,共4页Rare Metal Materials and Engineering

基　　金：the Fundamental Research Funds for the Central Universities

摘　　要：采用高温拉伸的方法对Ti-6Al-4V(TC4)钛合金激光焊接板材的超塑性进行了研究。实验工艺参数为:拉伸温度900℃,拉伸速度0.6 mm/min。采用SEM对激光焊接接头在焊接和超塑变形过程中的组织演变进行了分析。结果表明:Ti-6Al-4V钛合金激光焊接板材具有超塑性,但与母材相比,超塑性有所下降,激光焊接接头未表现出超塑性。由于激光焊接的冷却速度较快,焊缝组织为包含针状马氏体α’相的网篮组织,超塑变形后,针状马氏体α’相转变为层片状的α+β相。最后,对焊接金属超塑性变形机制进行了讨论。To investigate superplastic tensile behavior and microstructure evolution of laser welded Ti-6Al-4V(TC4) titanium alloy,hot tensile tests were carried out at 900 ℃ with 0.6 mm/min.The microstructure evolutions of the welded metals were analyzed by scanning electron microscope(SEM).Results show that Ti-6Al-4V butt-welded plates by laser beam welding(LBW) possess superplasticity,but the elongation decreases compared with the unwelded metal,and the joint shows no superplasticity.The basket-weave pattern microstructure consisted of acicular martensite α' phase is generated in weld bead due to phase transformation during the laser welding process.The acicular α' phase transforms into lamella α + β phase after hot superplastic deformation.The superplasticity mechanism of the welded metal was also discussed.

关 键 词：超塑性 激光焊 TI-6AL-4V 组织 

分 类 号：TG456.7[金属学及工艺—焊接]