TC4钛合金等离子弧焊接接头组织及性能

摘要

采用等离子弧焊接工艺焊接TC4钛合金,通过室温拉伸、显微硬度测试、金相分析及X射线衍射试验,对TC4钛合金等离子弧焊接接头的显微组织和性能进行了研究.实验结果表明:TC4钛合金等离子弧焊接接头焊缝的组织为针状马氏体α'相和残余β相,组织形态为粗大柱状晶,过渡区和近焊缝区中的组织为细小的针状α相和β相、少量的α'相,组织形态为较粗大的等轴晶;接头焊缝熔化区的硬度最高;接头断口的主要微观特征为韧窝,属于延性断裂,但部分区域韧窝很浅,趋向于脆性断裂.%TC4 alloy was welded by using plasma arc welding process.The microstructure and mechanical properties of its welded joints are analyzed through room-temperature tensile test,micro hardness test,and metallographic test and X-ray diffraction test.The results show that the micro-structure the joint weld zone is parallel acicular marten site α'phase and residual β phase,its morphology is coarse columnar grains.The highest hardness of the joints is in the melting zone.The dimples appear in the jonts in the tensile test,but the dimples appearing in some joint areas are shallow,generally,the joints trend to be brittle fracture.