激光焊接TC4钛合金组织性能研究  

Microstructure and Mechanical Properties of Laser Welded TC4 Alloys

作　　者：董智军[1,2] 吕涛[1] 雷正龙 陈彦宾[1] 李俐群[1] 周恺[3] 马瑞[3] 

机构地区：[1]哈尔滨工业大学先进焊接与连接国家重点实验室,哈尔滨150001 [2]上海航天精密机械研究所,上海201600 [3]北京动力机械研究所,北京100074

出　　处：《航天制造技术》2013年第1期27-30,共4页Aerospace Manufacturing Technology

摘　　要：研究激光焊接对TC4钛合金焊缝成形和力学性能的影响,并利用OM、XRD和TEM等手段对焊接接头的显微组织特征进行了分析。结果表明,激光焊接TC4钛合金成形较好,但在焊缝熔合线附近容易产生圆形气孔。焊缝由单一的α′马氏体构成,并呈网篮状分布。热影响区组织为α′马氏体和初始α相。焊缝和热影响区的显微硬度明显高于母材,而焊缝的硬度最高且硬度分布平缓。TC4钛合金焊接接头的室温平均抗拉强度为1126MPa,与母材的抗拉强度相当,延伸率为11.12%,比母材略低,焊接接头均断在母材区域。The effect of laser welding on the weld appearance and mechanical properties of TC4(Ti-6Al-4V) alloys were discussed,and the microstructure characterization of the joints was investigated by means of OM,XRD and TEM.The experimental results showed that a good weld appearance could be obtained;however,some round blowholes emerged easliy near the weld fusion line.The weld seam is only composed of α' martensite which takes on basket weave structure.And the microstructure of heat affected zone is constituted of α' martensite and the initial α phase.The microhardness of the weld seam and heat affected zone is higher than that of the base metal.And the weld seam exhibits the highest values in the welded joint.The tensile strength of the laser welded joints is 1126 MPa at room temperature,which is equal to that of the base metal.The elongation of the joint,however,is slightly lower than the base metal with a ductility of 11.12%.The welded joints of TC4 alloys are all broken on the area of the base metal.

关 键 词：钛合金 激光焊接 微观组织 显微硬度 抗拉强度 

分 类 号：V252[一般工业技术—材料科学与工程]