焊接接头性能的影响
(北京航空材料研究院，北京 100095)
摘 要: 对TC11钛合金在氮气氛下进行激光切割，并在氮气氛下进行热处理，对比热处理前后的显微组织和硬度，确定热影响层深度。去除激光切割影响层后进行电子束焊接，比较研究未激光切割和激光切割焊接接头的拉伸和疲劳性能。结果表明：激光切割热影响层深度在2~3 mm之间；未激光切割和激光切割TC11钛合金焊接接头低周疲劳性能未见明显差异，但是激光切割后的焊接接头抗拉强度和伸长率相对未激光切割焊接接头分别低45 MPa和3%左右。
关键字: 钛合金；焊接；激光切割；显微组织
（Beijing Institute of Aeronautical Materials, Beijing 100095, China）
Abstract:TC11 titanium alloy plates were cut by laser and then heat treated in nitrogen atmosphere. The microstructure and microhardness of the surface layers affected by laser cutting were investigated before and after heat treatment. The depth of the heat influence zones by laser cutting was tested. The influenced layers by laser cutting were removed and then the plates were joined by electron beam welding. The effect of laser cutting on the tensile and fatigue properties of the welding joints of TC11 titanium alloy was studied. The results show that the depth of the heat influence zones by laser cutting is in the range of 2 mm to 3 mm. The effect of laser cutting on the low-cycle fatigue property of the welding joint of TC11 titanium alloy is slight, but laser cutting make the tensile strength and elongation percentage decrease by 45 MPa and 3%, respectively.
Key words: titanium alloy; welding; laser cutting; microstructure
