大厚度TC4-DT钛合金电子束焊接接头微观组织和力学性能研究

Research of Microstructure and Mechanical Properties of EBW Joint for Large Thickness Titanium Alloy

对60mm厚TC4-DT钛合金锻件进行电子束焊接。通过对焊接接头显微组织观察,拉伸、冲击、断裂韧性测试,研究了该合金电子束焊接接头的力学性能。结果表明:TC4-DT钛合金具有良好的焊接工艺性能。焊缝为α相网篮组织,该合金电子束焊接接头的拉伸强度与基材相当,但冲击韧性与锻件相比略低。同时,该合金焊接接头也具有良好的损伤容限性能,与锻件相比焊接接头的断裂韧性下降约20%。

Electron beam welding(EBW)of a60mm thick TC4-DT titanium alloy is carried out.The properties ofEBW joint for the titanium alloy are researched by means of the microstructure,tension testing,impact testing and fracturetoughness testing.The results indicate that the welding performance of TC4-DT titanium alloy is excellent.The EBW jointof TC4-DT titanium alloy is composed by the basketweave structureα,compared with the matrix,the EBW joints of TC4-DT titanium alloy has similar tension strength.The impact toughness of the EBW joints is less than that of the forgings.Thefracture toughness performance of the EBW joints is excellent,but the fatigue crack propagation of the EBW joints is20%less than that of the forgings.