Comparison of low-cycle fatigue properties of two kinds of high energy beam welded joints of TC4 alloy
(1. State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049, China;
2. Xi’an Aerospace Power Machine Factory Co., Ltd., Xi’an 710025, China;
3. AVIC Xi’an Aircraft Industry (Group) Company Ltd., Xi’an 710089, China)
2. Xi’an Aerospace Power Machine Factory Co., Ltd., Xi’an 710025, China;
3. AVIC Xi’an Aircraft Industry (Group) Company Ltd., Xi’an 710089, China)
Abstract: The low-cycle fatigue properties of 30 mm Ti6Al4V titanium alloy joints welded by vacuum electron beam welding and laser wobble welding with filler wire were compared. The test results show that the low-cycle fatigue performance of the electron beam welding joint is close to that of the base meal, while the low-cycle fatigue performance of the laser wobble welding with a filler wire joint is clearly inferior to that of the electron beam welding joint and base meal. An examination of the microhardness of the base metal, heat-affected zones and weld area of the two joints found that the microhardness of the weld area of the electron beam welding joint is close to that of the base meal, but is lower than that of the heat-affected zones on both sides. The weld area of the laser wobble welding with the filler wire joint is significantly weakened.
Key words: Ti6Al4V titanium alloy; microstructure; microhardness; low-cycle fatigue