激光冲击次数对TC4氩弧焊焊缝微结构及性能的影响

Influence of Laser Shock Processing Times on TC4 Argon Arc Welding Joint Microstructure and Properties

采用脉宽30 ns,能量40 J的调Q掺钕玻璃激光对TC4钛合金钨极惰性气体（TIG）焊焊缝进行了1~3次的激光冲击强化（LSP）处理,并与未经LSP处理的焊缝的表面显微硬度、焊缝微观组织、接头的拉伸力学性能和拉伸断口的扫描电镜（SEM）照片进行比较,研究LSP处理次数对TC4钛合金TIG焊焊缝组织性能的影响。结果表明,LSP能够使焊缝横截面靠近材料表面的区域针状α′相数量减少,热影响区靠近材料表面的区域细小等轴晶数量增加;随着LSP处理次数的增加,TC4钛合金TIG焊接头表面的显微硬度增加;焊接接头的抗拉强度和屈服强度变化不明显,而断后延伸率出现降低趋势。

Q-switched Nd∶glass laser with 30 ns pulse-width and 40 J energy is introduced to shock TC4 titanium alloy tungsten inert gas（TIG） welding joints once,twice and three times,separately.In order to study the influence of laser shock processing（LSP） disposal times on TC4 TIG welding joints microstructure and properties,surface HV hardness,microstructure,tensile property and scanning electron microscope（SEM） fracture photos of these joints are analyzed.Comparing with those joints without LSP treatment,surface HV hardness of weld beads treated by LSP is decreased.HV hardness on weld bead surface and that on the heat affected zone（HAZ） surface are hardly different.The amount of α′ phase near LSP treatment weld bead surface is reduced,and fine grains are increased in the HAZ.With the increase of LSP treatment times,HV hardness is improved on weld joints surface.Although LSP treatment joints tensile strength and yield strength are not distinctly change,specific elongation is shown fall trend along with LSP treatment times increased.