超声冲击处理对TC4钛合金焊接试样微观组织及力学性能的影响

Effect of Ultrasonic Impact Treatment on Microstructure and Mechanical Properties of TC4 Welding Titanium Alloy Specimens

采用超声冲击对钛合金焊缝进行处理,对焊接接头的应力分布、显微组织和力学性能进行研究。结果表明,超声冲击处理会使焊缝表面形成一层厚度为80~120μm的致密强化层,减少了疲劳裂纹的长度和数量,提高了钛合金抗疲劳和抗腐蚀性能,降低了气孔、缩松等缺陷,使得拉应力转变为压应力,形成有利的压应力层。焊缝硬度增加且分布较为均匀,力学性能得到改善。

Ultrasonic impact was taken to treat the welding joints for TC4 titanium alloy, and the stress distribution and microstructure of welding joints were studied. The results show that a dense reinforcement layer thickness is about 80-120μm. The length and quantity of fatigue crack are decreased, and the fatigue properties and the corrosion resistance of the welding joints is improved, and the defects of welding as pore and shrinkage is decreasing. The tensile stress is transformed into a compressive stress and a favorable compressive stress layer is formed. The welding hardness increases and the distribution is more uniform, and the mechanical properties are improved.