摘要
AA2219 aluminium alloy joints were fabricated by variable polarity tungsten inert gas （VPTIG） welding process and the effects of post weld heat treatment （PWHT） on the tensile properties, microstructure and fatigue behaviour of the welded joints were investigated. The VPTIG welding process was adopted because it could meet the need of cathode cleaning and meanwhile it could reduce the deterioration of tungsten electrode furthest. The welded samples were divided into as-welded （AW） sample and PWHT sample. The PWHT method used on the samples was solution treatment （535 ℃, 30 rain）, water quenching and artificial aging （175 ℃, 12 h）. The experimental results show that, compared with the AW samples, the microstructure characteristics and mechanical properties of the AA2219 joints after PWHT were significantly improved. The improvement of yield strength, ultimate tensile strength, and fatigue strength are 42.6%, 43.1% and 18.4%, respectively.
采用变极性TIG焊接方法制备AA2219铝合金焊接接头,研究焊后热处理对接头的拉伸、微观组织和疲劳性能的影响。变极性TIG焊具有在保证阴极清理作用的前提下最大限度地降低对钨极的烧损的优点。焊接试样分为原始焊态试样和热处理态试样两种。热处理方案采用固溶处理(535°C,30 min)、水冷淬火和人工时效(175°C,12 h)。结果表明,焊后热处理能够显著地提高原始焊态试样的力学性能(屈服强度提高42.6%,抗拉强度提高43.1%),改善微观组织以及提高抗疲劳性能(疲劳强度提高18.4%)。
基金
Project(51275343)supported by the National Natural Science Foundation of China
