(1. 上海交通大学 上海市激光制造与材料改性重点实验室，上海 200240；
2. 宝山钢铁股份有限公司研究院，上海 201900；
3. 汽车用钢开发与应用技术国家重点实验室(宝钢)，上海 201900)
摘 要: 对6016铝合金激光焊接接头的力学性能开展研究，分析焊后时效热处理对其力学性能的影响规律。结果表明：焊后时效处理可以提高焊接接头的力学性能，采用(180 ℃+10 h)时效处理工艺可将焊缝中心的硬度从58 HV提高到82 HV，可将焊接接头的拉伸强度从180 MPa提高到274 MPa，时效强化效果明显。动力学分析表明，6016铝合金焊接接头时效强化过程符合 Johnson-Mehl-Avrami (JMA)方程。当时效温度升高，接头中强化相体积分数的变化率也随之增大，合金硬度上升速率增加，达到峰值硬度所需时间变短。
关键字: 6016铝合金；激光焊接；力学性能；时效；动力学分析
（1. Shanghai Key Laboratory of Materials Laser Processing and Modification, Shanghai Jiao Tong University,
Shanghai 200240, China;
2. Research Institute, Baoshan Iron & Steel Co., Ltd., Shanghai 201900, China;
3. State Key Laboratory of Development and Application Technology of Automotive Steels, Shanghai 201900, China）
Abstract:The mechanical properties of laser welded 6016 aluminum alloy joint were investigated firstly, and then the influence of aging process on the mechanical properties was analyzed. The results show that the mechanical properties of welded structure without post-weld heat treatment are lower than that of base metal. After an aging treatment of (180 ℃+ 10 h), the hardness at the center of welded joint can increase from 58 HV to 82 HV as well as the tensile strength from 180 MPa to 274 MPa. The dynamics analysis shows that the age-hardening process of the joint agrees the Johnson-Mehl-Avrami (JMA) law. The increase rates of volume fraction of strengthening phase and hardness of the joint increase with increasing of the aging temperature. The duration time of aging for obtaining maximum hardness decreases with increasing of the aging temperature. It is firmly believed that this work offers a positive reference for optimizing the aging process of welded 6016 aluminum alloy joint and improving its resultant mechanical properties.
Key words: 6016 aluminum alloy; laser welding; mechanical property; aging process; dynamics
