采用光纤激光对3 mm厚的7A52铝合金进行了焊接,用金相显微镜、扫描电镜、拉伸测试仪器、硬度计等分析测试手段,分析了焊接接头的微观分区组织及性能。结果表明: 采用优化后的工艺参数成功地采用光纤激光器对7A52铝合金进行了焊接,能够得到无明显缺陷的焊接接头,焊接接头由狭窄的热影响区、焊缝区以及母材三个区域组成,焊缝组织为细小的等轴晶组织,靠近熔合线附近的晶粒粗大;接头力学性能良好,拉伸试样均断裂在热影响区部位,接头的断口形貌显示混合型的断口特征。

The 7A52 aluminum alloy of 3 mm thickness was welded by fiber laser welding. The microstructure and mechanical property of welded joint were studied by optical microscope,SEM,tensile test, micro hardness,etc. The results show that: Adopting optimized processing parameters we have welded 7A52 aluminum successfully by fiber laser, no obvious defects can be find, the welded joint is composed of three zones, such as the narrow heat affected zone,nugget and base metals. The weld nugget zone consists of fine equiaxed grains, the grains near the fusion line get coarser; The mechanical properties of fiber laser welded 7A52 Al alloy joints are good, the tensile samples were broken in the heat affected zone, the fiber laser welded joints fracture is a ductile-brittle mixed fracture.