Du Lingzhi, Yang Zhibin, Wang Xing
School of Materials Science and Engineering, Dalian Jiaotong University, Dalian 116028, China.
Materials (Basel). 2023 Jan 1;16(1):404. doi: 10.3390/ma16010404.
To expand the application of laser-MIG hybrid welding in the arc-welded aluminum alloy profile manufacturing for high-speed trains, the laser-MIG hybrid welding characteristics of 4 mm thick A6N01S-T5 arc-welded aluminum profiles were studied in this work. The welding parameters were optimized using the orthogonal test; the microstructure and properties of the joints were analyzed. The results showed that the optimal welding parameters were: welding speed 1.0 m/min, laser power 2.7 kW, arc current 200 A, spot diameter 0.8 mm, heat source distance 3 mm, and defocusing amount 0 mm. The columnar crystals and dense dendrites were observed near the fusion line and in the weld center, respectively, and the grains in the heat-affected zone were slightly coarse. The microhardness of the softening zone in the heat-affected zone was the lowest. The average tensile strength of the joints was 212 MPa, about 86% of the base metal. The samples fractured in the heat-affected zone, and the fractures showed typical plastic fracture characteristics. The results showed that laser-MIG hybrid welding has good applicability and feasibility for the arc-welded profile welding manufacturing.
为了拓展激光 - MIG复合焊接在高速列车弧焊铝合金型材制造中的应用，本文对4mm厚的A6N01S - T5弧焊铝合金型材的激光 - MIG复合焊接特性进行了研究。采用正交试验对焊接参数进行了优化；分析了接头的组织和性能。结果表明，最佳焊接参数为：焊接速度1.0m/min、激光功率2.7kW、电弧电流200A、光斑直径0.8mm、热源距离3mm、离焦量0mm。在熔合线附近和焊缝中心分别观察到柱状晶和致密的树枝晶，热影响区的晶粒稍粗大。热影响区软化区的显微硬度最低。接头的平均抗拉强度为212MPa，约为母材的86%。试样在热影响区断裂，断口呈现典型的塑性断裂特征。结果表明，激光 - MIG复合焊接在弧焊型材焊接制造中具有良好的适用性和可行性。
