AZ31镁合金激光-MIG复合焊接接头组织和疲劳性能研究

Study on Microstructure and Fatigue Performance of AZ31 Alloy Laser-MIG Hybrid Welded Joints

为了提高AZ31镁合金激光-MIG复合焊接接头的可靠性,本文开展了10mm厚AZ31镁合金组织和疲劳性能研究,分析了复合焊接接头的组织、硬度及疲劳性能。结果表明:镁合金激光-MIG复合焊缝形貌呈V型,焊缝热影响区较小,焊缝区为细小的等轴晶组织,且电弧区晶粒大小大于激光区,焊接接头软化区小。镁合金激光-MIG复合焊接接头沿焊接方向疲劳性能呈现出"先减后增,而后再减"的变化规律。

To enhance the reliability of magnesium alloy Laser-MIG hybrid welding joints, the research on the microstmcture and fatigue performance of 10mm AZ31 Mg alloy Laser-MIG hybrid welding was carried out. The microstmcture, hardness and fatigue performance of the welded joints were analyzed. The results show that the weld morphology of magnesium alloy Laser-MIG hybrid welding presents the shape ＂V＂, the weld HAZ is smaller, the microstructure in weld zone contains fine equiaxed grains. The size of grains in the arc zone is bigger than that of the laser zone. The soften zone of the weld joint is small. The fatigue performance of magnesium alloy Laser-MIG hybrid welded joints along the direction of welding shows the changing role first decreasing and then increasing, last decreasing.