铝-镁合金的超声振动强化搅拌摩擦焊试验研究*

研究铝镁异种合金的连接可拓宽轻量化结构的应用领域，具有重要的学术意义和工程实用价值。进行常规搅拌摩擦焊(Friction stir welding， FSW)和超声振动辅助搅拌摩擦焊(Ultrasonic vibration enhanced friction stir welding， UVeFSW)的对比试验，并对结果进行分析。试验结果表明超声的施加可以拓宽工艺参数窗口，改善焊缝表面的成形，减少缺陷，优化界面结构，细化均化晶粒，提高接头的力学性能。进行载荷测试后发现，超声的加入可以降低焊接所需载荷，这有利于降低设备体积。而温度场的测试则说明，超声波对于焊件有预热作用。

Experimental Investigation on Ultrasonic Vibration Enhanced FSW of Al-Mg Dissimilar Materials

Joining of aluminum-magnesium dissimilar alloys can broaden the application of lightweight structures,so it is of great scientific value and economic benefits.The comparison tests between conventional friction stir welding (FSW) and ultrasonic vibration enhanced friction stir welding (UVeFSW) are conducted,and the experimental results are analyzed.It shows that the exerted ultrasound can broaden the process-parameter window,improve the surface smooth of the weld,reduce the occurrence tendency of defects,optimize the Al/Mg interface structure,homogenize and refine grains,and improve the mechanical properties of the joints.The load tests demonstrate that the exerted ultrasound can lower the load required for welding so that it's benefit for reducing the equipment volume.The measured temperature illustrates that the ultrasound produces some preheating effect on the weldment.