超声搅拌摩擦焊焊缝纹理面组织和性能研究

Study on Microstructure and Properties of Texture Surface on Ultrasonic Stirring Friction Welded Joints

对6061-T6铝合金板进行搅拌摩擦焊对接焊(friction stir welding,简称FSW),并在焊接中途加入20 k Hz超声辅助焊接(ultrasonic assisted friction stir welding,简称UAFSW),采用扫描电子显微镜(SEM)对比研究了UAFSW和FSW焊缝上表面带状纹理的宏观形貌、微观组织及力学性能。结果表明,超声的加入使得焊缝上表面纹理更加光滑细腻,组织晶粒更为均匀细小,耐腐蚀性变差并致使腐蚀后的金相组织宏观形貌色泽暗淡,SEM图中第二相整体排更具有一定方向性。显微硬度上,波峰处大于波谷处,最小值65.8 HV_(0.5)出现在前进侧,是母材区的52.2%,距离焊缝中心相同距离处UAFSW大于FSW。

The friction stir welding（ FSW） was carried out on 6061-T6 aluminum alloy plate,and20 k Hz ultrasonic assisted friction stir welding（ UAFSW） was added in half of welding. The macroscopic morphology,microstructure and mechanical properties of banding on the upper surface of UAFSW and FSW weld were studied by scanning electron microscopy（ SEM）. The results show that the surface texture of the weld was smoother and denser,the organization of grain was smaller. The corrosion resistance was deteriorated and the macro-morphology of the metallographic structure after corrosion was bleak. SEM second phase of the overall row had a certain direction. The micro-hardness was greater than the trough at the peak. The minimum value of 65. 8 HV0. 5 was 52. 2% in the base metal zone,while the distance from the weld center was greater than FSW at the same distance UAFSW.