In order to achieve high-quality welded joint of spray-formed (SF) 7055 aluminum alloy (Sc element added) plate, the electrically-magnetically-assisted friction stir welding (EMAFSW) method was used in this investigation, and the plate was docked by changing the coil current of the rotating magnetic field generator. The effects of rotating magnetic field and different coil currents on the microstructure and mechanical properties of friction stir welds were studied by methods of optical microscope (OM), scanning electron microscope (SEM), electron backscatter diffraction (EBSD), high resolution transmission electron microscopy (HRTEM) and mechanical properties test. The results show that after applying the rotating electromagnetic field generated by 100 Hz current, and with the increase of coil current, the grain refinement of weld microstructure is obvious, the toughness and ultimate tensile strength of weld joint are improved, and the tensile fracture morphology shows more ductile fracture characteristics. This is due to the fact that the rotating magnetic field weakens the dislocation density and strain of the joint during the FSW process, but the magnetic field plays a role in strengthening the microstructure fine grain simultaneously. The results of this investigation will provide a new welding method for obtaining good cemented aluminum alloy joints, help to better understand the magnetoplastic mechanism, and expand the FSW process window.

中文翻译：

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一种通过旋转磁场改善喷射成型的 7055-T76（Sc 添加）铝合金 FSW 接头的塑性流动性和机械性能的新方法。


为了实现喷涂成型 （SF） 7055 铝合金（添加 Sc 元件）板的高质量焊接接头，本研究采用电磁辅助搅拌摩擦焊 （EMAFSW） 方法，并通过改变旋转磁场发生器的线圈电流对接板。通过光学显微镜 （OM）、扫描电子显微镜 （SEM）、电子背散射衍射 （EBSD）、高分辨率透射电子显微镜 （HRTEM） 和力学性能测试等方法研究了旋转磁场和不同线圈电流对搅拌摩擦焊缝微观组织和力学性能的影响。结果表明：施加100Hz电流产生的旋转电磁场后，随着线圈电流的增加，焊缝组织晶粒细化明显，焊缝接头的韧性和极限抗拉强度得到提高，拉伸断裂形貌表现出更多的延展性断裂特性。这是由于旋转磁场在 FSW 过程中削弱了接头的位错密度和应变，但磁场同时起到了强化微观组织细晶粒的作用。本研究结果将为获得良好的胶合铝合金接头提供一种新的焊接方法，有助于更好地理解磁塑性机制，并扩大 FSW 工艺窗口。