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研究Al-Mg-Mn-Sc-Zr合金的焊接工艺和焊接接头组织和性能。采用搅拌摩擦焊(FSW)和氩弧焊(TIG)2种焊接工艺对该合金的热轧和冷轧-退火2种使用态板材进行焊接。采用比较研究的方法测定和研究焊接接头的力学性能和显微组织,利用光学显微镜和透射电子显微镜研究焊缝的显微组织和力学性能之间的关系。结果表明,与基材相比,Al-Mg-Mn-Sc-Zr合金的热轧和冷轧-退火板材的FSW和TIG焊接接头的强度均下降,但FSW焊接系数高于TIG焊接系数。这是因为FSW焊接接头焊核区亚结构强化的丧失和Al3(Sc,Zr)的析出强化作用的极少量丧失,而TIG焊焊接接头的软化主要原因是其形变强化的完全丧失和Al3(Sc,Zr)的析出强化作用的大部分丧失,且搅拌摩擦焊焊核区晶粒比TIG焊的焊缝区晶粒更细小。
Study of Al-Mg-Mn-Sc-Zr alloy welding process and weld joint organization and properties. Two kinds of welding processes, friction stir welding (FSW) and argon arc welding (TIG), were used to weld the hot rolled and cold rolled annealed alloys. The mechanical properties and microstructure of the welded joint were measured and studied by comparative method. The relationship between the microstructure and mechanical properties of the welded joint was studied by optical microscope and transmission electron microscope. The results show that the strength of FSW and TIG welded joints of hot-rolled and cold-rolled-annealed Al-Mg-Mn-Sc-Zr alloys are lower than that of the substrate, but the FSW welding coefficient is higher than the TIG welding coefficient. This is attributed to the loss of substructure strengthening and the minimal precipitation of Al3 (Sc, Zr) in the weld nugget zone of FSW welded joints, whereas the softening of TIG welded joints is mainly due to the complete loss of deformation strengthening and the loss of Al3 (Sc , Zr) loss of most of the precipitation strengthening, and friction stir welding nuclei grain than TIG welding weld grain finer.