Kang Kexin, Liu Yibo, Li Junzhao, Liu Chao, Zhen Zuyang, Wang Yaxin, Sun Qingjie
Shandong Provincial Key Laboratory of Special Welding Technology, Harbin Institute of Technology at Weihai, No.2 West Wenhua Road, Weihai 264209, China.
State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, No.92 West Dazhi Street, Harbin 150001, China.
Materials (Basel). 2020 Aug 14;13(16):3601. doi: 10.3390/ma13163601.
The 6061 aluminum alloy and 304 stainless steel were welded by hybrid cold metal transfer (CMT) welding with external axial magnetic field. The effects of magnetic intensity and frequency on joint microstructure and mechanical properties were studied. It was found that the magnetic field can promote the spreading of aluminum weld metal on the steel surface and thus increase the bonding area of Al/steel butt joint. The welding process stability improved, while the wetting behavior worsened with the introduction of alternating frequencies. The thickness of the intermetallic compound (IMC) layer at Al/steel interface was reduced to 3 μm with the coil current of 2 A. The application of the magnetic field promoted the aggregation of Si atoms at the interface and inhibited the formation of brittle (Al, Si)Fe phase. The fracture paths were transformed from (Al, Si)Fe layer to AlFeSi layer with the application of the magnetic field. The maximum tensile strength reached 130.2 MPa, an increase of 61.6% in comparison to the normal CMT process.
采用外加轴向磁场的混合冷金属过渡（CMT）焊接工艺对6061铝合金和304不锈钢进行焊接。研究了磁场强度和频率对接头微观组织和力学性能的影响。结果表明，磁场可促进铝焊接金属在钢表面的铺展，从而增加铝/钢对接接头的结合面积。随着交变频率的引入，焊接过程稳定性提高，但润湿性变差。当线圈电流为2 A时，铝/钢界面金属间化合物（IMC）层的厚度减小至3μm。磁场的施加促进了界面处Si原子的聚集，抑制了脆性（Al，Si）Fe相的形成。施加磁场后，断裂路径从（Al，Si）Fe层转变为AlFeSi层。最大抗拉强度达到130.2 MPa，与常规CMT工艺相比提高了61.6%。
