基于Ti中间层的AZ31镁合金/6061铝合金电阻点焊研究

Research on Resistance Spot Welding of AZ31 Magnesium Alloy/6061 Aluminum Alloy Based on Ti Interlayer

摘要:

通过添加钛箔中间层,研究了镁/铝合金异种金属电阻搭接接头的微观组织与力学性能。研究结果表明,添加0.2mm厚度钛箔中间层可以大幅提高镁/铝异种金属电阻点焊接头的结合强度,接头的最大拉剪力随焊接电流的增大先增大后减小；当焊接电流为14kA时,最大拉剪力达到最大为2.2kN。铝钛界面处有TiAl₃生成,接头断裂在镁侧热影响区上,经过换算接头的剪切强度能够达到156MPa。通过SEM和EDS分析,添加钛中间层阻断了镁合金和铝合金的相互扩散,钛中间层阻碍了Mg-Al金属间化合物的生成,从而大大提高接头的结合强度。

Abstract:

The microstructure and mechanical properties of Mg/Al alloy dissimilar metal resistance lap joints were studied by adding an interlayer of titanium foil. The research results show that adding a 0.2mm thick titanium interlayer can greatly increase the strength of Mg/Al dissimilar metal resistance spot welding joints. The maximum tensile shear force of the joint first increases and then decreases with the increase of welding current.; The maximum tensile shear force reaches the maximum of 2.2kN while the welding current is 14kA. TiAl3 is formed at the aluminum-titanium interface, and the joint fractures in the heat-affected zone on the magnesium side. After conversion, the shear strength of the joint can reach 156MPa. Through SEM and EDS analysis, the addition of a titanium interlayer blocks the mutual diffusion of magnesium alloy and aluminum alloy, and the titanium interlayer hinders the formation of Mg-Al intermetallic compounds, thereby greatly improving the bonding strength of the joint.