Abstract: By adding Ni interlayers to steel plates, the reliable connections between 6061T6 aluminum alloy plates and 08Al steel plates were successfully realized, and the mechanical properties of aluminum/steel spot welding joints were significantly improved. The results show that the thickness and distribution of Ni intermediate layers on steel plates may be controlled by using the prefabricated Ni intermediate layer processes, and the formation of Al-Fe brittle intermetallic compounds may be reduced. Compared with adding Ni foil intermediate layers directly, the prefabricated Ni intermediate layer processes may effectively increase the nugget diameter. The maximum tensile sheer force of aluminum/steel resistance spot welding joints with laser cladding Ni layer on steel plates is 35.5% higher than that without intermediate layers.

Key words: aluminum/steel resistance spot welding, 6061T6 aluminum alloy, interlayer, first-principle calculation

摘要： 通过在钢板上添加Ni中间层，成功实现了6061T6铝合金板与08Al钢板的可靠连接，显著提高了铝/钢点焊接头的力学性能。研究结果显示，采用预制Ni中间层工艺可控制Ni中间层在钢板上的厚度与分布，减少Al-Fe脆性金属间化合物的形成；相较于直接添加Ni箔中间层，预制Ni中间层工艺能有效增大焊核直径;钢板上激光熔覆Ni层的铝/钢电阻点焊接头最大拉剪力较高，比无中间层的接头最大拉剪力增大了35.5%。 

关键词: 铝/钢电阻点焊, 6061T6铝合金, 中间层, 第一性原理计算