铝-钢堆焊-搅拌摩擦复合焊接头特性分析

针对铝-钢异种金属焊接缺陷多、效率低等问题，提出一种堆焊-搅拌摩擦复合焊接方法，即采用旁路分流电弧焊先在钢板上堆敷铝合金，再采用搅拌摩擦焊进行铝合金堆敷层和铝合金母材的搭接焊，得到在铝-铝界面呈现典型搅拌摩擦焊“洋葱圆环”状结合的铝-铝-钢复合过渡接头. 针对典型焊缝进行铝-钢异种金属接头的组织结构分析.结果表明，搅拌摩擦焊可以有效消除铝合金堆敷层中存在的气孔等缺陷，并实现金属界面层的减薄. 对铝钢结合界面进行EDS扫描，在堆敷铝合金侧可以观察到呈树枝状的Fe相扩散和呈网状的不均匀Si相扩散，结合XRD(X-ray diffraction)分析其主要成分为Al₅Fe₂Zn_0.4和Al₇Fe₃Si_0.3. 对接头试样进行拉伸试验，拉伸接头断裂在铝合金母材处，达到铝合金母材强度的100%，符合接头应用的力学指标.

Aluminum-steel overlay-stir friction composite welded joint characteristics analysis

For aluminum and steel dissimilar metal welding defects, low efficiency and other issues, proposed a surfacing-stir friction composite welding method, that is, bypass shunt arc welding on the steel plate first, and then using stir friction welding for aluminum alloy surfacing layer and aluminum alloy base material lap welding, get in the aluminum-aluminum interface showing typical stir friction welding “onion ring” Combined aluminium-aluminium-steel composite transition joint. The results show that stir friction welding can effectively eliminate the defects such as porosity in the aluminium alloy deposit layer and achieve the thinning of the metal interface layer. EDS scanning of the aluminium-steel bonding interface shows that the dendritic Fe phase diffusion and the mesh-like inhomogeneous Si phase diffusion can be observed on the aluminium alloy side of the pile. The main components of the joint are Al₅Fe₂Zn_0.4 and Al₇Fe₃Si_0.3 when combined with XRD (X-ray diffraction) analysis. The tensile joint fractured at the base material and reached 100% of the strength of the aluminium alloy base material, meeting the mechanical specifications for the joint application.