Electromagnetic stirring control for resistance spot welding of SiCp/Al composites

Abstract Metal matrix composites (MMCs) have broad application prospects in high-end manufacturing fields. However, as typical MMCs, SiCp/Al composites have poor weldability due to the appearance of brittle phase, crack defects, and segregation phenomenon in the fusion welding process. Hence, this paper provides a magnetically assisted resistance spot welding (MA-RSW) method to achieve the reliable welding of SiCp/Al composites. The experimental results show that the MA-RSW technology can significantly extend the weld lobe by increasing the nugget diameter and decreasing the weld penetration, avoid the appearance of the acicular Al4C3, eliminate weld defects, and homogenize the distribution of the strengthening phase. This facilitates the transformation of the fracture mode from interfacial fracture (IF) to partial thickness fracture (PTF) at low welding current and to button pull (BP) at high welding current in lap-shear tests. Therefore, the weld strength, ductility, and energy absorption ability are greatly improved.