Magnetically assisted resistance spot welding: a comprehensive review

Magnetically assisted resistance spot welding (MARSW) is an advanced welding technique that integrates traditional resistance spot welding (RSW) with external magnetic fields to enhance weld quality and efficiency. This review provides a comprehensive analysis of MARSW, emphasizing its mechanisms and benefits over conventional RSW. Key findings include the significant role of Lorentz forces in improving joint strength, refining microstructure, and reducing defects such as shrinkage cavities and porosities. MARSW has demonstrated the capability to increase nugget diameter by up to 15% compared to traditional RSW, resulting in enhanced mechanical properties and failure mode transformation from interfacial fracture (IF) to button pull fracture (BPF). The paper also highlights the influence of magnetic fields on heat generation and material flow, which leads to changes in joint shape, size, and microhardness. Comparative analysis of MARSW and RSW processes for both similar and dissimilar materials reveals superior performance of MARSW in welding high-strength steels and lightweight alloys, particularly under challenging conditions. In addition, this review evaluates experimental methods and numerical simulations used to study the MARSW process, providing insights into optimizing magnetic field parameters for improved reliability and performance. Challenges, including electrode wear and integration with robotic systems, are discussed, along with future research directions to expand MARSW applications in modern industries.