Magnetic pulse-assisted semi-solid brazing of Cu/Al tubes: finite element simulation and experimental analysis

Abstract This study employs magnetic pulse-assisted semi-solid brazing (MPASSB) technology to join Cu/Al tubes. Through finite element simulation, an in-depth analysis of the clamping and brazing forming processes within the MPASSB method is conducted. Additionally, by examining the microstructure of the joint, the study explores the mechanism of filler metal shear rheology in the formation of joint defects, oxide removal, and metallurgical bonding. The results demonstrate that during the brazing forming process, the high-velocity shear rheology of the filler metal plays a critical role in promoting the detachment of oxides from the interface and facilitating the diffusion of joint elements. The continuous flow of the filler metal is identified as key to effective oxide removal. Notably, the MPASSB method has an extremely short forming time yet can achieve metallurgical bonding at the interface without generating brittle intermetallic compounds (IMCs) between Cu/Al tubes. Mechanical performance testing reveals that the extent of oxide removal at the interface is a decisive factor affecting the joint's mechanical properties. The maximum shear strength of the joint is 78.8 MPa; however, when an oxide layer is present at the interface, the shear strength drops to 53.3 MPa, with fracture occurring at the oxide layer.