Fabrication of B4C-AlSi10Mg heterogeneous joint structure via L-PBF process

Metal-ceramic bonding structures are widely used in fields such as electronics, energy, and protection. Laser powder bed fusion (LPBF) has excellent forming efficiency and the ability to manufacture complex structures, which can compensate for the shortcomings of traditional joining methods in terms of process complexity and bonding efficiency. However, due to significant differences in physical properties between metals and ceramics, as well as the rapid and complex thermal evolution during the LPBF process, significant residual stresses are generated at the interface during the joining process, leading to joint failure. To address this issue, effective control of interfacial residual stress was achieved through scanning strategy optimization and a laser energy gradient input method based on varying powder layer thickness, resulting in efficient and crack-free joining between B 4 C and AlSi10Mg. To elucidate the in-situ reaction mechanism at the interface during the LPBF forming process, characterization and analysis of the interfacial reaction products were conducted. The results indicate that the reaction mechanism at the B 4 C/AlSi10Mg interface follows the “dissolution-reaction” mechanism, and a B 4 C/α-AlB 12 /Al 3 BC + Al 4 C 3 /Al composite interfacial structure is formed. Combined with phase diagrams and heterogeneous nucleation theory, the in-situ reaction process at the interface was revealed. The average apparent interfacial shear strength of the bonding interface was measured to be 17.76 MPa through compression shear testing of the B 4 C-AlSi10Mg heterogeneous joint structure.