Microstructure and properties investigation of B₄C/Al composite materialsfabricated by selective laser melting

In order to solve the problems of uneven distribution of B₄C particles, agglomeration and violent reaction with Al matrix during the preparation of B₄C/Al composites. In this paper, B₄C/Al composites were prepared by selective laser melting method. The effects of laser power and Ti elements on microstructure and mechanical properties of B₄C/Al composites were studied. The results show that the density of B₄C/Al composites increases first and then decreases with the increase of laser power, and reaches the maximum density of 94.1% at 240 W. During the preparation process, B₄C particles are prone to interfacial reaction with Al matrix and increase with the increase of laser power, resulting in brittle phases and micro-cracks of Al₃BC and Al₃B₄₈C₂, resulting in decreased interfacial bonding properties. The density of B₄C/Al composite with Ti increases to 95.2%, the resulting interface products TiC and TiB₂ can effectively inhibit the interface reaction, and the interface is clear and complete with high bonding properties. The tensile strength and elongation of the composite are increased by 41% and 49.3%, respectively, and the tensile fracture mode changes from brittle fracture to ductile fracture.