Microstructure and properties investigation of B4C/Al composite materials fabricated 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. © 2024 Beijing University of Aeronautics and Astronautics (BUAA). All rights reserved.