Influence of MoB₂ and ZrB₂ ceramic particles on the microstructure, electrical conductivity, and mechanical properties of copper matrix composites

Boride ceramics are potential reinforcements for copper matrix composites due to their excellent mechanical and electrical properties. The synergistic effect of dual-phase and dual-scale boride can enhance both the wear resistance and electrical conductivity of composites. In this paper, MoB₂-ZrB₂/Cu hybrid composites with varying boride contents were prepared using spark plasma sintering. The microstructure and phase composition of these composites were characterized. The hardness, compressive strength, and tribological properties were measured. The results indicate that ZrB₂ microparticles and MoB₂ nanoparticles were dispersed within the Cu matrix. Additionally, the composites exhibited desirable interfacial bonding between the boride particles and the Cu matrix. The “hybrid effect” of the dual-phase borides enhanced the electrical conductivity, mechanical, and tribological properties of the MoB₂-ZrB₂/Cu composites. The wear mechanism of the MoB₂-ZrB₂/Cu composites involved a combination of abrasive wear, oxidation wear, and fatigue wear.