Synergistic effect of pre-oxidation and hot-pressing temperatures on microstructure and mechanical properties of B₄C/7055Al composite

For boron carbide (B₄C) particle-reinforced aluminum matrix composites, oxidation treatment of B₄C is an important method to control interfacial reactions. However, the influence of the pre-oxidation process on the mechanical properties of composites prepared by powder metallurgy technology at different hot-pressing temperatures remains unclear. This study focuses on investigating the effect of pre-oxidation treatment on the mechanical properties of an ultra-high-strength B₄C/7055Al composite prepared at different hot-pressing temperatures. A B₂O₃ layer was successfully formed on the surface of B₄C by means of pre-oxidation. Experimental results indicate that, compared to B₄C/7055Al composites without a B₂O₃ layer, the B₂O₃ layer exerts no significant influence on the mechanical properties of the composites at low hot-press sintering temperatures (500 °C). However, when the hot pressing temperature is increased to 590 °C, the B₂O₃ layer effectively inhibits the interfacial reaction, thereby significantly improving the strength. This study aims to provide guidance for controlling interfacial reactions in B₄C/7xxxAl composites and optimizing the powder metallurgy preparation process for such composites.