Advancing the mechanical properties of Si/B co-doped boron carbide through TiB2 reinforcement

Abstract

Boron carbide experiences glass-like brittle behavior when subjected to high shear stresses due to stress-induced amorphization. Strategies to mitigate amorphization have primarily focused on Si/B co-doping. However, the overall mechanical properties of Si/B co-doped boron carbide are unknown. Here, we delivered a comprehensive report on the mechanical properties of Si/B co-doped boron carbide; and proposed an effective strategy to improve the mechanical properties through TiB2 reinforcement. Vickers hardness of 25.0 GPa, indentation toughness of 2.1 MPa·m0.5, Young’s modulus of 430 GPa, and flexural strength of 338 MPa were measured for Si/B co-doped boron carbide. The reinforcement with TiB2 increased the overall mechanical properties to 26.6 GPa for hardness, 2.3 MPa·m0.5 for indentation toughness, and 410 MPa for flexural strength. The improvements were attributed to the combined effects of grain size refinement and crack propagation alteration due to TiB2 addition.