Multicomponent carbides reinforced tungsten matrix composites and their mechanical properties

Abstract Although tungsten (W) is widely employed at high temperatures, its inherent brittleness below the ductile‐to‐brittle transition temperature (DBTT) restricts its practical applications. This study aims to enhance the mechanical properties of W by reinforcing it with multicomponent carbides. A series of W‐matrix composites with binary and ternary carbides were synthesized via in situ reactions of metal oxides (TiO 2 , ZrO 2 , HfO 2 ) and tungsten carbide (WC), followed by spark plasma sintering (SPS). Thermodynamic calculations and XRD analysis reveal a complete reaction during the synthesis process. The sintered W/carbide composites show relative densities > 95%, uniform carbide phase distribution, small grain sizes, and improved mechanical properties. Among the prepared samples, W/(Ti, Hf)C composite showed optimal mechanical properties: flexural strength of 1166 ± 230 MPa, fracture toughness of 13.41 ± 1.42 MPa·m 1/2 , and Vickers hardness of 10.15 ± 0.12 GPa. SEM observations revealed that the fracture modes of the W/carbide composites varied with carbide phase composition. The W/monocarbide composites show a single fracture mode, transgranular or intergranular. In contrast, both W/(Ti, Zr)C composite and W/(Ti, Hf)C composite exhibit a mixed fracture mode of intergranular and transgranular, indicating changing the metal element composition in the carbide phase can adjust the interface bonding strength, consequently affecting the fracture mode and the mechanical properties of the W/carbide composites.