Effect of WC mass fraction on the microstructure and frictional wear properties of WC/Fe matrix composites

WC/Fe matrix composites with mass fractions of 30–50 wt% were prepared by gravity casting and infiltration, and the phase composition, microstructure, friction and wear properties of the composites were studied. In addition, the mechanism of the effect of the change of WC mass fraction on the structural evolution and wear properties of the composites was particularly investigated. The results show that the composites are mainly composed of WC, α-Fe, W ₂C, Fe ₆W ₆C, and M ₇C ₃ phases. With the increase of WC mass fraction, the microstructure of the composite shows different results, WC particles start to dissolve under the action of high temperature melt, W elements solidly dissolve into the matrix and precipitate into fishbone structure carbide. As the content of WC particles in the prefabricated body increases, the C atoms around the WC particles react with the dissolved W atoms, and due to the cooling of the metal liquid, the energy transferred between the WC and the metal liquid does not make it melt completely before solidification occurs, and the metallurgical reaction between the WC particles and the substrate occurs and produces a dense interface. The WC/Fe matrix composites showed a trend of increasing and then decreasing with the increase of WC content and friction coefficients of 0.36, 0.52, and 0.26. The wear rates were 1.52(mm ³/N-m) × 10 ⁻⁵, 1.24(mm ³/N-m) × 10 ⁻⁵, and 1.57(mm ³/N-m) × 10 ⁻⁵, which showed the opposite trend with the friction coefficients, and the wear rates were compared with the morphology. When the composite was added with 40% WC, the wear rate increased by 27% compared with other parameters. It shows that it has good wear resistance.