Interface characteristics and reinforcement mechanism of large-size WC-18Co reinforced Fe-matrix composites

Abstract

WC-Co hard alloy has advantages of high hardness, high melting point and excellent wear resistance and thermal stability, its significant effect to the mechanical properties of metal matrix composites (MMCS). In order to obtain FMCS with excellent comprehensive properties, the influence of large-size WC-18Co particles on FMCS was studied. In this paper, WC-18Co/Fe composites were prepared by infiltration casting method. The phase composition, microstructure and interface characteristics of WC-18Co/Fe composites were studied. The residual stress, microhardness and wear resistance of WC-18Co/Fe composites were tested. The result shows that large-size WC-18Co particles have an effect of solid solution strengthening and dispersion strengthening. Nano-compounds and twins are produced in the transition layer, resulting in dislocation reinforcement of FMCS. The large-size WC-18Co particles generate residual compressive stress under the action of thermal stress. Elemental diffusion forms a special interface structure at the junction. The large-size WC-18Co particles improve the tribological properties of FMCS.