The microstructure and mechanical properties of TiC-reinforced W-matrix composites prepared by spark plasma sintering

Abstract

W-(1 wt%, 3 wt%, 10 wt%)TiC composites with low density and good mechanical properties were successfully fabricated by high-energy ball milling and spark plasma sintering. The morphologies and the microstructure evolution of the composites were investigated. The mechanical properties, including microhardness and compressive strength, were evaluated. The results indicate that the addition of TiC can effectively inhibit the growth of W grains and plays a role in strengthening dispersion. With increasing TiC content, the W grain size decreased from (W-1wt%TiC) 5.32 μm to (W-10wt%TiC) 0.36 μm, and the reinforcement phase gradually changed from a granular spherical morphology to a continuous network structure morphology. A variety of second phases, such as TiC, Ti, WC and W2C, appeared in the W-TiC composites, and most of these were uniformly distributed on the W grain boundaries. Analysis indicated that TiW formed a coherent interface, and TiC-W and W2C-W formed incoherent interfaces. The grain refinement and the formation of incoherent interfaces can effectively improve the microhardness and compression strength of the composite. The Vickers microhardness and ultimate compressive strength of the W-10%TiC composite reached 962.43 HV and 2511 MPa, respectively. Meanwhile, the density of the composite was only 14.42 g/cm3.