Effects of vanadium and titanium addition on the densification, microstructure and mechanical properties of WC-Co cermets

Abstract

WC-Co cermets containing Ti and V metallic powders were prepared by ultra-fast microwave heating process. The mixing of WC-5wt%Co containing 5 wt% concentrations of Ti and V was performed by a high-energy mixer mill in ethanol media for 10 min. A fast microwave sintering process was carried out at temperatures of 1400, 1500 and 1600 °C with an average heating rate of 40 °C/min in a graphite bed without any soaking time. The XRD patterns showed WC, TiC and VC crystalline phases as reaction products. The FESEM images demonstrated uniform distribution of formed carbides in the microstructure of WC based cermet. By increasing the sintering temperature to 1600 °C, almost fully dense samples were obtained in both series of composites containing Ti and V. The maximum bending strength (981 ± 10 MPa), hardness (24.7 ± 0.1 GPa) and fracture toughness (8.6 ± 0.1) were measured for WC-Co-Ti hard metal at sintering temperature of 1600 °C.