Fracture toughness evaluation of WC–10 wt% Co hardmetal sintered under high pressure and high temperature

Abstract

This work focused on fracture toughness studies of WC-10 wt% Co hardmetal fabricated through the high pressure/high-temperature technique. A powder mixture of WC-10 wt% Co was sintered at 1500-1900°C under a pressure of 7.7 GPa for 2 and 3 min. Vickers hardness test at two different loads of 15 and 30 kgf was done and fracture toughness of the sintered bodies was measured using the indentation method to obtain the effect of sintering parameters. Structural analyses were also performed via X-ray diffraction to investigate structure-related properties. Full density was achieved for high sintering temperature along with abnormal grain growth that reduced hardness. High hardness was observed ranging from 1200 to 1670 HV and fracture toughness increased with increasing sintering temperature up to the highest value of 17.85 MPa/m 1/2 .