Effect of Al2O3 ceramic binder on mechanical and microstructure properties of spark plasma sintered WC-Co cermets

Abstract

This study investigates how the partial replacement of Co with Al2O3 ceramic binder has an effect on the sintering behaviour, microstructure, and final mechanical properties of WC-Co cermets via spark plasma sintering. To examine this, three batches (WC-6wt%Co, WC-3wt%Co-3wt%Al2O3, and WC-6wt%Al2O3) were mixed through high energy ball mill, and sintering was carried out at temperatures of 1350°C and 1600°C. The results showed nearly full dense WC-Co cermets at different temperatures. It was shown that WC-6wt%Al2O3, in comparison to reference WC-6wt%Co cermet, not only led to the rise in sintering temperature from 1350°C to 1600°C, but also reduced its strength and toughness. But replacing some part of Co with alumina (WC-3wt%Co-3wt%Al2O3) exhibited the combination of high strength (1095MPa), hardness (17.62GPa), and fracture toughness (19.46MPa·m1/2).