Role of Tungsten Carbide Reinforcement on Alumina Matrix Composites Fabricated by Powder Injection Moulding

Abstract

In this work, properties of tungsten carbide (WC) particulate reinforced alumina matrix composites fabricated by powder injection moulding (PIM) technology were reported. The 90 wt% of Al2O3 and 10 wt% of WC powders were mixed with a composite binder, composed of 85 wt% polyethylene glycol (PEG) and 15 wt% polyvinyl butyral (PVB). Feedstocks of alumina and alumina-tungsten carbide composites having powder loading from 44 to 52 vol% were prepared and injected into a mould of rectangular shape. The binders in the mouldings were leached by water and then thermally debinded prior to sintering at 1600 °C for 2 hours in argon atmosphere. Strength, Density, hardness and density of the alumina and alumina composites’ bodies were compared and reported. It was found that the properties of sintered specimens, both Al2O3 and Al2O3/WC composites, increased with increasing powder loadings. The properties enhancement was also presented in the WC reinforced alumina composites. The composite of 52 vol% powder loading had flexural strength and hardness of 253.8 MPa and 12.5 GPa, respectively.