Effects of Al2O3 platelet and VC additive on sintering and mechanical properties of WC-based composites by hot pressing

ABSTRACT Fully dense WC-Al2O3 platelet composites with VC additive were fabricated by hot-press sintering. Their mechanical properties and microstructure were examined. The contents of Al2O3 platelet (Al2O3pl) and VC were optimised. The fracture toughness of WC-based composites would be obviously improved with Al2O3pl addition. The defined addition of VC was beneficial for the densification and improved mechanical properties of the WC-based composites. The microstructure of the composites was fine, compact and homogeneous compared with the composites without VC addition. The range of fracture toughness of WC-Al2O3pl composites was 9.3–13.5 MPa m1/2. The flexural strength of the composites varied a little and the maximum was 1289 MPa when the content of Al2O3pl was 5 vol.-%, the content of VC was 0.5wt-%.