High Temperature Strength of WC-Co Base Cemented Carbide Having Highly Oriented Plate-Like Triangular Prismatic WC Grains.

Abstract

We have already reported that room temperature fracture toughness of our newly developed WC-Co base cemented carbide (alloy) having highly oriented plate-like triangular prismatic WC grains are larger than that of the conventional alloy at an identical hardness of alloy. In this study, high temperature mechanical properties such as transverse-rupture strength (TRS), creep-rupture time, etc., of the new alloy at 1273 K were clarified to be superior than those of the conventional alloy: TRS of the new alloy was higher by 10-20% and creep rupture time was longer by 50-100% than the conventional alloy. The cause for such superiority was attributed to the difficulty in the generation and propagation of stable cracks in the new alloy compared with in the conventional alloy, probably due to more rigid skeleton of WC which were generated and grown by the reaction of CoxWyCz with graphite.