Effects of TaC and TiC Addition on the Interaction between Liquid Copper and WC-Co Alloys

Abstract

Effects of carbide additives on the interaction between liquid copper and WC-Co alloys containing 20% Co have been studied at 1120°C by means of EPMA and optical microscopy.Addition of TaC or TiC checked the wetting of liquid copper on cemented carbide and the structures of diffusion layers were influenced markedly by the carbide addition with a more pronounced effect for TiC. Thus, the development of cobalt solid solution at the liquid copper/cemented carbide interface was checked by the carbide additives. These findings have been successfully interpreted as due to the poor wettability of liquid copper and also of cobalt solid solution to TaC and TiC.