Macro-contamination induced defects in ready to press WC-Co grade powder

Macro-contamination of ready to press (RTP) powders for the production of hard-metal components can result in catastrophic failure of the final sintered object. However, correctly identifying the root cause of the failure is often difficult due to the low concentration of the contaminating species, and the potential for that species to be masked via binder dilution. Investigation of Mo doping into standard RTP powder, followed by sintering tests over a broad temperature regime has allowed for a model to be constructed for the formation of surface pits. Additional work with an assortment of contaminant species doped into a standard RTP powder, has allowed for the establishment of contaminant categories that yield similar sintered defects. Finally, a method for identifying unknown contaminant species has been proposed, in the case where the contaminant has an appreciable physical size.