MECHANICAL PROPERTIES OF WC-25/17/12Co CERMETS SPRAYED BY HVOF AND CGS

After having successfully produced WC-25Co, WC-17Co and WC-12Co coatings by Cold Gas Spraying onto Al7075-T6 and carbon steel substrates their mechanical properties are studied and compared in this work to understand the advantages when confronted with conventional thermal spray techniques, i.e. HVOF. The addition of more ductile Co binder to the composite makes deposition by CGS easier while conferring proprieties that differ to those achieved with a WC-Co cermet with a lower content of ductile binder. WC-Co cermets are used for wear-resistant parts due to their combination of mechanical and electrochemical properties. Mechanical tests were performed and compared in this work. The bonding strength of the coatings was measured by adherence tests; their sliding and abrasive wear resistances, fracture toughness and others were studied.