Tribological properties of copper alloy-based composites reinforced with tungsten carbide particles

In today's oil/gas industry, use of drill bits in harsh drilling conditions is demanding the pursuit of innovated materials for higher performance and efficiency. This paper describes the successful application of indium doping in tungsten carbide particle reinforced Cu-alloy composites (Cu-alloy/WCp) for PDC (polycrystalline diamond compact) drill bit body in maximizing wear resistance with relatively low friction coefficient. The wear resistance of Cu-alloy/WCp composites with novel indium dopant is investigated by nano-scratch test and pin-on-disc wear test, and is compared with that of conventional materials. Doped indium improved the overall wear performance by 38% under a 10 N normal load with up to a sliding distance of 3000 m due mainly to the solid-solution strengthening effect of indium in the Cu-alloy matrix. The combination of ploughing in Cu-alloy matrix, and brittle fracture and fragmentation of WC reinforced particles appear to be the main wear mechanisms of Cu-alloy/WCp composites under macro scale sliding wear.

Research highlights
► Processed Cu-based composites reinforced with tungsten carbide particles using infiltration technique for earth-boring drill bit applications.
► Improved hardness, scratch, and wear resistance of the Cu-based alloy/tungsten carbide composites by doping with a small amount of indium.
► Indium addition improved the strength and wear resistance of the Cu-based alloy matrix by solid-solution hardening mechanism.