Wear resistance of WC particle reinforced copper matrix composites and the effect of porosity

The wear behavior of WC particle reinforced copper matrix composites has been determined with a pin-on-disk technique against a sintered SiC abrasive disk. The wear rate as a function of a normal wear stress and the composite porosity was investigated. Results have shown that up to a normal load of around 9 N (or 0.55 MPa pressure), the wear rate of fully dense Cu/WC (53 vol%) composites increases linearly with the applied pressure. Results also show that porosity in the Cu/WC composite increases wear. Surface pores, due to their non-load bearing characteristic, increase the effective contact wear stress. However, even with the effective stress accounted for, the pore containing composites still show a higher wear rate than the fully dense composite. Cracking of pore edges near the surface depending on the pore geometry and distribution as well as the transverse stress is responsible for such excess wear.