Tribological Properties of Plasma-Sprayed Cr_3C_2-NiCr Coating without or with Electroless Plated Ni

Tribological properties of plasma-sprayed Cr3C2-NiCr coatings without or with electroless plated Ni were investigated, and the worn surfaces were analyzed by employing SEM, XRD and XPS. It was found that both the self-mated rubbing pairs consisting of the Cr3C2-NiCr coating and the Cr3C2-NiCr coating electroless plated with Ni displayed higher friction coefficient and wear coefficient. However, The rubbing pair of the Cr3C2-NiCr coating electroless plated with Ni against the Cr3C2-NiCr coating had a friction coefficient of 0.12 and a wear coefficient close to 10-6mm3(Nm)-1 even if under dry sliding. The improvement in tribological properties could be attributed to that the wear mechanism of Cr3C2-NiCr coating transformed to particle fracturing along pores and microcracks from the intensive spalling along splat interfaces.