Wear mechanism of plasma-sprayed Cr3C2-NiCr against TiO2 coating

The friction and wear performance of plasma-sprayed Cr3C2-NiCr against TiO2 coating was investigated with a block-on-ring arrangement at different sliding speeds and loads. Furthermore, the morphologies, elements, phases and element valences of the worn surface and debris were observed, examined and analysed employing scanning electron microscopy, energy disperse spectrum, X-ray diffraction and X-ray photoelectron spectrometer, respectively. It was found that the friction coefficient decreased with increase in loads and sliding speeds. However, the exponent of load against wear rate of the C3C2-NiCr coating appeared as two values on changing from the lower to higher load. The wear mechanism of the coating was explained in terms of fatigue-induced detachment of transferred TiO2 layer at lower load, and plastic deformation, shear fracture and melting wear at higher load. (C) 1997 Elsevier Science S.A.