Wear mechanism of plasma-sprayed Cr 3C 2NiCr against TiO 2 coating

Abstract

The friction and wear performance of plasma-sprayed Cr 3C 2NiCr against TiO 2 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 C 3C 2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 TiO 2 layer at lower load, and plastic deformation, shear fracture and melting wear at higher load.