Tribological behaviour of thermally sprayed ceramic coating at high temperature

Abstract

The present study focuses on the wear behaviour of a Al2O3-13 wt.% TiO2 composite coating deposited by a flame spray method for high temperature applications. The microstructural characterisation and mechanical properties, such as microhardness and surface roughness were studied. In addition, the porosity characterisation of the coating was studied through quantitative image analysis using the software Image_J. The tribological testing of the deposited coating was performed at four different temperatures, i.e., 25 °C, 100 °C, 200 °C and 400 °C, using a high temperature pin-on-disk tribometer. The specific wear rate decreases with an increase in temperature of upto 200 °C and then increases slightly at 400 °C, whereas the coefficient of friction declines with temperature rise. The dominant wear mechanism is three-body abrasion and brittle fracture followed by erosion and oxidation wear at high temperatures.