High Temperature Sliding Wear Behaviour of Ti6Al4V Thermal Oxidised for Different Oxidation Durations

Most of the available literature discusses the room temperature tribological behaviour of thermal oxidation (TO) treated Ti6Al4V. There is only a few literature on the high temperature wear behaviour of TO-treated Ti6Al4V. Oxidation duration plays an important role in harnessing the benefit of solid solution strengthening from oxygen. No data is available on the effect of TO duration on the high temperature wear behaviour of TO-treated Ti6Al4V. Therefore, in the present investigation, Ti6Al4V was thermally oxidised at the optimised temperature of 650 °C for different oxidation duration of 16 h, 24 h, and 48 h, and its sliding wear behaviour was investigated at room temperature (RT) and 450 °C. Sliding wear studies were carried out using the ball on disk configuration against alumina as the counter body in dry condition. Wear characterisation was done using an optical profilometer, a scanning electron microscope, and a Raman spectrometer. Results showed that TO-treated samples showed reduced wear volume loss, i.e. improved wear resistance at RT and 450 °C. Wear volume loss was the least for TO-treated samples oxidised for 16 h, 90% less than that of untreated coupons at RT and 77% less at 450 °C. TO duration of 48 h degraded wear performance, increasing wear volume loss due to oxide failure at 450 °C. The morphological study indicated an abrasive mechanism for untreated samples at RT and oxidation and delamination wear at 450 °C, while TO-treated samples showed a delamination mechanism with fracture of the TiO2 layer. Graphical Abstract: [Figure not available: see fulltext.].