Evaluation of mechanical and frictional properties of CuO added MgO/ZTA ceramics

Abstract

The focus of the present work is to investigate the tribological effect of adding CuO as solid lubricant in MgO/ZTA (Magnesia-Zirconia Toughened Alumina) ceramics. Different wt% of CuO (0-5 wt%) have been added in MgO/ZTA ceramics using powder metallurgy process route to study the change in mechanical properties i.e., hardness, fracture toughness and flexural strength, as well as the tribological properties i.e., coefficient of friction (COF) and wear depth, against corundum alumina balls. The addition of CuO shows significant improvement in tribological properties but a diminishment of the mechanical properties. A significant reduction of 53.45% in COF with minimum wear depth is achieved with the addition of 1.5 wt% CuO inside the MgO/ZTA matrix. The improvement in COF and specific wear rate of the composite is observed with increasing sliding velocity due to the presence of uniform patchy layer along with a glossy surface on the wear track. The formation of patchy layer is enhanced with an increase in sliding velocity due to high squeezing and smearing of wear debris. A significant increment in specific wear rate is observed with increasing load due to the delamination process prevailing at the contact surfaces.