Investigation on structural, mechanical and tribological properties of plasma sprayed Al2O3-40% TiO2 coating

The present work deals with tribological investigation of Al2O3-40% TiO2 coating deposited using plasma spraying. The structural characterization of coating was done using Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and X-Ray Diffraction (XRD). The micro hardness was measured by vickers micro hardness tester whereas fracture toughness was determined by Indentation Fracture Toughness Test (IFT) method. The sliding wear tests were carried out at different test conditions involving simultaneous variation of load (P) ranging from 5 to 30 N and sliding velocity (V) ranging from 0.1 m/sec to 0.6 m/sec. The sliding wear rate increased with increasing parameter P × V and friction coefficient displayed minima at a load of 20 N and sliding velocity of 0.4 m/sec. The flash temperature showed the increasing trend with P × V parameter. The variation in coefficient of friction and wear rate with varying test conditions was associated with change in wear mechanism from plastic grooving to delamination of splats & splat fracture and formation & removal of tribo layer of Ti2O3 and Ti3O5 on worn surface.