Evolution of wear debris morphology during dry sliding of Ti–6Al–4V against SS316L under ambient and vacuum conditions

Abstract

For a given tribo system one of the methods to evaluate wear mechanism is to study the evolution of the wear debris. Environmental conditions alter the wear mechanism. In the present study, Ti–6Al–4V pins of 6.6 mm diameter were slid against a SS316L disc under ambient and vacuum conditions. Morphology of worn surfaces and wear debris were analyzed by Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and X-Ray Diffraction (XRD). At high (137.3 N) load, plate like debris were observed at low speeds under both ambient and vacuum conditions where Adiabatic Shear Band (ASB) was dominate mechanism. And an ambient condition of higher speeds produced fine wear particles where tribo oxidation (TO) and mechanically mixed layers (MML) were dominant mechanism and at vacuum condition of same speeds produced large lump wear debris due to the cause of high plastic deformation and phase transition from HCP to BCC. The analysis of the debris clearly indicates the synergism influence of three mechanisms (ASB, TO and MML) playing a role.