An exploration of debris types and their influence on wear rates in fretting

The effects of debris particles in fretting contacts are substantial and are believed to play a key role in the difference in wear rates observed between fretting and full sliding wear. Studies of debris have shown that the effects can have detrimental or palliative effects on the parent surfaces. This work aims to explore this phenomenon through the study of fretting contacts of EN24-T (steel) and Ti-6Al-4V (titanium alloy). All combination pairs of these materials were tested in oxidative and non-oxidative atmospheres. Methods were developed to measure the wear rates throughout each test and corresponding 'time stamped' debris samples were analysed. Vast differences were observed in the effects of oxygen on the wear rates of the two materials. Evidence suggests that the reason for this difference is the size of the particles in the contacts, not their hardness.