Friction and wear transitions in carbons (temperature and stress analysis)

In this paper the friction and wear behavior of a carbon composite is studi ed. Friction tests were performed under constant friction model The power i nputs were increased gradually to study their effects on friction transitio n at ambient air environment. Friction surfaces were examined using various macro and nanoscopic techniques to understand the evolution of friction tr ansition. Structural changes of friction film have been observed from graph itic allotropic form to amorphous type structure. This sudden change leads to an increase of the coefficient of friction. It seems that the inter-lami nar shearing, disruption of the film and sample cracking might cause the fr iction transition. Analysis from stress field simulation shows that cracks were more likely to occur at the trailing edge of the sample at the end of transition. This study shows that any type of failure (mechanical or therma l,fatigue) of the friction film or bulk material is sufficient to generate friction and wear instabilities.