ROLE OF TRIBOELECTRIFICATION MECHANISM IN THE WEAR BEHAVIOR OF AL2O3-SIC PLATELET COMPOSITES

Wear behaviour of Al2O3-SiC platelet composites has been analysed as a function of the content and the orientation of the platelets. The res ults have shown that wear volume increased with platelet content. For long sliding times (greater than or equal to 60 min) and high SiC plat elet additions (greater than or equal to 12 vol.%), a mild-severe wear transition took place. A mechanism based on the triboelectrification concept has been developed to explain the wear behaviour of Al2O3-SiC platelet composites. A strongly anisotropic wear behaviour, that has b een directly associated to the anisotropy in the electrical and mechan ical responses, was observed. This behaviour was a consequence of the platelet orientation during hot pressing.