COMPARATIVE STUDY OF FRICTION AND WEAR OF TWO GENERATION OF CVI C-C COMPOSITE

The physical changes in the braking material due to wear will reduce the brake lifetime and change both the material properties and braking capacity. Humidity has great effects on the coefficient of friction and wear. In this study the wear and friction behavior of a new and old generation of carbon-carbon composite were investigated. Identical samples were tested on a sub- scale dynamometer at different humidity, environment, and operating conditions. The friction coefficient was recorded and wear was measured. Visual examination, surface topography characterization, microscopy and spectroscopy techniques were used to determine the friction and wear mechanisms. Scanning Electron Microscopy, Raman Spectroscopy, and X-Rays were also used. The change in wear and friction coefficient with energy input were studies and wear transitional zones were detected. It is shown that friction, and wear are dependant on bulk material properties, environment (humid, dry and inert) and the produced friction film. It was shown that the relative humidity has strong influence on the tribological behavior of the old and new generation of composites. Wear and friction transitional zones were detected for both type of Composite.

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