Characterizations of C/C composites and wear debris after heavy braking demands

Carbon/Carbon disks worn by a reduced scale braking test were characterised by an experimental set-up allowing the analysis of the whole disk. In this way, the structure and the surface chemistry of the wear debris formed during the braking and trapped at the sliding interface were determined. The evolution of the surface chemistry and the structure during rubbing at different braking energies were studied by temperature programmed desorption with mass spectrometry analysis and by measuring the active surface area. The analysis of the composites before and after rubbing highlights the formation of highly disordered and oxygen-rich carbon wear debris at the sliding surface. The surface chemistry of the carbon dust trapped on the disk surface was found to be very similar to that of the wear debris ejected during braking. From this similarity a rough estimation of the amounts of carbon dust lying on the worn composites surface was made.