Nanoindentation, microscratch, friction and wear studies of carbon-fibre reinforced SiC-Si matrix composite

This paper describes some tribological properties of a carbon / silicon carbide - silicon composite (C/SiC-Si). Friction and wear tests were conducted at room temperature under various relative humidity rates using a pin-on-disc test apparatus. Further study aimed at assessing the extent of the damage induced by indentation / scratch through the different parts of the composite. The mechanisms involved were discussed after examining the morphology of the worn surfaces and debris by scanning electron microscopy. For the different friction conditions, rather polished surfaces were generated but the morphology of the debris varied according to the relative humidity of the atmosphere. The indentation / scratch study revealed that damage occurred mostly as fragmentation of the carbon fibres, cracking of the silicon carbide matrix, ductile deformation and to a less extent cracking of the silicon matrix.