UNLUBRICATED OSCILLATING SLIDING WEAR OF C C-SIC FIBER-REINFORCED COMPOSITES/

C/C-SiC fibre reinforced composites were produced by liquid infiltrati on technique. Porous C-fibre laminates containing carbonic resin were infiltrated with liquid silicon, leading to a SiC-matrix. Mechanical a nd thermal properties of the composites were measured. Tribological te sts were carried out on self-mated C/C-SiC and C/C-SiC mated with ZrO2 and steel, respectively, in unlubricated oscillating sliding contact using a ring-on-block tribometer. Environmental conditions such as rel ative humidity and testing temperature were varied. Microstructures of the composites as well as the worn surfaces were systematically analy sed using scanning electron microscopy. Experimental results showed a significant influence of the relative humidity and the testing tempera ture on tribological properties. Self-lubricating effects due to carbo n films occurred at sufficient humidity, contact temperatures < 90-deg rees-C and below a critical surface pressure.