Sliding Behavior of C/C and C/C-SiC Composites in Acidic Environment-Against High Chromium Steel Disc

Abstract

The wear behaviour of carbon-carbon (C/C) and carbon-carbon-silicon-carbide (C/C-SiC) composites were studied using a pin-on-disc test rig under dry condition before and after immersion in 25% concentrated H2SO4. The influence of the weight loss and worn temperature against sliding distance and time were investigated. It was found that the weight loss increases with increasing of sliding distance and time, where worn surface temperature increases slowly up to 1.5 Km sliding distance and then tended to become constant. Also, weight loss and worn surface temperature reduces with the exposure of 25% concentrated sulphuric acid. However, the C/C-SiC composites exhibiting a lower weight loss but higher worn surface temperature compare to C/C composites at constant load. The wear and worn temperature of C/C composite gradually in- creases compare to C/C-SiC composite, with an average fading ratio of 7.7% (C/C composite) and 7.4% (C/C-SiC composite). Scanning electron microscope and projection microscope micrographs show that the graphite film was transferred on the test pin side, which stabilized the increase in test pin temperature after the formation of a thick film of graphite debris.