Tribological Properties and Surface Chemistry of Silicon Carbide at Temperatures to 1500° C

Abstract

X-ray photoelectron and Auger electron spectroscopy analyses and tribological studies were conducted with a silicon carbide {0001} surface in sliding contact with iron at various temperature to 1500°C in a vacuum of 10 nPa. The results indicate that there is a significant temperature influence on both the friction properties and the surface chemistry of silicon carbide. Graphite and carbide-type carbon are seen primarily on the silicon carbide surface in addition to silicon at temperatures to 800°C. The coefficients of friction of iron sliding against a silicon carbide {0001} surface were high at temperatures to 800°C. When the friction experiments were conducted at temperature above 800°C, the coefficients of friction were dramatically lower. At 800°C, the silicon and carbide-type carbon are at a maximum intensity in the XPS spectra. With increasing temperature above 800°C, the concentrations of the graphite increase rapidly on the surface, whereas those of the carbide-type carbon and silicon decrease rapidly. This presence of graphite is accompanied by marked decrease in friction.

The higher the sliding temperature, to 800°C, the greater is the amount of metal transfer to silicon carbide. Multiangular- and spherical-shaped fracture pits are observed on the silicon carbide surface as a result of iron sliding. These are due to cleavage of both prismatic and basal planes, and a penny-shapped fracture along a circular stress trajectories under the local inelastic deformation zone, respectively.

Presented as an American Society of Lubrication Engineers paper at the ASLE/ASME Lubrication Conference in New Orleans, Louisiana, October 5–7, 1981

Notes

Presented as an American Society of Lubrication Engineers paper at the ASLE/ASME Lubrication Conference in New Orleans, Louisiana, October 5–7, 1981