Abstract
Al_2O_3-based self-lubricating composites have attracted much attention because they may be applicable to high-temperature mechanical elements. In this study, Al_2O_3-based self-lubricating composites containing CaF_2 as a solid lubricant and SiO_2 as binder were prepared by spark plasma sintering, and their tribological properties were investigated using a SRV testing machine from room temperature to 800℃ in air. The tibological effects of Al_2O_3 grain size on the composites were also examined. It was shown that adding SiO_2 to the Al_2O_3-based composites reduced their friction coefficients and wear rates above 600℃. The friction coefficients of the Al_2O_3-CaF_2-SiO_2 composites were reduced from room temperature to 800℃, by increasing the Al_2O_3 grain size.
