Abstract
Al_2O_3-BaF_2-CaF_2 composites containing SiO_2 as a sintering additive were prepared using spark plasma sintering, and their high-temperature tribological properties were investigated. After sintering blended Al_2O_3-BaF_2-CaF_2-SiO_2 powders, BaAl_2Si_2O_8 phase was formed. The volume fractions of BaAl_2Si_2O_8 and BaF_2 phases increased and decreased, respectively, when the particle size of Al_2O_3 powder and the amount of SiO_2 powder added to the composites were increased. Adding only 1wt% SiO_2 to the Al_2O_3-BaF_2-CaF_2 composites improved their wear properties without getting their friction coefficients increased.
