Sliding-wear resistance of ultrafine-grained SiC densified by spark plasma sintering with 3Y2O3 + 5Al2O3 or Y3Al5O12 additives

The sliding-wear behavior of ultrafine-grained SiC densified by spark plasma sintering (SPS) with 3Y2O3 + 5Al2O3 or Y3Al5O12 additives was compared to elucidate the effect of the intergranular-phase source. Significantly greater sliding-wear resistance (i.e. lower mild- and severe-wear rates, and delayed mild-to-severe wear transition) is observed with the Y3Al5O12 additive, due to its carbothermal reduction during SPS resulting in a harder YAlO3 phase while reducing the intergranular phase content. Implications for the processing of superior SiC triboceramics are discussed.