Friction and wear characteristics of fine ceramics at environmental temperatures up to 1273 K

The effect of environmental temperature on friction and wear characteristics of α-Sialon and alumina (Al₂O₃) was determined in a temperature range from room temperature to 1273 K in air and nitrogen. In the case of Sialon, the effect of environmental temperature on the friction coefficient was not clearly observed, but the wear volume tended to increase with a rise of environmental temperature. In the case of Al₂O₃, when testing in air at temperatures below 673 K, both the friction coefficient and the wear volume grew larger with an increase of environmental temperature, but when testing in nitrogen in a temperature range from room temperature to 1273 K, the wear volume decreased with a temperature rise. At 1273 K, both types of fine ceramics formed smooth surfaces by the transfer of wear particles, which resulted in a reduction of the friction coefficient and the termination of wear process. In the case of Sialon, friction and wear characteristics were affected by the formation of SiO₂ and in the case of Al₂O₃, in a temperature range from room temperature to 673 K, friction and wear characteristics were affected by the humidity of the environmental atmosphere.