Abstract
Sand erosion of silicon nitride by the impingement of alumina abrasives of an average diameterof 363 μm at a velocity of 65 m/s was investigated for a temperature range from room temperature to 919℃. Erosion rate increased with an increase of temperature, and also with an increase of impact angle except for room temperature. The erosion rate significantly increased above 800℃ where intergranular microfracture was observed on the eroded surface by SEM. X-ray diffraction study on the same silicon nitride specimen heated at 1000℃ level revealed the oxidation of the grain boundary phases, suggesting that the oxidation may accelerate the material removal by intergranular microcracking at high temperatures.
