Silicon nitride wear resistant member and method for producing silicon nitride sintered compact

Abstract

The present invention provides a silicon nitride wear resistant member comprising a silicon nitride sintered compact containing β-SiNcrystal grains as a main component, 2 to 4% by mass of a rare earth element in terms of oxide, 2 to 6% by mass of Al in terms of oxide, and 0.1 to 5% by mass of Hf in terms of oxide, wherein the silicon nitride sintered compact has rare earth-Hf—O compound crystals; in an arbitrary section, an area ratio of the rare earth-Hf—O compound crystals in a grain boundary phase per unit area of 30 μm×30 μm is 5 to 50%; and variation of the area ratios of the rare earth-Hf—O compound crystals between the unit areas is 10% or less. Due to above structure, there can be provided a wear resistant member comprising the silicon nitride sintered compact having an excellent wear resistance and processability.