Polycrystalline alumina abrasive grains, method for producing the same, and grindstone

Abstract

A method for producing the polycrystalline alumina abrasive grains at a low cost, and a grindstone using the polycrystalline alumina abrasive grains. The production method includes a step of obtaining a liquid mixture of pseudo-boehmite, predetermined silica, and water; a step of adding a deflocculant to the liquid mixture to obtain a sol; a step of adding alumina seeds to the sol to obtain a seed-containing sol; a step of drying the seed-containing sol, crushing a residual content, and then performing calcination at 550° C. or more and less than 1,200° C.; and a step of performing firing at 1,200° C. to 1,500° C. provides the polycrystalline alumina abrasive grains including an alumina content of 95.0% by mass or more and a silica content of 0.05 to 3.30% by mass, with a grain size of 0.100 to 0.400 μm, and a Vickers hardness of 21.00 or more.

Dependencies are inferred from the claim text.