Patent ID: 6053956
Filing Date: 2000-04-25
Classification: C01F,C04B,C09K

Abstract:
A method for making alpha alumina-based ceramic abrasive grains, said method comprising the steps of:(a) impregnating an impregnation composition comprising a liquid into a plurality of initial, porous, calcined, elongated particles of alpha alumina-based precursor each having a longitudinal axis and internal interconnected pores, to cause conchoidal fracture of at least a portion of said initial elongated particles into smaller elongated particles, said fracture occurring generally in the direction of said longitudinal axis, wherein said initial elongated particles are subjected to an external pressure of at least 1.25 atm. during at least a portion of said impregnation such that the number of smaller particles is increased as compared to such impregnation of such initial particles at 1 atm.; and(b) converting said smaller elongated particles to alpha alumina-based ceramic abrasive grain.