SILICON CARBIDE COMPOSITED SILICON NITRIDE ABRASIVE AND ITS PREPARATION

摘要

PROBLEM TO BE SOLVED: To obtain a low-cost silicon carbide composite silicon nitride abrasive having high hardness and being useful in high performance precision grinding. SOLUTION: This material is prepared by mixing 60-92 wt.% silicon nitride powder having a mean crystal grain diameter of 1 μm or below with 3-10 wt.% Al2 O3 having a mean crystal grain diameter of 1 μm or below and, at least one rare earth oxide and Y2 O3 , and 5-30 wt.% silicon carbide powder having a mean crystal grain diameter of 1 μm or below and firing the mixture and has a Vickers hardness of above 22 GPa.