| 摘要 |
PROBLEM TO BE SOLVED: To obtain sintered abrasive grains having a small mean crystal particle diameter and improved in the autogenous function and hardness of an edge by crushing a solid molding obtained by centrifuging a slurry containing a starting powder and firing the product of crushing. SOLUTION: A slurry containing a starting powder comprising a metal oxide having a mean crystal particle diameter of 0.1-0.6μm, desirably 0.1-0.3μm, a dispersant such as ammonium polycarboxylate and a binder such as an acrylic polymer is poured into a cylindrical mold 1 with a freely detachable bottom and centrifuged at a gravitational acceleration of 5,000 G or above to form a solid mold 4 having a water content of 25-75 wt.% on the bottom 2. This molding 4 is dried and crushed with a suitable means such as a hammer mill, and the product of crushing is classified by passing through sieves having gradually increasing openings to obtain a molding having a size of 2-4 mm or below. This molding is degreased by heat treatment at 700-900 deg.C for 30-90 min and rapidly fired at 1,300-1,500 deg.C, desirably 1,350-1,490 deg.C to obtain sintered abrasive grains having a mean crystal particle diameter of 0.5μm or below and a Vickers hardness of 15 GPa or above.
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