Aluminum oxide powders and process
AssigneeNorton Company
InventorsRalph Bauer, Arup K. Khaund, Ronald W. Trischuk, Joseph Similia
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Abstract
Fine alumina powders for making alumina bodies are produced by seeding of a non-alpha alumina with submicron alpha alumina particles, firing, and crushing and milling the fired product to a fine powder. The powder so produced may be formed by conventional techniques such as pressing, granulating, slip casting, tape casting, and extrusion, and sintered to produce the desired fired product.
Claims12
A method of preparing an alumina powder containing alpha alumina crystals having a size below 1 micron comprising seeding an alumina gel precursor of alpha alumina with submicron alpha alumina seed particles, sintering the seeded precursor at 900.degree. to 1350.degree. C. for a time sufficient to convert at least a portion of the non-alpha alumina to alpha alumina, and crushing the sintered product to a powder having a particle size of less than l micron.
An alpha alumina powder consisting of a mixture of equiaxed single crystals of seeded alpha alumina having a size below 1 micron and sintered porous agglomerates of said single crystals.
A milled powder consisting of seeded alpha alumina particles finer than 1 micron.
Dependencies are inferred from the claim text.