Process for improved densification of sol-gel produced alumina-based ceramics
AssigneeMinnesota Mining and Manufacturing Company
InventorAlvin P. Gerk
Life of this patent
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Abstract
The sol-gel process for forming dense, alumina-base ceramics, the process comprising 1. preparing a dispersion of aluminum oxide monohydrate containing a precursor of a modifying additive in the form of a soluble salt; 2. gelling the dispersion; 3. drying the gel dispersion to form a solid; 4. calcining the solid; and 5. sintering the calcined solid, is improved by adding to the dispersion at least about 10 weight percent, based on the oxide equivalent of the soluble salt precursor, of at least one densification aid selected from the group consisting of alcohols, glycols and polyether compounds having a vaporization point in excess of the temperature at which the dispersion is dried. This improved process is particularly useful for manufacturing abrasive grains.
Claims9
In the sol-gel process for forming a dense, solid, alumina-based ceramic, the process comprising:
- a. preparing an aqueous dispersion of aluminum oxide monohydrate containing a precursor of a modifying additive which is a metal-containing compound in the form of a strongly oxidizing, soluble salt;
- b. gelling the dispersion;
- c. drying the gelled dispersion to form a solid;
- d. calcining the solid;
- and
- e. sintering the calcined solid,
- the improvement comprising adding to the aqueous dispersion at least about 10 weight percent, based upon the oxide equivalent of the soluble salt precursor, of at least one densification aid selected from the group consisting of ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, glycerine, and di-isopropanol amine, said densification aid providing in the ceramic produced by said process a density which is noticeably increased over that produced by the same process without said densification aid.
Dependencies are inferred from the claim text.