Sintering metal powders into structures without sintering aids
AssigneeCorning Incorporated
InventorsSrinivas H. Swaroop, Raja R. Wusirika
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Abstract
Sintering metal powder in inert and/or reducing atmosphere has been found to result in a hard porous metal structure without the use of sintering aids. The oxidation resistance of the structure can be enhanced by the firing process comprised of the following steps: oxidation, reduction, and then inert gas sintering.
Claims7
A method of producing an oxidation resistant, hard, porous, sintered body of sinterable metal powder consisting essentially, as analyzed in weight percent, of 5-50% Al, 30-90% Fe, the sum of Al and Fe constituting at least 80% of the total powers, 0-10% Ns, 0-10% Cu, 0-10% Cr, the sum of Sn and Cu and Cr being no more than 20%, in the absence of sintering aids, which method comprises the sequential steps of:
- (a) wet mixing the metal powder with organic binder and forming a green body of the resultant mixture,
- (b) firing said green body in an oxidizing atmosphere to burn out said binder with some of said metal being consequentially oxidized,
- (c) firing said green body in a reducing atmosphere to reduce said oxidized metal, and
- (d) firing said green body in a nonoxidizing environment to sinter said metal powder and density said green body into said porous, sintered body.
Dependencies are inferred from the claim text.