The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 21, 1977
Filed:
Apr. 13, 1976
Donald R Muzyka, Reinholds, PA (US);
Robert F Walley, Shoemakersville, PA (US);
Carpenter Technology Corporation, Reading, PA (US);
Abstract
The process prevents prior powder particle boundary delineation by providing one or more surfactant elements which prevent nucleation of carbides at the particle surfaces with the result that carbide precipitation occurs within the powder particles rather than predominantly at the particle surfaces. In one embodiment, a small but effective amount of one or more surfactants is added to prealloyed powder before the powder is enclosed and densified at elevated temperature. In another embodiment, the surfactant is added to the melt of the prealloyed powder prior to atomization. The surfactant should be capable of forming a vapor under the conditions of hot densification, should be a strong oxide and/or sulfide former, must be a weak carbide former, should form oxides and/or sulfides which will not nucleate carbides of other elements, and which, if present in the article made from the powder, will not objectionably affect the desired properties. Useful surfactants include magnesium, barium, calcium, cerium, lanthanum, lithium, neodymium, praseodymium, yttrium, and misch metal.