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:
Mar. 07, 1995
Filed:
May. 21, 1992
Carlton D Fuerst, Royal Oak, MI (US);
Earl G Brewer, Warren, MI (US);
General Motors Corporation, Detroit, MI (US);
Abstract
In a preferred method, a magnetically hard composition is prepared by intermingling rare earth (RE) metal, transition metal (TM) and boron (B) alloy powders of the general formula RE-(Fe.sub.(1-x) Co.sub.x)-B. The value of x ranges from 0 to 1 and is different for each of the powders, thus providing a blend of alloy powders with diverse Curie temperature (T.sub.c) and a less abrupt rate of change of thermal expansion and/or specific heat with temperature, as compared to a single alloy powder. The magnetically hard compositions with improved thermomechanical properties are formed from two or more alloy powders. Preferably, two alloy powders are used and the value of x for the first alloy is less than about 0.1. The value of x for the second alloy is in a range of about 0.1 to about 0.6, and preferably 0.3 to 0.5. When the intermingled alloy powders of the invention are hot pressed with or without subsequent hot working, a magnetically hard body is formed and it is characterized by a lesser rate of change of specific heat and/or thermal expansion with temperature as compared to any one of the single alloy powders similarly hot pressed or hot worked.