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. 18, 1996
Filed:
May. 09, 1995
Yoshihisa Kishimoto, Ikoma, JP;
Nobushige Hiraishi, Nishinomiya, JP;
Wataru Takahashi, Nishinomiya, JP;
Masakazu Ohkita, Ashiya, JP;
Naoyuki Ishigaki, Otsu, JP;
Yutaka Matsuura, Hyogo-ken, JP;
Sumitomo Metal Industries, Ltd., Osaka, JP;
Sumitomo Special Metals Co. Ltd., Osaka, JP;
Abstract
To a fine R-Fe-B alloy powder comprised predominantly of 10-30 atomic % of R (wherein R stands for at least one elements selected from rare earth elements including yttrium), 2-28 atomic % of B, and 65-82 atomic % of Fe in which up to 50 atomic % of Fe may be replaced by Co, at least one boric acid ester compound such as tributyl borate is added as a lubricant in a proportion of 0.01%-2% by weight and mixed uniformly before, during, or after fine grinding of the alloy powder. The resulting powder mixture is compacted by compression molding in a magnetic field and the green compacts are sintered and aged. Compression molding can be performed continuously without need of mold lubrication, and the resulting magnets have improved magnet properties with respect to residual flux density, maximum energy product, and intrinsic coercive force.