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:
Apr. 06, 1993
Filed:
Nov. 29, 1990
Satoshi Hirosawa, Nagaokakyo, JP;
Atsushi Hanaki, Kobe, JP;
Hiroyuki Tomizawa, Ibaraki, JP;
Shuji Mino, Ibaraki, JP;
Sumitomo Special Metals Co., Ltd., Osaka, JP;
Abstract
An anisotropic sintered permanent magnet consists essentially of 12 to 18 at % R, wherein R represents Pr, Nd, Dy, Tb and other rare earth element or elements contained as inevitable impurities provided that 0.8.ltoreq.(Pr+Nd+Dy+Tb)/R.ltoreq.1.0, 5 to 9.5 at % B, 2 to 5 at % Mo, 0.01 to 0.5 at % Cu, 0.1 to 3 at % Al, and balance being Fe. B(x) and Mo(y) are (x-4.5).ltoreq.y.ltoreq.(x-3.0), and part of Fe may be replaced by Co to be 3-7 at % Co. Up to 90 at % of Mo may be replaced by V. The magnet is characterized by main tetragonal R.sub.2 (Fe, Mo).sub.14 B or R.sub.2 (Fe, Co, Mo).sub.14 B phase and boundary phase of (Fe, Mo)-B, or (Fe, Co, Mo)-B and R.sub.m (Fe, Co, Mo).sub.n where m/n=1/2 to 3/1. B-rich phase Nd.sub.1+.epsilon. Fe.sub.4 B.sub.4 disappears. Dy and/or Tb linearly increase iHc. High coercivity and maximum energy product are obtained: iHc.gtoreq.15 kOe (or 21 kOe) and (BH)max.gtoreq.20 MGOe (or 28 MGOe) with high corrosion resistance and high pulverizability of alloy.