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:
Feb. 06, 1990
Filed:
Apr. 11, 1989
Tsutomu Otsuka, Miyagi, JP;
Etsuo Otsuki, Miyagi, JP;
Tokin Corporation, Miyagi, JP;
Abstract
A rare earth metal-iron-boron permanent magnet is produced by the sintering method using a magnetic powder prepared from an ingot of R.sub.2 Fe.sub.14 B and another powder prepared from a rapidly-quenched alloy ribbon of R-T-B. R is at least one selected from yttrium and rare earth metals and T is at least one selected from transition metals. The rapidly-quenched alloy powder almost all melts to form a liquidus phase which cements the magnetic particles at a sintering temperature. The liquidus phase generates a magnetic crystalline phase and the solid solution phase upon cooling from the sintering temperature. A comparatively large amount of rapidly-quenched alloy powder is used to produce a magnet having a reduced amount of solid solution phase. In addition to this, the rapidly-quenched alloy can readily be finely ground and the rapidly-quenched alloy powder can therefore be uniformly mixed with the magnetic alloy powder so that the magnet having excellent magnetic properties can be produced wherein the magnetic particles are uniformly dispersed in the small amount of the solid solution phase. The magnet has a reduced oxygen content.