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. 06, 1989
Filed:
Jul. 10, 1987
Hitachi Metals, Ltd., Tokyo, JP;
Abstract
A method of producing a neodymium-iron-boron permanent magnet alloy having a composition of 25.0-50.0 weight % of neodymium, 0.3-5.0 weight % of boron and balance substantially iron, including the steps of adding metal calcium, calcium hydride or a mixture thereof as a reducing agent to neodymium fluoride, iron and boron (or ferroboron), and further adding thereto at least one of calcium chloride, sodium chloride and potassium chloride as a flux, melting the resulting mixture in an inert gas atmosphere, or in a reducing gas atmosphere or substantially in vacuum at 1,000.degree.-1,300.degree. C., thereby reducing said neodymium fluoride to provide said alloy with as small a calcium content as 0.1 weight % or less. The starting materials may contain dysprosium fluoride and niobium to provide Nd-Dy-Fe-B-Nb alloys containing 0.5-15.0 weight % Dy and 0.05-5.0 weight % Nb. This method makes it possible to produce Nd-Fe-B or Nd-Dy-Fe-B-Nb permanent magnet alloys with as small a calcium content as 0.1 weight % or less directly from starting materials. Accordingly, it is economically advantageous over the conventional reduction method which produces mother alloys.