Method for producing a magnetic alloy powder

US6352597B1 · kind B1 · utility

Assignee

• Institut fuer Festkoerper-und Werkstoffforschung Dresden e.V. · DE

Inventors

• Oliver Gutfleisch · Darmstadt, DE
• Michael Kubis · Mülheim an der Ruhr, DE
• Axel Handstein · Dresden, DE
• Bernhard Gebel · Coswig, DE
• Karl-Hartmut Mueller · Dresden, DE
• Ivor Rex Harris · Birmingham, GB
• Ludwig Schultz · Dresden, DE

Key dates

• Filing date: Jul 14, 2000
• Grant date: Mar 5, 2002
• Expiry date: Jul 14, 2020

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B22F2999/00
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A method is disclosed enabling a technologically controllable and economical production of a hard-magnetic powder composed of a samarium-cobalt base alloy for highly coercive permanent magnets. The method is based on a HDDR treatment in which a starting powder is subjected to hydrogenation with disproportionation of the alloy in a first method step under hydrogen and, in a subsequent, second method step under vacuum conditions, a hydrogen desorption with recombination of the alloy. A starting powder containing samarium and cobalt is treated in the first method step either at a high temperature in the range of 500° C. to 900° C. and with a high hydrogen pressure of >0.5 MPa or by applying an intensive fine grinding at a low temperature in the range of 50° C. to 500° C. and with a hydrogen pressure of >0.15 MPa. By means of the method of the invention, magnetic alloy powders can be produced from samarium-cobalt base alloys; highly coercive permanent magnets can be produced from these magnetic alloy powders, particularly by hot compacting or plastic bonding.