Metal treatment – Process of modifying or maintaining internal physical... – Magnetic materials
Patent
1993-06-24
1996-07-23
Wyszomierski, George
Metal treatment
Process of modifying or maintaining internal physical...
Magnetic materials
148120, 148121, H01F 102
Patent
active
055385656
ABSTRACT:
A rare earth iron permanent magnet including at least one rare earth element, iron and boron as primary ingredients. The magnet can have an average grain diameter of less than or equal to about 150 .mu.m and a carbon content of less than or equal to about 400 ppm and an oxygen content of less than or equal to about 1000 ppm. The permanent magnet is prepared by casting a molten alloy. In one embodiment, the cast body is heat treated at a temperature of greater than or equal to about 250.degree. C. Alternatively, the material can be cast and hot worked at a temperature of greater than or equal to about 500.degree. C. Finally, the material can be cast, hot worked at a temperature of greater than or equal to about 500.degree. C. and then heat treated at a temperature of greater than or equal to about 250.degree. C. The magnets provided in accordance with the invention are relatively inexpensive to produce an have excellent performance characteristics.
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Akioka Koji
Ishibashi Toshiyuki
Kobayashi Osamu
Ozaki Ryuichi
Shimoda Tatsuya
Seiko Epson Corporation
Wyszomierski George
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