| 摘要 |
PURPOSE:To obtain an intermetallic compound permanent magnet composed of rare-earth elements and cobalt, especially a Cu- -s ubstitution type permanent magnet whose heat-resistant property is excellent by a method wherein, after an alloy by a specific composition has been changed to a molten metal, a specific temperature range is cooled at a specific speed. CONSTITUTION:An alloy by a composition expressed by the general formula of R (Co1-a-b-cFeaCubZre)z (where R represents a combination of one kind or two or more kinds of rare-earth elements including Sm and Ce as central elements, 0.24<=a<=0.26, 0.058<=b<=0.064, 0.018<=c<=0.024 and 7.2<=z<=7.8) is changed to a molten metal. The alloy is changed to the molten metal; after that, a temperature range of 800 deg.C or higher is cooled at a peed of 2 to 25 deg.C/sec; the molten metal is crushed; fine powders which have been obtained are compressed and molded in a magnetic field; after that, the moldered powders are sintered, changed to a solution; an aging treatment is executed. Thereby, it is possible to obtain a rare-earth cobalt magnet whose maximum energy product is at 27MGOe or higher in a temperature range from room temperature to 150 deg.C and whose heat-resistant property is excellent. |
