PURPOSE: To improve a squareness and increase coercive force by executing aging treatment at 850W1,000°C while using a permanent magnet alloy having a special composition as a starting material, conducting cooling up to 400°C or lower at a cooling rate of 100°C/min or more and executing aging treatment at 500W750°C.
CONSTITUTION: Oxygen concentration in a permanent magnet alloy has a remark able effect on coercive force in a rare earth iron group permanent magnet. A composition is constituted of a 10W40wt% rare earth element, a 0.1W8wt% boron, a 0.5W5wt% aluminum, a 0.005W0.03wt% oxygen and the remainder mainly consisting of iron on the basis of said phenomenon. Coercive force and a square-shape property-that is, (BH)max-largely depend upon an aging treat ment method. The permanent magnet alloy is employed as a starting material and the alloy is aging-treated at 850W1,000°C, cooled up to 400°C or lower at a cooling rate of 100°C/min or more and aging-treated at 500W750°C on the basis of said phenomenon regarding coercive force and the square-shape property.
SAKAI ISAO
INOMATA KOICHIRO
| JPS60182107A | 1985-09-17 |
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