| 摘要 |
PURPOSE:To obtain a rare earth permanent magnet alloy having superior magnetic properties by controlling the composition of a cellular structure in an R2Co17 type rare earth magnetic alloy with a specific composition. CONSTITUTION:An ingot of a Co-(rare earth) alloy having a composition consisting of, by weight, 24-28% R (one or more kinds among rare earth elements), 10-20% Fe, 3-6% Cu, 2-4% Zr, and the balance Co is crushed by means of a jaw crusher, etc., pulverized by means of a ball mill, etc., and compacted in a magnetic field. The resulting green compact is sintered, e.g. at 1100-1250 deg.C, heated to and held at a temp. lower by 0-50 deg.C than the above temp. to undergo solution heat treatment, and successively held at 700-950 deg.C for a prescribed time and cooled to undergo aging treatment, thereby, a fine cellular structure is formed and the content of Fe contained in the R2Co17 phases constituting the cells is controlled to 18-25 atomic %. By this method, the R2Co17 type permanent magnet improved in magnetic properties as to have a residual magnetic flux density exceeding =11KG can be obtained. |
