| 摘要 |
Provided are raw material alloy flakes for a rare earth sintered magnet and a method for producing the same, which flakes have undergone suppressed generation of chill crystals, and have quite uniform 2-14-1-based main phase shapes and R-rich phase dispersion. The alloy flakes of the present invention have a roll-cooled face, are obtained by strip casing with a cooling roll, and satisfy the following requirements (1) to (3): (1) the alloy flakes contain at least one R selected from rare earth metal elements including Y, B, and the balance M including iron, at a particular ratio; (2) the alloy flakes, as observed in a micrograph at a magnification of 100× of its roll-cooled face, have not less than 5 crystals each of which is a dendrite grown radially from a point of crystal nucleation, has particular aspect ratio and grain size, and crosses a line segment corresponding to 880 µm; (3) the alloy flakes, as observed in a micrograph at a magnification of 200x of its section taken generally perpendicularly to its roll-cooled face, have an average distance between R-rich phases of not less than 1 µm and less than 10 µm. |
