Alloy ingot for permanent magnet, anisotropic powders for permanent magnet, method for producing same and permanent magnet

摘要

An alloy ingot for permanent magnet consists essentially of rare earth metal and iron and optionally boron. The two-component alloy ingot contains 90 vol % or more of crystals having a crystal grain size along a short axis of 0.1 to 100 mu m and that along a long axis of 0.1 to 100 mu m. The three-component alloy ingot contains 90 vol % or more of crystals having a crystal grain size along a short axis of 0.1 to 50 mu m and that along a long axis of 0.1 to 100 mu m. The alloy ingot is produced by solidifying the molten alloy uniformly at a cooling rate of 10 DEG to 1000 DEG C./sec. at a sub-cooling degree of 10 DEG to 500 DEG C. A permanent magnet and anisotropic powders are produced from the alloy ingot.