METHOD AND DEVICE FOR PRODUCING RARE EARTH ALLOY POWDER

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PROBLEM TO BE SOLVED : To suppress the reduction of magnetic properties in a rare earth alloy powder caused by oxidation by shortening cooling time after hydrogen storage treatment. SOLUTION : The rare earth alloy coarse powder after grinding by hydrogen storage is transferred to a coarse grinding stage or a fine grinding stage by high concentration powder transportation. In the high concentration powder transportation, compressed nonoxidizing gas is used as carrier gas, and its temperature is controlled to ≤25°C. In the grinding treatment by hydrogen storage, hydrogen is allowed to occlude into a raw material alloy lump within a vessel, thereafter, heat treatment is performed in a vacuum or in an inert gas atmosphere, and, next, movement is applied to the vessel. Cooling in the cooling part of the hydrogen storage device is defined as primary cooling, and cooling at transportation by the high concentration transportation is defined as secondary cooling. COPYRIGHT : (C)2006, JPO&NCIPI