NORMAL/DEFECTIVE JUDGEMENT METHOD FOR RARE EARTH MAGNET ALLOY INGOT, MANUFACTURING METHOD, RARE EARTH MAGNET ALLOY INGOT AND RARE EARTH MAGNET ALLOY

摘要

PROBLEM TO BE SOLVED: To provide a normal/defective judgement method for a rare earth magnet alloy ingot which discriminates the rare earth magnet alloy ingot capable of yielding alloy powder to make sintered magnets having good magnetic characteristics obtainable in the state of the alloy ingot. SOLUTION: The rare earth magnet alloy ingot is held in a reduced pressure atmosphere and is then placed under a hydrogen atmosphere. The behavior that the rare earth magnet alloy ingot occludes hydrogen when the ingot is placed under the hydrogen atmosphere and more preferably the change of the hydrogen occlusion amount of the rare earth magnet alloy ingot with time are measured.