| 摘要 |
PURPOSE:To produce a rare earth magnet alloy reduced in primary crystal alphaFe, having fine structure, and reduced in segregation by performing centrifugal casting while specifying the ratio between the amount of molten metal to be supplied and the area of the inner wall of a mold, at the time of casting a molten magnetic alloy containing rare earth elements in a mold. CONSTITUTION:By the same method as the conventional method, a magnetic alloy containing rare earth elements is first melted in vacuum or in an inert atmosphere of Ar gas, etc. Then, at the time of performing casting by centrifugal casting, casting is done while regulating M/S value, that is, the amount M of molten metal to be supplied per unit time divided by the total area S of the inner wall of a mold so that it takes a value in the range satisfying M/S<=0.5g/cm<2>.sec. By this method, the solidification of a cast molten metal can be almost completed before a new molten metal is supplied and an ingot of an alloy reduced in primary crystal alphaFe, having fine structure, and reduced in segregation can be obtained, and as a result, the alloy most suitable for a raw material for high efficiency rare earth magnet and close to a main phase bearing magnetism can be economically produced. |
