Abstract: A method of making a sintered body for a rare earth magnet includes the steps of (a) preparing a first coarse powder by coarsely pulverizing a rare earth alloy sintered body by a hydrogen pulverization process, (b) preparing a first fine powder by finely pulverizing the first coarse powder, (c) preparing a second fine powder by pulverizing an alloy block of a rare earth alloy material, and (d) sintering a mixed powder including the first and second fine powders. The first and second fine powders each includes a main phase represented by (LR1-xHRx)2T14A, where T is Fe and/or at least one non-Fe transition metal element; A is boron and/or carbon; LR is at least one light rare earth element; HR is at least one heavy rare earth element; and 0?x<1.

Abstract: The present invention aims to prevent heating and ignition of a material powder of a rare-earth alloy while reducing the oxygen content thereof so as to improve the magnetic properties of the rare-earth magnet. A rare-earth alloy powder is compacted by using a powder compacting apparatus including: an airtight container capable of storing a rare-earth alloy powder therein; an airtight feeder box moved between a powder-filling position and a retracted position; and an airtight powder supply device capable of supplying the rare-earth alloy powder from the container into the feeder box without exposing the rare-earth alloy powder to the atmospheric air.

Abstract: The method for producing a rare-earth sintered magnet of the present invention includes the steps of: compacting alloy powder for the rare-earth sintered magnet to form a green compact; loading the green compact into a case having a structure restricting a path through which gas flows between the outside and inside of the case, and placing a gas absorbent at least near the path; and sintering the green compact by heating the case including the green compact inside in a decompressed atmosphere.

Abstract: A method of making a sintered body for a rare earth magnet includes the steps of (a) preparing a first coarse powder by coarsely pulverizing a rare earth alloy sintered body by a hydrogen pulverization process, (b) preparing a first fine powder by finely pulverizing the first coarse powder, (c) preparing a second fine powder by pulverizing an alloy block of a rare earth alloy material, and (d) sintering a mixed powder including the first and second fine powders. The first and second fine powders each includes a main phase represented by (LR1-xHRx)2T14A, where T is Fe and/or at least one non-Fe transition metal element; A is boron and/or carbon; LR is at least one light rare earth element; HR is at least one heavy rare earth element; and 0≦x<1.

Abstract: The present invention aims to prevent heating and ignition of a material powder of a rare-earth alloy while reducing the oxygen content thereof so as to improve the magnetic properties of the rare-earth magnet. A rare-earth alloy powder is compacted by using a powder compacting apparatus including: an airtight container capable of storing a rare-earth alloy powder therein; an airtight feeder box moved between a powder-filling position and a retracted position; and an airtight powder supply device capable of supplying the rare-earth alloy powder from the container into the feeder box without exposing the rare-earth alloy powder to the atmospheric air.

Abstract: A green compact of a rare earth alloy magnetic powder is made by pressing the powder. The powder is pressed within an air environment that has a temperature controlled at 30° C. or less and a relative humidity controlled at 65% or less.

Abstract: The present invention aims to prevent heating and ignition of a material powder of a rare-earth alloy while reducing the oxygen content thereof so as to improve the magnetic properties of the rare-earth magnet. A rare-earth alloy powder is compacted by using a powder compacting apparatus including: an airtight container capable of storing a rare-earth alloy powder therein; an airtight feeder box moved between a powder-filling position and a retracted position; and an airtight powder supply device capable of supplying the rare-earth alloy powder from the container into the feeder box without exposing the rare-earth alloy powder to the atmospheric air.

Abstract: A green compact of a rare earth alloy magnetic powder is made by pressing the powder. The powder is pressed within an air environment that has a temperature controlled at 30° C. or less and a relative humidity controlled at 65% or less.

Abstract: The method for producing a rare-earth sintered magnet of the present invention includes the steps of: compacting alloy powder for the rare-earth sintered magnet to form a green compact; loading the green compact into a case having a structure restricting a path through which gas flows between the outside and inside of the case, and placing a gas absorbent at least near the path; and sintering the green compact by heating the case including the green compact inside in a decompressed atmosphere.

Abstract: A green compact of a rare earth alloy magnetic powder is made by pressing the powder. The powder is pressed within an air environment that has a temperature controlled at 30° C. or less and a relative humidity controlled at 65% or less.

Abstract: The present invention aims to prevent heating and ignition of a material powder of a rare-earth alloy while reducing the oxygen content thereof so as to improve the magnetic properties of the rare-earth magnet. A rare-earth alloy powder is compacted by using a powder compacting apparatus including: an airtight container capable of storing a rare-earth alloy powder therein; an airtight feeder box moved between a powder-filling position and a retracted position; and an airtight powder supply device capable of supplying the rare-earth alloy powder from the container into the feeder box without exposing the rare-earth alloy powder to the atmospheric air.

Abstract: Its basic means is a monolithically bonded construct prepared by monolithically bonding together a rare-earth magnet 2 and a an alloy material that is a high melting point metal or a high specific-tenacity material through the solid phase diffusion bonding by the hot isostatic pressing treatment, and a monolithically bonded construct with an interposal of a thin layer of the high melting point metal between a rare-earth magnet 2 and an alloy material 3, 4 that is a high specific-tenacity material.

Abstract: A case for hydrogen-pulverizing a rare earth metal-based magnetic material is disclosed. The case includes a case body which is formed of a material having a heat conductivity of 1 W/cm·deg or more. At least one heat-transferring/releasing member is mounted in the case body and formed of a material having a heat conductivity of 1 W/cm·deg or more. The magnetic material is accommodated in the case and subjected to a hydrogen pulverization with hydrogen occluded in the magnetic material.

Abstract: It is an object of the present invention to provide R-Fe-B permanent magnet materials having a good oxidation resistance and magnetic characteristics, and a process of producing the same capable of pulverizing efficiently, whereby an R-Fe-B molten alloy having a specific composition is casted into a cast piece having a specific plate thickness and a structure, in which an R-rich phase is finely separated below 5 .mu.m, by a strip casting process, the cast piece is subjected to a Hydrogenation for spontaneous decay, and thereafter, an alloy powder is dehydrogenated and stabilized for pulverization so as to fractionize crystal grains of a main phase constituting an alloy ingot, thereby the powder having a uniform grain distribution can be produced at an efficiency of about twice as much as the conventional process, and the R-rich phase and an R.sub.2 Fe.sub.

Abstract: A process for producing a starting powder material for use in the fabrication of high performance R--Fe--B permanent magnets comprising an R.sub.2 Fe.sub.14 B compound as the principal phase, which is characterized by adding 70% by weight or less of a specified alloy powder for adjusting the composition comprising an R.sub.2 Fe.sub.17 compound to a specified principal phase R--Fe--B alloy powder comprising an R.sub.2 Fe.sub.14 B compound as the principal phase. This process enables production of a starting alloy powder material considerably reduced in contents of the unfavorable B-rich and R-rich phases which impair the magnetic properties of the final magnet, because the starting powder blend allows the B-rich and R-rich compounds in the principal phase alloy powder to react with the R.sub.2 Fe.sub.17 compound being incorporated in the alloy powder for adjusting the composition.