Abstract: Provided is a manufacturing method of a rare-earth magnet with high coercive force, including a first step of pressing-forming powder as a rare-earth magnet material to form a compact S, the powder including a RE-Fe—B main phase MP (RE: at least one type of Nd and Pr) and a RE-X alloy (X: metal element) grain boundary phase surrounding the main phase; and second step of bringing a modifier alloy M into contact with the compact S or a rare-earth magnet precursor C obtained by hot deformation processing of the compact S, followed by heat treatment to penetrant diffuse melt of the modifier alloy M into the compact S or the rare-earth magnet precursor C to manufacture the rare-earth magnet RM, the modifier alloy including a RE-Y (Y: metal element and not including a heavy rare-earth element) alloy having a eutectic or a RE-rich hyper-eutectic composition.

Abstract: In an IPM motor rotor, a rotor core has a plurality of magnetic poles, and each magnetic pole is formed by two permanent magnets. The two permanent magnets of each magnetic pole are two split pieces obtained by splitting one parent permanent magnet that is larger than the permanent magnets.

Abstract: Provided is a method for manufacturing a rare-earth magnet enabling effective penetrant-diffusion of a melt of modifier alloy powder without generating oxidation reaction or hydroxylation reaction when the modifier alloy powder is used for a better coercive force as well.

Abstract: A rare-earth sintered magnet including a relatively large main phase, and method for manufacturing same. The rare-earth sintered magnet having excellent coercive-force performance that can be manufactured without using heavy rare-earth elements such as Dy, and including: a RE-T-B main phase C (RE: Nd or Pr, T: Fe or Fe and a part thereof substituted with Co), and a grain boundary phase B surrounding the main phase C, the grain boundary phase including the RE element and the T element. The T element at the grain boundary phase B has density of 60 at % or less, and the grain boundary B has a thickness decreasing from a surface S of the rare-earth sintered magnet M to an inside thereof, and the grain boundary phase B at an area SA of a surface layer of the rare-earth sintered magnet M has an average thickness of 10 nm or more.

Abstract: The present invention is a method capable of producing a rare-earth magnet with excellent magnetization and coercivity. The method includes producing a sintered body including a main phase and grain boundary phase and represented by (R11-xR2x)aTMbBcMd (where R1 represents one or more rare-earth elements including Y, R2 represents a rare-earth element different than R1, TM represents transition metal including at least one of Fe, Ni, or Co, B represents boron, M represents at least one of Ti, Ga, Zn, Si, Al, etc., 0.01?x?1, 12?a?20, b=100?a?c?d, 5?c?20, and 0?d?3 (all at %)); applying hot deformation processing to the sintered body to produce a precursor of the magnet; and diffusing/infiltrating melt of a R3-M modifying alloy (rare-earth element where R3 includes R1 and R2) into the grain boundary phase of the precursor.

Abstract: Provided is a manufacturing method of a rare-earth magnet capable of penetrant-diffusing a modifier alloy to increase a coercive force (especially a coercive force under a high-temperature atmosphere) at a temperature lower than the conventional method for manufacturing a rare-earth magnet without using heavy rare-earth metals such as Dy and Tb, and accordingly capable of manufacturing a high coercivity rare-earth magnet at the lowest cost possible.

Abstract: In an IPM motor rotor, a rotor core has a plurality of magnetic poles, and each magnetic pole is formed by two permanent magnets. The two permanent magnets of each magnetic pole are two split pieces obtained by splitting one parent permanent magnet that is larger than the permanent magnets.