Disclosed in the present invention are a heavy rare earth alloy, neodymium-iron-boron permanent magnet material, a raw material, and a preparation method. The heavy rare earth alloy comprises the following components: RH: 30-100 mas %, not including 100 mas %; X, 0-20 mas %, not including 0; B: 0-1.1 mas %; and Fe and/or Co: 15-69 mas %, RH comprising one or more heavy rare earth elements in Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Sc, and X being Ti and/or Zr. When the heavy rare earth alloy of the present invention is used as a sub-alloy to prepare the neodymium-iron-boron permanent magnet material, a high utilization rate of heavy rare earth is achieved, so that the coercivity can also be greatly improved while the neodymium-iron-boron permanent magnet material maintains high remanence.

The present disclosure relates to an iron-based mixed powder having excellent uniformity, fluidity and moldability by applying polyamide as a binder, and a method for manufacturing the same. The iron-based mixed powder according to an embodiment of the present disclosure is composed of a mixture of a raw material of mixed powder in which iron-based powder and additive powder are mixed, and polyamide as a binder, wherein 0.03 to 1.50 parts by weight of the binder is mixed based on 100 parts by weight of the raw material of the mixed powder.

Disclosed herein are embodiments of mechanically alloyed powder feedstock and methods for spheroidizing them using microwave plasma processing. The spheroidized powder can be used in metal injection molding processes, hot isostatic processing, and additive manufacturing. In some embodiments, mechanical milling, such as ball milling, can be used to prepare high entropy alloys for microwave plasma processing.

A method for producing a composite magnetic body includes: pressure molding a metal magnetic material into a predetermined shape, the metal magnetic material being an Fe—Si-based metal magnetic material; performing a primary heat treatment of heating the metal magnetic material in an atmosphere with a first oxygen partial pressure to form an Si oxide coating film on a surface of the metal magnetic material; and performing a secondary heat treatment of heating the metal magnetic material that has undergone the primary heat treatment in an atmosphere with a second oxygen partial pressure, which is higher than the first oxygen partial pressure, to form an Fe oxide layer at least partially on a surface of the Si oxide coating film.

A soft magnetic alloy including an internal area having a soft magnetic type alloy composition including Fe and Co, a Co concentrated area existing closer to a surface side than the internal area and having a higher Co concentration than in the internal area, and a SB concentrated area existing closer to the surface side than the Co concentrated area and having a higher concentration of at least one element selected from Si and B than in the internal area.

A method for manufacturing a sintered component includes a step of making a green compact having a relative density of at least 88% by compression-molding a base powder containing a metal powder into a metallic die, a step of machining a groove part having a groove width of 1.0 mm or less in the green compact by processing groove with a cutting tool, and a step of sintering the green compact in which the groove part is formed after the step of forming the groove part.

A method for producing a sintered member, including the steps of: preparing a raw powder; press-forming the raw powder to produce a green compact; and sintering the green compact by high-frequency induction heating, wherein a temperature of the green compact in the sintering step is controlled to satisfy all the following conditions (I) to (III): (I) the temperature is increased without maintaining the temperature in a temperature range equal to or higher than an A.sub.1 point of an Fe—C phase diagram and lower than the sintering temperature of the green compact, (II) a heating rate is set to 12° C./s or more in a temperature range of the A.sub.1 point to an A.sub.3 point of the Fe—C phase diagram, and (III) a heating rate is set to 4° C./s or more in a temperature range of the A.sub.3 point of the Fe—C phase diagram to the sintering temperature of the green compact.

Provided is an alloyed steel powder for powder metallurgy which has excellent compressibility and can be used to produce a sintered body that obtains improved strength simply by sintering. The alloyed steel powder for powder metallurgy contains Cu: 1.0 mass % or more and 8.0 mass % or less, Mo: more than 0.50 mass % and 2.00 mass % or less, and at least one selected from the group consisting of V: 0.05 mass % or more and 0.50 mass % or less, Nb: 0.02 mass % or more and 0.40 mass % or less, and Ti: 0.02 mass % or more and 0.40 mass % or less, with the balance consisting of Fe and inevitable impurities.

The present invention involves a graphene-containing rare earth permanent magnet material and preparation method thereof. The graphene-containing rare earth permanent magnet material, comprising: 20.6 to 23.4 weight percent of neodymium, 6.6 to 7.5 weight percent of praseodymium, 0.95 to 1.20 weight percent of boron, 0.4 to 0.6 weight percent of cobalt, 0.11 to 0.15 weight percent of copper, 2.0 to 2.4 weight percent of lanthanum, 1.7 to 2.1 weight percent of cerium, 1 to 5 weight percent of graphene, a remainder being iron. The graphene-containing rare earth permanent magnet material exhibits excellent temperature resistance, good conductivity and magnet properties even without any heavy rare earth elements like terbium or dysprosium, which dramatically reduces the cost, promotes the efficient utilization of rare earth resources and improves product quality. The preparation method within this invention is simple to realize, easy to control, cost-effective and has high production efficiency and stable product performances.

A method for producing a composite magnetic body includes: pressure molding a metal magnetic material into a predetermined shape, the metal magnetic material being an Fe—Si-based metal magnetic material; performing a primary heat treatment of heating the metal magnetic material in an atmosphere with a first oxygen partial pressure to form an Si oxide coating film on a surface of the metal magnetic material; and performing a secondary heat treatment of heating the metal magnetic material that has undergone the primary heat treatment in an atmosphere with a second oxygen partial pressure, which is higher than the first oxygen partial pressure, to form an Fe oxide layer at least partially on a surface of the Si oxide coating film.