A sintered bearing includes, on an inner peripheral surface, a cylindrical portion and a one-side increased-diameter portion, which are provided so as to be continuous in the axial direction. An end portion of one side in the axial direction of the cylindrical portion and an end portion of another side in the axial direction of the increased-diameter portion coincide, and the cylindrical portion and the increased-diameter portion are molded by performing sizing on a sintered compact having a tubular shape, which is introduced into a die.

An objective of the present invention is to provide a mixed powder for powder metallurgy that makes it possible to improve mold-filling ability and reduce spread in weight of molded bodies. The mixed powder for powder metallurgy according to the present invention is obtained by mixing a graphite powder with an average particle diameter D50 of 1.0 μm or more to 3.0 μm or less and D90 of 10 μm or less, without adding a binder, with an iron-based powder, while applying a sheer force. The thus obtained mixed powder for powder metallurgy according to the present invention is characterized by including the iron-based powder and the graphite powder present so as to be collected in concave portions of the iron-based powder.

An iron alloy manufacturing method which can suppress occurrence of distortion and crack in formed iron alloy layers is provided. During execution of a forming step, in a first temperature control step, an iron alloy layer temperature T1 of a predetermined number of laminated layers from a surface layer of iron alloy layers formed in the forming step is controlled to be kept within a range of Ms≤T1≤Ms+α, and in a second temperature control step, a base plate temperature T2 is controlled to be kept within a range of Mf−β≤T2≤Mf.

Provided herein is a soft magnetic alloy powder that can exhibit a high saturation flux density and desirable soft magnetic characteristics. A dust core using the soft magnetic alloy powder is also provided. The soft magnetic alloy powder is an Fe-based nanocrystalline soft magnetic alloy powder of a crystallized Fe-based amorphous soft magnetic alloy powder, and has a DSC curve with a first peak that is 15% or less of a first peak of the Fe-based amorphous soft magnetic alloy in terms of a maximum value.

Provided herein is a soft magnetic alloy powder that can exhibit a high saturation flux density and desirable soft magnetic characteristics. A dust core using the soft magnetic alloy powder is also provided. The soft magnetic alloy powder is an Fe-based nanocrystalline soft magnetic alloy powder of a crystallized Fe-based amorphous soft magnetic alloy powder, and has a DSC curve with a first peak that is 15% or less of a first peak of the Fe-based amorphous soft magnetic alloy in terms of a maximum value.

Disclosed is a partially diffusion-alloyed steel powder having excellent fluidity, formability, and compressibility without containing Ni, Cr, and Si. A partially diffusion-alloyed steel powder having excellent fluidity, formability, and compressibility that includes an iron-based powder and Mo diffusionally adhered to a surface of the iron-based powder, in which Mo content is 0.2 mass % to 2.0 mass %, a weight-based median diameter D50 is 40 μm or more, and among particles contained in the partially diffusion-alloyed steel powder, those particles having an equivalent circular diameter of 50 μm to 200 μm have a number average of solidity of 0.70 to 0.86, the solidity being defined as (particle cross-sectional area/envelope-inside area).

Elements formed from magnetic materials and their methods of manufacture are presented. Magnetic materials include a magnetic alloy material, such as, for example, an Fe—Co alloy material (e.g., the Fe—Co—V alloy Hiperco-50®). The magnetic alloy materials may comprise a powdered material suitable for use in additive manufacturing techniques, such as, for example direct energy deposition or laser powder bed fusion. Manufacturing techniques include the use of variable deposition time and energy to control the magnetic and structural properties of the materials by altering the microstructure and residual stresses within the material. Manufacturing techniques also include post deposition processing, such as, for example, machining and heat treating. Heat treating may include a multi-step process during which the material is heated, held and then cooled in a series of controlled steps such that a specific history of stored internal energy is created within the material. Magnetic elements may include, for example, motors, generators, solenoids and switches, sensors, transformers, and hall thrusters, among other elements.

Provided is a steel strip joining method that can appropriately evaluate risk of a fracture in a joined part and prevent a fracture more reliably. An iron-based mixed powder for powder metallurgy comprises: an iron-based alloy powder; and an alloying powder, wherein the iron-based alloy powder contains Mo: 0.2 mass % or more and 1.5 mass % or less, the alloying powder contains a graphite powder and a copper powder, a ratio of a mass of the graphite powder to a total mass of the iron-based alloy powder and the alloying powder is 0.10 mass % to 1.0 mass %, a ratio of a mass of the copper powder to the total mass of the iron-based alloy powder and the alloying powder is 0.5 mass % to 3.0 mass %, and the copper powder has an average particle size of 25 μm or less, and a specific surface area of 0.30 m.sup.2/g or more.

A metal powder for powder metallurgy contains Fe as a principal component, Cr in a proportion of 11.0 mass % or more and 25.0 mass % or less, Ni in a proportion of 8.0 mass % or more and 30.0 mass % or less, Si in a proportion of 0.20 mass % or more and 1.2 mass % or less, C in a proportion of 0.070 mass % or more and 0.40 mass % or less, Mn in a proportion of 0.10 mass % or more and 2.0 mass % or less, P in a proportion of 0.10 mass % or more and 0.50 mass % or less, and at least one of W and Nb in a proportion of 0.20 mass % or more and 3.0 mass % or less in total.

A magnetic body of the coil component contains, as soft magnetic alloy grains, first grains whose alloy components are substantially Fe, Si, and Cr, and second grains which contain, as alloy components, Fe, Si, and an element other than Si or Cr that oxidizes more easily than Fe; the average grain size of the second grains is smaller than the average grain size of the first grains; the first grains have, on their surface, an amorphous oxide film containing Si and Cr; the second grains have, on their surface, a crystalline oxide layer containing the element other than Si or Cr that oxidizes more easily than Fe; and the crystalline oxide forms adhesion parts, each contacting a multiple number of the first grains via the amorphous oxide film thereof and coupling or bridging the multiple number of the first grains. The coil component can offer improved mechanical strength.