The compact for a magnetic core is manufactured by filling a soft magnetic powder in the die hole, pressing it to form a compact at a density ratio of the soft magnetic powder being 91% or more, and extruding it from the die hole. Before filling the soft magnetic powder to the die hole, a lubricating coating containing lubricating oil and molybdenum disulfide particles is formed on the inner surface of the die hole. It is more effective when further containing insulating ceramic particles. On the extrusion-sliding surface, the compact has a surface layer of the structure that molybdenum disulfide particles and the insulating ceramic particles are interposed between the soft magnetic powder particles, and insulation of soft magnetic powder particles in the surface layer is not destroyed by extrusion. This provides a powder magnetic core suitable for high frequency application.

A composite is obtained by press-molding a mixed powder comprising 20-50 vol % of a metal powder and 50-80 vol % of a diamond powder for which a first peak in a volumetric distribution of particle size lies at 5-25 m, and a second peak lies at 55-195 m, and a ratio between the area of a volumetric distribution of particle sizes of 1-35 m and the area of a volumetric distribution of particle sizes of 45-205 m is from 1:9 to 4:6, thereby obtaining a composite having a high thermal conductivity and a coefficient of thermal expansion close to that of semiconductor devices, which is easy to mold into a prescribed shape.

A composite is obtained by press-molding a mixed powder comprising 20-50 vol % of a metal powder and 50-80 vol % of a diamond powder for which a first peak in a volumetric distribution of particle size lies at 5-25 m, and a second peak lies at 55-195 m, and a ratio between the area of a volumetric distribution of particle sizes of 1-35 m and the area of a volumetric distribution of particle sizes of 45-205 m is from 1:9 to 4:6, thereby obtaining a composite having a high thermal conductivity and a coefficient of thermal expansion close to that of semiconductor devices, which is easy to mold into a prescribed shape.

Embodiments provide for a method of manufacturing a part. In example embodiments, the method includes positioning a material within a cavity of a die, positioning solid lubricant within the cavity of the die between a surface of a plunging component and the material, and uniaxially applying pressure to the material with the plunging component via the solid lubricant until the material forms a desired shape.

An object of the invention is to provide a method that is for manufacturing a powder magnetic core through simple compression molding and capable of manufacturing a complicatedly shaped powder magnetic core with reliable high strength and insulating properties. The invention is directed to a method for manufacturing a powder magnetic core with a metallic soft magnetic material powder, the method including: a first step including mixing a soft magnetic material powder and a binder; a second step including compression molding the mixture obtained after the first step; a third step including performing at least one of grinding and cutting on the compact obtained after the second step; and a fourth step including heat-treating the compact after the third step, wherein in the fourth step, the compact is heat-treated so that an oxide layer containing an element constituting the soft magnetic material powder is formed on the surface of the soft magnetic material powder.

An object of the invention is to provide a method that is for manufacturing a powder magnetic core through simple compression molding and capable of manufacturing a complicatedly shaped powder magnetic core with reliable high strength and insulating properties. The invention is directed to a method for manufacturing a powder magnetic core with a metallic soft magnetic material powder, the method including: a first step including mixing a soft magnetic material powder and a binder; a second step including compression molding the mixture obtained after the first step; a third step including performing at least one of grinding and cutting on the compact obtained after the second step; and a fourth step including heat-treating the compact after the third step, wherein in the fourth step, the compact is heat-treated so that an oxide layer containing an element constituting the soft magnetic material powder is formed on the surface of the soft magnetic material powder.

The method including: applying a graphite-based lubricant to a cavity surface of a die; forming a first graphite-based powder layer by disposing graphite-based powder that does not contain a binder on a cavity surface of a lower punch, forming a magnet powder body by putting magnet powder on the first graphite-based powder layer, and forming a second graphite-based powder layer by disposing graphite-based powder that does not contain a binder on the magnet powder body; and producing a compact by performing press forming using the lower punch and a upper punch while heating the magnet powder body surrounded by the graphite-based lubricant applied to the cavity surface of the die, the first graphite-based powder layer, and the second graphite-based powder layer, and releasing the compact from a forming die.