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 dust core including soft magnetic particles having pure iron or an iron alloy and a grain boundary layer present between adjacent soft magnetic particles. The grain boundary layer has a main phase and a barrier phase. The main phase having a spinel-type ferrite of a metal element. The metal element serves as a divalent cation. The barrier phase having one or more of Cu, Sn, or Co. The dust core can be obtained by using a powder for magnetic cores including soft magnetic particles coated with a film in which a first ferrite and a second ferrite coexist. The barrier phase blocks the Fe diffusion from the soft magnetic particles and suppresses the deterioration of the main phase having the second ferrite responsible for the insulating property.

A dust core including soft magnetic particles having pure iron or an iron alloy and a grain boundary layer present between adjacent soft magnetic particles. The grain boundary layer has a main phase and a barrier phase. The main phase having a spinel-type ferrite of a metal element. The metal element serves as a divalent cation. The barrier phase having one or more of Cu, Sn, or Co. The dust core can be obtained by using a powder for magnetic cores including soft magnetic particles coated with a film in which a first ferrite and a second ferrite coexist. The barrier phase blocks the Fe diffusion from the soft magnetic particles and suppresses the deterioration of the main phase having the second ferrite responsible for the insulating property.

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.

The invention provides a powder magnetic core and a method 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. A method for manufacturing a powder magnetic core with a metallic soft magnetic material powder includes: 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 invention provides a powder magnetic core and a method 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. A method for manufacturing a powder magnetic core with a metallic soft magnetic material powder includes: 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 invention provides a method 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 invention provides a method 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.

A carrier-type heat-treatment apparatus including a furnace main body that includes heaters and a mesh belt that transports an object to be heat-treated into the furnace main body includes a gas pipe arranged inside the furnace main body, the gas pipe being configured to inject a gas into the furnace main body, in which a low-temperature zone and a high-temperature zone are provided inside the furnace main body with the gas, the low-temperature zone being provided on an entrance side of the furnace main body, the high-temperature zone being provided on an exit side of the furnace main body and having a temperature higher than the low-temperature zone.

A carrier-type heat-treatment apparatus including a furnace main body that includes heaters and a mesh belt that transports an object to be heat-treated into the furnace main body includes a gas pipe arranged inside the furnace main body, the gas pipe being configured to inject a gas into the furnace main body, in which a low-temperature zone and a high-temperature zone are provided inside the furnace main body with the gas, the low-temperature zone being provided on an entrance side of the furnace main body, the high-temperature zone being provided on an exit side of the furnace main body and having a temperature higher than the low-temperature zone.