An example of a composition includes a host metal present in an amount ranging from about 95.00 weight percent to about 99.99 weight percent, based on a total weight of the composition. A flow additive is present in an amount ranging from about 0.01 weight percent to about 5.00 weight percent, based on the total weight of the composition. The flow additive consists of a metal containing compound that is reducible to an elemental metal in a reducing environment at a reducing temperature less than or equal to a sintering temperature of the host metal. The elemental metal is capable of being incorporated into a bulk metal phase of the host metal in a final metal object. The composition is spreadable, having a Hausner Ratio less than 1.25.

An example of a composition includes a host metal present in an amount ranging from about 95.00 weight percent to about 99.99 weight percent, based on a total weight of the composition. A flow additive is present in an amount ranging from about 0.01 weight percent to about 5.00 weight percent, based on the total weight of the composition. The flow additive consists of a metal containing compound that is reducible to an elemental metal in a reducing environment at a reducing temperature less than or equal to a sintering temperature of the host metal. The elemental metal is capable of being incorporated into a bulk metal phase of the host metal in a final metal object. The composition is spreadable, having a Hausner Ratio less than 1.25.

A composite magnetic body according to one aspect of the present invention includes a first metal magnetic particle covered with a first resin portion made of a first resin material and a second metal magnetic particle having a smaller particle size than the first metal magnetic particle, where the second metal magnetic particle is bound to the first metal magnetic particle via a second resin portion made of a second resin material and the second resin material has a larger molecular weight than the first resin material.

A composite magnetic body according to one aspect of the present invention includes a first metal magnetic particle covered with a first resin portion made of a first resin material and a second metal magnetic particle having a smaller particle size than the first metal magnetic particle, where the second metal magnetic particle is bound to the first metal magnetic particle via a second resin portion made of a second resin material and the second resin material has a larger molecular weight than the first resin material.

Fine particles that can be sintered and grow to 100 nm or larger without oxidation even when retained at a baking temperature in an oxygen-containing atmosphere and that can suppress oxidation in a long-term preservation in the air or other oxygen-containing atmospheres, a method of producing the fine particles, and a method of producing fine particles that can suppress oxidation in a collecting process after the production of the fine particles. A fine particle production method for producing fine particles using feedstock powder by means of a gas-phase process includes a step of producing fine particle bodies by converting the feedstock powder into a mixture in a gas phase state using a gas-phase process and cooling the mixture in a gas phase state with a quenching gas containing an inert gas and a hydrocarbon gas having 4 or less carbon atoms, and a step of supplying an organic acid to the produced fine particle bodies.

Fine particles that can be sintered and grow to 100 nm or larger without oxidation even when retained at a baking temperature in an oxygen-containing atmosphere and that can suppress oxidation in a long-term preservation in the air or other oxygen-containing atmospheres, a method of producing the fine particles, and a method of producing fine particles that can suppress oxidation in a collecting process after the production of the fine particles. A fine particle production method for producing fine particles using feedstock powder by means of a gas-phase process includes a step of producing fine particle bodies by converting the feedstock powder into a mixture in a gas phase state using a gas-phase process and cooling the mixture in a gas phase state with a quenching gas containing an inert gas and a hydrocarbon gas having 4 or less carbon atoms, and a step of supplying an organic acid to the produced fine particle bodies.

Provided is a fine particle production apparatus and a fine particle production method capable of easily obtaining surface treated fine particles. The fine particle production apparatus produces fine particles using feedstock by means of a gas-phase process. The apparatus includes a treatment section configured to transform the feedstock into a mixture in a gas phase state by means of the gas-phase process, a feedstock supply section configured to supply the feedstock to the treatment section, a cooling section configured to cool the mixture in a gas phase state in the treatment section using a quenching gas containing an inert gas, and a supply section configured to supply a surface treating agent to fine particle bodies in a temperature region in which the surface treating agent is not denatured, the fine particle bodies being produced by cooling the mixture in the gas phase state with the quenching gas.

A dust core contains a powder of a crystalline magnetic material powder and a powder of an amorphous magnetic material. The sum of the content of the crystalline magnetic material powder and the content of the amorphous magnetic material powder is 83 mass percent or more. The mass ratio of the content of the crystalline magnetic material powder to the sum of the content of the crystalline magnetic material powder and the content of the amorphous magnetic material powder is 20 mass percent or less. The median diameter D50 of the amorphous magnetic material powder is greater than or equal to the median diameter D50 of the crystalline magnetic material powder.

A dust core contains a powder of a crystalline magnetic material powder and a powder of an amorphous magnetic material. The sum of the content of the crystalline magnetic material powder and the content of the amorphous magnetic material powder is 83 mass percent or more. The mass ratio of the content of the crystalline magnetic material powder to the sum of the content of the crystalline magnetic material powder and the content of the amorphous magnetic material powder is 20 mass percent or less. The median diameter D50 of the amorphous magnetic material powder is greater than or equal to the median diameter D50 of the crystalline magnetic material powder.

A method of producing a SmFeN-based rare earth magnet, the method including: dispersing a SmFeN-based anisotropic magnetic powder comprising Sm, Fe, and N using a resin-coated metal media or a resin-coated ceramic media to obtain a dispersed SmFeN-based anisotropic magnetic powder; mixing the dispersed SmFeN-based anisotropic magnetic powder with a modifier powder to obtain a powder mixture; compacting the powder mixture in a magnetic field to obtain a magnetic field compact; pressure-sintering the magnetic field compact to obtain a sintered compact; and heat treating the sintered compact.