A permanent magnet includes R and T (R essentially includes Sm one or more of rare earth elements in addition to Sm, and T essentially includes Fe, or Fe and Co, one or more of transition metal elements in addition to Fe, or Fe and Co). A composition ratio of R in the permanent magnet is 20 at % or more and 40 at % or less. A remaining part is substantially only T, or only T and C. T amount is more than 1.5 times of R amount and less than 4.0 times of the R amount. Main phase grains included in the permanent magnet have an Nd5Fe17 type crystal structure. An average crystal grain size of the main phase grains of the permanent magnet is greater than 1 μm. A number ratio of main phase grains having a crystal grain size of less than 0.4 μm is less than 20%.

A permanent magnet includes R and T (R essentially includes Sm one or more of rare earth elements in addition to Sm, and T essentially includes Fe, or Fe and Co, one or more of transition metal elements in addition to Fe, or Fe and Co). A composition ratio of R in the permanent magnet is 20 at % or more and 40 at % or less. A remaining part is substantially only T, or only T and C. T amount is more than 1.5 times of R amount and less than 4.0 times of the R amount. Main phase grains included in the permanent magnet have an Nd5Fe17 type crystal structure. An average crystal grain size of the main phase grains of the permanent magnet is greater than 1 μm. A number ratio of main phase grains having a crystal grain size of less than 0.4 μm is less than 20%.

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.

The present disclosure provides a preparation method of a metal powder material. An alloy sheet composed of a matrix phase and a dispersive phase with different chemical reactivities is prepared by the rapid solidification technique of alloy melt. Metal powder is prepared by the reaction of the alloy sheet and an acid solution. Please refer to the description for the detailed preparation method. This method is simple in operation, can be used to prepare many kinds of metal powder materials of different shapes and at the nanometer scale, the submicron scale and the micron scale, and has a good application prospect in the fields of catalysis, powder metallurgy and 3D printing.

The present disclosure provides a preparation method of a metal powder material. An alloy sheet composed of a matrix phase and a dispersive phase with different chemical reactivities is prepared by the rapid solidification technique of alloy melt. Metal powder is prepared by the reaction of the alloy sheet and an acid solution. Please refer to the description for the detailed preparation method. This method is simple in operation, can be used to prepare many kinds of metal powder materials of different shapes and at the nanometer scale, the submicron scale and the micron scale, and has a good application prospect in the fields of catalysis, powder metallurgy and 3D printing.

To provide an R—Fe—B-based rare earth magnet excellent in the squareness and magnetic properties at high temperatures, and a production method thereof.

The present disclosure provides a rare earth magnet including a main phase 10 and a grain boundary phase 20 present. The overall composition of the rare earth magnet of the present disclosure is represented, in terms of molar ratio, by the formula: (R.sup.1.sub.(1-x)La.sub.x).sub.y(Fe.sub.(1-z)Co.sub.z).sub.(100-y-w-v)B.sub.wM.sup.1.sub.v, wherein R.sup.1 is one or more predetermined rare earth elements, and M.sup.1 is one or more predetermined elements, and wherein 0.02≤x≤0.1, 12.0≤y≤20.0, 0.1≤z≤0.3, 5.0≤w≤20.0, and 0≤v≤2.0. The main phase 10 has an R.sub.2Fe.sub.14B-type crystal structure, the average particle diameter of the main phase 10 is from 1 to 10 μm, and the volume ratio of a phase having an RFe.sub.2-type crystal structure in the grain boundary phase 20 is 0.60 or less relative to the grain boundary phase 20.

An aluminum alloy having a composition including 0.1% by mass or more and 2.8% by mass or less of Fe; and 0.002% by mass or more and 2% by mass or less of Nd.

An aluminum alloy having a composition including 0.1% by mass or more and 2.8% by mass or less of Fe; and 0.002% by mass or more and 2% by mass or less of Nd.

An R-T-B based permanent magnet includes a rare earth element R, a transition metal element T, and B. The permanent magnet includes at least Nd as R. The permanent magnet includes at least Fe as T. The permanent magnet contains main phase grains and R-rich phases. The main phase grains include at least R, T, and B. The R-rich phases include at least R. The main phase grains observed in a cross section of the permanent magnet are flat. The cross section is parallel to an easy magnetization axis direction of the permanent magnet. Each of the R-rich phases is located between the main phase grains. An average value of intervals between the R-rich phases in the easy magnetization axis direction is from 5 μm to a width of the permanent magnet in the easy magnetization axis direction.