An improved atomized powder metal material containing an increased amount of free graphite after heat treatment and/or sintering is provided. The powder metal material is typically a ferrous alloy and includes carbon in an amount of 1.0 wt. % to 6.5 wt. % and silicon in an amount of 0.1 wt. % to 6.0 wt. %, based on the total weight of the powder metal material. The powder metal material can also include various other alloying elements, for example at least one of nickel (Ni), cobalt (Co), copper (Cu), tin (Sn), aluminum (Al), sulfur (S), phosphorous (P), boron (B), nitrogen (N), chromium (Cr), manganese (Mn), molybdenum (Mo), vanadium (V), niobium (Nb), tungsten (W), titanium (Ti), tantalum (Ta) zirconium (Zr), zinc (Zn), strontium (Sr), calcium (Ca), barium (Ba) magnesium (Mg), lithium (Li), sodium (Na), and potassium (K).

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.

A soft magnetic alloy powder contains Fe, Si, and at least one of Cr and Al, as constituent elements, wherein, on the surface of each grain constituting the alloy powder, an oxide film is provided which is such that: it contains Si, as well as at least one of Cr and Al, as constituent elements; these elements are contained at higher percentages by mass than those in the alloy part inside the grain; and the content of Si, expressed in percentage by mass, is higher than the total content of Cr and Al. The soft magnetic metal powder can achieve a higher filling rate.

A soft magnetic alloy powder contains Fe, Si, and at least one of Cr and Al, as constituent elements, wherein, on the surface of each grain constituting the alloy powder, an oxide film is provided which is such that: it contains Si, as well as at least one of Cr and Al, as constituent elements; these elements are contained at higher percentages by mass than those in the alloy part inside the grain; and the content of Si, expressed in percentage by mass, is higher than the total content of Cr and Al. The soft magnetic metal powder can achieve a higher filling rate.

A soft magnetic alloy powder contains Fe, Si, and at least one of Cr and Al, as constituent elements, wherein, on the surface of each grain constituting the alloy powder, an oxide film is provided which is such that: it contains Si, as well as at least one of Cr and Al, as constituent elements; these elements are contained at higher percentages by mass than those in the alloy part inside the grain; and the content of Si, expressed in percentage by mass, is higher than the total content of Cr and Al. The soft magnetic metal powder can achieve a higher filling rate.

The present invention discloses a method for refining large-particle-size pure copper or copper alloy particles by high-energy ball milling, the method comprising the following steps: (1) using large-particle-size pure copper or copper alloy coarse particles as a raw material and cyclohexane or water as a process control agent, and crushing and refining the particles by high-energy ball milling to obtain small-particle-size copper or copper alloy powder; and (2) decreasing an oxygen content in the powder obtained in step (1) in a reducing atmosphere to obtain pure copper or copper alloy powder. In the present invention, by improving the overall process flow of the preparation method and the parameter conditions of each process step, the method greatly decreases energy consumption compared with existing copper powder preparation techniques. In addition, the method features a simple process and low production costs.

The present invention discloses a method for refining large-particle-size pure copper or copper alloy particles by high-energy ball milling, the method comprising the following steps: (1) using large-particle-size pure copper or copper alloy coarse particles as a raw material and cyclohexane or water as a process control agent, and crushing and refining the particles by high-energy ball milling to obtain small-particle-size copper or copper alloy powder; and (2) decreasing an oxygen content in the powder obtained in step (1) in a reducing atmosphere to obtain pure copper or copper alloy powder. In the present invention, by improving the overall process flow of the preparation method and the parameter conditions of each process step, the method greatly decreases energy consumption compared with existing copper powder preparation techniques. In addition, the method features a simple process and low production costs.

Disclosed is a method for producing transition metal oxide fine particles having a size smaller than several micrometers (μm), and more preferably, having a size of several hundred nanometers (nm). To this end, the method for producing transition metal oxide fine particles of the present invention comprises dissolving a transition metal oxide in a strongly basic aqueous solution, and titrating same with a strongly acidic aqueous solution, thereby precipitating transition metal oxide fine particles.

Disclosed is a method for producing transition metal oxide fine particles having a size smaller than several micrometers (μm), and more preferably, having a size of several hundred nanometers (nm). To this end, the method for producing transition metal oxide fine particles of the present invention comprises dissolving a transition metal oxide in a strongly basic aqueous solution, and titrating same with a strongly acidic aqueous solution, thereby precipitating transition metal oxide fine particles.