It has been unexpected found that the machinability and corrosion resistance of powder metal parts can be greatly improved by incorporating calcium aluminoferrite powder, such as naturally occurring brownmillerite powder (Ca.sub.2(Al,Fe).sub.2O.sub.5), into the part. Improved machinability is of enormous value in manufacturing countless parts where it is necessary or desirable to machine the part after it has been sintered, such as is frequently the case with gears, rotors and sprockets. In the practice of this invention, calcium aluminoferrite powder can also be incorporated into parts which will not necessarily be machined for the sole purpose of attaining better corrosion resistance. Surprisingly, the incorporation of the calcium aluminoferrite powder into such parts does not significantly compromise the strength, durability, or wear characteristics of the part and generally improves the service life of the part by providing better corrosion resistance.

The present disclosure provides a coated iron particle, or reaction product of a coating and the iron particle, comprising an iron particle and a ceramic coating disposed on the iron particle. Aspects of the present disclosure provide a coated iron particle, or reaction product of a coating and the iron particle, including an iron particle having a diameter of from about 0.5 micron to about 100 microns; and a ceramic coating disposed on the iron particle. Aspects of the present disclosure further provide compositions comprising a coated iron particle and a polymer or adhesion promoter. Aspects of the present disclosure further provide components, such as components, such as vehicle components, having a surface and a composition of the present disclosure disposed on the surface.

A dust core includes large particles having an average particle size of 8-15 μm, medium particles having an average particle size of 1-5 μm, and small particles having an average particle size of 300-900 nm when a cross section thereof is observed. An area ratio occupied by the large particles is 50% to 90%, an area ratio occupied by the medium particles is 0% to 30%, and an area ratio occupied by the small particles is 5% to 30%, when a total area ratio occupied by the large particles, the medium particles and the small particles is 100% in the cross section. Vickers hardness (Hv) of the large particles, the medium particles and the small particles is 150-600 respectively. The small particles are alloy powder containing Fe and at least Si or N. The dust core may be included in an inductor element.

A soft magnetic powder contains a particle having a composition represented by Fe.sub.xCu.sub.aNb.sub.b(Si.sub.1-yB.sub.y).sub.100-x-a-b, and 0.3≤a≤2.0, 2.0≤b≤4.0, and 72.5≤x≤75.5, and y is a number satisfying f(x)≤y≤0.99, and f(x)=(4×10.sup.−34)×17.56. The particle includes a crystal grain having a grain size of 1.0 nm to 30.0 nm, a Cu segregation portion, and a crystal grain boundary. A content proportion of the crystal grain is 30% or more. When the Cu segregation portion positioned in a surface layer portion and having a grain size of 1.0 nm to 5.0 nm is referred to as a first Cu segregation portion, and the Cu segregation portion positioned in an inner portion and having a grain size of 3.0 nm to 10.0 nm is referred to as a second Cu segregation portion, a number proportion of the first Cu segregation portion is 80% or more, and a number proportion of the second Cu segregation portion is 80% or more.

A method for a workpiece comprising a material composed of a base material and an additive is disclosed, the method including spreading a granular material in superimposed layers. The granular material contains the base material and an organic binder. An ink contains a solvent for dissolving the binder, and a suspension of the additive. Using the ink, patterns are printed onto individual layers. The ink dissolves the binder in the region of the patterns, and introduces the additive in the region of the patterns. The patterns in the layers together produce a three-dimensional shape of the workpiece. The solvent is expelled so that the granular material is connected by the binder and the additive is fixed. Granular material unwetted by the solvent is removed to reveal the green compact of the workpiece. The green compact is thermally treated to convert the base material and the additive into the material.

A soft magnetic alloy powder includes soft magnetic alloy particles having an amorphous phase. Each of the soft magnetic alloy particles has chemical composition represented by Fe.sub.aSi.sub.bB.sub.cC.sub.dP.sub.eCu.sub.fSn.sub.gM1.sub.hM2.sub.i, where M1 is one or more elements of Co and Ni, M2 is one or more elements of Ti, Zr, Hf, Nb, Ta, Mo, W, Cr, Al, Mn, Ag, V, Zn, As, Sb, Bi, Y, and a rare earth element, and 79≤a+h+i≤86, 0≤b≤5, 7.2≤c≤12.2, 0.1≤d≤3, 7.3≤c+d≤13.2, 0.5≤e≤10, 0.4≤f≤2, 0.3≤g≤6, 0≤h≤30, 0≤i≤5, and a+b+c+d+e+f+g+h+i=100 (parts by mol) are satisfied.

A material for producing a three-dimensionally printed part including a metal material and at least one sintering aid in an amount effective to give the three-dimensionally printed part a density of between about 90% and about 100% after sintering is disclosed. A method of printing a three-dimensional part including selecting a metal material, incorporating at least one sintering aid into the metal material to form a print material, and printing the three-dimensional part is also disclosed. A method of producing a sintered metal part including providing a metal material for the sintered metal part incorporating boron as a first sintering aid, incorporating phosphorus as a second sintering aid, forming the metal part in a predetermined form the metal material, and heating the formed metal part to a sintering temperature is also disclosed. Three-dimensionally printed parts are also disclosed.

Bearing steel comprising cubic boron nitride (c-BN) and/or nickel coated cBN spark plasma sintered at a temperature in the range of 850-1050° C. is disclosed. The tribological and corrosion resistance of the bearing steel improved with increasing the amount of c-BN. Further improvement in the properties was achieved with the incorporation of nickel coated c-BN, which caused a phase transition of the bearing steel from magnetic to non-magnetic phase accompanied by interdiffusion enhancement between the matrix and c-BN reinforcement.

A soft magnetic composite comprising an iron or iron alloy ferromagnetic material coated with an oxide material. An interface between the ferromagnetic material and the layer of oxide contains antiphase domain boundaries. Two processes for producing a soft magnetic composite are also provided. One process includes depositing an oxide layer onto an iron or iron alloy ferromagnetic material by molecular beam epitaxy at a partial oxygen pressure of from 1×10.sup.−5 Torr to 1×10.sup.−7 Torr to form a coated composite. The other process includes milling an iron or iron alloy ferromagnetic material powder and an oxide powder by high-energy milling to form a mixture; compacting the mixture and curing in an inert gas atmosphere at a temperature from 500° C. to 1200° C. to form a soft magnetic composite.

Alloy nanoparticles, and a method for forming the alloy nanoparticles, an alloy nanocatalyst comprising the alloy nanoparticles are provided. The alloy nanoparticles are formed by a method comprising mixing a first metal complex including a first metal and a second metal complex including a second metal to form a multimetal compound and heat-treating the multimetal compound to form an alloy compound. The first metal and the second metal comprise transition metal, the first metal complex comprises a pyridine-based ligand, and a carbon shell containing N is formed on the surface of the alloy compound by the heat treatment.