A method of manufacturing a pressed powder magnetic core disclosed herein may include: mixing soft magnetic metal particles, low-melting-point glass particles and lubricant and heating a mixture of the soft magnetic metal particles, the low-melting-point glass particles and the lubricant at a temperature that is higher than a melting point of the lubricant and is lower than a softening point of the low-melting-point glass particles so as to obtain powder of coated metal particles in which surfaces of the soft magnetic metal particles are coated by the lubricant and the low-melting-point glass particles are distributed in coating layers of the lubricant; filling a mold with the powder; press-molding the powder in the mold; and annealing the press-molded powder. In the pressed powder magnetic core, an amount of the low-melting-point glass particles may be 0.1 wt % to 5.0 wt % relative to an amount of the soft magnetic metal particles.

A method of manufacturing a pressed powder magnetic core disclosed herein may include: mixing soft magnetic metal particles, low-melting-point glass particles and lubricant and heating a mixture of the soft magnetic metal particles, the low-melting-point glass particles and the lubricant at a temperature that is higher than a melting point of the lubricant and is lower than a softening point of the low-melting-point glass particles so as to obtain powder of coated metal particles in which surfaces of the soft magnetic metal particles are coated by the lubricant and the low-melting-point glass particles are distributed in coating layers of the lubricant; filling a mold with the powder; press-molding the powder in the mold; and annealing the press-molded powder. In the pressed powder magnetic core, an amount of the low-melting-point glass particles may be 0.1 wt % to 5.0 wt % relative to an amount of the soft magnetic metal particles.

Produced is an iron-based sintered alloy in which hard particles derived from a titanium carbide powder are dispersed in the form of islands in a matrix comprising a two phase structure of austenite+martensite. The iron-based sintered alloy is obtained by mixing the titanium carbide powder, a Cr powder, a Mo powder, a Co powder, a Fe powder and a powder of Al, Ti or Nb so as to obtain a mixed powder that contains, in terms of mass %, 20-35% of titanium carbide, 3.0-12.0% of Cr, 3.0-8.0% of Mo, 8.0-23% of Ni, 0.6-4.5% of Co and 0.6-1.0% of Al, Ti or Nb, with the balance Fe, and then subjecting the mixed powder to cold isostatic compression molding, vacuum sintering and solution treatment.

An iron-based powder for powder metallurgy includes an iron-based powder and a composite oxide powder, and the composite oxide contains, by mass, from 15% to 30% Si, from 9% to 18% Al, from 3% to 6% B, from 0.5% to 3% Mg, from 2% to 6% Ca, from 0.01% to 1% Sr, and from 45% to 55% O.

An iron-based powder for powder metallurgy includes an iron-based powder and a composite oxide powder, and the composite oxide contains, by mass, from 15% to 30% Si, from 9% to 18% Al, from 3% to 6% B, from 0.5% to 3% Mg, from 2% to 6% Ca, from 0.01% to 1% Sr, and from 45% to 55% O.

The metallurgical composition comprises a main particulate metallic material, for example iron or nickel, and at least one alloy element for hardening the main metallic material, which form a structural matrix; a particulate solid lubricant, such as graphite, hexagonal boron nitride or mixture thereof; and a particulate alloy element which is capable of forming, during the sintering of the composition conformed by compaction or by injection molding, a liquid phase, agglomerating the solid lubricant in discrete particles. The composition may comprise an alloy component to stabilize the alpha-iron matrix phase, during the sintering, in order to prevent the graphite solid lubricant from being solubilized in the iron. The invention further refers to the process for obtaining a self-lubricating sintered product.

An article and method of forming the article are disclosed. The article has a surface comprising a nanostructured ferritic alloy. The surface includes a plurality of nanofeatures that include complex oxides of yttrium and titanium disposed in an iron-bearing alloy matrix. The iron-bearing alloy matrix at the surface includes about 5 weight percent to about 30 weight percent of chromium, and about 0.1 weight percent to about 10 weight percent of molybdenum. Further, a concentration of a chi phase or a sigma phase in the nanostructured ferritic alloy at the surface is less than about 5 volume percent. The method generally includes the steps of milling, thermo-mechanically consolidating, annealing, and then cooling at a rate that hinders the formation of chi and sigma phases in the nanostructured ferritic alloy at the surface.

An article and method of forming the article are disclosed. The article has a surface comprising a nanostructured ferritic alloy. The surface includes a plurality of nanofeatures that include complex oxides of yttrium and titanium disposed in an iron-bearing alloy matrix. The iron-bearing alloy matrix at the surface includes about 5 weight percent to about 30 weight percent of chromium, and about 0.1 weight percent to about 10 weight percent of molybdenum. Further, a concentration of a chi phase or a sigma phase in the nanostructured ferritic alloy at the surface is less than about 5 volume percent. The method generally includes the steps of milling, thermo-mechanically consolidating, annealing, and then cooling at a rate that hinders the formation of chi and sigma phases in the nanostructured ferritic alloy at the surface.

The metallurgical composition comprises a main particulate metallic material, for example iron or nickel, and at least one alloy element for hardening the main metallic material, which form a structural matrix; a particulate solid lubricant, such as graphite, hexagonal boron nitride or mixture thereof; and a particulate alloy element which is capable of forming, during the sintering of the composition conformed by compaction or by injection molding, a liquid phase, agglomerating the solid lubricant in discrete particles. The composition may comprise an alloy component to stabilize the alpha-iron matrix phase, during the sintering, in order to prevent the graphite solid lubricant from being solubilized in the iron. The invention further refers to the process for obtaining a self-lubricating sintered product.

A sintered friction material, in which a content of a copper component is 0.5 mass % or less, is provided. The sintered friction material includes a titanate and a metal material other than copper, as a matrix. A content of the metal material other than copper is 10.0 volume % to 34.0 volume %. A method for manufacturing a sintered friction material is provided. The method includes a mixing step of mixing raw materials containing a titanate and a metal material other than copper, a molding step of molding the raw materials mixed in the mixing step, and a sintering step of sintering, at 900? C. to 1300? C., a molded product molded in the molding step. In the sintered friction material, the titanate and the metal material other than copper form a matrix, and a content of the metal material other than copper is 10.0 volume % to 34.0 volume %.