A powder metal material comprises pre-alloyed iron-based powder including carbon present in an amount of 0.25 to 1.50% by weight of the pre-alloyed iron-based powder. Graphite is admixed in an amount of 0.25 to 1.50% by weight of the powder metal material. The admixed graphite includes particles finer than 200 mesh in an amount greater than 90.0% by weight of the admixed graphite. Molybdenum disulfide is admixed in an amount of 0.1 to 4.0% by weight of the powder metal material, copper is admixed in an amount of 1.0 to 5.0% by weight of the powder metal material, and the material is free of phosphorous. The powder metal material is then compacted and sintered at a temperature of 1030 to 1150 C. At least 50% of the admixed graphite of the starting powder metal material remains as free graphite after sintering.

A powder metal material comprises pre-alloyed iron-based powder including carbon present in an amount of 0.25 to 1.50% by weight of the pre-alloyed iron-based powder. Graphite is admixed in an amount of 0.25 to 1.50% by weight of the powder metal material. The admixed graphite includes particles finer than 200 mesh in an amount greater than 90.0% by weight of the admixed graphite. Molybdenum disulfide is admixed in an amount of 0.1 to 4.0% by weight of the powder metal material, copper is admixed in an amount of 1.0 to 5.0% by weight of the powder metal material, and the material is free of phosphorous. The powder metal material is then compacted and sintered at a temperature of 1030 to 1150 C. At least 50% of the admixed graphite of the starting powder metal material remains as free graphite after sintering.

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.

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 iron-based sintered alloy for sliding member, in which seizure resistance is improved, and a production method therefor, are provided. The iron-based sintered alloy for sliding member consists of, by mass %, 10 to 30% of Cu, 0.2 to 2.0 % of C, 0.03 to 0.9 % of Mn, 0.36 to 3.65% of S, and the balance of Fe and inevitable impurities in the overall composition. The iron-based sintered alloy for sliding member exhibits a metallic structure in which copper phases and pores are dispersed in the matrix that includes mainly a martensite structure and sulfide particles are dispersed in the matrix and the copper phases. The sulfide particles are dispersed at 1 to 30 vol. % with respect to the matrix.

A new pre-alloyed metal based powder, intended to be used in surface coating of metal parts. The powder is deposited using e.g. laser cladding or plasma transfer arc welding (PTA), or thermal spray (e.g. HVOF). The powder is useful for reducing friction and improving wear reducing properties of the deposited coating. Such coatings may also improve machinability. As friction or wear reducing component, inclusions of manganese sulphide or tungsten sulphide in the pre-alloyed powder may be used.

The mixed powder for iron-based powder metallurgy of the present invention comprises an iron-based powder and a CaS raw material powder containing one or more selected from the group consisting of calcium sulfate anhydrite III, calcium sulfate anhydrite II, calcium sulfate dihydrate, calcium sulfide, and calcium sulfate hemihydrate. The CaS raw material powder is coated with at least one selected from a lubricant and a binder.

A new pre-alloyed metal based powder, intended to be used in surface coating of metal parts. The powder is deposited using e.g. laser cladding or plasma transfer arc welding (PTA), or thermal spray (e.g. HVOF). The powder is useful for reducing friction and improving wear reducing properties of the deposited coating. Such coatings may also improve machinability. As friction or wear reducing component, inclusions of manganese sulphide or tungsten sulphide in the pre-alloyed powder may be used.

The mixed powder for iron-based powder metallurgy of the present invention comprises a powder containing calcium sulfate anhydrite II such that the CaS weight ratio after sintering is 0.01 wt % or more to 0.1 wt % or less. The powder containing calcium sulfate anhydrite II preferably has a volume-average particle size of 0.1 m or more to 60 m or less and preferably additionally contains one or more ternary oxides selected from the group consisting of CaAlSi oxides and CaMgSi oxides. The weight ratio of the ternary oxides and CaS after the sintering is preferably 3:7 to 9:1.

An iron-based sintered sliding member consists of, by mass %, 0.1 to 10% of Cu, 0.2 to 2.0% of C, 0.03 to 0.9% of Mn, 0.52 to 6.54% of S, and the balance of Fe and inevitable impurities. The iron-based sintered sliding member satisfies the following First Formula in which [S %] represents mass % of S and [Mn %] represents mass % of Mn in the overall composition. The iron-based sintered sliding member exhibits a metallic structure in which pores and sulfide particles are dispersed in the matrix that includes a martensite structure at not less than 50% by area ratio in cross section. The sulfide particles are dispersed at 3 to 30 vol. % with respect to the matrix.
[S %]=0.6[Mn %]+0.5 to 6.0First Formula