The present invention provides a sintered metal friction material that has excellent wear resistance, heat resistance even at high load and has a higher friction coefficient while maintaining a friction coefficient and wear resistance that are hard to decrease, and has a reduced content of copper of less than 5 mass %. There is provided a sintered metal friction material characterized in that the sintered metal friction material comprises a sintered material of a friction material composition, the friction material composition comprises matrix metals and a friction modifier, the matrix metals comprise following 20 to 40 mass % of iron powder, 20 to 40 mass % of nickel powder, 0.5 to 10 mass % of zinc powder, 0.5 to 5 mass, of tin powder, 0.5 to 4 mass % of copper powder and 0.5 to 5 mass % of sintering assist powder.

A production method for water-atomized metal powder includes: in a region in which the average temperature of a molten metal stream having an Fe concentration of 76.0 at % or more and less than 82.9 at % is 100° C. or more higher than the melting point, spraying primary cooling water at a convergence angle of 10° to 25°, where the convergence angle is an angle between an impact direction on the molten metal stream from one direction and an impact direction on the molten metal stream from any other direction; and in a region in which 0.0004 seconds or more have passed after an impact of the primary cooling water and the average temperature of metal powder is the melting point or higher and (the melting point+100° C.) or lower, spraying secondary cooling water on the metal powder under conditions of an impact pressure of 10 MPa or more.

The invention relates to a method for producing precise components, preferably machining tools or cold forming tools, cold extrusion punches and dies, by laser melting or laser sintering or laser deposit welding or FDM or binder jetting of a powder material, which consists of a mixture of at least two powder elements, the powder mixture being formed by the primary component iron powder and additional powder alloying elements, which are present in elemental, pre-alloyed or partially pre-alloyed form, the powder elements each being added separately or in arbitrary combination in the following quantities according to the standard DIN EN 10027-2 no. 1.33XX or DIN EN 10027-2 no. 1.27XX, in particular according to the standard DIN EN 10027-2 no. 1.3343 with the short name HS6-5-2C or DIN EN 10027-2 no. 1.2709, a powder alloy being created from said powder elements over the course of the laser sintering process, wherein the following powder elements, present in elemental, alloyed or pre-alloyed form, are each additionally added to the alloy separately or in arbitrary combination: tungsten in the range of between 35, 10 and 0.7 mass%, preferably 10 mass%, titanium in the range of between 0.2, 3.2 to 10.7 mass%, preferably 3.2 mass%, carbon in the range of between 0.08, 1.23 up to 4.1 mass%, preferably 1.23 mass%, O in the range of between 0.00 up to 0.02 mass%, N in the range of between 0.00 up to 0.02 mass%, undefined residual substances at less than 0.1 mass%.

A magnetic material and an inductor capable of attaining both higher magnetic permeability and improved DC superposition characteristics. A composite magnetic material contains metal magnetic particles, in which the metal magnetic particles include first particles having a median diameter D.sub.50 of 1.3 .Math.m or more and 5.0 .Math.m or less (i.e., from 1.3 .Math.m to 5.0 .Math.m), and second particles having a median diameter D.sub.50 larger than the first particles. The first and second particles each include a core portion made of a metal magnetic material, and an insulating film provided on a surface of the core portion. The insulating film of the second particles has an average thickness of 40 nm or more and 100 nm or less (i.e., from 40 nm to 100 nm). The insulating film of the first particles has an average thickness smaller than that of the insulating film of the second particles.

The present invention provides a permanent magnet suitable as a variable flux magnet for a variable magnetic flux motor. A permanent magnet comprising R (R is composed of 75 at % or more of Nd and 25 at % or less of at least one element selected from the group consisting of Y, Ce, La, Pr, Sm, Eu, Gd, Er, Tm, Yb and Lu), Fe and B as the main component, wherein, said permanent magnet is composed of a main phase of a crystal structure represented by R.sub.2Fe.sub.14B, a ratio of the element R to all constituent element satisfies 11.8 at %≦R≦12.2 at %, a cross-sectional area ratio Are of the sub-phase with a higher concentration of R than that of the main phase to the whole magnet structure satisfies 0%<Are≦1.3%, and a cross-sectional area ratio Ama of the main phase to the whole magnet structure is 97%≦Ama.

A preparation method for a metal soft magnetic composite material inductor includes: smelting Fe, Si and Cr and then employing a water atomization or gas atomization means to fabricate an alloy powder; after sifting by particle size, mixing powders of different particle size levels and performing coating insulation, and performing post-granulation to obtain a metal soft composite material granulation powder; adopting the granulation powder to press a material cake, and transferring and molding same; adopting a hollow coil in a liquid-phase coating mold cavity, curing and demolding to obtain a semi-finished product, then continuously heating and curing the semi-finished product, and preparing an end electrode to obtain a finished inductor.

A method for fabricating an article includes forming a billet consisting essentially of a stainless steel composition of manganese 2.00 wt. %-24.00 wt. % chromium 19.00 wt. %-30 wt. % molybdenum 0.50 wt. %-4.0 wt. % nitrogen 0.25 wt. %-1.10 wt. % carbon ≤1 wt. % phosphorus ≤0.03 wt. % sulfur ≤1 wt. % nickel <22 wt. % cobalt <0.10 wt. % silicon ≤1 wt. % niobium ≤0.80 wt. % oxygen ≤1 wt. % copper ≤0.25 wt. % balance iron.
The billet is annealed and cold worked to form an article. Without annealing of the article, the article is subsequently case hardened at a single case hardening temperature to form a surface layer on a top surface thereof. Articles formed with the indicated stainless steel composition with case hardened surface layers are also provided.

A magnetic core includes a metal magnetic powder, which has a large size powder, an intermediate size powder, and a small size powder. A particle size of the large size powder is 10 μm or more and 60 μm or less. A particle size of the intermediate size powder is 2.0 μm or more and less than 10 μm. A particle size of the small size powder is 0.1 μm or more and less than 2.0 μm. The large size powder, the intermediate size powder, and the small size powder have an insulation coating. When A1 represents an average insulation coating thickness of the large size powder, A2 represents an average insulation coating thickness of the intermediate size powder, A3 represents an average insulation coating thickness of the small size powder, A3 is 30 nm or more and 100 nm or less, A3/A1≥1.3, and A3/A2≥1.0.

Disclosed are a rare-earth permanent magnet having improved magnetic properties and a method of manufacturing the same. A method of manufacturing a rare-earth permanent magnet may include: preparing a mixed powder including i) a first alloy represented by R1.sub.aR2.sub.bB.sub.cM.sub.dFe.sub.bal and ii) a second alloy represented by R2.sub.bB.sub.cM.sub.dFe.sub.bal where R1 is one or two or more of La, Ce, and Y; R2 is a rare-earth element except for La, Ce, and Y; and M is a metal element; press-forming and sintering the prepared mixed powder in a magnetic field to prepare a sintered body; and performing a heat treatment based on diffusion temperature conditions of an R1 component and an R2 component contained in the prepared sintered body.

This sintered R-T-B based rare-earth magnet includes: R.sub.2Fe.sub.14B type compound crystal grains, including a light rare-earth element RL (which includes at least one of Nd and Pr) as a major rare-earth element R, as main phases; and a heavy rare-earth element RH (which includes at least one of Dy and Tb). Before its surface region is removed, the sintered R-T-B based rare-earth magnet has no layer including the rare-earth element R at a high concentration in that surface region. The sintered R-T-B based rare-earth magnet has a portion in which coercivity decreases gradually from its surface region toward its core portion. The difference in the amount of TRE between a portion of the sintered R-T-B based rare-earth magnet that reaches a depth of 500 μm as measured from its surface region toward its core portion and the core portion of the sintered R-T-B based rare-earth magnet is 0.1 through 1.0.