The present invention provides an R-T-B based sintered magnet including R.sub.2T.sub.14B crystal grains wherein; a grain boundary is formed by two or more adjacent R.sub.2T.sub.14B crystal grains, an R—O—C concentrated part, in which concentrations of R, O and C are higher than those in the R.sub.2T.sub.14B crystal grains respectively, is in the grain boundary, and a ratio (O/R) of O atom to R atom in the R—O—C concentrated part satisfies the following formula (1):
0.4<(O/R)<0.7.

The present invention provides an R-T-B based permanent magnet, comprising: a main phase which is composed of the structure of R.sub.2T.sub.14B (R is at least one element selected from Y, La, Ce, Pr, Nd, Sm, Eu and Gd, and T is one or more transition metal elements having Fe or a combination of Fe and Co as necessary); and a grain boundary phase which is composed of Ce.sub.xM.sub.1-x (M is at least one element selected from Mg, Al, Si, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Y, Zr, Nb, Mo, Ag, In, Sn, La, Pr, Nd, Sm, Eu, Gd, Hf, Ta, W and Bi, and x is within the range of 0.20≦x≦0.55), and the cross-sectional ratio Atre of the grain boundary phase to the whole magnet structure is within the range of 0.03<Atre<0.07.

In one embodiment, a permanent magnet has a composition expressed by a composition formula: RN.sub.x(Cr.sub.pSi.sub.qM.sub.1-p-q).sub.z (R is at least one element selected from Y and rare-earth elements, M is at least one element selected from Fe and Co, and x, p, q, and z are atomic ratios satisfying 0.5≦x≦2.0, 0.005≦p≦0.2, 0.005≦q≦0.2, and 4≦z≦13, respectively). The permanent magnet has a density of 6.5 g/cm.sup.3 or more and satisfies the relationship of I(110)/{I(110)+I(303)}≦0.05, in which I(303) represents a diffraction peak intensity from a (303) plane of a Th.sub.2Zn.sub.17 phase obtained through powder X-ray diffraction of the permanent magnet, and I(110) represents a diffraction peak intensity from a (110) plane of an α-Fe phase obtained through the powder X-ray diffraction.

Frangible firearm projectiles, firearm cartridges containing the same, and methods for forming the same. The firearm projectiles are formed from a compacted mixture of metal powders that includes zinc and iron powders and which may include an anti-sparking agent. The compacted mixture is heat treated for a time sufficient to form a plurality of discrete alloy domains within the compacted mixture. The frangible firearm projectile may be formed by a mechanism that includes vapor-phase diffusion bonding and oxidation of the metal powders and that does not include forming a liquid phase of any of the metal powders or utilizing a polymeric binder. A majority component of the frangible firearm projectile may be iron. One or more of zinc, bismuth, tin, copper, nickel, tungsten, boron, and/or alloys thereof may form a minority component of the frangible firearm projectile. The anti-sparking agent may include a borate, such as boric acid.

A bearing steel composition contains 0.1 to 0.2 wt % C, 3.25 to 4.25 wt % Cr, 9.5 to 11.5 wt % Mo, 5.75 to 6.75 wt % W, 1.5 to 2.5 wt % V, and 2.5 to 3.5 wt % Ni. A bearing component, such as a rolling element, an inner race or outer race, is formed from the bearing steel composition, for example, by a powder metallurgical technique and then is subjected to a case hardening treatment. The bearing component may have a microstructure composed of martensite, retained austenite and at least one of carbides and/or carbonitrides. The carbon level at the surface of the bearing component may be 0.5 to 1.1 wt %.

A manufacturing method is performed in an additive manufacturing printing apparatus. An embodiment of the manufacturing method includes: S1—feeding inert gas into the additive manufacturing printing apparatus, and performing laser scanning on silicon steel metal particles to start to melt the silicon steel metal particles from bottom to top layer by layer into a silicon steel metal layer; S2—feeding treatment gas into the additive manufacturing printing apparatus, performing laser scanning on the silicon steel particles again to enable the treatment gas to react with the molten silicon steel metal particles to finally form an insulating nitride layer, and alternately performing S1 and S2 until the laminated iron core of a structure having a plurality of alternate silicon steel metal layers and insulating nitride layers is formed. An embodiment of the present invention may manufacture a customized laminated iron core with a complex shape and good performance.

Provided is a powder suitable for a magnetic member capable of suppressing noise in a frequency range of 100 kHz to 20 MHz. The powder for a magnetic member contains a plurality of particles 2. The main part of the particle 2 is made of an alloy. The alloy contains B. The content of B in the alloy is 5.0 mass % or more and 8.0 mass % or less. The alloy may further contain one or more elements selected from the group consisting of Cr, Mn, Co, and Ni. The content of these elements is 0 mass % or more and 25 mass % or less. The balance of the alloy is Fe and unavoidable impurities. The alloy contains an Fe.sub.2B phase. The area percentage of the Fe.sub.2B phase in the alloy is 20 mass % or more and 80 mass % or less.

Methods and alloy systems for non-Be BMG matrix composite materials that can be used to additively manufacturing parts with superior mechanical properties, especially high toughness and strength, are provided. Alloys are directed to BMGMC materials comprising a high strength BMG matrix reinforced with properly scaled, soft, crystalline metal dendrite inclusions dispersed throughout the matrix in a sufficient concentration to resist fracture.

A production method for water-atomized metal powder includes: in a region in which the average temperature of a molten metal stream is higher than the melting point by 100° C. or more, spraying primary cooling water from a plurality of directions at a convergence angle of 10° to 25°, where the convergence angle is an angle between an impact direction on the molten metal stream of the primary cooling water from one direction and an impact direction on the molten metal stream of the primary cooling water 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+50° C.) or lower, spraying secondary cooling water on the metal powder under conditions of an impact pressure of 10 MPa or more.

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.