A zirconium nitride powder having a volume resistivity of 107 Ω.Math.cm or more in the state of the pressurized powder body hardened at a pressure of 5 MPa, and a particle size distribution D90 of 10 μm or less when ultrasonically dispersed for 5 minutes in a state of being diluted with water or an alcohol having a carbon number of which is in a range of 2 to 5. Also, the zirconium nitride powder is dispersed in an acrylic monomer or an epoxy monomer to prepare a monomer dispersion. Further, the zirconium nitride powder is dispersed in a dispersing medium as a black pigment and further a resin is mixed to prepare a black composition.

A sintered magnet contains Sm—Fe—N-based crystal grains and has high coercivity; and a magnetic powder is capable of forming a sintered magnet without lowering the coercivity even if heat is generated in association with the sintering. A sintered magnet comprises a crystal phase composed of a plurality of Sm—Fe—N-based crystal grains and a nonmagnetic metal phase present between the Sm—Fe—N crystal grains adjacent to each other, wherein a ratio of Fe peak intensity I.sub.Fe to SmFeN peak intensity I.sub.SmFeN measured by an X-ray diffraction method is 0.2 or less. A magnetic powder comprises Sm—Fe—N-based crystal particles and a nonmagnetic metal layer covering surfaces of the Sm—Fe—N crystal particles.

A nanocomposite metal material includes a carrier formed of Zr and two-element metal particles supported on the carrier. The two-element metal is formed of Cu and Ni, and a degree of oxidation of the carrier is more than 31% and 100% or less. In a case where the nanocomposite metal material is disposed in a reaction furnace of a thermal reactor, the inside of the reaction furnace is brought into a vacuum state, and the inside of the reaction furnace is heated to a temperature range of 250° C. or higher and 350° C. or lower with a heating mechanism included in the thermal reactor while supplying at least one of hydrogen gas and deuterium gas into the reaction furnace, excessive heat of the nanocomposite metal material is 100 W/kg or more.

The present invention provides a high-strength and high-plasticity titanium matrix composite and a preparation method thereof. The preparation method includes: preparing high-oxygen hydride-dehydride titanium powder using a high-temperature rotary ball grinding treatment process, in which the prepared hydride-dehydride titanium powder has a particle size of 10-40 μm, and has an oxygen content of 0.8-1.5 wt. %; preparing high-purity ultra-fine oxygen adsorbent powder using a wet grinding method of high-energy vibration ball grinding treatment process; in which a purity of the oxygen adsorbent powder is ≥99.9%, and a particle size of the oxygen adsorbent powder is ≤8 μm; mixing the high-oxygen hydride-dehydride titanium powder with the oxygen adsorbent powder in a protective atmosphere, and then press-forming the powder obtained after mixing to obtain a raw material blank; and performing atmosphere protective sintering treatment on the raw material blank to obtain a titanium matrix composite. The method prepares a titanium matrix composite reinforced by in-situ self-generating multi-scale Ca—Ti—O, TiC, TiB particles. The microstructure and grains are effectively refined, and the strength and plasticity of the material are significantly improved.

A method can include blending materials to form a blend where the materials include a first particulate material and a second particulate material and where the first particulate material is water reactive and includes aluminum and one or more metals selected from a group consisting of metals, alkaline earth metals, group 12 transition metals, and basic having an atomic number equal to or greater than 31; and forming a degradable object from the blend.

A method can include blending materials to form a blend where the materials include a first particulate material and a second particulate material and where the first particulate material is water reactive and includes aluminum and one or more metals selected from a group consisting of metals, alkaline earth metals, group 12 transition metals, and basic having an atomic number equal to or greater than 31; and forming a degradable object from the blend.

An R-T-B based permanent magnet includes main phase grains composed of R.sub.2T.sub.14B type compound. R is a rare earth element. T is iron group element(s) essentially including Fe or Fe and Co. B is boron. An average grain size of the main phase grains is 0.8 μm to 2.8 μm. The R-T-B based permanent magnet contains at least C and Ga in addition to R, T, and B. B is contained at 0.71 mass % to 0.86 mass %. C is contained at 0.13 mass % to 0.34 mass %. Ga is contained at 0.40 mass % to 1.80 mass %. A formula (1) of 0.14≦[C]/([B]+[C])≦0.30 is satisfied, where [B] is a B content represented by atom %, and [C] is a C content represented by atom %.

An R-T-B based permanent magnet includes main phase grains composed of R.sub.2T.sub.14B type compound. R is a rare earth element. T is iron group element(s) essentially including Fe or Fe and Co. B is boron. An average grain size of the main phase grains is 0.8 μm to 2.8 μm. The R-T-B based permanent magnet contains at least C and Ga in addition to R, T, and B. B is contained at 0.71 mass % to 0.86 mass %. C is contained at 0.13 mass % to 0.34 mass %. Ga is contained at 0.40 mass % to 1.80 mass %. A formula (1) of 0.14≦[C]/([B]+[C])≦0.30 is satisfied, where [B] is a B content represented by atom %, and [C] is a C content represented by atom %.

A method for producing a sintered R-T-B based magnet of this disclosure includes the steps of preparing a plurality of sintered R-T-B based magnet bodies (R is at least one of rare earth elements and necessarily contains Nd and/or Pr; and T is at least one of transition metals and necessarily contains Fe); preparing a plurality of alloy powder particles having a size of 90 μm or less and containing a heavy rare earth element RH (the heavy rare earth RH is Tb and/or Dy) at a content of 20 mass % or greater and 80 mass % or less; loading the plurality of sintered R-T-B based magnet bodies and the plurality of alloy powder particles of a ratio of 2% by weight or greater and 15% by weight or less with respect to the plurality of sintered R-T-B based magnet bodies into a process chamber; and heating, while rotating and/or swinging, the process chamber to move the sintered R-T-B based magnet bodies and the alloy powder particles continuously or intermittently to perform an RH supply and diffusion process.

Disclosed is a method for preparing vanadium or vanadium alloy powder from a vanadium-containing raw material through a shortened process, including: calcinating a mixture of a vanadium-containing raw material and an alkali compound for oxidation to form a water-soluble vanadate; purifying the vanadate followed by vanadium precipitation to produce an intermediate CaV.sub.2O.sub.6 with high purity; dissolving CaV.sub.2O.sub.6 in a molten-salt medium together with other raw materials to form a uniform reaction system; and introducing a reducing agent to the system followed by separation, washing and drying to produce vanadium or vanadium alloy powder having a particle size of 50-800 nm and a purity of 99.0 wt % or more. The method can continuously process vanadium-containing raw materials to prepare vanadium or vanadium alloy powder.