A process for producing silicon nano-particles from a raw silicon material, the process including steps of alloying the raw silicon material with at least one alloying metal to form an alloy; thereafter, processing the alloy to form alloy nano-particles; and thereafter, distilling the alloying metal from the alloy nano-particles whereby silicon nano-particles are produced.

The present invention provides a high-entropy Half-Heusler thermoelectric material with a low lattice thermal conductivity and a preparation method thereof. The general formula of the high-entropy Half-Heusler thermoelectric material with a low lattice thermal conductivity is Zr.sub.xHf.sub.1-xNi.sub.yPd.sub.1-ySn, where x is equal to 0.6 to 0.8, and y is equal to 0.8 to 0.9. The preparation method of the high-entropy Half-Heusler thermoelectric material with a low lattice thermal conductivity comprises the following steps: preparing and mixing materials according to the general formula of Zr.sub.0.7Hf.sub.0.3Ni.sub.0.85Pd.sub.0.15Sn, putting the mixed raw materials in a levitation melting for melting, grinding the obtained ingot into powder and drying it, and sintering the powder by using spark plasma sintering into a bulk high-entropy Half-Heusler thermoelectric material with a low lattice thermal conductivity. The high-entropy Half-Heusler thermoelectric material of the present invention has a relatively low lattice thermal conductivity and a relatively high ZT value.

The present invention provides a high-entropy Half-Heusler thermoelectric material with a low lattice thermal conductivity and a preparation method thereof. The general formula of the high-entropy Half-Heusler thermoelectric material with a low lattice thermal conductivity is Zr.sub.xHf.sub.1-xNi.sub.yPd.sub.1-ySn, where x is equal to 0.6 to 0.8, and y is equal to 0.8 to 0.9. The preparation method of the high-entropy Half-Heusler thermoelectric material with a low lattice thermal conductivity comprises the following steps: preparing and mixing materials according to the general formula of Zr.sub.0.7Hf.sub.0.3Ni.sub.0.85Pd.sub.0.15Sn, putting the mixed raw materials in a levitation melting for melting, grinding the obtained ingot into powder and drying it, and sintering the powder by using spark plasma sintering into a bulk high-entropy Half-Heusler thermoelectric material with a low lattice thermal conductivity. The high-entropy Half-Heusler thermoelectric material of the present invention has a relatively low lattice thermal conductivity and a relatively high ZT value.

The disclosure relates to a method for preparing Ti(C,N)-based superhard metal composite materials, with Ti(C,N) powder and (W,Mo,Ta)(C,N) powder as main raw materials and Co powder as binding phase for preparation, thereby obtaining a material in which a microstructure is a double-core rim structure that has both a black core rim and a white core rim. The material has a complete and evenly distributed double-core rim structure. In the condition that the ensured hardness of the material is not reduced and even slightly increased, the toughness of the material is significantly improved, wherein the fracture toughness of the material is in the range of 11.3 to 12.5 MPa.Math.m.sup.1/2.

A method based on fluidizing for modifying and preparing low-cost titanium powders for 3D printing includes: using hydrogenated-dehydrogenated irregularly-shaped titanium powders as the raw material, adding the titanium powders to a fluidized bed reactor, and introducing Ar or H.sub.2 at the flow rate of 0.5-1.5 L/min, heating the reactor to 300-700 C., and fluidizing for 5-90 min to modify the titanium powders. When filled with high-purity argon gas and heated at high temperature, the sharp edges and corners of irregularly-shaped titanium powders are ground collision of the particles due to the friction among powder particles.

A method based on fluidizing for modifying and preparing low-cost titanium powders for 3D printing includes: using hydrogenated-dehydrogenated irregularly-shaped titanium powders as the raw material, adding the titanium powders to a fluidized bed reactor, and introducing Ar or H.sub.2 at the flow rate of 0.5-1.5 L/min, heating the reactor to 300-700 C., and fluidizing for 5-90 min to modify the titanium powders. When filled with high-purity argon gas and heated at high temperature, the sharp edges and corners of irregularly-shaped titanium powders are ground collision of the particles due to the friction among powder particles.

Provided is a thermoelectric material having an intermetallic compound in an AlFeSi system as a main component, exhibiting a thermoelectric effect in a temperature range from a room temperature to 600 C., and becoming a p-type or n-type thermoelectric material by a composition control, a manufacturing method thereof, and a thermoelectric power generation module thereof. A thermoelectric material according to the present invention including at least Al, Fe, and Si and represented by a general formula of Al.sub.22+pqFe.sub.38.5+3qSi.sub.49.5p2q (where p satisfies 0p16.5 and q satisfies 0.34q0.34) and including a phase represented by Al.sub.2Fe.sub.3Si.sub.3 as a main phase.

A structured multi-phase composite which include a metal phase, and a low stiffness, high thermal conductivity phase or encapsulated phase change material, that are arranged to create a composite having high thermal conductivity, having reduced/controlled stiffness, and a low CTE to reduce thermal stresses in the composite when exposed to cyclic thermal loads. The structured multi-phase composite is useful for use in structures such as, but not limited to, high speed engine ducts, exhaust-impinged structures, heat exchangers, electrical boxes, heat sinks, and heat spreaders.

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 m to 2.8 m. 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 m to 2.8 m. 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 %.