A Composition of matter defined by the general formula of M1M2M3M4X.sub.3 wherein: X is carbon; and M1, M2, M3, and M4 each represent a different transition metal selected from the group consisting of Ti, Ta, Sc, Cr, Zr, Hf, Mo, V, and Nb.

A high-hardness composite oxide dispersion-strengthened tungsten alloy and a preparation method thereof are disclosed. The high-hardness composite oxide dispersion-strengthened tungsten alloy consists essentially of a tungsten phase, and nano-scale Y.sub.2O.sub.3 and ZrO.sub.2 particles dispersed in the tungsten phase, wherein there is a Y—Zr—O ternary phase structure at a coherent/semi-coherent interface.

A method for manufacturing an alloy formed from a boride of a precious metal, may involve reacting a source of the precious metal with a source of boron in a salt or a mixture of salts in the molten state. An alloy formed from a boride of a precious metal may include crystalline nanoparticles of M.sub.xB.sub.y with M being a precious metal, distributed in an amorphous matrix of B or in an amorphous matrix of B and of M.sub.zB.sub.a.

A nanoparticle or agglomerate which contains connected multi-walled spherical fullerenes coated in layers of graphite. In different embodiments, the nanoparticles and agglomerates have different combinations of: a high mass fraction compared to other carbon allotropes present, a low concentration of defects, a low concentration of elemental impurities, a high Brunauer, Emmett and Teller (BET) specific surface area, and/or a high electrical conductivity. Methods are provided to produce the nanoparticles and agglomerates at a high production rate without using catalysts.

An aluminum based composite material includes an aluminum parent phase and dispersions dispersed in the aluminum parent phase and formed such that a portion or all of additives react with aluminum in the aluminum parent phase, an average particle diameter of the dispersions is 20 nm or less, a content of the dispersions is 0.25% by mass or more and 0.72% by mass or less in terms of carbon amount, and an interval between the dispersions adjacent to each other is 210 nm or less.

A synthetic titanium-corundum composite includes a titanium alloy and a coherently bonded corundum phase. The titanium alloy includes at least one elemental titanium solid solution and the atomic percentage of aluminum in the titanium alloy ranges from 0.5% to 24.5%.

A synthetic titanium-corundum composite includes a titanium alloy and a coherently bonded corundum phase. The titanium alloy includes at least one elemental titanium solid solution and the atomic percentage of aluminum in the titanium alloy ranges from 0.5% to 24.5%.

Methods are provided for synthesizing high purity niobium or rhenium powders by a combustion reaction. The methods can include: forming a combustion synthesis solution by dissolving in water an oxidizer, a fuel, and at least one base-soluble, ammonium salt of niobium or rhenium in amounts that yield a stoichiometric burn when combusted; and heating the combustion synthesis solution to a temperature sufficient to substantially remove the water and to initiate a self-sustaining combustion reaction.

The present disclosure provides a metal-ceramic composite structure and a fabrication method thereof. The metal-ceramic composite structure includes a ceramic substrate having a groove on a surface thereof; a metal member filled in the groove, including a main body made of zirconium base alloy, and a reinforcing material dispersed in the main body and selected from at least one of W, Mo, Ni, Cr, stainless steel, WC, TiC, SiC, ZrC, ZrO.sub.2, BN, Si.sub.3N.sub.4, TiN and Al.sub.2O.sub.3; a luminance value L of the metal member surface is in a range of 36.92-44.07 under a LAB Chroma system.

The invention relates to a cermet material comprising a first phase MAX having the general formula Ti.sub.n+1AlC.sub.n and a second intermetallic phase having the general formula Ti.sub.xAl.sub.y, where n equals 1 or 2, x is between 1 and 3, y is between 1 and 3, and x+y4. The proportion by volume of the first phase in the material is between 70% and 95%. The proportion by volume of the second phase in the material is between 30% and 5%. The void ratio is less than 5%.