Metallic matrix composites are synthesized by mixing a first reactant, a second reactant and a nucleator compound to obtain a reaction mixture, and heating the reaction mixture to an auto-activation temperature to initiate a self-propagating high-temperature synthesis reaction between the first and second reactants. The metallic matrix composite can include a metallic matrix and an in situ formed reinforcement. The reinforcement can be formed of discrete particles substantially uniformly dispersed within the metallic matrix. Each of the particles can have a reinforcement constituent disposed about a core formed of the nucleator compound.

Articles are manufactured using self-propagating high-temperature synthesis (SHS) reactions. Particulates including reactants can be blended to form a particulate blend. The particulate blend can be preformed. The preform article can be heated to a pre-heat temperature being below an auto-activation temperature and above a minimum compression activated synthesis temperature. Compressive stress can be exerted on the preform article at the pre-heat temperature to initiate the SHS reaction between the reactants and thereby form a product metallic compound. At approximately peak temperature, a flow stress of the product metallic compound can be exceeded to substantially reduce porosity and thereby form a shaped substantially dense article.

Articles are manufactured using self-propagating high-temperature synthesis (SHS) reactions. Particulates including reactants can be blended to form a particulate blend. The particulate blend can be preformed. The preform article can be heated to a pre-heat temperature being below an auto-activation temperature and above a minimum compression activated synthesis temperature. Compressive stress can be exerted on the preform article at the pre-heat temperature to initiate the SHS reaction between the reactants and thereby form a product metallic compound. At approximately peak temperature, a flow stress of the product metallic compound can be exceeded to substantially reduce porosity and thereby form a shaped substantially dense article.

Disclosed is a nano dispersion copper alloy with high air-tightness and low free oxygen content and a brief manufacturing process thereof, wherein alloy comprises the following components: Al.sub.2O.sub.3, Ca and La. The manufacturing process comprises the following steps of: preparing Cu—Al.sub.2O.sub.3 alloy powder by an internal oxidation method; mixing the Cu—Al.sub.2O.sub.3 alloy powder with Cu—Ca—La alloy powder; sheathing the mixed powder under protection of argon; performing hot extrusion and then rotary forging; vacuumizing the sheath after the rotary forging; and sealing and placing the sheath in a nitrogen atmosphere with a temperature of 450° C. to 550° C. and a pressure intensity of 40 Mpa to 60 Mpa for 3 hours to 5 hours. The dispersion copper prepared by the present disclosure has the advantages of low free oxygen content (≤15 ppm), high dimensional stability, good air-tightness and an air leakage rate≤1.0×10.sup.−10 Pa m.sup.3/s after hydrogen annealing.

The disclosure relates to sintering compositions that can be used in three-dimensional printing or additive manufacturing processes. The sintering compositions generally include one or more metallic iron-containing powders and a minor amount of a boron-containing powder as a sintering aid. Sintered models or products formed from the sintering compositions have substantially improved density and surface roughness values relative to models formed without the boron-containing powder.

The disclosure relates to sintering compositions that can be used in three-dimensional printing or additive manufacturing processes. The sintering compositions generally include one or more metallic iron-containing powders and a minor amount of a boron-containing powder as a sintering aid. Sintered models or products formed from the sintering compositions have substantially improved density and surface roughness values relative to models formed without the boron-containing powder.

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.

Nanocrystalline metal powders comprising tungsten, molybdenum, rhenium and/or niobium can be synthesized using a combustion reaction. Methods for synthesizing the nanocrystalline metal powders are characterized by forming a combustion synthesis solution by dissolving in water an oxidizer, a fuel, and a base-soluble, ammonium precursor of tungsten, molybdenum, rhenium, or niobium in amounts that yield a stoichiometric burn when combusted. The combustion synthesis solution is then heated to a temperature sufficient to substantially remove water and to initiate a self-sustaining combustion reaction. The resulting powder can be subsequently reduced to metal form by heating in a reducing gas environment.

Mixed powder that contains first hard particles, second hard particles, graphite particles, and iron particles is used to manufacture a sintered alloy. The first hard particle is a Fe—Mo—Cr—Mn based alloy particle, the second hard particle is a Fe—Mo—Si based alloy particle. The mixed powder contains 5 to 50 mass % of the first hard particles, 1 to 8 mass % of the second hard particles, and 0.5 to 1.0 mass % of the graphite particles when total mass of the first hard particles, the second hard particles, the graphite particles, and the iron particles is set as 100 mass %.

Mixed powder that contains first hard particles, second hard particles, graphite particles, and iron particles is used to manufacture a sintered alloy. The first hard particle is a Fe—Mo—Cr—Mn based alloy particle, the second hard particle is a Fe—Mo—Si based alloy particle. The mixed powder contains 5 to 50 mass % of the first hard particles, 1 to 8 mass % of the second hard particles, and 0.5 to 1.0 mass % of the graphite particles when total mass of the first hard particles, the second hard particles, the graphite particles, and the iron particles is set as 100 mass %.