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.

This disclosure, and the exemplary embodiments provided herein, include AM processed Ti-MMCs reinforced with either aluminum oxide or tantalum pentoxide. According to an exemplary embodiment, composite feedstock powders of Ti-6Al-4V (Ti64) with 1% and 3% (by volume) reinforcements of either nano-Al.sub.2O.sub.3 or Ta.sub.2O.sub.5 are prepared by high energy ball milling and then 3-D printed using SLM.

This disclosure, and the exemplary embodiments provided herein, include 3D printed titanium composites and methods including 1 vol. % carbon nanotube reinforcements on selective laser melt printed Ti64. The interrelationships with laser energy density, laser power, and laser scan speed are demonstrated and discussed. Utilizing selective laser melting, according to one exemplary embodiment of this disclosure, a >99% dense Ti-CNT composite is disclosed with microhardness of 4.75 GPa—a 30% enhancement over its Ti64 counterpart.

This disclosure, and the exemplary embodiments provided herein, include 3D printed titanium composites and methods including 1 vol. % carbon nanotube reinforcements on selective laser melt printed Ti64. The interrelationships with laser energy density, laser power, and laser scan speed are demonstrated and discussed. Utilizing selective laser melting, according to one exemplary embodiment of this disclosure, a >99% dense Ti-CNT composite is disclosed with microhardness of 4.75 GPa—a 30% enhancement over its Ti64 counterpart.

A method for manufacturing a porous metal body according to the present invention includes: a surface oxidizing step of heating a titanium-containing powder in an atmosphere containing oxygen at a temperature of 250° C. or more for 30 minutes or more to provide a surface-oxidized powder; and a sintering step of depositing the surface-oxidized powder in a dry process, and sintering the surface-oxidized powder by heating it in a reduced pressure atmosphere or an inert atmosphere at a temperature of 950° C. or more.

A tungsten-base alloy material and a preparation method therefor. The preparation method comprises: 1) evenly grinding composite powder containing tungsten and zirconium oxide, and then performing annealing treatment at 700-1000° C. to obtain powder A; and 2) grinding and then compression moulding the powder A, and then performing liquid-phase sintering to obtain a tungsten-base alloy blank so as to obtain the tungsten-base alloy material.

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.

Methods of fabricating objects using additive manufacturing are provided. The methods create in situ dispersoids within the object. The methods are used with refractory alloy powders which are pretreated to increase the oxygen content to between 500 ppm and 3000 ppm or to increase the nitrogen content to between 250 ppm and 1500 ppm. The pretreated powders are then formed into layers in an environmentally controlled chamber of an additive manufacturing machine. The environmentally controlled chamber is adjusted to have between 500 ppm and 200 ppm oxygen. The layer of pretreated powder is then exposed to a transient moving energy source for melting and solidifying the layer; and creating in situ dispersoids in the layer.

A method for forming tungsten-refractory metal alloy powders, and tungsten-refractory metal alloy powders formed by the method. The method includes mixing a majority portion by weight of a base tungsten powder with a minority portion by weight of a base refractory metal powder to form a mixture, which is then milled for a period of time sufficient to at least partially mechanically alloy the base tungsten powder and base refractory metal powder together to form at-least-partially-mechanically-alloyed particles, which are then heat treated to a temperature sufficient to promote diffusion between tungsten and the refractory metal and obtain agglomerations of particles having only a tungsten phase, which are then milled to break up the agglomerations of particles and obtain the tungsten-refractory metal alloy powder.

A method for forming tungsten-refractory metal alloy powders, and tungsten-refractory metal alloy powders formed by the method. The method includes mixing a majority portion by weight of a base tungsten powder with a minority portion by weight of a base refractory metal powder to form a mixture, which is then milled for a period of time sufficient to at least partially mechanically alloy the base tungsten powder and base refractory metal powder together to form at-least-partially-mechanically-alloyed particles, which are then heat treated to a temperature sufficient to promote diffusion between tungsten and the refractory metal and obtain agglomerations of particles having only a tungsten phase, which are then milled to break up the agglomerations of particles and obtain the tungsten-refractory metal alloy powder.