Morphology, microstructure, compressive behavior, and biocorrosive properties of magnesium or magnesium alloy foams allow for their use in biodegradable biomedical, metal-air battery electrode, hydrogen storage, and lightweight transportation applications. Magnesium or Mg alloy foams are usually very difficult to manufacture due to the strong oxidation layer around the metallic particles; however, in this invention, they can be synthesized via a camphene-based freeze-casting process with the addition of graphite powder using precisely controlled heat-treatment parameters. The average porosity ranges from 45 to 85 percent and the median pore diameter is about a few tens to hundreds of microns, which are suitable for bio and energy applications utilizing their enhanced surface area. This invention based on powder-slurry freeze-casting method using camphene as a volatile solvent is also applicable for other metal foams such as iron, copper, or others to produce three-dimensional metal foams with high strut connectivity.

The present invention provides a method for the manufacture of transition metal oxide fine particles, the method comprising the steps of: heating a strong-alkaline aqueous solution while stirring same; adding to and dissolving in the heated strong-alkaline aqueous solution a transition metal oxide; adding a strong-acid aqueous solution to the strong alkaline aqueous solution in which the transition metal oxide is dissolved, while stirring same, thereby re-dissolving a solid generated at the interface between the strong-alkaline aqueous solution and the strong-acid aqueous solution; adjusting the pH of the mixed aqueous solution resulting from mixing the strong-alkaline aqueous solution and the strong acid aqueous solution, through adjustment of the adding rate and amount of the strong-acid aqueous solution, to precipitate transition metal oxide fine particles; and separating the transition metal oxide fine particles from the mixed aqueous solution and sequentially washing, drying, and thermally treating the separated transition metal oxide fine particles.

A method of increasing volume ratio of magnetic particles in a MnBi alloy includes depositing a MnBi alloy powder containing magnetic particles and non-magnetic particles on a sloped surface having a magnetic field acted thereupon. The method further includes collecting falling non-magnetic particles while separated magnetic particles are magnetically retained on the sloped surface.

A method of increasing volume ratio of magnetic particles in a MnBi alloy includes depositing a MnBi alloy powder containing magnetic particles and non-magnetic particles on a sloped surface having a magnetic field acted thereupon. The method further includes collecting falling non-magnetic particles while separated magnetic particles are magnetically retained on the sloped surface.

An additive manufacturing method of manufacturing a product by laminating metal includes: laminating the metal so as to form a half-finished product of the product and a support; and spraying dry ice pellets having a particle shape to the support, after the laminating.

An additive manufacturing method of manufacturing a product by laminating metal includes: laminating the metal so as to form a half-finished product of the product and a support; and spraying dry ice pellets having a particle shape to the support, after the laminating.

Some variations provide a system for producing a functionalized powder, comprising: an agitated pressure vessel; first particles and second particles contained within the agitated pressure vessel; a fluid contained within the agitated pressure vessel; an exhaust line for releasing the fluid from the agitated pressure vessel; and a means for recovering a functionalized powder containing the second particles disposed onto surfaces of the first particles. A preferred fluid is carbon dioxide in liquefied or supercritical form. The carbon dioxide may be initially loaded into the pressure vessel as solid carbon dioxide. The pressure vessel may be batch or continuous and is operated under reaction conditions to functionalize the first particles with the second particles, thereby producing a functionalized powder, such as nanofunctionalized metal particles in which nanoparticles act as grain refiners for a component ultimately produced from the nanofunctionalized metal particles. Methods for making the functionalized powder are also disclosed.

A method can include pressing material to form a billet where the material includes aluminum and one or more metals selected from a group consisting of alkali metals, alkaline earth metals, group 12 transition metals, and basic metals having an atomic number equal to or greater than 31; extruding the billet to form extrudate; and forming a degradable component from the extrudate.

A system for producing an object from a powder by selective laser sintering. The system includes a chamber and a support platform in the chamber. A spreader applies a layer of powder to a bed surface. An irradiation source irradiates select points in the powdered layer prepared on the support platform. A radiant heater heats at least a portion of the bed surface. A temperature sensor monitors the temperature of select points on the bed surface. A controller adjusts the radiant heater in response to temperature data provided by the temperature sensor.

A system for producing an object from a powder by selective laser sintering. The system includes a chamber and a support platform in the chamber. A spreader applies a layer of powder to a bed surface. An irradiation source irradiates select points in the powdered layer prepared on the support platform. A radiant heater heats at least a portion of the bed surface. A temperature sensor monitors the temperature of select points on the bed surface. A controller adjusts the radiant heater in response to temperature data provided by the temperature sensor.