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 latent heat storage body microcapsule includes a core including gallium or gallium alloy; and a shell covering the core and including gallium oxide. A method for producing the same includes a particle-forming step of forming gallium or an alloy of gallium in a liquid state into particles; a water treatment step of heating the particles in distilled water to form a gallium hydrate on a surface of each of the particles; and an oxidation treatment step of oxidizing the gallium hydrate to form a shell including gallium oxide. The method includes a particle-forming step of forming gallium or an alloy of gallium in a liquid state into particles; a cooling step of cooling the particles to a solid state; and a pH treatment step of immersing the particles in an aqueous solution having a predetermined pH to form a shell including gallium hydrate.

A latent heat storage body microcapsule includes a core including gallium or gallium alloy; and a shell covering the core and including gallium oxide. A method for producing the same includes a particle-forming step of forming gallium or an alloy of gallium in a liquid state into particles; a water treatment step of heating the particles in distilled water to form a gallium hydrate on a surface of each of the particles; and an oxidation treatment step of oxidizing the gallium hydrate to form a shell including gallium oxide. The method includes a particle-forming step of forming gallium or an alloy of gallium in a liquid state into particles; a cooling step of cooling the particles to a solid state; and a pH treatment step of immersing the particles in an aqueous solution having a predetermined pH to form a shell including gallium hydrate.

Techniques are disclosed for milling an iron-containing raw material in the presence of a nitrogen source to generate anisotropically shaped particles that include iron nitride and have an aspect ratio of at least 1.4. Techniques for nitridizing an anisotropic particle including iron, and annealing an anisotropic particle including iron nitride to form at least one α″-Fe.sub.16N.sub.2 phase domain within the anisotropic particle including iron nitride also are disclosed. In addition, techniques for aligning and joining anisotropic particles to form a bulk material including iron nitride, such as a bulk permanent magnet including at least one α″-Fe.sub.16N.sub.2 phase domain, are described. Milling apparatuses utilizing elongated bars, an electric field, and a magnetic field also are disclosed.

Techniques are disclosed for milling an iron-containing raw material in the presence of a nitrogen source to generate anisotropically shaped particles that include iron nitride and have an aspect ratio of at least 1.4. Techniques for nitridizing an anisotropic particle including iron, and annealing an anisotropic particle including iron nitride to form at least one α″-Fe.sub.16N.sub.2 phase domain within the anisotropic particle including iron nitride also are disclosed. In addition, techniques for aligning and joining anisotropic particles to form a bulk material including iron nitride, such as a bulk permanent magnet including at least one α″-Fe.sub.16N.sub.2 phase domain, are described. Milling apparatuses utilizing elongated bars, an electric field, and a magnetic field also are disclosed.

To provide novel low-temperature sinterable copper particles that can be sintered even at a low temperature of, for example, around 100° C. or less, and a method for producing a sintered body by using the same. The low-temperature sinterable copper particles according to the present invention are coated with a carboxylic acid, and a surface of the copper particle is oxidized so as to have a cuprous oxide fraction (Cu.sub.2O/(Cu+Cu.sub.2O)) in the copper particle of 4% by mass or less or so as to have an average coating thickness of cuprous oxide of 10 nm or less. The low-temperature sinterable copper particles are subjected to low-temperature firing in an atmosphere of 0.01 Pa or less.

To provide novel low-temperature sinterable copper particles that can be sintered even at a low temperature of, for example, around 100° C. or less, and a method for producing a sintered body by using the same. The low-temperature sinterable copper particles according to the present invention are coated with a carboxylic acid, and a surface of the copper particle is oxidized so as to have a cuprous oxide fraction (Cu.sub.2O/(Cu+Cu.sub.2O)) in the copper particle of 4% by mass or less or so as to have an average coating thickness of cuprous oxide of 10 nm or less. The low-temperature sinterable copper particles are subjected to low-temperature firing in an atmosphere of 0.01 Pa or less.

The present disclosure discloses an yttrium (Y)-added rare-earth permanent magnetic material and a preparation method thereof. A chemical formula of the material expressed in atomic percentage is (YxRE1-x)aFebalMbNc, wherein 0.05≤x≤0.4, 7≤a≤13, 0≤b≤3, 5≤c≤20, and the balance is Fe, namely, bal=100-a-b-c; RE represents a rare-earth element Sm, or a combination of the rare-earth element Sm and any one or more elements of Zr, Nd and Pr; M represents Co and/or Nb; and N represents nitrogen. In the preparation method, the rare-earth element Y is utilized to replace the element Sm of a samarium-iron-nitrogen material. By regulating a ratio of the element Sm to the element Y, viscosity of an alloy liquid can be reduced, and an amorphous forming ability of the material is enhanced.

The present disclosure discloses an yttrium (Y)-added rare-earth permanent magnetic material and a preparation method thereof. A chemical formula of the material expressed in atomic percentage is (YxRE1-x)aFebalMbNc, wherein 0.05≤x≤0.4, 7≤a≤13, 0≤b≤3, 5≤c≤20, and the balance is Fe, namely, bal=100-a-b-c; RE represents a rare-earth element Sm, or a combination of the rare-earth element Sm and any one or more elements of Zr, Nd and Pr; M represents Co and/or Nb; and N represents nitrogen. In the preparation method, the rare-earth element Y is utilized to replace the element Sm of a samarium-iron-nitrogen material. By regulating a ratio of the element Sm to the element Y, viscosity of an alloy liquid can be reduced, and an amorphous forming ability of the material is enhanced.

A process for manufacturing a multi-material part by additive manufacturing, includes the following steps: a) a step of providing a pre-treated metal powder comprising grains and an oxidized and porous layer on a surface of the grains; b) a selective laser powder-bed fusion step comprising implementation of steps i) and ii) as follows: i) a step of forming a layer from the pre-treated metal powder; ii) a step of melting by laser the layer, the melting step being carried out under a reactive atmosphere and comprising changing parameters of application of the laser so that at least a first region of the layer is converted so as to lower the electrical conductivity thereof, thus forming a dielectric, and so that at least a second region of the layer is densified without converting it, the at least a first region being formed when the parameters of application of the laser allow a first energy density to be applied to the first region and/or the laser beam to be kept for a first dwell time on the first region, the at least a second region being formed when the parameters of application of the laser allow a second energy density to be applied to the second region and/or the laser beam to be kept for a second dwell time on the second region, and the first energy density being higher than the second energy density and/or the first dwell time being longer than the second dwell time. A part obtained using the process is also provided.