In some embodiments, a method of producing a metallic article includes providing a metallic powder, selecting a predetermined concentration for a reactive component, providing a controlled atmosphere including the reactive component at the predetermined concentration, and additively manufacturing the metallic article from the metallic powder under the controlled atmosphere. The metallic powder includes a metallic element or metallic alloy. The reactive component reacts with the metallic powder in a weld pool formed during the additive manufacturing to form a dispersion of nano-particles in the weld pool. The nano-particles are dispersed throughout the metallic article in a substantially uniform manner. In some embodiments, the metallic powder includes the reactive component. Metallic articles formed by the disclosed methods are also disclosed.

The present application describes an article having a first metal component joined to a second metal component by a metallurgic joint of presintered powdered metal interposed between contiguous surfaces of the first metal component and the second metal component. The present application also describes a composition for use in a brazing process comprising a presintered powdered metal. The present application also describes a process for brazing including the following steps: presintering a powdered metal; adding the presintered powdered metal to a first and second metal component; and heating the combination of the first and second metal components containing the presintered powdered metal until the powdered metal melts and joins the metal components to form a metallurgic joint.

The present application describes an article having a first metal component joined to a second metal component by a metallurgic joint of presintered powdered metal interposed between contiguous surfaces of the first metal component and the second metal component. The present application also describes a composition for use in a brazing process comprising a presintered powdered metal. The present application also describes a process for brazing including the following steps: presintering a powdered metal; adding the presintered powdered metal to a first and second metal component; and heating the combination of the first and second metal components containing the presintered powdered metal until the powdered metal melts and joins the metal components to form a metallurgic joint.

A functionally graded carbide body (400) can include a group 5 metal carbide substrate having a bulk composition region (410) that contains at least 70 wt % of a rhombohedral -phase carbide. A -phase-rich region (420) having a -phase-rich composition can be at a surface (430) of the substrate, and a phase composition gradient region (440) can transition from the -phase-rich composition region at the surface to the bulk composition region at a gradient depth (450) below the surface.

A functionally graded carbide body (400) can include a group 5 metal carbide substrate having a bulk composition region (410) that contains at least 70 wt % of a rhombohedral -phase carbide. A -phase-rich region (420) having a -phase-rich composition can be at a surface (430) of the substrate, and a phase composition gradient region (440) can transition from the -phase-rich composition region at the surface to the bulk composition region at a gradient depth (450) below the surface.

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 composite powder comprising powder particles is disclosed. Each powder particle comprises a core element and a diffusion layer at least partially surrounding the core element. The core element comprises copper, gold or silver and an alloy element capable of forming a nitride, a carbide or a carbonitride. The diffusion layer comprises the alloy element and a nitride, carbide or carbonitride compound. The nitride, carbide or carbonitride compound comprises the alloy element.

A composite powder comprising powder particles is disclosed. Each powder particle comprises a core element and a diffusion layer at least partially surrounding the core element. The core element comprises copper, gold or silver and an alloy element capable of forming a nitride, a carbide or a carbonitride. The diffusion layer comprises the alloy element and a nitride, carbide or carbonitride compound. The nitride, carbide or carbonitride compound comprises the alloy element.

A rare-earth permanent magnetic powder, a bonded magnet containing thereof and a device using the bonded magnet are provided of the present disclosure. The rare-earth permanent magnetic powder comprises: 70 vol % to 99 vol % of a hard magnetic phase and 1 vol % to 30 vol % of a soft magnetic phase, the hard magnetic phase has a TbCu.sub.7 structure, and the grain size of the hard magnetic phase is 5 nm to 100 nm; the soft magnetic phase is a Fe phase having a bcc structure, the average grain size of the soft magnetic phase is 1 nm to 30 nm, and the standard deviation of the grain size is below 0.5.

A rare-earth permanent magnetic powder, a bonded magnet containing thereof and a device using the bonded magnet are provided of the present disclosure. The rare-earth permanent magnetic powder comprises: 70 vol % to 99 vol % of a hard magnetic phase and 1 vol % to 30 vol % of a soft magnetic phase, the hard magnetic phase has a TbCu.sub.7 structure, and the grain size of the hard magnetic phase is 5 nm to 100 nm; the soft magnetic phase is a Fe phase having a bcc structure, the average grain size of the soft magnetic phase is 1 nm to 30 nm, and the standard deviation of the grain size is below 0.5.