Abstract: Some variations provide a method of making a nanofunctionalized metal powder, comprising: providing metal particles containing metals selected from iron, nickel, copper, titanium, magnesium, zinc, silicon, lithium, silver, chromium, manganese, vanadium, bismuth, gallium, or lead; providing nanoparticles selected from zirconium, tantalum, niobium, or titanium; disposing the nanoparticles onto surfaces of the metal particles, in the presence of mixing media, thereby generating nanofunctionalized metal particles; and isolating and recovering the nanofunctionalized metal particles as a nanofunctionalized metal powder. Some variations provide a composition comprising a nanofunctionalized metal powder, the composition comprising metal particles and nanoparticles containing one or more elements selected from the group consisting of zirconium, tantalum, niobium, titanium, and oxides, nitrides, hydrides, carbides, or borides thereof, or combinations of the foregoing.

Abstract: Some variations provide a method of making a nanofunctionalized metal powder, comprising: providing metal particles containing metals selected from aluminum, iron, nickel, copper, titanium, magnesium, zinc, silicon, lithium, silver, chromium, manganese, vanadium, bismuth, gallium, or lead; providing nanoparticles selected from zirconium, tantalum, niobium, or titanium; disposing the nanoparticles onto surfaces of the metal particles, in the presence of mixing media, thereby generating nanofunctionalized metal particles; and isolating and recovering the nanofunctionalized metal particles as a nanofunctionalized metal powder. Some variations provide a composition comprising a nanofunctionalized metal powder, the composition comprising metal particles and nanoparticles containing one or more elements selected from the group consisting of zirconium, tantalum, niobium, titanium, and oxides, nitrides, hydrides, carbides, or borides thereof, or combinations of the foregoing.

Abstract: We have developed a scalable approach to directly incorporate grain-refining nanoparticles into conventional hot-tear-susceptible pure aluminum or aluminum alloy powders. These aluminum alloy powders may be additively manufactured into high-strength, crack-free aluminum alloys with fine equiaxed microstructures by incorporating nanoparticle nucleants to control solidification during additive manufacturing. Some variations provide an additively manufactured aluminum alloy comprising aluminum and at least one grain-refining element, wherein the additively manufactured aluminum alloy has a microstructure with equiaxed grains. Pure aluminum or aluminum alloys, combined with grain refiners, are useful in many processes beyond additive manufacturing. Some variations provide an aluminum alloy comprising aluminum and grain-refining nanoparticles selected from zirconium, tantalum, niobium, or titanium, wherein the aluminum alloy has a microstructure that is substantially crack-free with equiaxed grains.

Abstract: Provided are maraging steel alloys having improved microstructures. Some variations provide maraging steel alloys including a base maraging steel alloy, a grain refiner, and optionally, a strengthening element. The base maraging steel alloy is surface-functionalized with the grain refiner. Other variations provide a method of method of manufacturing maraging steel including mixing a base maraging steel alloy with a grain refiner resulting in a maraging steel mixture, melting the maraging steel mixture, and solidifying the maraging steel mixture forming an equiaxed microstructure.

Abstract: A universal approach is described to produce welding filler materials with enhanced grain refining, for making welded objects with hot-crack resistance. Some variations provide a welding filler material comprising a functionalized metal-containing powder, wherein the functionalized metal-containing powder comprises metal or metal alloy particles and a plurality of nanoparticles disposed on surfaces of the metal or metal alloy particles, and wherein the nanoparticles are consolidated in a three-dimensional architecture throughout the welding filler material. A welded object contains a welding filler material comprising the functionalized metal-containing powder, enabling the welded object to be free of hot cracks. Other variations provide methods of making a welding filler material. This approach has been successfully demonstrated by incorporating zirconium-based nanoparticle grain refiners within a welding precursor material for welding aluminum alloy Al 7075, as one non-limiting example.

Abstract: We have developed a scalable approach to directly incorporate grain-refining nanoparticles into conventional hot-tear-susceptible pure aluminum or aluminum alloy powders. These aluminum alloy powders may be additively manufactured into high-strength, crack-free aluminum alloys with fine equated microstructures by incorporating nanoparticle nucleants to control solidification during additive manufacturing. Some variations provide an additively manufactured aluminum alloy comprising aluminum and at least one grain-refining element, wherein the additively manufactured aluminum alloy has a microstructure with equated grains. Pure aluminum or aluminum alloys, combined with grain refiners, are useful in many processes beyond additive manufacturing. Some variations provide an aluminum alloy comprising aluminum and grain-refining nanoparticles selected from zirconium, tantalum, niobium, or titanium, wherein the aluminum alloy has a microstructure that is substantially crack-free with equated grains.

Abstract: Disclosed herein are surface-functionalized powders which alter the solidification of the melted powders. Some variations provide a powdered material comprising a plurality of particles fabricated from a first material, wherein each of the particles has a particle surface area that is continuously or intermittently surface-functionalized with nanoparticles and/or microparticles selected to control solidification of the powdered material from a liquid state to a solid state. Other variations provide a method of controlling solidification of a powdered material, comprising melting at least a portion of the powdered material to a liquid state, and semi-passively controlling solidification of the powdered material from the liquid state to a solid state. Several techniques for semi-passive control are described in detail.

Abstract: Disclosed herein are surface-functionalized powders which alter the solidification of the melted powders. Some variations provide a powdered material comprising a plurality of particles fabricated from a first material, wherein each of the particles has a particle surface area that is continuously or intermittently surface-functionalized with nanoparticles and/or microparticles selected to control solidification of the powdered material from a liquid state to a solid state. Other variations provide a method of controlling solidification of a powdered material, comprising melting at least a portion of the powdered material to a liquid state, and semi-passively controlling solidification of the powdered material from the liquid state to a solid state. Several techniques for semi-passive control are described in detail.

Abstract: We have developed a scalable approach to directly incorporate grain-refining nanoparticles into conventional hot-tear-susceptible pure aluminum or aluminum alloy powders. These aluminum alloy powders may be additively manufactured into high-strength, crack-free aluminum alloys with fine equiaxed microstructures by incorporating nanoparticle nucleants to control solidification during additive manufacturing. Some variations provide an additively manufactured aluminum alloy comprising aluminum and at least one grain-refining element, wherein the additively manufactured aluminum alloy has a microstructure with equiaxed grains. Pure aluminum or aluminum alloys, combined with grain refiners, are useful in many processes beyond additive manufacturing. Some variations provide an aluminum alloy comprising aluminum and grain-refining nanoparticles selected from zirconium, tantalum, niobium, or titanium, wherein the aluminum alloy has a microstructure that is substantially crack-free with equiaxed grains.

Abstract: A precursor material is provided for additive manufacturing of a low-density, high-porosity ceramic part. The precursor material includes a body of refractory fibers and a binder in admixture with the body of refractory fibers. The precursor material further includes a viscosity control additive in admixture with the binder and the body of refractory fibers to provide an overall mixture with a viscosity between about 0.3 centipoise and about 150,000 centipoise.

Abstract: Some variations provide an additively manufactured aluminum alloy comprising from 84.5 wt % to 92.1 wt % aluminum; from 1.1 wt % to 2.1 wt % copper; from 1.8 wt % to 2.9 wt % magnesium; from 4.5 wt % to 6.1 wt % zinc; and from 0.5 wt % to 2.8 wt % zirconium. The additively manufactured aluminum alloy is in the form of a three-dimensional component. The zirconium functions as a grain-refiner element within the additively manufactured aluminum alloy. The additively manufactured aluminum alloy may be characterized by an average grain size of less than 10 microns. The additively manufactured aluminum alloy may have a substantially crack-free microstructure with equiaxed grains.

Abstract: We have developed a scalable approach to directly incorporate grain-refining nanoparticles into conventional hot-tear-susceptible aluminum alloy powders. These aluminum alloy powders may be additively manufactured into high-strength, crack-free aluminum alloys with fine equiaxed microstructures by incorporating nanoparticle nucleants to control solidification during additive manufacturing. Some variations provide an additively manufactured aluminum alloy comprising aluminum, one or more strengthening elements, and at least one grain-refining element, wherein the additively manufactured aluminum alloy has a microstructure with equiaxed grains. Aluminum alloys with grain refiners are useful in many processes beyond additive manufacturing.

Abstract: A precursor material is provided for additive manufacturing of a low-density, high-porosity ceramic part. The precursor material includes a body of refractory fibers and a binder in admixture with the body of refractory fibers. The precursor material further includes a viscosity control additive in admixture with the binder and the body of refractory fibers to provide an overall mixture with a viscosity between about 0.3 centipoise and about 150,000 centipoise.

Abstract: Some variations provide a method of making a nanofunctionalized metal powder, comprising: providing metal particles containing metals selected from aluminum, iron, nickel, copper, titanium, magnesium, zinc, silicon, lithium, silver, chromium, manganese, vanadium, bismuth, gallium, or lead; providing nanoparticles selected from zirconium, tantalum, niobium, or titanium; disposing the nanoparticles onto surfaces of the metal particles, in the presence of mixing media, thereby generating nanofunctionalized metal particles; and isolating and recovering the nanofunctionalized metal particles as a nanofunctionalized metal powder. Some variations provide a composition comprising a nanofunctionalized metal powder, the composition comprising metal particles and nanoparticles containing one or more elements selected from the group consisting of zirconium, tantalum, niobium, titanium, and oxides, nitrides, hydrides, carbides, or borides thereof, or combinations of the foregoing.

Abstract: Some variations provide a process for additive manufacturing of a nanofunctionalized metal alloy, comprising: providing a nanofunctionalized metal precursor containing metals and grain-refining nanoparticles; exposing a first amount of the nanofunctionalized metal precursor to an energy source for melting the precursor, thereby generating a first melt layer; solidifying the first melt layer, thereby generating a first solid layer; and repeating many times to generate a plurality of solid layers in an additive-manufacturing build direction. The additively manufactured, nanofunctionalized metal alloy has a microstructure with equiaxed grains.

Abstract: A universal approach is described to produce welding filler materials with enhanced grain refining, for making welded objects with hot-crack resistance. Some variations provide a welding filler material comprising a functionalized metal-containing powder, wherein the functionalized metal-containing powder comprises metal or metal alloy particles and a plurality of nanoparticles disposed on surfaces of the metal or metal alloy particles, and wherein the nanoparticles are consolidated in a three-dimensional architecture throughout the welding filler material. A welded object contains a welding filler material comprising the functionalized metal-containing powder, enabling the welded object to be free of hot cracks. Other variations provide methods of making a welding filler material. This approach has been successfully demonstrated by incorporating zirconium-based nanoparticle grain refiners within a welding precursor material for welding aluminum alloy Al 7075, as one non-limiting example.

Abstract: A precursor material is provided for additive manufacturing of a low-density, high-porosity ceramic part. The precursor material comprises a body of refractory fibers and a binder in admixture with the body of refractory fibers. The precursor material further comprises a viscosity control additive in admixture with the binder and the body of refractory fibers to provide an overall mixture with a viscosity between about 0.3 centipoise and about 150,000 centipoise. The overall mixture can be extruded through a nozzle to manufacture the low-density, high porosity ceramic part. The precursor material is produced by obtaining a refractory fiber slurry, and adding a viscosity control additive to the slurry to provide the slurry with a viscosity that is suitable for extrusion through a nozzle to manufacture a low-density, high-porosity ceramic part.

Abstract: This invention describes spherical nanoparticle hydrides and a method for making them. A method of producing spherical nanoparticle hydrides comprises obtaining an electrically conductive or semiconductive wire fabricated from a base material capable of forming a hydride; exposing the wire to a hydrogen-containing processing gas under pressure; vaporizing the wire by electrical discharge, to generate a vapor phase; and reacting with hydrogen and condensing the vapor phase, generating a plurality of spherical nanoparticle hydrides.

Abstract: A precursor material is provided for additive manufacturing of a low-density, high-porosity ceramic part. The precursor material comprises a body of refractory fibers and a binder in admixture with the body of refractory fibers. The precursor material further comprises a viscosity control additive in admixture with the binder and the body of refractory fibers to provide an overall mixture with a viscosity between about 0.3 centipoise and about 150,000 centipoise. The overall mixture can be extruded through a nozzle to manufacture the low-density, high porosity ceramic part. The precursor material is produced by obtaining a refractory fiber slurry, and adding a viscosity control additive to the slurry to provide the slurry with a viscosity that is suitable for extrusion through a nozzle to manufacture a low-density, high-porosity ceramic part.

Abstract: Disclosed herein are surface-functionalized powders which alter the solidification of the melted powders. Some variations provide a powdered material comprising a plurality of particles fabricated from a first material, wherein each of the particles has a particle surface area that is continuously or intermittently surface-functionalized with nanoparticles and/or microparticles selected to control solidification of the powdered material from a liquid state to a solid state. Other variations provide a method of controlling solidification of a powdered material, comprising melting at least a portion of the powdered material to a liquid state, and semi-passively controlling solidification of the powdered material from the liquid state to a solid state. Several techniques for semi-passive control are described in detail.