Abstract: The present invention provides an approach to control the generation and grow of nanocrystal with membrane diffusion method and related apparatuses to produce inorganic oxide nanopowders and metal nanoparticles. With this method, the size and size distribution of inorganic oxide nanopowders and metal nanoparticles can be tuned. It overcomes the shortcomings possessed by the common chemical and physical method of preparing nanoparticles.

Abstract: In a method of producing a metal structure by photoreducing metal ion, a substance capable of suppressing growth of metal crystal is added to a medium in which metal ion is dispersed to prevent growth of the metal crystal produced by photoreduction of the metal ion, thereby processing resolution of a metal structure formed of the metal crystal is improved.

Abstract: A method for producing nickel nanoparticles is described, including a first step of heating a mixture of a nickel carboxylate with 1-12 carbon atoms in its moiety excluding —COOH and a primary amine to obtain a complexed reaction solution with a nickel complex foiiiied therein, and a second step of heating the complexed reaction solution by a microwave to obtain a Ni-nanoparticle slurry. In the first step, the heating is preferably conducted at a temperature of 105-175° C. for 15 minutes or longer. In the second step, the heating is preferably conducted at a temperature of 180° C. or higher.

Abstract: Method for the production of mixed oxides and permanent magnetic particles, based on rare earths-transition metals to produce RETM magnetic materials, comprising the preparation of a parent compounds mixture; introducing the parent compound mixture into a reactor with heat energy input, where the atomization die generates fine droplets as spray or aerosol; subjecting the fine droplets formed to pyrolysis and combustion, and; reducing the mixed oxide particles formed and collected as homogenous powder, obtaining permanent magnetic particles; being a simple method and allowing to obtain homogeneous and versatile compositions, especially for Rare Earth-Transition Metal (RETM) type permanent magnets, where RE (rare earth) can be, for example, an element such as neodymium, praseodymium, dysprosium or a combination thereof, among other possibilities, and TM (transition metal) can be, for example, iron, cobalt, nickel or a combination thereof.

Abstract: In various embodiments, low-oxygen metal powder is produced by heating a metal powder to a temperature at which an oxide of the metal powder becomes thermodynamically unstable and applying a pressure to volatilize the oxygen.

Abstract: Various embodiments include a method of producing chemically pure and stably dispersed metal and metal-alloy nanoparticle colloids with ultrafast pulsed laser ablation. A method comprises irradiating a metal or metal alloy target submerged in a liquid with ultrashort laser pulses at a high repetition rate, cooling a portion of the liquid that includes an irradiated region, and collecting nanoparticles produced with the laser irradiation and liquid cooling. The method may be implemented with a high repetition rate ultrafast pulsed laser source, an optical system for focusing and moving the pulsed laser beams, a metal or metal alloy target submerged in a liquid, and a liquid circulating system to cool the laser focal volume and collect the nanoparticle products. By controlling various laser parameters, and with optional liquid flow movement, the method provides stable colloids of dispersed metal and metal-alloy nanoparticles. In various embodiments additional stabilizing chemical agents are not required.

Abstract: Disclosed is a method of manufacturing a solder powder having a diameter of sub-micrometers or several micrometers, the method including: mixing solder powder having a diameter of 10 to 1000 micrometers with a polymer resin to obtain a mixture; heating the mixture to a temperature higher than a melting point of the solder powder in the mixture; applying ultrasonic waves to the heated mixture so that the diameter of the solder powder becomes 0.1 to 10 micrometers; and cooling the mixture to the room temperature without exposing the solder powder of 0.1 to 10 micrometers to the air.

Abstract: The present invention provides a nanowire production method that is simpler than conventional nanowire production methods, and that makes it easier to control the size and shape of the nanowires by using a technique completely different from the conventional ones. A powder particle containing a metal element is divided into nanometer-size wires containing the metal element by irradiating a suspension of the powder particles with a femtosecond laser. The present invention also makes it possible to divide the nanometer-size wires thus formed into nanometer-size particles containing the metal element by irradiating further the nanometer-size wires with the femtosecond laser.

Abstract: A method for purifying metal M1 particles manufactured by an electrochemical reduction process, the method comprising the steps of introducing the metal M1 particles into a heat source (13) at a temperature substantially equal to or higher than the melting point of M1 so as to cause vaporisation of some or substantially all of the contaminating impurities present, removing the vaporised impurities from the vicinity of the particles, and cooling the purified metal M1 particles. The purified particles can be used directly in lower temperature powder metallurgy processes and have a fully dense spherical particle morphology, imparting good flowability. The purification process can also be incorporated as an integral stage of sheet or stock production processes based on particle feedstocks that have been produced by electrochemical reduction.

Abstract: Various embodiments include a method of producing chemically pure and stably dispersed metal and metal-alloy nanoparticle colloids with ultrafast pulsed laser ablation. A method comprises irradiating a metal or metal alloy target submerged in a liquid with ultrashort laser pulses at a high repetition rate, cooling a portion of the liquid that includes an irradiated region, and collecting nanoparticles produced with the laser irradiation and liquid cooling. The method may be implemented with a high repetition rate ultrafast pulsed laser source, an optical system for focusing and moving the pulsed laser beams, a metal or metal alloy target submerged in a liquid, and a liquid circulating system to cool the laser focal volume and collect the nanoparticle products. By controlling various laser parameters, and with optional liquid flow movement, the method provides stable colloids of dispersed metal and metal-alloy nanoparticles. In various embodiments additional stabilizing chemical agents are not required.

Abstract: The invention relates to a gas phase method for producing nanometric particles in a reactor for producing particles in a gas phase, in which there is an interaction between a reaction flow and an energy flow. This method comprises the following steps: a step for coupling a device for producing gaseous chlorides with this reactor, a step for producing gaseous chlorides from a base precursor in the form of powders, and a step for injecting such a reaction flow into the reactor.

Abstract: One non-limiting embodiment of an apparatus for forming an alloy powder or preform includes a melting assembly, an atomizing assembly, and a field generating assembly, and a collector. The melting assembly produces at least one of a stream of a molten alloy and a series of droplets of a molten alloy, and may be substantially free from ceramic in regions contacted by the molten alloy. The atomizing assembly generates electrons and impinges the electrons on molten alloy from the melting assembly, thereby producing molten alloy particles. The field generating assembly produces at least one of an electrostatic field and an electromagnetic field between the atomizing assembly and the collector. The molten alloy particles interact with the at least one field, which influences at least one of the acceleration, speed, and direction of the molten alloy particles. Related methods also are disclosed.

Abstract: One non-limiting embodiment of an apparatus for forming an alloy powder or preform includes a melting assembly, an atomizing assembly, and a field generating assembly, and a collector. The melting assembly produces at least one of a stream of a molten alloy and a series of droplets of a molten alloy, and may be substantially free from ceramic in regions contacted by the molten alloy. The atomizing assembly generates electrons and impinges the electrons on molten alloy from the melting assembly, thereby producing molten alloy particles. The field generating assembly produces at least one of an electrostatic field and an electromagnetic field between the atomizing assembly and the collector. The molten alloy particles interact with the at least one field, which influences at least one of the acceleration, speed, and direction of the molten alloy particles. Related methods also are disclosed.

Abstract: A system and method to tailor the optical properties of nanomaterials using a core-alloy-shell nano-ultrastructure. Atomic diffusion is used at the nanoscale in order to process as-synthesized nanomaterials into core-alloy-shell architectures. The alloy formation is controlled by the deposition of the alloy solute atoms, and then by alloy interdiffusion of the solute into the core nanoparticle. By controlling temperature, it is possible to control how far the solute diffuses into the core, which in turn allows the tailoring of the optical response of the particle itself. The alloy formation and subsequent interdiffusion allows tailoring of the nanoparticle composition and ultrastructure, resulting in a dramatic tunability of the metal nanostructures surface plasmon response.

Abstract: A process for synthesizing carbon-metal nanocomposites. In one embodiment, the process includes the steps of preparing a metal derivative or a metal chelated derivative of a carbon-containing precursor in solid form, and subjecting the metal derivative or metal chelated derivative of a carbon-containing precursor in solid form to microwave radiation at a frequency in the range of 900 MHz to 5.8 GHz, for a period of time effective to generate a heat flow from inside of the metal derivative or metal chelated derivative of a carbon-containing precursor in solid form to the outside such that the temperature of the metal derivative or metal chelated derivative of a carbon-containing precursor in solid form reaches 1,000° C. in less than 6 minutes with a temperature (T) derivative over time (t), ?T/?t, no less than 2.5° C./second to form carbon-metal nanocomposites.

Abstract: The present invention has an object of providing a single-stage production method that enables the production of ultra fine metal nanoparticles and ordered alloy nanoparticles within solution. The production method includes irradiating a solution of a salt or complex of a metal element, thereby decomposing and/or reducing the salt or complex within the solution and generating metal nanoparticles having an average particle size within a range from 0.3 to 100 nm within the solution.

Abstract: An arrangement producing metal nanoparticles includes a ?-ray irradiator installed in a radioactive shielding room, a reactor that is disposed to oppose the ?-ray irradiator, and a power supply installed outside the radioactive shielding room to supply power to the reactor. The reactor includes a container receiving reaction materials and transmitting the energy of ?-rays to reaction materials arranged inside of the reactor, an agitator that is installed in the container to be capable of rotating, and a driving source for receiving the power from the power supply to drive the agitator.

Abstract: Efficiently produce micro-dispersion water of super-fine noble metal particles having a desired concentration by using a very safe, compact production apparatus comprising a power supply for high-voltage/current discharge, a high-voltage discharge generator equipped with a noble metal electrode and its counter electrode, a water tank, a water inlet to the water tank, and an outlet for micro-dispersion water of super-fine noble metal particles, by causing plasma discharge in water between the noble metal electrode and its counter electrode and then causing the generated noble metal ion vapor to contact, and micro-disperse in, water. The obtained water can be effectively used as drinking water.

Abstract: A titanium halide, preferably titanium tetrachloride, is reacted with suitable reductant, preferably an alkali metal or alkaline earth metal, under ultrasonic excitation in a liquid reaction medium to form nanometer size particles of titanium which may incorporate unreacted reductant. The nanosized titanium particles may be a precursor for nanosized titanium oxide which is formed by oxidizing the titanium, preferably with a low molecular weight alcohol. When the titanium particles incorporate unreacted reductant the oxidation reaction will yield nanometer sized titanates. The nanosized particles, whether titanium oxide or titanates may be extracted by first filtering them from the reaction medium, followed by washing with water to remove any water-soluble reaction products followed by spray drying.

Abstract: A method for making nanoparticles includes the steps of dipping a metal element in a solution that contains metallic ions or ions with a metal, wherein the metal element has a lower electronegativity or redox potential than that of the metal in the ions, and rubbing the metal element to make nanoparticles. Another method for making nanoparticles includes the steps of dipping a metal element in a solution that contains metallic ions or ions with a metal, wherein the metal element has a lower electronegativity or redox potential than that of the metal in the ions, and applying sonic energy to at least one of the metal element and solution. A further method for making copper nanoparticles includes the step of adding ascorbic acid to a copper salt solution.

Abstract: A method of producing metallic powder for use in the manufacture of a capacitor comprises the step of reducing a non-metallic compound to metal in contact with a molten salt. The salt comprises, for at least a portion of the process, a dopant element that acts as a sinter retardant in the metal. In preferred examples, the metallic powder is Ta or Nb powder produced by the reduction of a Ta or Nb oxide and the dopant is boron, nitrogen, or phosphorous.

Abstract: A method of creating simulated agglutinate particles by applying a heat source sufficient to partially melt a raw material is provided. The raw material is preferably any lunar soil simulant, crushed mineral, mixture of crushed minerals, or similar material, and the heat source creates localized heating of the raw material.

Abstract: A relatively simple and inexpensive method for the synthesis of silver nanoparticles within a short period of time using a household microwave or the like is provided. The energy needed to heat the synthesis reaction is minimized and the organic reducing reagents of the prior art are replaced with natural products such as purified carbohydrates (e.g., glucose, sucrose, fructose, galactose, ribose, lactose) or their readily available and inexpensive forms (e.g., high fructose corn syrup, sucrose syrup). The resulting nanoparticles are purified from the remaining silver ion which is then recaptured for the safe disposal of the waste reaction mixture.

Abstract: There is provided a producing method of metal fine particles or metal oxide fine particles for producing metal fine particles or metal oxide fine particles by atomizing raw materials by performing processes including an oxidizing process and a reducing process to the raw materials composed of metal or a metal compound.

Abstract: A nanoparticle manufacturing device capable of particle size control of nanoparticles made of a raw material metal powder and control of the occurrence condition of chaining of nanoparticles and of necking. The device 1 is provided for manufacturing nanoparticles by heating and melting a mixture of a raw material metal powder and a carrier gas in a heating space, cooling the mixture in a cooling space and collecting the mixture in a collection space. The heating space, the cooling space and the collection space form a continuous flow path without a back flow, and the cross-sectional area of the collection space is set at a large value compared to the cross-sectional area of the heating space and the cooling space. Further, there is provided a method of manufacturing a nanoparticle-dispersed liquid alkali metal by dispersing nanoparticles in a liquid alkali metal.

Abstract: In various aspects provided are methods for producing a nanoparticle within a cross-linked, collapsed polymeric material. In various embodiments, the methods comprise (a) providing a polymeric solution comprising a polymeric material; (b) collapsing at least a portion of the polymeric material about one or more precursor moieties; (c) cross-linking the polymeric material; (d) modifying at least a portion of said precursor moieties to form one or more nanoparticles and thereby forming a composite nanoparticle.

Abstract: A method of forming stable nanoparticles comprising substantially uniform alloys of metals. A high dose of ionizing radiation is used to generate high concentrations of solvated electrons and optionally radical reducing species that rapidly reduce a mixture of metal ion source species to form alloy nanoparticles. The method can make uniform alloy nanoparticles from normally immiscible metals by overcoming the thermodynamic limitations that would preferentially produce core-shell nanoparticles.

Abstract: A method for manufacturing metal nanorods includes: a step of adding a reducing agent to a metallic salt solution; a step of radiating light into the metallic salt solution containing the reducing agent; and a step of leaving the light-radiated metallic salt solution containing the reducing agent stationary in a dark place so as to grow metal nanorods. Metal nanorods can be also grown by forming a mixed solution by fractionating the above light-radiated metallic salt solution and mixing the fractionated metallic salt solution into a non-radiated metallic salt solution containing the reducing agent, or mixing a non-radiated metallic salt solution and the reducing agent into the above light-radiated metallic salt solution; and leaving the mixed solution stationary in a dark place so as to grow metal nanorods.

Abstract: Disclosed herein is a method of manufacturing a metal flake, including the steps of: applying metal ink containing an organic metal compound onto a substrate; calcining the metal ink applied on the substrate to form a thin metal film; separating the formed thin metal film from the substrate; and pulverizing the separated thin metal film. The method of manufacturing a metal flake is characterized in that the thickness and size of metal flakes can be easily adjusted, metal flakes having excellent conductivity and gloss can be obtained, and metal flakes can be mass-produced using environmentally friendly and economical methods.

Abstract: In various aspects provided are methods for producing a nanoparticle within a cross-linked, collapsed polymeric material. In various embodiments, the methods comprise (a) providing a shape-static polymer template with a size in the range between about 1 nm to about 100 nm; (b)) incorporating one or more nanoparticle precursor moieties with the shape-static polymer template; and either (c) oxidizing the precursor moieties to form a composite nanoparticle comprising one or more of an inorganic oxide and hydroxide nanoparticle; or (c) adding an ion with an opposite charge polarity to the at least one nanoparticle precursor moieties to effect formation of a composite nanoparticle.

Abstract: The present invention generally relates to compositions and methods comprising polyoxometalates (POMs). In some cases, a reduced form of a POM may be formed via electrolysis in the presence of essentially no supporting electrolyte. The reduced POMs may be used for various applications, for example, for the formation of metallic nanoparticles. Some embodiments of the present invention provide compositions and methods comprising reduced forms of the polyoxometalate, [alpha-SiW12O40]4?.

Abstract: The invention relates to a process for the preparation of metal nanoparticles, selected from the group consisting of lead, bismuth, zinc, antimony, indium, gold, nickel, cobalt, palladium, platinum, iridium, osmium, rhodium, ruthenium, rhenium, vanadium, chromium, manganese, niobium, molybdenum, tungsten, tantalum, cadmium, silver and/or copper, on a rotating body, characterized in that a reduction of corresponding metal salts, corresponding metal salt complexes, corresponding metal hydroxides and/or corresponding metal oxides by polyols having a number of hydroxyl groups in the polyol of 1 to 10 and a molecular weight of the polyols of 2000 to 18 000 Da is effected.

Abstract: The present invention relates to an apparatus and a method of manufacturing metal nanoparticles, and more particularly to an apparatus including: a precursor supplying part which supplies a precursor solution of metal nanoparticles; a first heating part which is connected with the precursor supplying part, includes a reactor channel having a diameter of 1 to 50 mm, and is heated to the temperature range where any particle is not produced; a second heating part which is connected with the first heating part, includes a reactor channel having a diameter of 1 to 50 mm, and is heated to the temperature range where particles are produced; and a cooler which is connected with the second heating part and collects and cools metal nanoparticles produced at the second heating part which allows continuous mass production of metal nanoparticles.

Abstract: The various embodiments herein provide method of producing a rod-shape and branched metal nano-structures with polyol compounds as a reducing agent. The metal nano-structures are produced in a closed chamber of microwave system with variable irradiation power at a designed temperature. The metal nano-structures produced exhibits localized plasmon-polariton resonance, exhibit spectral resonance positions at microwave or radio frequencies and exhibit multiple spectral resonance peak at microwave or radio frequencies. The metal nano-structures produced are suitable as a coating composition material, a coating, a film, a wiring material, an electrode material, a catalyst, a colorant, a cosmetic, a near-infrared absorber, an anti-counterfeit ink and an electromagnetic shielding material, a surface enhanced fluorescent sensor, a biomarker and a nano-waveguide.

Abstract: A method of purifying a target powder having an oxygen content, the method comprising: flowing hydrogen gas through a microwave production chamber; applying microwaves to the hydrogen gas as the hydrogen gas flows through the microwave production chamber, thereby forming hydrogen radicals from the hydrogen gas; flowing the hydrogen radicals out of the microwave production chamber to the target powder disposed outside of the microwave production chamber; and applying the hydrogen radicals to the target powder, thereby removing a portion of the oxygen content from the powder. Preferably, the target powder is agitated as the hydrogen radicals are being applied.

Abstract: A method for producing metallic nanoparticles in a continuous flow-through reactor comprising combining at least one metallic precursor and at least one radical precursor in a reactant reservoir to form a reactant stream; flowing the reactant stream through at least one channel having a first channel end connected to the reactant reservoir, a second channel end connected to a product reservoir, and at least one clear channel section, which is transparent to activating radiation used to generate a radical reducing agent from the radical precursor, for exposing the reactant stream to a radiation source; exposing the reactant stream in the clear channel section to the radiation source to generate the radical reducing agent, initiate a reaction, and form a product stream comprising metallic nanoparticles; and optionally, collecting the product stream in the product reservoir.

Abstract: A metal powder production system includes a vacuum chamber having a vacuum chamber interior, a stock feed mechanism communicating with the vacuum chamber interior, a radiation source provided in the vacuum chamber interior, a cooling chamber having a cooling chamber interior communicating with the vacuum chamber interior and a container communicating with the cooling chamber interior. A metal powder production method is also disclosed.

Abstract: The present invention relates to an apparatus and a method of manufacturing metal nanoparticles, and more particularly to an apparatus including: a precursor supplying part which supplies a precursor solution of metal nanoparticles; a first heating part which is connected with the precursor supplying part, includes a reactor channel having a diameter of 1 to 50 mm, and is heated to the temperature range where any particle is not produced; a second heating part which is connected with the first heating part, includes a reactor channel having a diameter of 1 to 50 mm, and is heated to the temperature range where particles are produced; and a cooler which is connected with the second heating part and collects and cools metal nanoparticles produced at the second heating part which allows continuous mass production of metal nanoparticles.

Abstract: A nanopowder and a method of making are disclosed. The nanopowder may be in the form of nanoparticles with an average size of less than about 200 nm and contain a reactive transition metal, such as hafnium, zirconium, or titanium. The nanopowder can be formed in a liquid under sonication by reducing a halide of the transition metal.

Abstract: Nanomaterial and methods for generating nanomaterial are described wherein a reaction, for example, decomposition, for generating nanomaterial occurs utilizing a hot wall reactor.

Abstract: The invention discloses a method for continuously fabricating silver nanowires. The method mixes a glycol solution of a silver salt and a glycol solution of a polyvinyl pyrrolidone, and the mixed solution reacts in a temperature range and a time range to form the silver nanowires. The polyvinyl pyrrolidone has high boiling point and reduction ability so as to reduce the silver salt to the silver nanoparticles, and simultaneously, the polyvinyl pyrrolidone can provide barriers for limiting the particle growth. Besides, the oxygen functional groups on the long chains of the polyvinyl pyrrolidone can keep the stably one-dimensional growth of the silver nanoparticles to form the silver nanowires during the aging process.

Abstract: One non-limiting embodiment of an apparatus for forming an alloy powder or preform includes a melting assembly, an atomizing assembly, and a collector. The melting assembly produces at least one of a stream of a molten alloy and a series of droplets of a molten alloy, and may be substantially free from ceramic in regions contacted by the molten alloy. The atomizing assembly generates electrons and impinges the electrons on molten alloy from the melting assembly, thereby producing molten alloy particles.

Abstract: The present invention provides metal fine particles which have selective wavelength absorption characteristics in a wavelength region from visible light to near infrared light, and have sharp absorption characteristics, and influences little the surrounding wavelength, and therefore, they yield tones having high chroma. The present invention provides metal fine particles wherein an aspect ratio is in a range from 1.1 to 8.0, a maximum absorption wavelength in plasmon absorption is in a range from 400 nm to 1,200 nm, and an absorption coefficient at a peak position of the maximum absorption wavelength is in a range from 6,000 to 20,000 L/mol·cm (measurement concentration: 1.6×10?4 mol/L, and solvent: water).

Abstract: A method for removal of heavy metal ions from water including submerging an aquatic plant or dried material thereof in said water and subsequently irradiating the water in which the aquatic plant or dried material has been submerged with microwave irradiation.

Abstract: Silver nanoprisms having a unimodal size distribution are disclosed. The size of the nanoprisms can be controlled by adjusting the pH during irradiation of silver nanocrystals.

Abstract: Various embodiments include a method of producing chemically pure and stably dispersed metal and metal-alloy nanoparticle colloids with ultrafast pulsed laser ablation. A method comprises irradiating a metal or metal alloy target submerged in a liquid with ultrashort laser pulses at a high repetition rate, cooling a portion of the liquid that includes an irradiated region, and collecting nanoparticles produced with the laser irradiation and liquid cooling. The method may be implemented with a high repetition rate ultrafast pulsed laser source, an optical system for focusing and moving the pulsed laser beams, a metal or metal alloy target submerged in a liquid, and a liquid circulating system to cool the laser focal volume and collect the nanoparticle products. By controlling various laser parameters, and with optional liquid flow movement, the method provides stable colloids of dispersed metal and metal-alloy nanoparticles. In various embodiments additional stabilizing chemical agents are not required.

Abstract: A process and apparatus for producing chain agglomerations of nano-scale metal particles includes feeding at least one decomposable moiety selected from the group consisting of organometallic compounds, metal complexes, metal coordination compounds and mixtures thereof into a reactor vessel; exposing the decomposable moiety to a source of energy sufficient to decompose the moiety and produce nano-scale metal particles; and deposit or collection of chain agglomerations of nano-scale metal particles.

Abstract: A relatively simple and inexpensive method for the synthesis of silver nanoparticles within a short period of time using a household microwave or the like is provided. The energy needed to heat the synthesis reaction is minimized and the organic reducing reagents of the prior art are replaced with natural products such as purified carbohydrates (e.g., glucose, sucrose, fructose, galactose, ribose, lactose) or their readily available and inexpensive forms (e.g., high fructose corn syrup, sucrose syrup). The resulting nanoparticles are purified from the remaining silver ion which is then recaptured for the safe disposal of the waste reaction mixture.

Abstract: A powder batch is described comprising single crystal metal-containing particles having a crystal size of less than 50 nm as measured by X-ray diffraction and having a weight average particle size of from about 10 nanometers to less than 100 nanometers as measured by transmission electron microscopy and including a continuous or non-continuous coating of a ceramic material. The powder batch is preferably produced by flame spraying.

Abstract: The present invention relates to pulverulent materials suitable for storing hydrogen, and more particularly to a method of preparing such a material, in which: (A) a composite metallic material having a specific granular structure is prepared by co-melting the following mixtures: a first metallic mixture (m1), which is an alloy (a1) of body-centred cubic crystal structure, based on titanium, vanadium, chromium and/or manganese, or a mixture of these metals in the proportions of the alloy (a1); and a second mixture (m2), which is an alloy (a2), comprising 38 to 42% zirconium, niobium, molybdenum, hafnium, tantalum and/or tungsten and 56 to 60 mol % of nickel and/or copper, or else a mixture of these metals in the proportions of the alloy (a2), with a mass ratio (m2)/(m1+m2) ranging from 0.1 wt % to 20 wt %; and (B) the composite metallic material thus obtained is hydrogenated, whereby the composite material is fragmented (hydrogen decrepitation).