Scalable manufacturing process for manufacturing high-electrical conductivity aluminum-graphene (al-gr) and aluminum-carbon nanotube (al-CNT) metal matrix composites (MMCS)

Abstract

Disclosed herein are scalable processes for manufacturing high-conductivity aluminum matrix composite materials. In some cases, a process as described herein enables the production of high electrical conductivity aluminum-graphene or aluminum-carbon nanotube composites suitable for diverse industrial applications. An example process can include combining graphene or carbon nanotubes into aluminum or a heavier metal powder and introducing the mixture into a flowing molten aluminum stream. In some cases, the process can include applying ultrasonication to the liquid aluminum flow, casting the molten aluminum, and subjecting a resultant sheet to a rolling process including an asymmetric rolling process. In some cases, the process can include annealing to form an annealed sheet product. In some cases, the process can include rolling, extruding, or wire drawing an annealed sheet product to align the grains in a direction corresponding to the flow of electrical current when the composite material is in use in the form of flat plates (e.g., bus bars), sheets, wires, foils, etc.

Description

SCALABLE MANUFACTURING PROCESS FOR MANUFACTURING HIGH- ELECTRICAL CONDUCTIVITY ALUMINUM-GRAPHENE (AL-GR) AND ALUMINUM-CARBON NANOTUBE (AL-CNT) METAL MATRIX COMPOSITES (MMCS)CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to U.S. Provisional Application No. 63 / 557,177 filed February 23, 2024, the disclosure of which is hereby incorporated by reference in its entirety.FIELD

[0001] The present disclosure generally relates to materials engineering and industrial scale manufacturing processes, and, more particularly, to the industrial scale fabrication of aluminum Metal Matrix Composites (MMCs) with enhanced electrical conductivity.BACKGROUND

[0002] Copper, highly conductive yet increasingly scarce and costly, presents challenges for industries reliant on electrical materials. In contrast, aluminum, favored for its abundant availability, low cost and lightweight attributes, falls short in electrical (and thermal) conductivity and current carrying capacity compared to copper. This disparity underscores a need for alternative materials with enhanced electrical properties.SUMMARY

[0003] Embodiments of the present disclosure provide scalable processes for manufacturing high-conductivity composite materials. In some cases, a process as described herein enables the industrial scale production of high-conductivity aluminum-graphene or aluminum-carbon nanotube composites suitable for diverse industrial applications. An example process can include combining graphene or carbon nanotubes into metal powder and introducing the mixture into a flowing molten aluminum stream. In some cases, the process can include applying ultrasonication to the liquid aluminum flow, casting the molten aluminum, and subjecting a resultant sheet to an asymmetric rolling process. In some cases, the process can include annealing of such a rolled sheet. Annealing can be performed to increase grain size and also electrical conductivity. In some cases, the process can include rolling, extruding, or wire drawing the annealed sheet to align the grains and added graphene, carbonnanotubes or other forms of nano-carbon in a direction corresponding to the flow of electrical current.

[0004] A method for manufacturing an aluminum nanocarbon composite material is provided, the method comprising: combining a nanocarbon with a metal powder to form a nanocarbon metal powder mixture; adding the nanocarbon metal powder mixture to a liquid aluminum flow to form a molten aluminum nanocarbon composite; and casting the molten aluminum nanocarbon composite to form the aluminum nanocarbon composite material. In some cases, the nanocarbon is a graphene. In some cases, the nanocarbon is carbon nanotubes. In some cases, the nanocarbon is a combination of graphene and carbon nanotubes.

[0005] In some cases, the combining of the nanocarbon with the metal powder comprises mixing the nanocarbon into the metal powder or coating the metal powder with the nanocarbon to form the nanocarbon metal powder mixture, optionally wherein the mixing comprises one or more of dry mixing, ball milling, tumbler milling, chemical mixing, wet mixing, and / or spray drying.

[0006] In some cases, the method further comprises applying ultrasonication to the liquid aluminum flow to uniformly mix with the nanocarbon metal powder mixture and deagglomerate the nanocarbon to form the molten aluminum nanocarbon composite.

[0007] In some cases, the concentration of the nanocarbon in the nanocarbon metal powder mixture is from about 10 times to about 1000 times, about 50 times to about 750 times, about 60 times to about 600 times, about 75 times to about 500 times, about 80 to about 300 times, about 90 times to about 150 times, or about 100 times of final concentration of the nanocarbon in the metal nanocarbon composite material.

[0008] In some cases, the metal powder is an aluminum powder or a heavier metal powder. In some cases, the heavier metal powder is selected from the group consisting of Sb, Cd, Bi, Sn, Ni, Fe, Cr, Mn, and Zn powder.

[0009] In some cases, the nanocarbon metal powder mixture is consolidated and / or compacted prior to the adding.

[0010] In some cases, the adding comprises adding the nanocarbon metal powder mixture below the surface of the liquid aluminum flow.

[0011] In some cases, the adding comprises adding the nanocarbon metal powder mixture to the surface of the liquid aluminum flow.

[0012] In some cases, the adding comprises adding the nanocarbon metal powder mixture at the surface and below the surface of the liquid aluminum flow

[0013] In some cases, the nanocarbon metal powder mixture is added in from about 0.05 to about 5 wt%, about 0.1 to about 4 wt%, 0.5 to about 5 wt%, about 0.5 to about 2.5 wt%, about 0.6 to about 1.2 wt%, about 0.7 to about 0.9 wt%, about 0.6 to about 0.8 wt%, about 0.6 wt%, about 0.7 wt%, about 0.8 wt%, about 0.9 wt%, or about 1 wt% of the liquid aluminum flow.

[0014] In some cases, the casting is selected from the group consisting of HPDC, GDC (permanent mold casting), SC, continuous billet, twin roll casting, squeeze casting, investment casting, stir casting, rheocasting, thixocasting, and strip casting. In some cases, the casting process can include any appropriate type of severe plastic deformation (SPD). In some cases, the SPD can be useful to reduce the grain size. In some cases, the SPD can be useful to help deagglomerate the nanocarbon.

[0015] In some cases, the method further comprises casting the molten aluminum nanocarbon composite to form a plate or sheet using a twin roll caster; subjecting the plate or sheet to an rolling process to reduce the grain size of the material to form a rolled sheet product; and annealing the rolled sheet product to achieve recrystallization and grain growth, thereby embedding the nanocarbon at the grain boundaries within the metal matrix. In some cases, the rolling process comprises asymmetric rolling. In some cases, the rolling process comprises symmetric rolling.

[0016] In some cases, the method further comprises rolling, extruding, and / or wire drawing of the annealed sheet to align the grains and nanocarbon in a direction corresponding to the flow of electrical current when the composite material is in use.

[0017] In some cases, the aluminum nanocarbon composite material comprises the nanocarbon in a range of 10-900 ppm, 10-800 ppm, 10-700 ppm, 10-600 ppm, 15-600 ppm, 15-500 ppm, 15-300 ppm, 15-200 ppm, 20-100 ppm, 20-75 ppm, 20-50 ppm, 25-35 ppm, or about 30 ppm.

[0018] An aluminum nanocarbon composite material is provided, the material comprising: aluminum; and a nanocarbon dispersed within the aluminum, positioned at grain boundaries within the aluminum, wherein the composite material exhibits electrical conductivity in the range of about 65 to about 95 % IACS, about 70 to about 95% IACS, about 70 to about 90 % IACS, or about 75 to about 85 % International Annealed Copper Standard (IACS).

[0019] In some cases, the aluminum nanocarbon composite material comprises the nanocarbon in a range of 10-900 ppm, 10-800 ppm, 10-700 ppm, 10-600 ppm, 15-600 ppm, 15-500 ppm, 15-300 ppm, 15-200 ppm, 20-100 ppm, 20-75 ppm, 20-50 ppm, 25-35 ppm, orabout 30 ppm. In some cases, the nanocarbon is graphene. In some cases, the material is carbon nanotubes. In some cases, the material is a combination of graphene and carbon nanotubes.

[0020] In some cases, the aluminum nanocarbon composite material further comprises a heavier metal selected from the group consisting of Sb, Cd, Bi, Sn, Ni, Fe, and Zn.

[0021] In some cases, the aluminum nanocarbon composite material composite comprises from about 0.05 to about 5 wt%, about 0.1 to about 4 wt%, 0.5 to about 5 wt%, about 0.5 to about 2.5 wt%, about 0.6 to about 1.2 wt%, about 0.7 to about 0.9 wt%, about 0.6 to about 0.8 wt%, about 0.6 wt%, about 0.7 wt%, about 0.8 wt%, about 0.9 wt%, or about 1 wt% of the heavier metal.

[0022] In some cases, the aluminum nanocarbon composite material comprises 10-900 ppm of the nanocarbon; 0-5 wt% or 0.5-5 wt% of the heavier metal; and a balance of the aluminum.

[0023] A shaped part comprising the aluminum nanocomposite material according to the disclosure is provided. On some cases, the shaped part is selected from a bus bar, plate, wire, sheet, wire, or foil.BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Throughout the drawings, reference numbers can be re-used to indicate correspondence between referenced elements. The drawings are provided to illustrate embodiments of the present disclosure and do not limit the scope thereof.

[0025] FIG. 1 illustrates an example industrial scale metal composite manufacturing system 100 in accordance with some embodiments of the present disclosure.

[0026] FIG. 2 illustrates a data flow diagram illustrative of an example process 200 for the fabrication of nanocarbon-infused aluminum composite materials.

[0027] FIG. 3A illustrates a process 300 to disperse and deagglomerate graphene in Al at an industrial scale including Al melt, separate mixing of Al and graphene powder, casting of sheets, homogenization, asymmetric rolling, optional annealing, and final Al-graphene sheet or wire.

[0028] FIG. 3B shows representative concentrations of graphene in a nanocarbon metal powder mixture (3000 ppm), in Al melt after adding powder mix (30 ppm), and in final Al- graphene composite (30 ppm), for example, as an Al-graphene sheet (e.g., for bus bar) or wire (e.g., for conductors).

[0029] FIG. 4 illustrates one method 400 of adding Al graphene powder to the melt to improve uniform mixing and decrease agglomeration of graphene. The Al graphene powder isadded below the surface of the Al melt flow prior to in line sonication assemblies before twin roll casting.

[0030] FIG. 5 shows two methods of adding graphene to liquid Al to improve uniform mixing and decrease agglomeration of graphene. In some cases, the Al graphene powder mixture can be added below the surface towards the bottom of the melt 510. In some cases, graphene mixed with a heavier metal powder is added to the liquid Al such that the graphene mixture will travel to the bottom of the liquid Al due to higher density 520. In some cases, a combination of both methods of addition of graphene to liquid aluminum 510 and 520 can be employed.

[0031] FIG. 6 shows a method 600 of adding graphene to heavier metal element by mixing or coating graphene or CNT with powder of heavier metal element, optional compacting of mixed powder, addition of mixed powder, or consolidated or compacted mixed powder to liquid Al, sonication of liquid metal, and casting of liquid Al.

[0032] FIG. 7 shows a method of adding graphene mixed with a heavier metal powder or consolidated or compacted form to the liquid Al such that the graphene mixture will travel to the bottom of the liquid Al due to higher density 700.DETAILED DESCRIPTION

[0033] Copper, highly conductive yet increasingly scarce and costly, presents challenges for industries reliant on electrically conducting materials. In contrast, aluminum, favored for its abundant availability, low cost and lightweight attributes, falls short in electrical (and thermal) conductivity and current carrying capacity compared to copper. This disparity underscores a need for alternative materials with enhanced electrical properties. Efforts are made by some scientists to produce Al based MMCs having high electrical conductivity and current carrying capacity. However, the work is limited to lab scale with small quantities being produced.

[0034] Challenges exist for addition of graphene or other nanocarbons to liquid aluminum. Nanocarbons such as graphene are light and have a lower density (lower specific gravity) than liquid aluminum so they tend to rise to the surface of liquid aluminum. Liquid aluminum has a density of about 2.375 g / cm3. Graphene has a lower density of 1.6-2.1 g / cm3. In addition, graphene doesn’t easily become wetted by liquid aluminum. As a result, it can be difficult to get graphene to mix uniformly with liquid aluminum. Also, graphene has a high surface area per unit weight (e.g., >2625 m2 / g) and tends to agglomerate when provided with sufficient energy, in this case from hot liquid aluminum.

[0035] To address these or other challenges, disclosed herein is a set of scalable processes for manufacturing high-conductivity metal matrix composites (MMCs), achieved by integrating specific forms of nanocarbon into aluminum matrices. The disclosed techniques can facilitate the creation of aluminum-nanocarbon (Al-NC) composites, including but not limited to aluminum-graphene (Al-Gr) or aluminum-carbon nanotube (Al-CNT) variants. The disclosed techniques advantageously enhance the electrical conductivity of aluminum, thereby offering an effective alternative to traditional materials such as copper for diverse industrial applications.

[0036] Methods are provided to get graphene to the bottom of liquid aluminum melt. In some cases, a nanocarbon such as graphene is mixed with a metal powder. The metal powder can be aluminum or a heavier metal powder. Optionally, the metal powder nanocarbon mixture is consolidated and / or compacted, for example, to form a pellet. In some cases, the nanocarbon metal powder mixture is consolidated and / or compacted to from 40-100%, 50-90%, or 60-80% of maximum. In some cases, the metal powder nanocarbon mixture can be added to the liquid aluminum as it flows from the furnace toward a sonicator or other mixing mechanism. In some cases, an aluminum powder nanocarbon mixture or pellet thereof is added toward the bottom of the melt using a mechanical arrangement, for example, a screw conveyer. In some cases, a heavier metal powder nanocarbon mixture or pellet thereof can be added to the surface of the liquid aluminum flow and allowed to travel toward the bottom of the melt due to the higher density of the heavier metal. As the heavier metal melts, the nanocarbon, such as a graphene, travels upward in the melt due to a lower density. The subsequent solidified aluminum would comprise embedded nanocarbon. The heavier metal has a higher density than liquid aluminum. The heavier metal has a minimal negative effect of the electrical conductivity of liquid aluminum. The heavier metal can have a lower melting point than aluminum.

[0037] It will be appreciated that, within the context of this disclosure, the term "nanocarbon" is intended to encompass a broad range of carbon-based nanomaterials. This includes, but is not limited to, graphene, graphene oxide, reduced graphene oxide, graphene nanoplatelets, graphene fiber, carbon nanotubes (CNTs), fullerenes, carbon black, and carbon nanofibers. The carbon nanotubes can include single walled carbon nanotubes (SWNTs) and / or multiwalled carbon nanotubes (MWNTs). In some cases, the nanocarbon is selected from the group consisting of a graphene and a carbon nanotube (CNT). In some cases, the nanocarbon is a graphene. In some cases, the nanocarbon is a carbon nanotube (CNT). Each of these nanocarbon variants offers unique electrical, thermal, and mechanical properties that can be strategically selected and exploited to enhance the performance characteristics of metal matrixcomposites. The choice of nanocarbon may vary based on factors such as the desired electrical conductivity, mechanical strength, thermal conductivity, manufacturability of the composite material, etc.

[0038] The high electrical conductivity Metal Matrix Composites (MMCs) produced through the integration of nanocarbon materials such as graphene and carbon nanotubes can include heavier metals in the matrix for these composites. In some cases, the heavier metals include, but are not limited to, antimony (Sb), cadmium (Cd), bismuth (Bi), zinc (Zn), iron (Fe), Chromium (Cr), manganese (Mn), tin (Sn), or Nickel (Ni). In some cases, the MMC aluminum composite comprises aluminum, a nanocarbon, and from about 0.05 to about 5 wt%, about 0.1 to about 4 wt%, 0.5 to about 5 wt%, about 0.5 to about 2.5 wt%, about 0.6 to about 1.2 wt%, about 0.7 to about 0.9 wt%, about 0.6 to about 0.8 wt%, about 0.6 wt%, about 0.7 wt%, about 0.8 wt%, about 0.9 wt%, or about 1 wt% of a heavier metal. In some cases, the nanocarbon is selected from graphene and carbon nanotubes. In some cases, the heavier metal is selected from the group consisting of Sb, Cd, Bi, Sn, Ni, Cr, Mn, Fe, and Zn. In some cases, the MMC aluminum composite exhibits an electrical conductivity of about 65 to about 95 % IACS, about 70 to about 95 % IACS, about 70 to about 90 % IACS, or about 75 to about 85 % IACS.Environment Overview

[0039] FIG. 1 illustrates an example industrial scale system 100 in accordance with some embodiments of the present disclosure. As show, the system 100 can include a mixing system 110, a composite incorporation system 120, an ultrasonic disintegration and mixing system 130, a composite casting system 140, a microstructure refinement system 150, a thermal processing system 160, and an optional direction alignment system 170. It will be appreciated that the system 100 can include fewer, more, or different components, as desired. For example, as shown, the system 100 can exclude one or more of the mixing system 110, the composite incorporation system 120, the ultrasonic disintegration and mixing system 130, the composite casting system 140, the microstructure refinement system 150, the thermal processing system 160, or the direction alignment system 170.

[0040] The mixing system 110 can be equipped to facilitate the substantially uniform blending of a nanocarbon such as graphene with aluminum powder to produce a graphene- aluminum powder mixture. The system can incorporate devices such as mechanical mixers, blenders, etc. that are capable of mixing to achieve a homogeneous mixture. In some cases, the mixing or coating of the aluminum powder or heavier metal powder with the nanocarbon such as graphene can include dry mixing of powders, for example, by ball milling, tumbler mixing,or chemical mixing. In some cases, the mixing is wet mixing of the nanocarbon with the metal powder followed by drying of the metal nanocarbon powder, for example, by spray drying. Graphene can be introduced into the metal powder or coated to the metal powder at a concentration that is significantly higher than what is desired in the final composite material, which can facilitate an adequate distribution within the metal matrix. In some embodiments, additives or binding agents can be added to the mixture to enhance the exfoliation of graphene, the mixing process with metal powder, and to improve the handling characteristics of the powder.

[0041] The composite incorporation system 120 can be configured to incorporate the graphene-aluminum powder mixture into a liquid aluminum flow. The composite incorporation system 120 includes various components such as, but not limited to, conduits, injectors, or mixing chambers, which are designed to control the addition of the powder mixture into the liquid metal, maintaining the integrity of the graphene throughout the process. The composite incorporation system 120 can include mechanisms to adjust the temperature and flow rate of the molten aluminum and / or the aluminum-graphene mixture, which can facilitate the dispersion of graphene within the metal matrix. These adjustments facilitate substantially even distribution of the nanocarbon particles throughout the molten aluminum.

[0042] The ultrasonic disintegration and mixing system 130 can be designed to achieve a substantially uniform dispersion of graphene within the liquid aluminum flow by utilizing ultrasonic energy. The ultrasonic disintegration and mixing system 130 can include elements such as, but not limited to, ultrasonic probes, generators, or control systems that can be calibrated to manage the sonication process. By applying ultrasonic waves, the ultrasonic disintegration and mixing system 130 can help break down agglomerations of powder and improve the wetting of graphene particles by the molten aluminum, which can facilitate the forming of a homogenous composite mixture. In some cases, to ensure effective mixing, the ultrasonic disintegration and mixing system 130 can maintain the sonication at shallow depths, such as for example, at from about 2 mm to about 100 mm. In some cases, the depth of the ultrasonication effect can be adjustable.

[0043] The composite casting system 140 can facilitate the formation of sheets from the molten aluminum-graphene mixture using a twin roll caster. The composite casting system 140 can utilize various casting methods, including a twin roll caster, to transform the molten aluminum-graphene mixture into sheets. The composite casting system 140 can include, but is not limited to, casting rolls, cooling systems, or precision mechanisms for controlling sheet thickness. The casting process can be conducted with a high level of control to solidify thecomposite into sheets with a generally uniform graphene distribution. In some cases, the composite casting system 140 can be adaptable, supporting alternative casting methods like single roll or belt casting, which can be selected based on their capacity to influence the speed and pressure of casting.

[0044] The microstructure refinement system 150 can use asymmetric rolling to reduce grain size in the cast composite sheet. The microstructure refinement system 150 can include rolling mills that have adjustable roll diameters, speeds, or pressures, enabling the production of a material with a generally uniform, relatively small grain size across its thickness. The process can modify the grains through controlled deformation.

[0045] The thermal processing system 160 can facilitate the annealing of the rolled composite sheet to achieve recrystallization and grain growth. The thermal processing system 160 can include, but is not limited to, furnaces, temperature control units, or atmosphere management systems to provide thermal treatments. The annealing process can arrange the nanocarbon at the grain boundaries within the metal matrix.

[0046] The optional directional alignment system 170 can facilitate the alignment of grains and nanocarbon including but not limited to carbon nanotubes within the sheet or other object manufactured in a direction corresponding to the flow of electrical current. The directional alignment system 170 system can include rolling, extruding, or wire drawing mechanisms to align grains and nanocarbon within the annealed sheet. The directional alignment system 170 can include rolling, extruding, or wire drawing equipment, designed to orient the microstructure of the composite material for optimal electrical conductivity. Process parameters, such as deformation rate and direction, can be adjusted to achieve the desired grain orientation and composite performance.Example Flow Diagram

[0047] FIG. 2 illustrates a flow diagram illustrative of an example process 200 for the fabrication of nanocarbon-infused (e.g., graphene-infused or CNT-infused) metal composite materials. This process 200 outlines a sequence of operations for integrating nanocarbon (e.g., graphene) within an aluminum matrix to enhance the electrical conductivity and mechanical properties of the resultant composite material.

[0048] At block 202, the process 200 can include mixing graphene or other forms of nanocarbon into a metal powder such as an aluminum powder or a heavier metal powder to form a metal nanocarbon powder mixture. In some cases, the nanocarbon can be introduced at a concentration that is substantially higher (e.g., lOx, 50x, lOOx, 250x, 500x higher) than the final desired concentration in the composite material. An elevated concentration can beimportant for ensuring that the graphene is sufficiently dispersed within the aluminum matrix upon subsequent processing steps.

[0049] The mixing or coating can be carried out using a variety of techniques such as, but not limited to, mechanical stirring, ball milling, or ultrasonic agitation. In some cases, the graphene is coated onto the metal powder. In some cases, the mixing or coating of the nanocarbon with the aluminum powder or heavier metal powder can include dry mixing of powders, for example, by ball milling, tumbler mixing, or chemical mixing. In some cases, the mixing is wet mixing of the nanocarbon with the metal powder followed by drying of the metal nanocarbon powder, for example, by spray drying. In some cases, the mixing achieves a homogeneous distribution of nanocarbon within the metal powder.

[0050] At block 204, the process 200 includes adding the nanocarbon-aluminum powder mixture to a liquid aluminum flow. In some cases, this addition can be facilitated by devices such as injectors or conveyors that are designed to introduce the powder mixture into the molten metal uniformly. In some cases, this step can ensure the nanocarbon particles are evenly dispersed throughout the molten aluminum, which can be conducive to enhancing the overall properties of the composite material.

[0051] At block 206, the process 200 includes applying ultrasonication to the liquid aluminum flow. In some embodiments, ultrasonication can be applied to deagglomerate and distribute the nanocarbon uniformly within the molten aluminum. The application of ultrasonic energy can be precisely controlled, with the depth of sonication adjusted to a shallow level, such as from about 2 mm to about 100 mm, which can be optimal for effective deagglomeration and dispersion throughout the molten metal. This targeted application of ultrasonication can facilitate a homogeneous mixture and deagglomeration of nanocarbon in the aluminum flow, which can be beneficial for the structural and / or conductive properties of the final composite.

[0052] In some cases, the depth of the sonication field is deliberately kept shallow (e.g., less than 2cm, less than 1cm, less than 7mm, less than 5mm) to ensure the ultrasonic energy is effectively utilized throughout the molten metal. The depth can be particularly relevant when the surface area of the nanocarbon, such as graphene, is significantly large, which can lead to challenges with re-agglomeration due to the thermal energy present in the liquid metal. By employing sonication in a shallow path, the process can reduce the time between the dispersion of nanocarbon particles and their solidification within the metal matrix, thereby enhancing the likelihood of achieving a substantially uniform distribution. A shallow path can facilitate working with high-volume liquid metal flows in industrial settings, where maintaining consistent properties throughout the composite is important.

[0053] At block 208, the process 200 includes the casting of molten aluminum with uniformly distributed nanocarbon to form a sheet by employing a twin roll caster. This casting step can include the solidification of the molten aluminum-nanocarbon mixture into a sheet form, leveraging the twin roll caster's ability to produce sheets with consistent thickness and material properties. The twin roll caster can be particularly advantageous due to its precision in thickness control and its rapid solidification capabilities, which can be important for preserving the distribution of nanocarbon achieved by prior processing steps. The casting can ensure that the nanocarbon remains evenly dispersed within the aluminum matrix as the material transitions from a liquid to a solid state, which can establish a strong foundation for the composite's enhanced electrical conductivity, thermal conductivity, and / or mechanical strength, etc.

[0054] At block 210, the process 200 includes subjecting the sheet to an asymmetric rolling process. In some cases, this asymmetric rolling process can include utilizing rollers of different diameters and / or rollers that move at different velocities to impose relatively uniform strain across the sheet's cross-section, which can lead to a finer and more uniform grain size throughout the composite material. The asymmetry in the rolling process can be deliberately employed to enhance the distribution of strain, which can significantly reduce grain size as compared to conventional symmetrical rolling. In some cases, the refinement in the material's microstructure can improve its mechanical strength and electrical conductivity. In some cases, by achieving a generally consistent grain size distribution, the composite material can facilitate the nanocarbon being effectively deagglomerated and / or exfoliated, thereby enhancing the composite's overall performance characteristics.

[0055] At block 212, the process 200 includes annealing the rolled sheet. The annealing process can initiate recrystallization, which tends to occur more favorably at the interfaces with another material, in this case, nanocarbon. As the annealing progresses, with the application of higher temperatures and for extended durations, grain growth is promoted, allowing nanocarbon to become arranged at the grain boundaries within the metal matrix. In some cases, this embedding can significantly impact the electrical, thermal, and mechanical properties, etc., of the final composite material.

[0056] At block 214, the process 200 includes the optional step of mechanically processing the annealed sheet through methods such as rolling, extruding, or wire drawing. These methods can serve to orient the grains and added nanocarbon within the composite in a direction that facilitates the flow of electrical current. Rolling, whether performed symmetrically or asymmetrically, can help ensure that the grains and nanocarbon sheets are aligned parallel tothe direction of current flow, a feature that can be especially effective for composites with metal-CNTs due to their highly directional electrical conductivity. The process selected — whether rolling for flat sheets, extruding for rod-like shapes, or wire drawing for creating wires — may depend on the final desired form of the composite. By aligning the grains and nanocarbon appropriately, these post-annealing processes can enhance the material's electrical conductivity and also refine its microstructure. This fine-tuning of the anisotropic properties, such as the composite's strength and conductivity, can allow for the material to be customized to meet the specific demands of a variety of applications.

[0057] FIG. 3A shows a process 300 to disperse and deagglomerate graphene in liquid Al at an industrial scale operation. In the operation, melting of Al, including composition adjustment, drossing, etc., is performed in an industrial furnace 310. Separately, graphene is mixed with powdered Al 320. A continuous feeding of liquid Al and graphene mixed with metal powder (e.g., 1% of the liquid metal) is performed prior to in-line sonication for proper mixing and deagglomeration of graphene in the liquid Al. After the in-line sonication, continuous feeding of the liquid Al to twin roll casting 330 is performed to form sheets. The sheets are subjected to homogenization 340 and asymmetric rolling 350 for uniform grain size reduction. Optional annealing 360 can be performed for grain growth and further rolling. The Al-graphene composite can be formed 370 into a sheet, a shape (e.g., for bus bar) or wire (e.g., for wire conductors).

[0058] FIG. 4 illustrates one method of adding Al graphene powder to the Al melt to disperse and deagglomerate graphene in liquid Al at an industrial scale operation. The liquid Al travels in a flow 410 from the holding furnace. The metal- graphene powder mixture can be added below the surface of the Al melt 420 flow prior to in line sonication assemblies 430 before twin roll casting 440. The metal -graphene mixture can be added to the bottom of the melt, for example, using a mechanical arrangement, such as for example, a screw conveyer.

[0059] The density of graphene 1.6 to 2.1 g / cm3 is lower than the density of liquid aluminum 2.375 g / cm3, so the graphene has a tendency to rise to the surface in the Al melt. FIG. 5 shows two methods of adding graphene to liquid Al to disperse and deagglomerate graphene in liquid Al at an industrial scale operation. In some cases, the metal graphene powder mixture is added below the surface of the liquid aluminum towards the bottom of the melt 510. In some cases, graphene is mixed with a heavier metal powder, optionally consolidated and / or compacted, and added to the liquid Al such that the metal-graphene mixture will travel to the bottom of the liquid Al due to higher density 520. In some cases, both methods of addition of graphene to liquid metal shown in 510 and 520 are employed.

[0060] Heavier metals for addition of nanocarbon to Al

[0061] In some cases, graphene can be added to the bottom of the Al melt by first mixing with a heavier metal to form a heavier metal graphene powder, adding the heavier metal graphene powder to the liquid Al, and allowing the heavier metal graphene powder to sink toward the bottom of the liquid Al due to higher density. As the heavier metal melts and / or as graphene starts separating from metal powder, the graphene can travel upward in the melt due to its lower density.

[0062] The term “heavier metal” refers to a metal having a higher density (higher specific gravity) than liquid aluminum or higher density (higher specific gravity) > than about 2.375 g / cm3. The heavier metal is selected based on having a higher density than Al, and preferably a lower melting point than Al. In some cases, the heavier metal is selected based on having the least negative effect on electrical conductivity of the Al composite. Detrimental effects of alloying elements on conductivity of 99.99% Al can be found, for example, in Czerwinski, Aluminum alloys for electrical engineering: a review, J Mater Sci (2024) 59: 14847-14892, which is incorporated herein by reference. In some cases, the heavier metal element has a lower melting point (m.p.) than Al (about 660 deg C). In some cases, the heavier metal has a higher melting point than Al, such as Fe or Ni, and can be useful for intermetallic formation. In some cases, the heavier metal is selected from Sb, Cd, Bi, Sn, Ni, Fe, Mn, Cr, and Zn. In some cases, the heavier metal can be selected from Table 1.

[0063] Table 1. Exemplary Candidate Heavier Metal Elements

[0064] In some cases, the heavier metal element is selected from the group consisting of Sb, Cd, Bi, Sn, Ni, and Zn. In some cases, the heavier metal candidate has lowest possible human toxicity. In some cases, the heavier metal is selected from the group consisting of Sb, Bi, and Sn. In some cases, the heavier metal is Sb. In some cases, the heavier metal is Cd. In some cases, the heavier metal is Bi. In some cases, the heavier metal is Sn. In some cases, theheavier metal is Zn. In some cases, the heavier metal is Ni. In some cases, the heavier metal is Fe. In some cases, the heavier metal is Mn. In some cases, the heavier metal is Cr.By employing the manufacturing processes described herein, the integration of nanocarbon (e.g., graphene) at grain boundaries can facilitate an increase in the electrical conductivity of aluminum to levels that can range from about 65% to about 95% IACS, about 70 to about 95 % IACS, about 70% to about 90% IACS, or about 75% to about 85% IACS. In some embodiments, the manufacturing processes can achieve electrical conductivities for the aluminum-graphene composite greater than about 65%, 70%, 75%, 80%, 85%, 90%, or 95% IACS.

[0065] In some cases, the disclosed manufacturing methods can integrate approximately 10-900 ppm, 10-800 ppm, 10-700 ppm, 10-600 ppm, 15-600 ppm, 15-500 ppm, 15-300 ppm, 15-200 ppm, 20-100 ppm, 20-75 ppm, 20-50 ppm, 25-35 ppm, or about 30 ppm of nanocarbon such as graphene or CNTs into the Al to achieve the targeted enhancements in conductivity. This nanocarbon graphene content is determined to effectively elevate the electrical conductivity of the aluminum composite. However, in some embodiments, the concentrations can include approximately 10, 15, 20, 25, 30, 35, 40, 45, or 50 ppm, or approximately 100, 200, 300, 400, 500, 600, 700, 800, or 900 ppm (+ / - about 5, 10, 20, 25, or 50 ppm). In some cases, the content of nanocarbon can be calculated. In some cases, the content of nanocarbon can be calculated from one or more of grain size of aluminum nanocarbon composite, nature and quality of graphene, grain boundary coverage of graphene.

[0066] FIG. 6 shows an addition procedure 600 for adding a nanocarbon to liquid aluminum. In this case, the nanocarbon is graphene, but any other appropriate nanocarbon such as carbon nanotubes can be employed. Selection of the required content of graphene and metal and amount of heavier metal powder is made 610. Mixing of nanocarbon such as graphene or CNT with the selected element heavier metal powder or coating of the heavier metal powder with graphene is performed 620. The mixing or coating of the nanocarbon with the aluminum powder or heavier metal powder can include dry mixing of powders, for example, by ball milling, or chemical mixing. In some cases, the mixing is wet mixing of the nanocarbon with the metal powder followed by drying of the metal nanocarbon powder, for example, by spray drying. In some cases, the drying is performed in an inert atmosphere, such as under an inert gas. Optionally, the metal graphene mixed powder is compacted or consolidated with an appropriate technique to form pellets, discs, cubes, or other compacted form 630. Addition to liquid aluminum of the metal graphene mixed powder, pellets, discs, cubes, or other compacted is performed 640. Sonication of the liquid metal ensures the graphene separates effectivelyfrom the heavier metal, gets distributed in the liquid metal volume, and remains deagglomerated 650. Casting of the liquid aluminum is performed, preferably in minimal time, to avoid agglomeration of the graphene 660. The casting can be any appropriate casting. For example, the casting can be HPDC, GDC, SC, continuous billet, twin roll casting, or strip casting.

[0067] FIG. 7 shows a method 700 of adding a nanocarbon such as a graphene mixed with a heavier metal powder or a compacted form thereof 720 to the liquid Al flow from a holding furnace 710 before an in-line sonication assembly 730 such that the heavier metal graphene mixture will travel to the bottom of the liquid Al due to higher density. As the heavier metal melts, the graphene is released where it will travel upward in the flow due to its lower density(lower specific gravity). The aluminum flow travels toward a casting assembly, such as a twin roll caster 740.

[0068] Calculation of density of Sb-Gr composite for addition to castings. In some cases, the heavier metal is antimony (Sb). Density calculation of compacted metal-graphene composites for addition to liquid Al-Sb can be performed as follows.

[0069] Table 2A. Calculation of Density of Sb-Gr Composite for addition to castings

[0070] Table 2B. Calculation of Density of Sb-Gr Composite for addition to castingsmixture can be calculated. More highly compacted forms have a higher density approaching the theoretical effective density as seen in Table 2C. In any case, the density of the optionally compacted Sb-Gr composite should be higher than the density of the molten aluminum.

[0072] Table 2C. Calculation of Density of Sb-Gr Composite for addition to castingsCalculation of density of Cd-Gr composite for addition to castings

[0073] In some cases, the heavier metal is cadmium (Cd). Density calculation of compacted metal-graphene composites for addition to liquid Al-Cd can be performed as follows.

[0074] Table 3 A. Calculation of Density of Cd-Gr Composite for addition to castings

[0075] Table 3B. Calculation of Density of Cd-Gr Composite for addition to castings

[0076] In some cases, the relative density of compacted forms of the cadmium nanocarbon mixture can be calculated. More highly compacted forms have a higher density approaching the theoretical effective density as seen in Table 3C. In any case, the density of the optionally compacted Cd-Gr composite should be higher than the density of the molten aluminum.

[0077] Table 3C. Calculation of Density of Cd-Gr Composite for addition to castingsCalculation of density of Bi-Gr composite for addition to castings

[0078] In some cases, the heavier metal is bismuth (Bi). Density calculation of compacted metal-graphene composites for addition to liquid Al-Bi can be performed as follows.

[0079] Table 4A. Calculation of Density of Bi-Gr Composite for addition to castings

[0080] Table 4B. Calculation of Density of Bi-Gr Composite for addition to castings

[0081] In some cases, the relative density of compacted forms of the bismuth nanocarbon mixture can be calculated. More highly compacted forms have a higher density approaching the theoretical effective density as seen in Table 4C. In any case, the density of the optionally compacted Bi-Gr composite should be higher than the density of the molten aluminum.

[0082] Table 4C. Calculation of Density of Bi-Gr Composite for addition to castingsCalculation of density of Sn-Gr composite for addition to castings

[0083] In some cases, the heavier metal is tin (Sn). Density calculation of compacted metal- graphene composites for addition to liquid Al-Sn can be performed as follows.

[0084] Table 5 A. Calculation of Density of Sn-Gr Composite for addition to castings

[0085] Table 5B. Calculation of Density of Sn-Gr Composite for addition to castings

[0086] In some cases, the relative density of compacted forms of the tin nanocarbon mixture can be calculated. More highly compacted forms have a higher density approaching the theoretical effective density as seen in Table 5C. In any case, the density of the optionally compacted Sn-Gr composite should be higher than the density of the molten aluminum.

[0087] Table 5C. Calculation of Density of Sn-Gr Composite for addition to castingsCalculation of density of Ni-Gr composite for addition to castings

[0088] In some cases, the heavier metal is nickel (Ni). Density calculation of compacted metal-graphene composites for addition to liquid Al-Ni can be performed as follows.

[0089] Table 6A. Calculation of Density of Ni-Gr Composite for addition to castings

[0090] Table 6B. Calculation of Density of Ni-Gr Composite for addition to castings

[0091] In some cases, the relative density of compacted forms of the nickel nanocarbon mixture can be calculated. More highly compacted forms have a higher density approaching the theoretical effective density as seen in Table 6C. In any case, the density of the optionally compacted Ni-Gr composite should be higher than the density of the molten aluminum.

[0092] Table 6C. Calculation of Density of Ni-Gr Composite for addition to castingsCalculation of density of Zn-Gr composite for addition to castings

[0093] In some cases, the heavier metal is zinc (Zn). Density calculation of compacted metal-graphene composites for addition to liquid Al-Zn can be performed as follows.

[0094] Table 7A. Calculation of Density of Zn-Gr Composite for addition to castings

[0095] Table 7B. Calculation of Density of Zn-Gr Composite for addition to castings

[0096] In some cases, the relative density of optionally compacted forms of the zinc nanocarbon mixture can be calculated. More highly compacted forms have a higher density approaching the theoretical effective density as seen in Table 7C. In any case, the density of the optionally compacted Zn-Gr composite should be higher than the density of the molten aluminum.

[0097] Table 7C. Calculation of Density of Zn-Gr Composite for addition to castings

[0098] Definitions

[0099] The singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0100] The term "and / or" refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0101] The term "about," when referring to a measurable value such as an amount of a compound, dose, time, temperature, and the like, is meant to encompass variations of + / -10%, 5%, 1%, 0.5%, or even 0.1% of the specified amount.

[0102] The terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. Unless otherwise defined, all terms, including technical and scientific terms used in the description, have the same meaning ascommonly understood by one of ordinary skill in the art to which this disclosure belongs. In the event of conflicting terminology, the present specification is controlling.

[0103] All patents, patent applications and publications referred to herein are incorporated by reference in their entirety.

[0104] Unless otherwise specified, the term “percent,” or “%,” refers to weight percent.

[0105] The embodiments described in one aspect of the present disclosure are not limited to the aspect described. The embodiments may also be applied to a different aspect of the disclosure as long as the embodiments do not prevent these aspects of the disclosure from operating for its intended purpose.

[0106] The term “alloy” refers to a solid or liquid mixture of two or more metals or of one or more metals with certain metalloid elements.

[0107] The term “ambient room temperature” or “ambient temperature” or “room temperature” refers to the temperature of the surrounding air. In some cases, the term “ambient room temperature” refers to a temperature in a range of 20 to 30 deg C (68 to 86 deg F). In some cases, ambient room temperature is 25 deg C ± 2.0 deg C (77 deg F ± 3.6 deg F).

[0108] The term “high pressure die casting” (HPDC) is a process for mass manufacturing of aluminum (Al) alloy castings. High production volume castings are frequently made by HPDC.

[0109] The term “gravity die casting” (GDC) refers to a process for mass manufacturing of aluminum (Al) alloy castings. Castings that need high mechanical strength are often manufactured by GDC. The GDC castings typically need to be heat treated for development of mechanical strength. GDC comprises pouring molten metal into a mold.

[0110] The term “sand casting” (SC) refers to another process comprising pouring molten metal into a mold. Sand casting uses disposable sand molds, where GDC typically uses reusable metal molds.

[0111] The term “strip casting” refers to a casting process where aluminum sheets are produced in a twin roll caster. The molten metal is introduced between a pair of counter rotating horizontal casting rolls where solidification is initiated when the molten metal contacts the rolls.

[0112] The term “twin roll casting” (TRC) is a process that produces thin sheets of metal directly from molten metal. It combines casting and rolling into one step which can reduce costs and energy consumption. In twin roll casting molten metal is fed onto water-cooled rolls, where it solidifies and is then rolled.

[0113] The term “billet casting” refers to a process of creating a semi-finished aluminum blocks, or billets, by pouring molten aluminum into a mold. In some cases, molten aluminum is pored into a shallow, water-cooled mold. When the metal begins to solidify in the mold, the false bottom of the mold is lowered at a controlled speed and water is sprayed on the surface of the freshly solidified billet as it comes out of the mold.

[0114] The term “squeeze casting” refers to a casting process that combines gravity and pressurized casting. In some cases, molten metal is poured into a pre-heated die. When filling is complete, a ram is used to slowly apply high pressure to the molten metal head. The process can help minimize shrinkage and micro shrinkage porosity.

[0115] The term “investment casting” refers to a casting process that uses a wax pattern to create a ceramic mold for casting metal parts. Once the ceramic has dried and hardened, the wax is melted out leaving an internal cavity. Molten metal is pored into the cavity and the metal solidifies within the cavity, cools, and the ceramic is removed from the metal casting.

[0116] The term “stir casting” refers to a casting process wherein the melt is actively stirred while solidifying and mixing with reinforcement particles. The mixing can be performed by a motor-driven stirring mechanism or an ultrasonic transducer.

[0117] The term “rheocasting” refers to a semi-solid die casting process that comprises cooling a liquid metal or alloy into a semisolid state to form a slurry and then injecting the slurry into a die.

[0118] The term “thixocasting” refers to a semi-solid metal processing process comprising pre-cast billets that are heated to a thixotropic state. The semi-solid billet is injected into a mold under high pressure. Once in the mold the material cools and solidifies to form a part.

[0119] The term “severe plastic deformation” (SPD) refers to a metal forming process in which a very large plastic strain is imposed on a bulk process in order to make an ultra-fine grained (UFG) metal (d <1000 nm, or in some cases between 100 nm-1,000 nm) or nanocrystalline (NC) structure (d <100 nm). Methods for SPD are known in the art, for example, as described in Edalati et al., 2022, Materials Research Letters, 10:4, 163-256.

[0120] The term “hardness” refers to the mechanical resistance of a material (test specimen) to mechanical indentation by another harder body (indenter).

[0121] The term “Vickers hardness” refers to a hardness measurement determined by indenting the test material with an indenter subjected to a load of 0.1 to 100 kgf for a period of time. The hardness test method according to Vickers is described in ISO 6507 (Metallic materials- Vickers hardness test-Part 1 : Test method), ASTM E92, or ASTM E384 (Standard Test Method for Microindentation Hardness of Materials to Vickers and Knoop). Vickershardness may be expressed in units of HV. A Vickers Hardness Testing Machine may be employed. Unless otherwise specified, Vickers hardness is measured under Micro-Vicker’s hardness test ASTM E384-22 Standard Test Method for Microindentation Hardness of Materials using a square-based pyramidal shaped diamond indenter with face angles of 136 degrees and test forces in the range of 9.8 x 10-3 to 9.8 N (1 to 1000 gf). In some cases, the indenter for aluminum is Vickers diamond and force load is 1000 gf (1 kg).

[0122] The term “Brinell hardness” refers to a hardness measurement determined by ISO 6506 or ASTM E10. Unless otherwise specified, ASTM El 0-18 test version is employed. In some cases, the term “Brinell hardness” expressed in units of HBS refers to indenter steel 10mm ball and 500-kgf force, e.g., for aluminum products.

[0123] The term “Rockwell hardness” refers to a hardness measurement made by a differential-depth method where the residual depth of the indent made by the indenter is measured. The deeper a defined indenter penetrates the surface of a test specimen, the softer the material being tested. Rockwell hardness may be determined by standardized test methods such as ISO 6508 or ASTM El 8. The Rockwell hardness (HR) is determined from the residual indentation depth. Th indenter and test force must be specified. For example, under ISO 6508, method HRHW employs a tungsten carbide 1 / 8” metal ball and 60 kgf force, e.g., for aluminum materials. Method HRB refers to a 1 / 16” ball indenter and 100 kg test force.

[0124] The requirement to convert from one hardness test scale to another is covered by various International Standards (ASTM E140 or ISO 18265). Conversion charts are available according to hardness test scale conversion algorithms provided within ASTM E140.

[0125] Standard test methods for tension testing of metallic materials including the aluminum alloys disclosed herein may be performed at room temperature including methods of determining yield strength, yield point elongation, tensile strength, elongation, and reduction of area may be determined by standardized test ASTM E8ZE8M. Unless otherwise specified, ASTM E8ZE8M-22 test version may be employed.

[0126] The term “tensile strength” refers to the maximum tensile stress that a material is capable of sustaining. Tensile strength for aluminum alloys may be determined by standardized test ASTM E8ZE8M. Unless otherwise specified, ASTM E8ZE8M-22 test version may be employed.

[0127] The term “yield strength” or “yield stress” refers to the engineering stress at which, by convention, it is considered that plastic elongation of the material has commenced, i.e., the stress a material can withstand without permanent deformation; the stress at which a material begins to deform plastically. Yield strength for aluminum alloys may be determined bystandardized test ASTM E8ZE8M. Unless otherwise specified, ASTM E8ZE8M-22 test version may be employed.

[0128] The term “grain size” refers to the size of individual grains in a material which is influenced by factors such as nucleation, growth processes, and annealing temperature. The final grain size can vary within a specimen and is often distributed close to a log-normal distribution. The grain size of the aluminum composite material can be determined by ASTM El 12-24, a standard test method of determining average grain size. In some cases, the grain size is from 1 to 12, 2 to 10, 4 to 9, 5 to 8, 5 to 10, 5 to 9, or 3 to 8.

[0129] Distribution of nanocarbon along aluminum grain boundaries and grain size can be determined by image analysis, for example, using transmission electron microscopy (TEM).

[0130] The conductivity of the aluminum composite materials can be measured, for example, by ASTM B193-20 at 20 deg C. Conductivity of pure aluminum (99.99+%) is about 65.1 % IACS, whereas conductivity of copper (99.99+%) is about 102.7 % IACS. 100% IACS is equivalent to 58.108 MegaSiemens per meter (M S / m) at 20 deg C or a resistivity of 1 / 58.108 ohm per meter for a wire one square millimeter in cross section. IACS% = (172.41 / resistivity) where resistivity, p (ro), is in micro-ohms per centimeter.Terminology

[0131] Any or all of the features and functions described above can be combined with each other, except to the extent it may be otherwise stated above or to the extent that any such embodiments may be incompatible by virtue of their function or structure, as will be apparent to persons of ordinary skill in the art. Unless contrary to physical possibility, it is envisioned that the methods / steps described herein may be performed in any sequence and / or in any combination, and the components of respective embodiments may be combined in any manner.

[0132] Although the subject matter has been described in language specific to structural features and / or acts, it is to be understood that the subj ect matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as examples of implementing the claims, and other equivalent features and acts are intended to be within the scope of the claims.

[0133] Conditional language, such as, among others, “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements and / or steps. Thus, such conditional language is notgenerally intended to imply that features, elements and / or steps are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without user input or prompting, whether these features, elements and / or steps are included or are to be performed in any particular embodiment.

[0134] Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise,” “comprising,” and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense, e.g., in the sense of “including, but not limited to.” As used herein, the terms "connected," "coupled," or any variant thereof means any connection or coupling, either direct or indirect, between two or more elements; the coupling or connection between the elements can be physical, logical, or a combination thereof. Additionally, the words “herein,” “above,” "below," and words of similar import, when used in this application, refer to this application as a whole and not to any particular portions of this application. Where the context permits, words using the singular or plural number may also include the plural or singular number, respectively. The word "or" in reference to a list of two or more items, covers all of the following interpretations of the word: any one of the items in the list, all of the items in the list, and any combination of the items in the list. Likewise, the term “and / or” in reference to a list of two or more items, covers all of the following interpretations of the word: any one of the items in the list, all of the items in the list, and any combination of the items in the list.

[0135] Conjunctive language such as the phrase “at least one of X, Y and Z,” unless specifically stated otherwise, is otherwise understood with the context as used in general to convey that an item, term, etc. may be either X, Y or Z, or any combination thereof. Thus, such conjunctive language is not generally intended to imply that certain embodiments require at least one of X, at least one of Y and at least one of Z to each be present. Further, use of the phrase “at least one of X, Y or Z” as used in general is to convey that an item, term, etc. may be either X, Y or Z, or any combination thereof.

[0136] Language of degree used herein, such as the terms “approximately,” “about,” “generally,” and “substantially” as used herein represent a value, amount, or characteristic close to the stated value, amount, or characteristic that still performs a desired function or achieves a desired result. For example, the terms “approximately”, “about”, “generally,” and “substantially” may refer to an amount that is within less than 10% of, within less than 5% of, within less than 1% of, within less than 0.1% of, and within less than 0.01% of the stated amount. As another example, in certain embodiments, the terms “generally parallel” and “substantially parallel” refer to a value, amount, or characteristic that departs from exactlyparallel by less than or equal to 10 degrees, 5 degrees, 3 degrees, or 1 degree. As another example, in certain embodiments, the terms “generally perpendicular” and “substantially perpendicular” refer to a value, amount, or characteristic that departs from exactly perpendicular by less than or equal to 10 degrees, 5 degrees, 3 degrees, or 1 degree.

[0137] Any terms generally associated with circles, such as “radius” or “radial” or “diameter” or “circumference” or “circumferential” or any derivatives or similar types of terms are intended to be used to designate any corresponding structure in any type of geometry, not just circular structures. For example, “radial” as applied to another geometric structure should be understood to refer to a direction or distance between a location corresponding to a general geometric center of such structure to a perimeter of such structure; “diameter” as applied to another geometric structure should be understood to refer to a cross sectional width of such structure; and “circumference” as applied to another geometric structure should be understood to refer to a perimeter region. Nothing in this specification or drawings should be interpreted to limit these terms to only circles or circular structures.

[0138] Any patents and applications and other references noted above, including any that may be listed in accompanying filing papers, are incorporated herein by reference. Aspects of the invention can be modified, if necessary, to employ the systems, functions, and concepts of the various references described above to provide yet further implementations of the invention. These and other changes can be made to the invention in light of the above Detailed Description. While the above description describes certain examples of the invention, and describes the best mode contemplated, no matter how detailed the above appears in text, the invention can be practiced in many ways. Details of the system may vary considerably in its specific implementation, while still being encompassed by the invention disclosed herein. As noted above, particular terminology used when describing certain features or aspects of the invention should not be taken to imply that the terminology is being redefined herein to be restricted to any specific characteristics, features, or aspects of the invention with which that terminology is associated. In general, the terms used in the following claims should not be construed to limit the invention to the specific examples disclosed in the specification, unless the above Detailed Description section explicitly defines such terms. Accordingly, the actual scope of the invention encompasses not only the disclosed examples, but also all equivalent ways of practicing or implementing the invention under the claims.

[0139] To reduce the number of claims, certain aspects of the invention are presented below in certain claim forms, but the applicant contemplates other aspects of the invention in any number of claim forms. Any claims intended to be treated under 35 U.S.C. §112(f) will beginwith the words “means for,” but use of the term “for” in any other context is not intended to invoke treatment under 35 U.S.C. §112(f). Accordingly, the applicant reserves the right to pursue additional claims after filing this application, in either this application or in a continuing application.Clauses

[0140] Clause 1. A method for manufacturing an aluminum nanocarbon composite material, the method comprising: combining a nanocarbon with a metal powder to form a nanocarbon metal powder mixture; adding the nanocarbon metal powder mixture to a liquid aluminum flow to form a molten aluminum nanocarbon composite; and casting the molten aluminum nanocarbon composite to form the aluminum nanocarbon composite material.

[0141] Clause 2. The method of clause 1, wherein the nanocarbon is a graphene.

[0142] Clause 3. The method of clause 1, wherein the nanocarbon is carbon nanotubes.

[0143] Clause 4. The method of clause 1, wherein the nanocarbon is a combination of graphene and carbon nanotubes.

[0144] Clause 5. The method of any one of clauses 1-4, wherein the combining of the nanocarbon with the metal powder comprises mixing the nanocarbon into the metal powder or coating the metal powder with the nanocarbon to form the nanocarbon metal powder mixture, optionally wherein the mixing comprises one or more of dry mixing, ball milling, tumbler milling, chemical mixing, wet mixing, and / or spray drying.

[0145] Clause 6. The method of clause any one of clauses 1-5, further comprising applying ultrasonication to the liquid aluminum flow to uniformly mix with the nanocarbon metal powder mixture and deagglomerate the nanocarbon to form the molten aluminum nanocarbon composite.

[0146] Clause 7. The method of ant one of clauses 1-6, wherein the concentration of the nanocarbon in the nanocarbon metal powder mixture is from about 10 times to about 1000 times, about 50 times to about 750 times, about 60 times to about 600 times, about 75 times to about 500 times, about 80 to about 300 times, about 90 times to about 150 times, or about 100 times of final concentration of the nanocarbon in the metal nanocarbon composite material.

[0147] Clause 8. The method of any one of clauses 1-7, wherein the metal powder is an aluminum powder or a heavier metal powder.

[0148] Clause 9. The method of clause 8, wherein the heavier metal powder is selected from the group consisting of Sb, Cd, Bi, Sn, Ni, Fe, Cr, Mn, and Zn powder.

[0149] Clause 10. The method of any one of clauses 1-9, wherein the nanocarbon metal powder mixture is consolidated and / or compacted prior to the adding, optionally wherein thenanocarbon metal powder mixture is consolidated and / or compacted to from 40-100%, 50- 90%, or 60-80% of maximum.

[0150] Clause 11. The method of any one of clauses 1-10, wherein the adding comprises adding the nanocarbon metal powder mixture below the surface of the liquid aluminum flow.

[0151] Clause 12. The method of any one of clauses 1-10, wherein the adding comprises adding the nanocarbon metal powder mixture to the surface of the liquid aluminum flow.

[0152] Clause 13. The method of any one of clauses 1-10, wherein the adding comprises adding the nanocarbon metal powder mixture at the surface and below the surface of the liquid aluminum flow

[0153] Clause 14. The method of any one of clauses 1-13, wherein the nanocarbon metal powder mixture is added in from about 0.05 to about 5 wt%, about 0.1 to about 4 wt%, 0.5 to about 5 wt%, about 0.5 to about 2.5 wt%, about 0.6 to about 1.2 wt%, about 0.7 to about 0.9 wt%, about 0.6 to about 0.8 wt%, about 0.6 wt%, about 0.7 wt%, about 0.8 wt%, about 0.9 wt%, or about 1 wt% of the liquid aluminum flow.

[0154] Clause 15. The method of any one of clauses 1-14, wherein the casting is selected from the group consisting of HPDC, GDC (permanent mould casting), SC, continuous billet, twin roll casting, squeeze casting, investment casting, stir casting, rheocasting, thixocasting, and strip casting.

[0155] Clause 16. The method of any one of clauses 1-15, further comprising casting the molten aluminum nanocarbon composite to form a plate or sheet using a twin roll caster; subjecting the plate or sheet to an asymmetric rolling process to reduce the grain size of the material to form a rolled sheet product; and annealing the rolled sheet product to achieve recrystallization and grain growth, thereby embedding the nanocarbon at the grain boundaries within the metal matrix.

[0156] Clause 17. The method of clause 16, further comprising rolling, extruding, and / or wire drawing of the annealed sheet to align the grains and nanocarbon in a direction corresponding to the flow of electrical current when the composite material is in use.

[0157] Clause 18. The method of any one of clauses 1-17, wherein the aluminum nanocarbon composite material comprises the nanocarbon in a range of 10-900 ppm, 10-800 ppm, 10-700 ppm, 10-600 ppm, 15-600 ppm, 15-500 ppm, 15-300 ppm, 15-200 ppm, 20-100 ppm, 20-75 ppm, 20-50 ppm, 25-35 ppm, or about 30 ppm.

[0158] Clause 19. An aluminum nanocarbon composite material comprising: aluminum; anda nanocarbon dispersed within the aluminum, positioned at grain boundaries within the aluminum, wherein the composite material exhibits electrical conductivity in the range of about 65 to about 95 % IACS, about 70 to about 95% IACS, about 70 to about 90 % IACS, or about 75 to about 85 % International Annealed Copper Standard (IACS).

[0159] Clause 20. An aluminum nanocarbon composite material prepared according to the method of any one of clauses 1-18, the aluminum nanocarbon composite material comprising: aluminum; and a nanocarbon dispersed within the aluminum, positioned at grain boundaries within the aluminum, wherein the composite material exhibits electrical conductivity in the range of about 65 to about 95 % IACS, about 70 to about 90 % IACS, or about 75 to about 85 % International Annealed Copper Standard (IACS).

[0160] Clause 21. The aluminum nanocarbon composite material of clause 19 or 20, wherein the aluminum nanocarbon composite material comprises the nanocarbon in a range of 10-900 ppm, 10-800 ppm, 10-700 ppm, 10-600 ppm, 15-600 ppm, 15-500 ppm, 15-300 ppm, 15-200 ppm, 20-100 ppm, 20-75 ppm, 20-50 ppm, 25-35 ppm, or about 30 ppm.

[0161] Clause 22. The aluminum nanocarbon composite material of any one of clauses 19- 21, wherein the nanocarbon is graphene.

[0162] Clause 23. The aluminum nanocarbon composite material of any one of clauses 19- 21, wherein the material is carbon nanotubes.

[0163] Clause 24. The aluminum nanocarbon composite material of any one of clauses 19- 21, wherein the material is a combination of graphene and carbon nanotubes.

[0164] Clause 25. The aluminum nanocarbon composite material of any one of clauses 19- 24, further comprising a heavier metal selected from the group consisting of Sb, Cd, Bi, Sn, Ni, Fe, and Zn.

[0165] Clause 26. The aluminum nanocarbon composite material of clause 25, wherein the composite comprises from about 0.05 to about 5 wt%, about 0.1 to about 4 wt%, 0.5 to about 5 wt%, about 0.5 to about 2.5 wt%, about 0.6 to about 1.2 wt%, about 0.7 to about 0.9 wt%, about 0.6 to about 0.8 wt%, or about 0.6 wt%, about 0.7 wt%, about 0.8 wt%, about 0.9 wt%, or about 1 wt% of the heavier metal.

[0166] Clause 27. The aluminum nanocarbon composite material of any one of clauses19-26, comprising10-900 ppm of the nanocarbon;0-5 wt% or 0.5-5 wt% of the heavier metal; and a balance of the aluminum.

[0167] Clause 28. A shaped part comprising the aluminum nanocomposite material of any one of clauses 19-27, optionally wherein the shaped part is selected from a bus bar, plate, wire, sheet, wire, or foil.

Claims

WHAT IS CLAIMED IS:

1. A method for manufacturing an aluminum nanocarbon composite material, the method comprising: combining a nanocarbon with a metal powder to form a nanocarbon metal powder mixture; adding the nanocarbon metal powder mixture to a liquid aluminum flow to form a molten aluminum nanocarbon composite; and casting the molten aluminum nanocarbon composite to form the aluminum nanocarbon composite material.

2. The method of claim 1, wherein the nanocarbon is selected from the group consisting of a graphene, carbon nanotubes, and a combination of graphene and carbon nanotubes.

3. The method of claim 1, wherein the combining of the nanocarbon with the metal powder comprises mixing the nanocarbon into the metal powder or coating the metal powder with the nanocarbon to form the nanocarbon metal powder mixture, optionally wherein the mixing comprises one or more of dry mixing, ball milling, tumbler milling, chemical mixing, wet mixing, and / or spray drying.

4. The method of claim 1, further comprising applying ultrasonication to the liquid aluminum flow to uniformly mix with the nanocarbon metal powder mixture and deagglomerate the nanocarbon to form the molten aluminum nanocarbon composite.

5. The method of claim 1, wherein the concentration of the nanocarbon in the nanocarbon metal powder mixture is from about 10 times to about 1000 times, about 50 times to about 750 times, about 60 times to about 600 times, about 75 times to about 500 times, about 80 to about 300 times, about 90 times to about 150 times, or about 100 times of final concentration of the nanocarbon in the metal nanocarbon composite material.

6. The method of claim 1, wherein the metal powder is an aluminum powder or a heavier metal powder.

7. The method of claim 6, wherein the heavier metal powder is selected from the group consisting of Sb, Cd, Bi, Sn, Ni, Fe, Cr, Mn, and Zn powder.

8. The method of claim 1, wherein the nanocarbon metal powder mixture is consolidated and / or compacted prior to the adding.

9. The method of claim 1, wherein the adding comprises adding the nanocarbon metal powder mixture below the surface of the liquid aluminum flow, adding the nanocarbon metal powder mixture to the surface of the liquid aluminum flow, or adding the nanocarbon metal powder mixture to the surface and below the surface of the liquid aluminum flow.

10. The method of claim 1, wherein the nanocarbon metal powder mixture is added to the liquid aluminum flow in from about 0.05 to about 5 wt%, about 0.1 to about 4 wt%, 0.5 to about 5 wt%, about 0.5 to about 2.5 wt%, about 0.6 to about 1.2 wt%, about 0.7 to about 0.9 wt%, about 0.6 to about 0.8 wt%, or about 0.6 wt%, about 0.7 wt%, about 0.8 wt%, about 0.9 wt%, or about 1 wt% of the liquid aluminum flow.

11. The method of claim 1 wherein the casting is selected from the group consisting of HPDC, GDC (permanent mould casting), SC, continuous billet, twin roll casting, squeeze casting, investment casting, stir casting, rheocasting, thixocasting, and strip casting.

12. The method of claim 1, further comprising casting the molten aluminum nanocarbon composite to form a plate or sheet using a twin roll caster; subjecting the plate or sheet to an asymmetric rolling process to reduce the grain size of the material to form a rolled sheet product; and annealing the rolled sheet product to achieve recrystallization and grain growth, thereby embedding the nanocarbon at the grain boundaries within the metal matrix.

13. The method of claim 12, further comprising rolling, extruding, and / or wire drawing of the annealed sheet to align the grains and nanocarbon in a direction corresponding to the flow of electrical current when the composite material is in use.

14. The method of claim 1, wherein the aluminum nanocarbon composite material comprises the nanocarbon in a range of 10-900 ppm, 10-800 ppm, 10-700 ppm, 10-600 ppm,15-600 ppm, 15-500 ppm, 15-300 ppm, 15-200 ppm, 20-100 ppm, 20-75 ppm, 20-50 ppm, 25-35 ppm, or about 30 ppm.

15. An aluminum nanocarbon composite material comprising: aluminum; and a nanocarbon dispersed within the aluminum, positioned at grain boundaries within the aluminum, wherein the composite material exhibits electrical conductivity in the range of about 65 to about 95 % IACS, about 70 to about 95% IACS, about 70 to about 90 % IACS, or about 75 to about 85 % International Annealed Copper Standard (IACS).

16. The aluminum nanocarbon composite material of claim 15, wherein the aluminum nanocarbon composite material comprises the nanocarbon in a range of 10-900 ppm, 10-800 ppm, 10-700 ppm, 10-600 ppm, 15-600 ppm, 15-500 ppm, 15-300 ppm, 15-200 ppm, 20-100 ppm, 20-75 ppm, 20-50 ppm, 25-35 ppm, or about 30 ppm.

17. The aluminum nanocarbon composite material of claim 15, wherein the nanocarbon is selected from the group consisting of a graphene, carbon nanotubes, and a combination of graphene and carbon nanotubes.

18. The aluminum nanocarbon composite material of claim 15, further comprising a heavier metal selected from the group consisting of Sb, Cd, Bi, Sn, Ni, Fe, and Zn.

19. The aluminum nanocarbon composite material of claim 18, wherein the aluminum nanocarbon composite material comprises from about 0.05 to about 5 wt%, about 0.1 to about 4 wt%, 0.5 to about 5 wt%, about 0.5 to about 2.5 wt%, about 0.6 to about 1.2 wt%, about 0.7 to about 0.9 wt%, about 0.6 to about 0.8 wt%, or about 0.6 wt%, about 0.7 wt%, about 0.8 wt%, about 0.9 wt%, or about 1 wt% of the heavier metal.

20. A shaped part comprising the aluminum nanocarbon composite material of any one of claims 15-19, optionally wherein the shaped part is selected from a bus bar, plate, wire, sheet, wire, or foil.

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