Graphene composite profiles prepared from brass waste, preparation process and applications

Abstract

The present invention relates to the field of powder metallurgy technology, and more particularly to a graphene composite profile preparation process prepared using brass scrap, wherein according to the application scenario of the graphene composite profile, brass scrap containing different components is selected; the brass scrap is crushed into brass block fragments; 0.001-10% graphene is added to the brass block fragments, and a first-size mixed powder liquid is formed through wet ball milling; it is subjected to semi-solid rotary shear stirring processing; the graphene-brass mixed substrate is continuously extruded to form a graphene composite profile blank, and the graphene composite profile blank is obtained by post-processing to overcome brass point, line and surface defects. The present invention realizes efficient and pollution-free direct recycling of brass scrap by combining a medium-temperature continuous extrusion process with a powder metallurgy process, thereby significantly improving the physical properties and chemical properties of the composite material, such as hardness, strength, electrical conductivity, corrosion resistance, and high-temperature creep resistance. The present invention also discloses a corresponding graphene composite profile and application.

Description

Technical Field

[0001] The present invention relates to the technical field of powder metallurgy, and in particular to a graphene composite profile prepared from brass waste, a preparation process and applications thereof. Background Art

[0002] As an important nonferrous metal alloy, brass is widely used in numerous fields. Due to its excellent overall properties, such as high strength, good processability, and corrosion resistance, it is widely used in the manufacture of mechanical parts, electronic components, pipe fittings, and other products.

[0003] Ordinary brass is primarily composed of electrolytic copper and electrolytic zinc, while complex brass is made by adding trace elements to ordinary brass to enhance its physical and chemical properties. The production of brass, which uses large quantities of electrolytic copper, electrolytic zinc, electrolytic aluminum, and electrolytic tin, requires ore mining, which causes significant environmental damage. Because the mainstream production methods are horizontal continuous casting and vertical pouring, followed by rolling and drawing, the production cycle is long and generates large amounts of waste gas, wastewater, dust, and waste residue during the production process. The melting points of copper, zinc, and trace elements differ significantly, especially since zinc evaporates violently at high temperatures. Volatile substances produce odor and dust, seriously polluting the environment. Therefore, factories must be equipped with specialized fume and dust collection devices and regularly clean these collection devices. However, the fine particles of zinc dust make cleaning time-consuming and labor-intensive.

[0004] Due to the high melting point of CuZn alloys, the complex brass production process involves adding trace elements (Sn, Mn, Fe, P, Mg, Al, Ni, Si, rare earth elements, and others). This process is complex, with significant element loss and difficulty, leading to severe segregation. This severely impacts the quality of brass plates, bars, strips, bars, wires, and tubes. With technological advancements, demand for materials in specialized environments such as electrical control, high temperatures, and corrosion is increasing, placing ever-higher demands on fatigue resistance, corrosion resistance, high conductivity, and a high fatigue life span. Conventional brass profiles no longer meet these requirements. Suitable material solutions are scarce for use in specialized environments such as marine, humid environments, and outer space.

[0005] In addition, in order to improve the reuse of brass, there are currently two main ways to recycle brass scrap: direct and indirect. However, whether it is to directly smelt high-quality copper scrap into finished products, or to indirectly smelt copper scrap into electrolytic copper or electrolytic zinc through electrolysis, it is inseparable from smelting, sulfide liquid preparation, and electrolytic purification processes. These processes will generate solid waste pollution, waste gas and waste residue, and waste liquid emissions.

[0006] Due to the scarcity of suitable material solutions in special environments such as the ocean, humid environments, and outer space, the industry has conducted research and achieved certain results through methods such as microalloying and the addition of rare earth elements to meet the production needs of new materials. For example, our company's authorized invention patent application number 202411661383.7 discloses a method and application for preparing graphene-composite copper strips from copper waste. It specifically discloses that through a powder metallurgy process combined with a medium-temperature continuous extrusion process, graphene is fully squeezed into the lattice gaps of the copper waste, forming a high-performance graphene-composite copper strip with high strength, high thermal conductivity, and high electrical conductivity. This preparation method not only achieves efficient and pollution-free direct recycling of copper waste, but also solves the problem of non-smelting methods for the recycling and production of copper waste.

[0007] On this basis, in order to solve the problems of stress corrosion resistance, cavitation corrosion, high temperature corrosion, reduced mechanical strength of brass materials in corrosive environments and high temperature environments, as well as the problems existing in brass production and waste recycling, this application is specially proposed. Summary of the Invention

[0008] In order to solve at least one of the above technical problems, the present invention proposes a method for preparing graphene composite profiles, a preparation process and an application of brass waste by powder metallurgy combined with a medium-temperature continuous extrusion process, so as to solve the problems of serious pollution, long production cycle, high production cost and performance indicators of the produced profiles that cannot meet the use requirements in the non-smelting recycling and reuse of brass waste.

[0009] To achieve the above object, the present invention adopts the following technical solutions:

[0010] The first aspect of the present invention provides a graphene composite profile prepared using brass scrap, wherein the brass scrap and graphene are subjected to powder metallurgy combined with a medium-temperature continuous extrusion process to produce the graphene composite profile;

[0011] The graphene composite profile comprises the following raw material components in percentage by mass: Cu: 45-97%, P: 0.001-0.4%, Fe: 0.01-1%, graphene: 0.001-10%, Zn: 3-49%, and the remainder is one or more of Ag, Au, Ni, Sn, Mn, and Al, and the total amount is less than 0.5%;

[0012] Alternatively, the graphene composite profile comprises the following raw material components in percentage by mass: Cu: 45-97%, Ag: 0.0001-0.1%, Fe: 0.01-1.5%, P: 0.001-0.4%, graphene: 0.001-10%, Zn: 3-49%, and the remainder is one or more of Ni, Fe, Au, Sn, Mn, and Al, and the total amount is less than 0.5%;

[0013] Alternatively, the graphene composite profile comprises the following raw material components in percentage by mass: Cu: 50-97%, Mn: 0.001-5%, Al: 0.001-7.5%, Fe: 0.01-1%, P: 0.001-0.4%, graphene: 0.001-10%, Zn: 3-49%, and the remainder is one or more of Ni, Sn, Ag, and Au, and the total amount is less than 0.5%;

[0014] Alternatively, the graphene composite profile comprises the following raw material components in the following amounts, calculated by mass percentage: Cu: 50-90%, Ni: 0.01-45%, Fe: 0.01-2%, Mn: 0.01-14%, P: 0.001-0.4%, graphene: 0.001-10%, and one or more of the trace elements Al, Si, S, Mg, Bi, As, Sb, Ag, and Au, with a total amount less than 0.5%, and the balance being Zn;

[0015] Alternatively, the graphene composite profile comprises the following raw material components in percentage by mass: Cu: 50-97%, Fe: 0.1-1%, Sn: 0.01-5%, P: 0.001-0.4%, graphene: 0.001-10%, Zn: 3-49%, and the remainder is one or more of Mn, Au, Ag, Ni, and Al, and the total amount is less than 0.5%.

[0016] A second aspect of the present invention provides a process for preparing a graphene composite profile using brass scrap, comprising the following steps:

[0017] S1, selecting brass scrap containing different components according to the application scenario of the graphene composite profile;

[0018] S2, crushing the brass scrap into brass block fragments;

[0019] S3, adding 0.001-10% by mass of graphene to the brass block material according to the application scenario of the graphene composite profile, and wet ball milling to form a first-size mixed powder liquid;

[0020] S4, subjecting the first-sized mixed powder liquid to a semi-solid state rotational shear stirring process, so that the graphene is evenly filled in the brass fine grain structure to form a graphene-brass mixed substrate;

[0021] S5, heating the extrusion die cavity of the continuous extruder, and continuously extruding the graphene-brass mixed substrate when it is in a semi-liquid state, so that the graphene as a filling element is completely squeezed into the lattice gaps of the brass fine grain structure, forming a graphene composite profile blank that overcomes the point, line, and surface defects of the brass;

[0022] S6, processing the graphene composite profile blank with reference to the subsequent process of conventional brass to obtain a graphene composite profile, wherein the graphene composite profile forms a three-dimensional radial staggered structure for efficient electron transmission inside the structure through continuous extrusion and subsequent processes.

[0023] Preferably, the size of the brass block fragments is 1-2 cm, and the particle size of the first-size mixed powder liquid is less than 50 μm.

[0024] Preferably, the S4 includes the following steps:

[0025] S41, feeding the first-sized mixed powder liquid into the front section of a circular feeder equipped with an ultrasonic device, and homogenizing the first-sized mixed powder liquid by utilizing the cavitation effect of the ultrasonic wave on the liquid;

[0026] S42, feeding the homogenized first-size mixed powder liquid into the rear section of a circular feeder equipped with a heating device, heating the circular feeder to 500-650° C. according to the copper content of the first-size mixed powder liquid, injecting an inert gas into the rear section and maintaining the temperature, so that the first-size mixed powder liquid reaches a semi-solid state to form a graphene-brass mixed substrate;

[0027] S43, the graphene-brass mixed substrate is subjected to rotational shear stirring by the twin-screw rotating mechanism of the circular feeder, the screw stirring speed is 10r / min-400r / min, and after stirring for 10-20min, it is transported to the discharge port of the circular feeder.

[0028] Preferably, the circular feeder is made of nickel-based high-temperature metal GH3044; the twin-screw pushing pressure range is 50-65 MPa, at which time, the density of the graphene-brass mixed substrate is more than 65% of the normal solid theoretical density.

[0029] Preferably, the S5 includes the following steps:

[0030] S51, feeding the graphene-brass mixed substrate into a continuous extruder;

[0031] S52, according to the ratio of copper and zinc in the brass scrap, setting the extrusion die cavity temperature of the continuous extruder to 800-950° C. so that the copper alloy is in a semi-liquid state in the extrusion die cavity, setting the extrusion pressure to not less than 1000 MPa, and continuously extruding the graphene-brass mixed substrate to obtain the graphene composite profile blank.

[0032] Preferably, the continuous extruder is a Conform continuous extruder, and the extrusion die cavity is made of nickel-based high-temperature metal GH3044.

[0033] Preferably, the subsequent processes of the brass profile include rolling and drawing.

[0034] Preferably, the graphene composite profile is a graphene composite copper busbar, a graphene composite copper plate, a graphene composite copper strip, a graphene composite copper rod, a graphene composite copper wire, or a graphene composite copper tube.

[0035] The third aspect of the present invention provides a graphene composite profile prepared by the preparation process of the second aspect, which is used in aircraft or consumer electronic connectors, data center connectors, new energy vehicle connectors or automotive circuit terminals or relays or electrical and electrical components that are conductive, elastic, and support components or corrosion-resistant, highly elastic, and highly conductive components in corrosive and high-temperature environments.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] 1. This invention utilizes a powder metallurgy process combined with a medium-temperature continuous extrusion process to fully squeeze graphene as a filler element into the lattice interstices of brass scrap. This results in a high-performance graphene composite profile with high strength, high thermal conductivity, high electrical conductivity, and high corrosion resistance, overcoming the point, line, and surface defects inherent in brass. This preparation process allows for efficient and pollution-free direct recycling of brass scrap, improving the physical and chemical properties of the composite material, including hardness, strength, electrical conductivity, corrosion resistance, and high-temperature creep resistance.

[0038] 2. This embodiment utilizes a continuous extrusion process. Based on the copper-zinc ratio in the brass scrap, the extrusion die temperature of the continuous extruder is set to 800-950°C, and the extrusion pressure is set to no less than 1000 MPa. At this point, the solid-to-liquid ratio of the graphene-brass hybrid matrix is ​​less than 40%, and the elements in the graphene-brass hybrid matrix are arranged in a disordered manner. The semi-liquid graphene-brass hybrid matrix is ​​continuously extruded. Because the graphene-brass hybrid matrix is ​​composed of multiple elements, including Zn, Ni, and Fe (the primary element of copper is Cu), through extrusion and subsequent rolling and drawing processes, the graphene forms a fibrous, three-dimensional, radially interlaced structure along the rolling and extrusion directions, as well as in the radial direction (graphene in the copper composite material only forms a linearly extended structure along the rolling and extrusion directions). The three-dimensional fibrous radial interlaced structure constitutes an efficient electron transmission channel, effectively improving the conductivity of the composite material. At the same time, it also effectively reduces the potential difference between the elements in the matrix, eliminates the galvanic cell reaction between the elements of the graphene-brass mixed matrix, improves the dezincification corrosion problem of the brass material itself, and effectively improves the corrosion resistance of the graphene-brass composite material.

[0039] 3. The present invention uses brass scrap containing different components to effectively solve the problem of continuous recycling of brass scrap in society, while significantly reducing the production cycle of brass profiles, achieving the purpose of low energy consumption, efficient utilization of waste brass scraps to produce high-performance composite copper profiles without the emission of wastewater, waste residue, and waste gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 The figure is a flow chart of the preparation process of graphene composite profiles prepared from brass waste. DETAILED DESCRIPTION

[0041] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments of the present invention.

[0042] Example 1

[0043] Please refer to Figure 1 A process for preparing a graphene composite profile using brass waste comprises the following steps:

[0044] S1, according to the application scenario of graphene composite profiles, brass scrap containing different components is selected.

[0045] It should be noted that the purpose of selecting brass scrap containing different components is to screen brass scrap containing different components and, through the following preparation process, produce graphene-composite copper sheets and strips with varying physical and chemical properties. Specifically, physical properties include, but are not limited to, high electrical conductivity, high thermal conductivity, high strength, high toughness, and high specific surface area. Chemical properties include, but are not limited to, corrosion resistance, oxidation resistance, and heat resistance.

[0046] Compared with the traditional production process of existing brass profiles, such as horizontal continuous casting and vertical casting processes, in order to enhance the physical or chemical properties of brass profiles, it is necessary to add trace elements such as Sn, Mn, Fe, P, Mg, Al, Ni, Si, and rare earths. The addition process is complicated, the loss of added elements is large, the difficulty is high, and various segregation problems are serious, making the quality of the brass profiles cannot be guaranteed.

[0047] The present invention uses brass scrap containing different components to effectively solve the problem of continuous recycling of brass scrap in society. At the same time, the following preparation process is adopted to significantly reduce the production cycle of brass profiles, and achieve the purpose of low energy consumption and efficient utilization of waste brass scraps to produce high-performance composite copper profiles without the emission of wastewater, waste residue, or waste gas.

[0048] S2, crushing the brass scrap into brass block fragments.

[0049] It should be noted that the brass scrap in this embodiment is crushed using a metal crusher. In order to facilitate subsequent ball milling or milling of the brass block scraps into powder of a specified particle size, the size of the brass block scraps in this embodiment is controlled to be 1-2 cm.

[0050] S3, according to the application scenario of the graphene composite profile, adding 0.001-10% by mass of graphene to the brass block crushed material, and wet ball milling to form a first-size mixed powder liquid.

[0051] It should be noted that the organic solvent used in the wet ball milling process described above is an alcohol (such as anhydrous ethanol). Specifically, an appropriate amount of anhydrous ethanol is added based on the ratio of graphene to brass. A certain number of milling balls (which can be made of zirconia) are also added, and the milling process is performed at a controlled speed and for a controlled time. In this embodiment, the mill speed is set to 300-500 rpm for a time of 3-6 hours. In this embodiment, a large industrial ball mill is used, and the solid particle size in the first-size mixed powder liquid is less than 50 μm.

[0052] It can be understood that by ball milling the brass block crushed materials using a ball mill, the graphene and the brass block crushed materials can be evenly mixed, which helps to improve the physical and chemical properties of the composite material formed by the two and play a synergistic role.

[0053] The wet ball milling with ethanol added in this embodiment has at least the following advantages:

[0054] 1. Good dispersibility and reduced surface tension: Anhydrous ethanol is a good organic solvent that can effectively reduce the surface tension between graphene and copper powder, making the graphene more evenly dispersed in the copper powder and preventing graphene agglomeration. At the same time, anhydrous ethanol can improve the wettability of graphene and copper powder, allowing them to mix better, thereby improving the uniformity of the composite material.

[0055] 2. Protecting the graphene structure and reducing defects during ball milling: During wet ball milling, anhydrous ethanol acts as a medium to cushion the direct impact between the milling balls and the graphene, reducing structural defects and maintaining its integrity. Compared to dry ball milling, wet ball milling produces larger graphene with fewer defects and a more complete crystal structure.

[0056] 3. Enhance the bonding and adhesion between graphene and copper atoms: Anhydrous ethanol can help graphene adhere better to the surface of copper powder during the ball milling process, thereby enhancing the bonding between the two and forming a more uniform composite material during the subsequent sintering or densification process.

[0057] 4. Environmentally friendly and pollution-free: Anhydrous ethanol is a relatively environmentally friendly solvent. The wet ball milling process using anhydrous ethanol as a medium does not pollute the environment. At the same time, anhydrous ethanol evaporates quickly under high temperature and is easy to remove.

[0058] 5. Improved Material and Mechanical Properties: Graphene-copper composites prepared through wet ball milling exhibit significantly enhanced mechanical properties. For example, yield strength is increased by 219.8% compared to pure copper, while also exhibiting excellent ductility and electrical conductivity. The uniform dispersion of graphene within the copper matrix effectively improves the composite's electrical conductivity.

[0059] 6. Oxidation Inhibition: Due to the large amount of zinc in brass, the powder temperature rises during ball milling, which easily leads to oxidation reactions with oxygen in the air. Anhydrous ethanol forms a protective film on the surface, isolating the brass from air and reducing its contact with oxygen. This, in turn, inhibits brass oxidation to a certain extent.

[0060] Furthermore, during the ball milling process, the brass scraps and graphene are continuously stirred, collided, and milled within the high-speed rotating ball mill. During this process, the brass alloy powder (the first-size mixed powder-liquid mixture) undergoes repeated deformation, cold welding, and fracture, while simultaneously exfoliating the graphene sheets. Significant atomic diffusion and solid-state reactions occur within the brass alloy powder structure. The external forces of ball milling create numerous defects within the crushed particles—vacancies, dislocations, grain boundaries, and phase boundaries—that provide pathways and locations for graphene embedding.

[0061] These defects can lead to an increase in deformation energy storage within the lattice. When the deformation energy storage is greater than the formation free energy required for the supersaturated solid solution, the solid solubility of the graphene as the second phase in the matrix in this embodiment will be improved. At the same time, the heat generated during the ball milling process and the interfacial interaction between brass and graphene also contribute to the solid solution of graphene in brass. The interatomic forces at the interface promote the formation of certain chemical bonds between graphene and brass atoms, enhancing the solid solution stability of graphene in brass.

[0062] In addition, the above defects will reduce the diffusion energy of the CuZn alloy, generate a large number of new surfaces, and create good physical conditions for the high-temperature hard point element graphene to form a coating and filling on the surface and inside of the following fine-crystallized CuZn alloy element.

[0063] Therefore, based on the aforementioned solid solution mechanism of brass and graphene, this embodiment adjusts and extends the ball milling time, ball milling speed, and ball-to-material ratio to increase solid solubility, thereby improving the material properties of the solid solution. Furthermore, the amount of graphene added in this embodiment is also determined based on the aforementioned solid solution mechanism. Excessive addition of graphene can easily lead to agglomeration, reducing the solid solubility of graphene in brass.

[0064] S4, performing a semi-solid rotary shear stirring process on the first-size mixed powder liquid to uniformly fill the graphene in the brass fine grain structure to form a graphene-brass mixed matrix.

[0065] To improve the uniformity of the first-size mixed powder and liquid and the uniformity of graphene filling, the circular feeder in this embodiment uses a two-stage design with a counter-rotating twin screw. Specifically, the wet-milled first-size mixed powder and liquid is fed into the front section of the circular feeder equipped with an ultrasonic device. The ultrasonic cavitation effect on the liquid is used to homogenize the first-size mixed powder and liquid, further evenly dispersing the various structures in the first-size mixed powder and liquid, preventing the precipitation of high-density elements. This also strengthens the surface adhesion of the graphene and copper atoms.

[0066] In this embodiment, the ultrasonic frequency is 30-45 KHz, and the time for the first size mixed powder liquid to pass through the front section of the circular feeding pipe is set to 3-5 minutes to ensure that the ultrasonic wave fully and evenly disperses the first size mixed powder liquid.

[0067] Considering the need for semi-solidification of the first-size mixed powder, a heating device is installed at the rear end of the circular feed tube in this embodiment. Depending on the copper content of the first-size mixed powder, the heating device raises the temperature within the circular feed tube to 500-650°C and maintains this temperature, maintaining the first-size mixed powder in a semi-solid state. Simultaneously, the counter-rotating twin screws shear and fragment the graphene-brass mixed substrate, resulting in a fine-grained brass structure. In this embodiment, the screw stirring speed ranges from 10 to 400 rpm, and the stirring time is 10-20 minutes.

[0068] In order to avoid the occurrence of oxidation reaction, in this embodiment, inert gas is injected into the rear section through the gas inlet provided at the rear section of the circular feed pipe. At the same time, the high-temperature evaporated anhydrous ethanol gas is extracted through the gas outlet provided at the circular feed pipe.

[0069] Understandably, semi-solid metal alloys exhibit typical rheological characteristics in their semi-solid crystallization state, with the deformation shear stress within the crystalline structure closely related to the solid phase volume ratio and growth morphology. Specifically, when the solid phase volume ratio in brass crystalline structure exceeds 15%, dendrites begin to form in the solid phase, and the metal begins to solidify.

[0070] At this time, the crushing, shearing, and stirring mechanical vibrations generated by the high-speed rotating double-helix mechanism and the relative rotation of the twin screws will cause relative movement between the liquid phase and the solid phase. Through the flow of liquid metal, the columnar and dendritic crystals in the organizational structure of the graphene-brass hybrid substrate are effectively broken, limiting the continued growth of the recrystallized organization.

[0071] Furthermore, the crushing, shearing, and stirring mechanical vibration also promotes fine-grained microstructure growth and grain refinement. By utilizing the high specific surface area (2600 m2 / g) of ball-milled graphene, the graphene is distributed more evenly and stably within the semi-solid structure, improving the physical and chemical properties of the structure. This paves the way for the continuous extrusion of graphene composite profiles.

[0072] Considering that the semi-solid graphene-brass mixed substrate may undergo an oxidation reaction with oxygen in the air, in this embodiment, an inert gas, specifically argon, is injected into the circular feeder.

[0073] In addition, injecting argon into the circular feeder can effectively control the oxygen content in the circular feeder, thereby ensuring that the oxygen content in the tissue structure is effectively controlled.

[0074] To ensure that the density of the semi-solid structure reaches at least 65% of the theoretical density of a solid state, the twin-screw extruder in this embodiment operates at a pressure range of 50-65 MPa. At this pressure, the density of the semi-solid structure (graphene-brass hybrid matrix) reaches at least 65% of the theoretical density of a solid state, thereby ensuring the initial formation of the structure and the stability of the formed crystalline structure.

[0075] It should be noted that since the inside of the circular feeder needs to be heated to 500-650℃, the material of the circular feeder must have sufficient high temperature strength and hardness, high tempering temperature resistance, good heat resistance, good machining properties, good material toughness, low thermal expansion coefficient and good thermal conductivity.

[0076] Based on the above factors, the circular feeder in this embodiment uses nickel-based high-temperature metal GH3044.

[0077] Specifically, nickel-based high-temperature metal GH3044 has at least the following advantages:

[0078] 1. High temperature resistance

[0079] The theoretical high temperature resistance limit of GH3044 alloy can reach 1000℃. Under extreme high temperature conditions such as 1100℃, an extremely dense oxide film will quickly form on the surface of GH3044 alloy, effectively preventing oxygen from further contacting the interior of the alloy, thereby greatly slowing down the oxidation process.

[0080] At the same time, GH3044 alloy maintains high strength even in high-temperature environments, with a tensile strength of 650 MPa at 1000°C. It also exhibits excellent creep resistance, with a creep rupture strength of 400 MPa at 850°C. This enables GH3044 alloy products to operate stably even in harsh environments of high temperature and high pressure.

[0081] 2. Anti-oxidation and corrosion resistance

[0082] GH3044 alloy contains high levels of chromium (Cr) and tungsten (W), along with smaller amounts of molybdenum (Mo) and aluminum (Al). In a high-temperature oxidizing environment, these elements work together to form a dense oxide film on the alloy's surface. Chromium preferentially reacts with oxygen to form stable chromium oxide, which provides the alloy's first protective barrier. The addition of tungsten enhances the stability and density of the oxide film. Molybdenum and aluminum further optimize the film's structure, improving its protective properties and significantly enhancing the alloy's oxidation resistance.

[0083] In terms of corrosion resistance, the alloy shows good tolerance to highly corrosive media such as chlorine, sulfur, and nitrogen. In the oxidation test at 1100°C, the oxidation rate of GH3044 is only about , showing good antioxidant capacity.

[0084] 3. Chemical composition and physical properties

[0085] The main chemical composition of GH3044 is as follows: Nickel (Ni) serves as the matrix of the alloy, providing a good comprehensive performance foundation for the alloy. The remainder is: Chromium (Cr) content is 23.5-26.5%, which is a key element in forming an anti-oxidation film. Tungsten (W) content is 13.0-16.0%, which contributes significantly to improving the high-temperature strength and oxidation resistance of the alloy; Titanium (Ti) content is 0.30-0.70%, which helps to optimize the microstructure of the alloy; Iron (Fe) content ≤4.0%, aluminum (Al) content ≤0.50%, silicon (Si) content ≤0.80%, manganese (Mn) content ≤0.50%, phosphorus (P) content 0.013%, sulfur (S) content 0.013%, molybdenum (Mo) content ≤1.50%, carbon (C) content ≤0.10%.

[0086] In terms of physical properties, its density is 8.89g / cm³, and its melting point ranges from 1352-1375℃. Its thermal conductivity ranges from 100-900℃. Gradually changes to The linear expansion coefficient is within the range of 20-900℃. After solution treatment at 1200℃, the alloy presents a structure mainly composed of single-phase austenite, with carbides distributed in chain-like shapes at the grain boundaries. This unique microstructure further enhances its high-temperature stability.

[0087] Based on these advantages and characteristics, GH3044 nickel-based superalloy, with its excellent high-temperature strength, oxidation resistance, and stability, can maintain excellent performance in high-temperature environments up to 1100°C. Furthermore, this material exhibits excellent stamping and welding properties, making it easy to form and join during processing. As such, it is an ideal high-temperature material for manufacturing high-temperature equipment, key components in the energy sector, reactors and piping in the chemical industry, and high-temperature nonferrous metal processing equipment.

[0088] This example uses a circular feeder made of GH3044 high-temperature alloy and the extrusion die cavity of the continuous extruder described below, which can meet the needs of long-term, high-temperature and high-speed stirring and vibration, and fundamentally solves the problem of long-term stability and life of processing equipment in high-temperature environments.

[0089] S5, heating the graphene-brass mixed substrate until the graphene-brass mixed substrate is in a semi-liquid state, and then continuously extruding the graphene-brass mixed substrate so that the graphene as a filling element is completely squeezed into the lattice gaps of the brass fine grain structure to form a graphene composite profile blank that overcomes the point, line, and surface defects of the brass.

[0090] Specifically, in this embodiment, a Conform continuous extruder was used to extrude the graphene-brass hybrid substrate. To ensure that the graphene retains its intact structure when the copper substrate melts, the extrusion die cavity temperature of the Conform continuous extruder was set at 800-950°C.

[0091] It should be noted that the brass scrap recycled by the society mainly includes copper-zinc binary brass, tin brass, aluminum brass, iron brass, manganese brass, nickel brass, lead brass and some arsenic brass, as well as complex brass scrap with silver, gold, tin and nickel plating on the surface.

[0092] Brass scrap is primarily composed of Cu, Zn, Ag, γ-Fe (912°-1394°), Au, Sn, Al, and Ni. The crystal lattices of these elements form a face-centered cubic lattice, with Zn forming a close-packed hexagonal lattice. Both the face-centered cubic and close-packed hexagonal lattices contain 12 atoms per unit cell.

[0093] The compactness of atomic stacking in a crystal is often measured by "density." Based on this density, both face-centered cubic and hexagonal close-packed crystal planes are the most densely packed planes of atoms of equal diameter. The atomic arrangement patterns are identical.

[0094] It is known that density refers to the ratio of the total volume occupied by atoms in a unit cell to the total volume of the unit cell, that is, the density formula is K=nv / V;

[0095] Where: K--crystal density;

[0096] N--The actual number of atoms contained in a unit cell:

[0097] v--the volume of an atom (rigid sphere), its value is 4πR 3 / 3 (R is the atomic radius);

[0098] V - total volume of unit cell.

[0099] From the above, we can know that the face-centered cubic density is: 0.74.

[0100] The density of hexagonal close-packed is: 0.74.

[0101] Among them, a and c are the edge lengths of the unit cell, also called lattice constants, and in hexagonal close-packed crystals c / a=1.633.

[0102] From this, we can see that the voids in the lattice of elements such as Cu (atomic diameter 0.255nm), Ag (atomic diameter 0.288nm), Au (atomic diameter 0.278nm), Al (atomic diameter 0.286nm), Ni (atomic diameter 0.248nm), Zn (atomic diameter 0.278nm), and γ-Fe (912°-1394°, atomic diameter 0.254nm) are 26%.

[0103] Because graphene's elemental radius is small (the atomic diameter of carbon is conventionally 140 pm), far smaller than the atomic diameters of the aforementioned elements, and combined with the principle of copper alloy intermetallic compounds, normal-valence compounds are composed of elements that are far apart on the periodic table and have significantly different electronegativities. Metallic elements form compounds with non-metallic elements in Groups IVA, VA, and VIA of the periodic table. The graphene filler element used in this implementation belongs to Group IVA, and therefore can form compounds with the metallic elements in the brass scrap.

[0104] Based on the above factors, in order to ensure that graphene as a filling element can be completely squeezed into the 26% voids of the face-centered cubic lattice of Cu (atomic diameter 0.255nm), Ag (atomic diameter 0.288nm), Al (atomic diameter 0.286nm), Ni (atomic diameter 0.248nm), Zn (atomic diameter 0.278nm), and γ-Fe (912°-1394°, atomic diameter 0.254nm), solute atoms are formed to strengthen the element unit cell, and a dispersed filling and coating phase is formed on the periphery of the original hard crystal core in the matrix, thereby forming a high-strength and highly conductive filler.

[0105] This embodiment adopts a continuous extrusion process. According to the ratio of copper and zinc in the brass scrap, the extrusion die cavity temperature of the continuous extruder is set to 800-950°C to make the copper alloy in the extrusion die cavity in a semi-liquid state. The extrusion pressure is set to not less than 1000 MPa. The graphene-brass mixed substrate is continuously extruded to obtain a graphene composite profile blank.

[0106] At this point, the solid-to-liquid ratio of the graphene-brass hybrid matrix is ​​less than 40%, and the arrangement of the elements in the graphene-brass hybrid matrix is ​​disordered. Furthermore, because the graphene-brass hybrid matrix is ​​composed of multiple elements, including Zn, Ni, and Fe (the main element of copper is Cu), through extrusion and subsequent rolling and drawing processes, the graphene forms a fibrous, three-dimensional radial interlaced structure along the rolling and extrusion directions and radial extension directions (graphene in the copper composite material only forms a linear extension structure along the rolling and extrusion directions). This fibrous, three-dimensional radial interlaced structure constitutes an efficient electron transmission channel, effectively improving the composite's electrical conductivity. It also effectively reduces the potential difference between the elements in the matrix, eliminating the galvanic cell reaction between the elements in the graphene-brass hybrid matrix, improving the dezincification corrosion problem of the brass material itself, and effectively improving the corrosion resistance of the graphene-brass composite material.

[0107] After the above process, we can obtain a graphene-composite brass billet. The process in this embodiment, combined with subsequent rolling, drawing and other processes, can be used to prepare graphene-composite profiles. Among them, the graphene-composite profiles include but are not limited to graphene-composite copper bars, graphene-composite copper plates, graphene-composite copper strips, graphene-composite copper rods, graphene-composite copper wires, or graphene-composite copper tubes. Among them, the specifications of the graphene-composite copper bars, plates, and strips can be 1-25mm thick and 5-600mm wide; the diameters of the graphene-composite rods, wires, and tubes can be 1-200mm.

[0108] At the same time, it should be noted that the preparation process of the present invention can also be used to prepare composite profiles of copper scrap with a graphene addition amount of less than 0.1% and aluminum-based composite profiles with a graphene addition amount of 0.001-10%.

[0109] It should be noted that existing brass has defects in points, lines, and surfaces. Due to the above defects, the brass alloys used in the preparation of profiles will have various problems such as excessively high resistance, severe high-temperature creep, reduced critical shear stress during complex bending, excessive material strength, reduced plasticity, and increased brittleness, which seriously restrict the production and use of complex brass alloys.

[0110] The preparation process of the present invention can fundamentally solve the above-mentioned point, line and surface defects. Specifically:

[0111] 1. Point defects

[0112] Point defects include vacancies and interstitials. A vacancy is an empty lattice position in a crystal where no atoms occupy the lattice. An interstitial defect is an atom that has entered the lattice between the atoms.

[0113] Based on the above defects, this preparation process adds highly conductive graphene (whose conductivity is , the highest among known materials at room temperature), forming a uniformly distributed graphene filler within the material matrix. Under continuous extrusion at moderate temperatures and pressure, the hard graphene nuclei are squeezed into the unit cells of the structural crystal, replacing substitutional and interstitial solute atoms within the matrix, thereby forming new graphene solute atoms with high conductivity and strength.

[0114] Graphene solute atoms reduce voids in the microstructure, ameliorating the structural instability caused by displacement of previously displaced atoms. Simultaneously, graphene, with its high strength and modulus, fills the lattice voids, limiting the relative sliding of atoms in the brass matrix. When the material is subjected to shear forces, graphene absorbs some of the load, enhancing the material's resistance to shear deformation, manifested macroscopically as an increase in the shear modulus.

[0115] Furthermore, from an electronic structure perspective, graphene's large π-bond electron cloud overlaps with the electron clouds of copper and zinc atoms, altering the electron distribution and shifting the electron conduction path throughout the system. Electrons previously conducted through the brass matrix now form new transmission pathways due to the presence of graphene, thereby optimizing electron conduction efficiency and improving the material's electrical conductivity. Furthermore, the high melting point of graphene and the high formation energies of Fe, Ni, and Mn reduce the vacancy concentration in the CuZn alloy, fundamentally remedying the low conductivity and severe high-temperature creep caused by point defects.

[0116] 2. Line defects

[0117] Line defects are characterized by dislocations. Analysis shows that when copper and zinc are used as the base material and diversified elements are added, dislocations will appear inside the base material due to the different elastic moduli of each metal atom. The existence of dislocations will seriously affect the shear stress resistance of the material.

[0118] Multi-element alloys often contain a variety of crystal structures. Grains with different orientations have varying shear stresses, and the number of slip systems that meet the initiation conditions when a dislocation occurs also varies. Grains of elements that can ameliorate dislocations also have relatively high shear stresses. When a material undergoes plastic deformation, a high number of slip system elements indicates improved plastic deformation. Furthermore, when a dislocation occurs, a stress field inevitably develops around it.

[0119] Based on the above defects and formation factors, this preparation process adds graphene, utilizing the high strength (tensile strength 130GPa) and high toughness of graphene elements, and squeezes them into the matrix unit cell to restrain and block the movement of dislocations.

[0120] Experiments have shown that stress fields are generated around dislocations and the added graphene elements. Dislocations interact elastically with the graphene solute atoms, causing the graphene, acting as solute atoms, to redistribute within the crystal. Graphene tends to the lowest energy position near the dislocation, forming clusters of solute atoms surrounding the dislocation. These clusters significantly hinder dislocation motion, increasing dislocation density and refining the grain size. Dislocation slip in the brass alloy shifts from planar slip to cross-slip, ultimately achieving solid solution strengthening and completely blocking dislocations within the matrix, resolving the problem of line defects. This increases the critical shear stress of the graphene-composite brass alloy during complex bending, as well as the critical shear stress of the material, resulting in high strength, high ductility, high plasticity, and low springback during forming.

[0121] 3. Surface defects

[0122] Brass surface defects are primarily characterized by grain boundaries. In a crystal, if two adjacent parts differ in orientation, composition, lattice type, and lattice constant, an interface exists at their point of contact. In single-phase metals or alloys, the interface between adjacent grains with different orientations is called a grain boundary. Brass is a copper-zinc alloy, and during its solidification and processing, numerous grain boundaries form due to differences in atomic arrangement and orientation in different regions.

[0123] Based on the aforementioned defects and their formation factors, this preparation process fully utilizes high-temperature hard particles to form refined crystal nuclei, resulting in a uniform distribution of high-strength graphene particles throughout the microstructure. Low-temperature stirring technology breaks up copper dendrites, restricting the growth of recrystallized copper grains and allowing them to form fine crystals around the high-temperature hard nuclei. Simultaneously, high-strength dispersed graphene particles, formed during uniform distribution and subsequent medium-temperature extrusion, fill the unit cells of the nuclei. Graphene's high conductivity and strength significantly reduce the material's surface energy, fundamentally addressing surface defects and improving the material's problems of excessive strength, reduced plasticity, and increased brittleness.

[0124] This invention utilizes a powder metallurgy process combined with a medium-temperature continuous extrusion process to fully squeeze graphene as a filler element into the lattice voids of brass scrap. This results in a high-strength, high-thermal and high-electrical conductivity, highly corrosion-resistant graphene-composite copper strip that overcomes the point, line, and surface defects inherent in brass. This production process allows for efficient and pollution-free direct recycling of brass scrap, improving the physical and chemical properties of the resulting composite material, including strength, conductivity, corrosion resistance, high-temperature resistance, and wear resistance.

[0125] Example 2

[0126] It should be noted that the same process and the same components in the preparation process of brass scrap under the same process conditions have the same or similar performance effects on the graphene composite profile, which will not be repeated in this embodiment and the following embodiments.

[0127] Different from Example 1, in this embodiment, the brass scrap contains the following raw material components in terms of mass percentage: Cu: 45-97%, P: 0.001-0.4%, Fe: 0.01-1%, graphene: 0.001-10%, Zn: 3-49%, and the remainder is one or more of Ag, Au, Ni, Sn, Mn, and Al, and the total amount is less than 0.5%.

[0128] Based on the above-mentioned component content requirements, the brass scraps selected in this embodiment are copper, zinc, and unplated stamping scraps generated after the stamping of electrical and electronic parts, automobile waste wiring harnesses (with brass tinned terminal blocks), waste wires and cables, and unplated scrap brass recycled from the society.

[0129] Brasses with different CuZn contents were tested and compared, and some brand comparison data are shown in the table below:

[0130]

[0131] From the test results in the table above, it can be seen that the yield strength of different CuZn substrates with the addition of graphene is increased by 142%, the tensile strength is increased by 23%, the Vickers hardness is increased by 27.6%, and the elastic modulus is increased by 4.48%.

[0132] Example 3

[0133] Different from the above embodiment, in this embodiment, the graphene composite profile contains the following raw material components in terms of mass percentage: Cu: 45-97%, Ag: 0.0001-0.1%, Fe: 0.01-1.5%, P: 0.001-0.4%, graphene: 0.001-10%, Zn: 3-49%, and the remainder is one or more of Ni, Fe, Au, Sn, Mn, and Al, and the total amount is less than 0.5%.

[0134] Based on the above-mentioned component content requirements, the brass scraps selected in this embodiment are copper, zinc, and gold-plated, silver-plated, and copper-plated brass scraps recycled from society as raw materials.

[0135] In this embodiment, the Ag element is used to enhance the pinning effect of the strengthening phase in the CuZn, CuFe, and CuSn alloy structures, thereby refining the grains and enhancing the bonding strength between Zn, Fe, and Cu atoms. This significantly increases the number of crystal nuclei in the structure, increases the density of the material, effectively improves the critical shear stress of the lattice in the structure, and reduces the probability of dislocations.

[0136] Experiments show that compared with H96 ordinary brass material, the resistivity of the composite material with 0.02% graphene and 0.01% Ag is reduced by 8%. , down to The elastic modulus increased by 6.6%, from 115GPa to 122GPa, and the conductivity increased by 8%, from the original 54%IACS to 58%IACS.

[0137] The composite material prepared in this experiment can comprehensively address the demand for high conductivity, high strength, and high electrical conductivity in automotive wiring harnesses, chip frame materials, and connectors. Furthermore, this material significantly reduces production costs, effectively extends the service life of vehicles, chip frames, and connectors, and successfully overcomes the problem of signal attenuation during signal transmission, reducing the failure rate of signal transmission in new energy vehicles and high-power connectors during operation.

[0138] Due to its high conductivity, the temperature rise problem of high-power chips and connectors can be completely solved, the power reduction problem caused by resistance value problems can also be effectively improved, and the loss problem in signal transmission can be completely eliminated.

[0139] Example 4

[0140] Different from the above embodiment, in this embodiment, the graphene composite profile contains the following raw material components in terms of mass percentage: Cu: 50-97%, Mn: 0.001-5%, Al: 0.001-7.5%, Fe: 0.01-1%, P: 0.001-0.4%, graphene: 0.001-10%, Zn: 3-49%, and the remainder is one or more of Ni, Sn, Ag, and Au, and the total amount is less than 0.5%.

[0141] Based on the above-mentioned component content requirements, the brass scrap selected in this embodiment is manganese brass and aluminum brass scrap recycled from the society, a certain amount of iron-containing C194 and C192 frames are added, and scraps are recycled. The above-mentioned preparation process is used for production, the main purpose of which is to solve the problem of high-temperature corrosion resistance of brass materials.

[0142] The following factors are known to cause brass corrosion:

[0143] 1. Brass undergoes oxidative corrosion in hot air, producing copper oxide (CuO) and zinc oxide (ZnO). These oxides form a loose oxide layer, with ZnO on the inner surface and CuO on the outer surface. This oxide layer provides poor protection and cannot effectively prevent further oxidative corrosion.

[0144] 2. Dezincification: Under high temperature conditions, the zinc in brass is more likely to volatilize or oxidize, resulting in a decrease in the zinc content of the alloy and an imbalance in the copper-zinc ratio, which in turn triggers dezincification corrosion. Dezincification significantly reduces the mechanical properties and corrosion resistance of brass.

[0145] 3. Stress corrosion cracking: Brass is susceptible to stress corrosion cracking in high-temperature environments containing ammonia or chlorides. This is because at high temperatures, ammonia or chlorides react with elements such as copper and zinc in brass to form compounds that are sensitive to stress concentration. High temperatures also increase the material's stress level, leading to the formation and expansion of cracks.

[0146] Based on the above-mentioned corrosion factors of brass, this example forms an FeMn alloy by adding the Mn element. Through precipitation strengthening of the FeMn alloy, without affecting its electrical conductivity, it not only effectively improves the mechanical properties and corrosion resistance of the FeMn alloy, but also significantly improves the eddy current corrosion resistance of the substrate.

[0147] At the same time, by adding Al elements, high-strength hard points are formed in the matrix. Since the standard potential of aluminum is more negative than that of zinc, it preferentially combines with oxygen in the environment to form a dense and hard aluminum oxide film on the surface of the graphene material. , significantly improving the strength and corrosion resistance of brass.

[0148] Experiments have shown that the graphene composite material obtained by adding graphene and Mn and Al elements through powder metallurgy and medium-temperature extrusion, under high temperature conditions of 200°C and chlorine-containing environment, did not show dezincification, stress corrosion, oxidation discoloration, and changes in organizational structure on the surface of the graphene composite material for 4 hours.

[0149] In the neutral salt spray test of no less than 96 hours, which is standard in the automotive field, the graphene composite material showed no weight gain, weight loss, stress corrosion, or cracking after 120 hours of testing. The organizational structure was intact, the physical and chemical indicators did not change, and the overall corrosion resistance time was extended by 24 hours, an extension of 25%.

[0150] Through simulated seawater erosion experiments, taking ordinary brass as an example, after adding Al, graphene and Mn, the corrosion resistance of the substrate in seawater is improved by 600%, from the original 0.0075mm-0.1mm / year corrosion rate to 0.00125mm-0.0166mm / year.

[0151] It can be seen that the composite material prepared by this embodiment has good high temperature resistance and corrosion resistance, which can solve the high temperature corrosion problem of instruments and pipelines of some non-critical components in the aerospace field, and ensure the flight safety of aircraft. In high-temperature components such as automobile engines and exhaust systems, the above-mentioned optimized graphene brass alloy formula and surface oxide film production effectively improve the high temperature corrosion resistance of the substrate and extend the service life of the components. In addition, it also solves the high temperature corrosion problem in high-temperature heat exchangers, boilers and other equipment in the energy field, extends the service life of the equipment, reduces the failure rate, and greatly protects personal safety.

[0152] Example 5

[0153] Different from the above embodiment, in this embodiment, the graphene composite profile contains the following raw material components in terms of mass percentage: Cu: 50-90%, Ni: 0.01-45%, Fe: 0.01-2%, Mn: 0.01-14%, P: 0.001-0.4%, graphene: 0.001-10%, and one or more of the trace elements Al, Si, S, Mg, Bi, As, Sb, Ag, and Au, and the total amount is less than 0.5%, and the balance is Zn.

[0154] Based on the above-mentioned component content requirements, the brass scrap selected in this embodiment is copper scrap with nickel (Ni) plated on the surface from social recycled materials, which is optimized for use, and C194 and C192 recycled materials are added at the same time.

[0155] This example utilizes the excellent wettability of Ni and graphene in the raw materials, combined with a semi-solid mixing process, to further homogenize the graphene structure after ball milling. Because Ni and graphene have good wettability, the added graphene and Ni form a binary eutectic solid solution reinforcement, which strengthens the matrix.

[0156] During the semi-solid process, the good wettability of Ni hard crystal core and graphene is utilized to continuously coat the graphene around the periphery of Ni crystal core, thus forming a crystal core with Ni as the element, which effectively limits the growth of copper grains. Then, through the solid solution strengthening effect of Ni, copper and graphene, the Fe element in the matrix is ​​used to further refine the grains and strengthen the creep resistance of the material. Then, through the stirring and extrusion production process, a finer and strengthened microstructure is obtained. Utilizing the high strength and high conductivity properties of graphene itself, after the later rolling and drawing, the graphene forms a fibrous radial interlaced structure in the microstructure along the rolling and extrusion directions and the radial extension direction, forming an efficient electron transmission channel, so that the problem of Fe and Ni elements deteriorating the conductivity can be improved.

[0157] At the same time, NIMn alloy can be formed by adding Mn elements. Through precipitation strengthening of the alloy, the mechanical properties and corrosion resistance of the alloy can be effectively improved without affecting the conductivity. At the same time, the eddy current corrosion resistance of the substrate can also be significantly improved.

[0158] Experiments show that this example produces a complex graphene copper alloy with high hardness, high-temperature creep resistance, high conductivity, and high strength. Compared to conventional BZn15-20, the addition of 0.02% graphene increases its tensile strength by 29%, from 415 MPa to 535.35 MPa; its Vickers hardness by 37%, from 180 to 246.6; and its yield strength by 190%, from 256 MPa to 486.4 MPa.

[0159] Based on the above performance parameters, the graphene composite material prepared in this embodiment can be used in aerospace antenna brackets, support structures of thermal protection layers, shielded antennas of electronic communication equipment, pins of electronic integrated circuits and other fields, greatly enhancing the stability of structural parts, extending the service life of equipment and components in the above fields, and reducing replacement and maintenance costs.

[0160] Example 6

[0161] Different from the above embodiment, in this embodiment, the graphene composite profile contains the following raw material components in terms of mass percentage: Cu: 50-97%, Fe: 0.1-1%, Sn: 0.01-5%, P: 0.001-0.4%, graphene: 0.001-10%, Zn: 3-49%, and the remainder is one or more of Mn, Au, Ag, Ni, Au, and Al, and the total amount is less than 0.5%.

[0162] Based on the aforementioned component content requirements, the brass scrap selected in this example is primarily recycled from the integrated circuit and chip industries, lead legs, and connector industry leads, supplemented with Sn-containing recycled materials such as oil radiator fins. This is intended to address the impact corrosion issues associated with brass materials in all pipes and wires exposed to seawater, oil, and gas, as well as in equipment components exposed to seawater.

[0163] This example utilizes recycled Sn-plated brass, adding graphene to it and employing a semi-solid-state fine-grain stirring process to achieve graphene incorporation into the refined CuSnZn alloy grain structure. Through continuous extrusion curing at medium temperatures, the graphene forms a fibrous, three-dimensional, radially interlaced structure along the rolling and extrusion directions, as well as along the radial extension direction. Graphene's high conductivity eliminates potential differences in impurity elements, significantly reducing the copper matrix's cathodic reduction reaction in seawater environments and improving the corrosion resistance of the graphene composite material.

[0164] Thanks to the support of graphene's fibrous radial interlaced structure, the microhardness of the CuSnZn alloy is greatly improved. At the same time, the reinforced matrix structure produced by the mutual complementation of graphene and Sn atoms presents a fine-grained state, which increases the wear resistance and erosion resistance of the copper matrix in seawater.

[0165] Experiments have shown that the corrosion resistance of graphene-composite copper in simulated seawater is 25 times higher than that of mechanically polished copper alloy without graphene. This indicates that graphene effectively blocks the penetration of Cl and oxygen into the copper matrix, resulting in a corrosion inhibition efficiency of over 90% for the graphene alloy.

[0166] The results of erosion corrosion tests show that its critical flow velocity reaches 5.7 m / s compared with the critical flow velocity of 3 m / s of arsenic-aluminum marine brass, which exceeds the materials used in existing mainstream marine environments and has outstanding erosion resistance.

[0167] Based on the aforementioned performance parameters, the graphene composite material prepared in this example can address corrosion issues for components in various types of operating equipment, including marine vessels, deep-sea drilling platforms, offshore power plants, desalination plants, and purification plants, as well as impact corrosion issues for all pipes and lines that come into contact with seawater, oil, and gas, and for equipment components exposed to seawater environments. This not only significantly reduces the frequency of replacement and maintenance of marine equipment and related components, but also lowers maintenance costs for equipment in seawater environments, significantly extending the equipment's service life.

[0168] The graphene composite profiles prepared based on the above embodiments can at least be applied to aircraft, connectors, automobile terminals, relays, or conductive, elastic, supporting components in electrical, electrical, and electronic fields, or corrosion-resistant, highly elastic, and highly conductive components in corrosive and high-temperature environments.

[0169] The above is a specific implementation of the embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of this application.

Claims

1. A process for preparing a graphene composite profile using brass waste, characterized in that: The steps include: S1, selecting brass scrap containing different components according to the application scenario of the graphene composite profile; S2, crushing the brass scrap into brass block fragments; S3, adding 0.001-10% by mass of graphene to the brass block material according to the application scenario of the graphene composite profile, and wet-milling to form a first-size mixed powder liquid; S4, feeding the first size mixed powder liquid into a two-stage circular feeder provided with an ultrasonic device at the front section and a heating device at the rear section for semi-solid state rotary shear stirring processing, so that the graphene is evenly filled in the brass fine grain structure to form a graphene-brass mixed substrate; S5, heating the extrusion die cavity of the continuous extruder, and continuously extruding the graphene-brass mixed substrate when the graphene-brass mixed substrate is in a semi-liquid state, so that the graphene as a filling element is completely squeezed into the lattice gaps of the brass fine-grained structure to form a graphene composite profile blank that overcomes the point, line, and surface defects of the brass; S6, processing the graphene composite profile blank with reference to the subsequent process of conventional brass profile to obtain a graphene composite profile, wherein after continuous extrusion and subsequent processing, the graphene composite profile has a fibrous three-dimensional radial interlaced structure formed therein for efficient electron transmission; The graphene composite profile comprises the following raw material components in percentage by mass: Cu: 45-97%, P: 0.001-0.4%, Fe: 0.01-1%, graphene: 0.001-10%, Zn: 3-49%, and the balance is one or more of Ag, Au, Ni, Sn, Mn, and Al, and the total amount is less than 0.5%, and the sum of the contents of each component is 100%; Alternatively, the graphene composite profile comprises the following raw material components in percentage by mass: Cu: 45-97%, Ag: 0.0001-0.1%, Fe: 0.01-1.5%, P: 0.001-0.4%, graphene: 0.001-10%, Zn: 3-49%, and the remainder is one or more of Ni, Au, Sn, Mn, and Al, and the total amount is less than 0.5%, and the sum of the contents of each component is 100%; Alternatively, the graphene composite profile comprises the following raw material components in percentage by mass: Cu: 50-97%, Mn: 0.001-5%, Al: 0.001-7.5%, Fe: 0.01-1%, P: 0.001-0.4%, graphene: 0.001-10%, Zn: 3-49%, and the remainder is one or more of Ni, Sn, Ag, and Au, and the total amount is less than 0.5%, and the sum of the contents of each component is 100%; Alternatively, the graphene composite profile comprises the following raw material components in percentage by mass: Cu: 50-90%, Ni: 0.01-45%, Fe: 0.01-2%, Mn: 0.01-14%, P: 0.001-0.4%, graphene: 0.001-10%, and one or more of the trace elements Al, Si, S, Mg, Bi, As, Sb, Ag, and Au, with a total amount less than 0.5%, and the balance being Zn, and the sum of the contents of each component is 100%; Alternatively, the graphene composite profile comprises the following raw material components in percentage by mass: Cu: 50-97%, Fe: 0.1-1%, Sn: 0.01-5%, P: 0.001-0.4%, graphene: 0.001-10%, Zn: 3-49%, and the remainder is one or more of Mn, Au, Ag, Ni, and Al, and the total amount is less than 0.5%, and the sum of the contents of each component is 100%.

2. The process for preparing a graphene composite profile using brass scrap according to claim 1, wherein: The size of the brass block fragments is 1-2 cm, and the particle size of the first-size mixed powder liquid is less than 50 μm.

3. The process for preparing a graphene composite profile using brass scrap according to claim 1, wherein: The S4 comprises the following steps: S41, at the front section of the circular feeder, utilizing the cavitation effect of ultrasound on the liquid to homogenize the first-sized mixed powder liquid, raising the temperature of the circular feeder to 500-650° C. depending on the copper content of the first-sized mixed powder liquid, injecting inert gas into the rear section and maintaining the temperature, so that the first-sized mixed powder liquid reaches a semi-solid state to form a graphene-brass mixed substrate; S42, rotating and shearing the graphene-brass mixed substrate through the twin-screw rotating mechanism of the circular feeder, with the screw stirring speed being 10r-400r / min. After stirring for 10-20min, the mixed substrate is transported to the discharge port of the circular feeder.

4. The process for preparing a graphene composite profile using brass scrap according to claim 3, wherein: The circular feeder is made of nickel-based high-temperature metal GH3044; the twin-screw pushing pressure range is 50-65 MPa. At this time, the density of the graphene-brass mixed substrate is more than 65% of the normal solid theoretical density.

5. The process for preparing a graphene composite profile using brass scrap according to claim 2, wherein: The S5 comprises the following steps: S51, feeding the graphene-brass mixed substrate into a continuous extruder; S52, according to the ratio of copper and zinc in the brass scrap, setting the extrusion die cavity temperature of the continuous extruder to 800-950° C. so that the copper alloy is in a semi-liquid state in the extrusion die cavity, setting the extrusion pressure to not less than 1000 MPa, and continuously extruding the graphene-brass mixed substrate to obtain the graphene composite profile blank.

6. The process for preparing a graphene composite profile using brass scrap according to claim 5, characterized in that: The continuous extruder is a Conform continuous extruder, and the extrusion die cavity is made of nickel-based high-temperature metal GH3044.

7. The process for preparing a graphene composite profile using brass scrap according to claim 2, wherein: The subsequent processes include rolling and drawing.

8. The process for preparing a graphene composite profile using brass scrap according to any one of claims 2 to 7, characterized in that: The graphene composite profile is a graphene composite copper busbar, a graphene composite copper plate, a graphene composite copper strip, a graphene composite copper rod, a graphene composite copper wire, or a graphene composite copper tube.

9. The graphene composite profile prepared according to any one of the preparation processes of claims 2-8 is applied to aircraft or consumer electronics connectors, data center connectors, new energy vehicle connectors, automotive circuit terminals, and relays.

10. The graphene composite profile prepared according to any one of the preparation processes of claims 2-8 is used for conductive, elastic, supporting components in electrical and electrical components, or corrosion-resistant, highly elastic, and highly conductive components in corrosive and high-temperature environments.

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