Metal matrix composite and preparation method therefor, fin, heat exchanger, and application

Abstract

The present application discloses a metal matrix composite and a preparation method therefor, a fin, a heat exchanger, and an application. The metal matrix composite comprises a metal matrix (100) and a functional coating (200); the functional coating (200) is provided on at least one surface of the metal matrix (100); the functional coating (200) at least comprises an corrosion-resistant layer (210); the corrosion-resistant layer (210) comprises an organic coating containing graphene and / or a derivative thereof; the thickness of the corrosion-resistant layer (210) in a cured state is 0.8-1.5 microns; the flake size of the graphene and / or the derivative thereof is 1-8 microns, and the content of the graphene and / or the derivative thereof in the corrosion-resistant layer (210) in the cured state is 0.5-4.5 wt%; and the thermal diffusivity of the composite in the vertical direction is greater than or equal to 28 mm2 / s.

Description

Metal matrix composites and their preparation methods, fins, heat exchangers and their applications

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese Patent Application No. 202410903326.9, filed on July 8, 2024, entitled "Metal Matrix Composite Materials and Preparation Methods Thereof, Fins, Heat Exchangers and Applications Thereof", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of heat exchange material technology, and in particular to a metal matrix composite material and its preparation method, fins, heat exchanger and their applications. Background Technology

[0004] As the core heat exchange component of an air conditioner, the performance of the heat exchanger is directly related to the overall performance of the unit. To improve drainage performance and reduce performance degradation caused by corrosion, a hydrophilic and anti-corrosion coating is typically applied to the surface of the heat exchanger's metal substrate. However, during the use of an air conditioner, the coating on the metal heat sink surface will experience aging phenomena such as cracking and edge peeling under complex operating environments. This not only directly affects the performance of the organic coating but also leads to large-scale corrosion of the substrate. Taking aluminum foil substrate as an example, tests have shown that aluminum foil corrosion can reduce the heat exchange performance of an air conditioner by more than 20% and increase energy consumption by 16%.

[0005] Summary of the Invention

[0006] This application aims to at least partially solve one of the technical problems existing in the prior art. To this end, one of the objectives of this application is to provide a metal-based composite material.

[0007] The second objective of this application is to provide a method for preparing the aforementioned metal matrix composite material.

[0008] The third objective of this application is to provide a fin.

[0009] The fourth objective of this application is to provide a heat exchanger.

[0010] The fifth objective of this application is to provide an air handling device.

[0011] A first aspect of this application provides a metal-based composite material, comprising a metal substrate and a functional coating; the functional coating is disposed on at least one surface of the metal substrate;

[0012] The functional coating includes at least an anti-corrosion layer;

[0013] The anti-corrosion layer includes an organic coating containing graphene and / or its derivatives;

[0014] The thickness of the cured anti-corrosion layer is 0.8 micrometers to 1.5 micrometers;

[0015] The graphene and / or its derivatives have a sheet diameter of 1 micrometer to 8 micrometers;

[0016] The content of graphene and / or its derivatives in the cured anti-corrosion layer is 0.5 wt% to 4.5 wt%.

[0017] The metal matrix composite material has a thermal diffusivity ≥28 mm in the vertical direction. 2 / s.

[0018] The anti-corrosion layer thickness mentioned in the embodiments of this application refers to the thickness of a single-sided coating.

[0019] According to some embodiments of this application, the graphene and / or its derivatives have 1 to 10 layers.

[0020] According to some embodiments of this application, the maximum sheet diameter of the graphene and / or its derivatives is ≤ 5 times the thickness of the anti-corrosion layer.

[0021] The maximum sheet diameter of graphene and / or its derivatives as described in the embodiments of this application refers to the maximum value among the sheet diameters of graphene and / or its derivatives.

[0022] According to some embodiments of this application, the graphene and / or its derivatives have a sheet diameter of 1 micrometer to 3 micrometers.

[0023] According to some embodiments of this application, the thermal diffusivity of the metal matrix composite material in the vertical direction is 28 mm. 2 / s~40mm 2 / s. The vertical direction, also known as the longitudinal direction, refers to the thickness direction of the metal matrix composite material.

[0024] According to some embodiments of this application, the temperature for measuring the thermal diffusivity is 50°C.

[0025] According to some embodiments of this application, the organic coating forming the anti-corrosion layer contains graphene and / or its derivatives at a mass percentage of 0.5% to 2%.

[0026] According to some embodiments of this application, the anti-corrosion layer is mainly an amide-modified acrylic resin coating or an epoxy-modified acrylic resin coating, wherein the amide-modified acrylic resin coating or the epoxy-modified acrylic resin coating contains graphene and / or its derivatives.

[0027] According to some embodiments of this application, the graphene derivatives include graphene oxide, reduced graphene oxide, or grafted modified graphene, etc.

[0028] According to some embodiments of this application, the overall weight loss rate of the metal matrix composite material in the alkali resistance test is less than 6%. Thus, the metal matrix composite material exhibits good alkali resistance and high corrosion resistance. The alkali resistance test refers to testing the metal matrix composite material in a 100g / L sodium hydroxide solution at a test temperature of 20℃±2℃ for 1 hour.

[0029] According to some embodiments of this application, the corrosion area of ​​the metal matrix composite material is ≤0.02% after 1500 hours of neutral salt spray testing.

[0030] According to some embodiments of this application, the corrosion area rating of the weathering test for the metal matrix composite material is ≥8. Thus, the metal matrix composite material exhibits high weather resistance and excellent aging resistance. The weathering test refers to subjecting the metal matrix composite material to 120 hours of ultraviolet light irradiation and 72 hours of neutral salt spray testing sequentially.

[0031] According to some embodiments of this application, the metal substrate has a functional coating on both surfaces opposite each other in the thickness direction, and the functional coating includes an anti-corrosion layer.

[0032] According to some embodiments of this application, the functional coating further includes a hydrophilic layer disposed on the surface of the anti-corrosion layer away from the metal substrate.

[0033] According to some embodiments of this application, the functional coating further includes:

[0034] A hydrophilic layer, wherein the hydrophilic layer is disposed on the surface of the anti-corrosion layer away from the metal substrate; and

[0035] A lubricating layer is disposed on the surface of the hydrophilic layer away from the metal substrate.

[0036] According to some embodiments of this application, the metal substrate includes aluminum, copper, iron, or alloys thereof.

[0037] The second aspect of this application provides a method for preparing the metal-based composite material described in the first aspect of this application, comprising the following steps:

[0038] A coating is applied to at least one surface of a metal substrate to form a functional coating, thereby obtaining the metal-based composite material.

[0039] A third aspect of this application provides a fin with a thickness of 0.05 mm to 0.12 mm. The fin includes the metal matrix composite material described in the first aspect of this application, or the metal matrix composite material obtained by the preparation method described in the second aspect of this application.

[0040] A fourth aspect of this application provides a heat exchanger including the fins described in the third aspect of this application.

[0041] The fifth aspect of this application provides an air treatment device, including the metal matrix composite material described in the first aspect of this application, or the metal matrix composite material obtained by the preparation method described in the second aspect of this application, or the fins described in the third aspect of this application, or the heat exchanger described in the fourth aspect of this application.

[0042] According to some embodiments of this application, the air handling device is an air conditioner or a dehumidifier.

[0043] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0044] Figure 1 is a schematic diagram of a metal matrix composite material according to an embodiment of this application;

[0045] Figure 2 is a schematic diagram of a metal-based composite material according to another embodiment of this application;

[0046] Figure 3 is a schematic diagram of a metal matrix composite material according to another embodiment of this application;

[0047] Figure 4 is a schematic diagram of a metal matrix composite material according to another embodiment of this application;

[0048] Figure 5 is a schematic diagram of a metal-based composite material according to another embodiment of this application;

[0049] Figure 6 is a schematic diagram of a fin in one embodiment of this application;

[0050] Figure 7 shows the thermal diffusivity of the coated aluminum foil sample in the vertical direction at 50℃.

[0051] Figure 8 shows the overall weight loss percentage of the coated aluminum foil samples in the alkali resistance test.

[0052] Figure 9 shows the corrosion rating of the coated aluminum foil samples after acetic acid salt spray tests at different times;

[0053] Figure 10 shows the weather resistance rating chart of the coated aluminum foil samples; and

[0054] Figure 11 shows a performance comparison of the two types of heat exchanger prototypes nine months after the air conditioning unit was installed.

[0055] Figure label:

[0056] Metal substrate 100,

[0057] Functional coating 200,

[0058] Anti-corrosion layer 210, first anti-corrosion layer 211, second anti-corrosion layer 212,

[0059] Hydrophilic layer 220, first hydrophilic layer 221, second hydrophilic layer 222

[0060] Lubricating layer 230, first lubricating layer 231, second lubricating layer 232.

[0061] Fin 300. Detailed Implementation

[0062] The embodiments of this application are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0063] In the description of this application, it should be understood that the terms "length," "width," "thickness," "upper," "lower," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, features defined with "first" or "second" may explicitly or implicitly include one or more of that feature.

[0064] As the core heat exchange component of an air conditioner, the performance of the heat exchanger is directly related to the overall performance of the unit. To improve drainage performance and reduce performance degradation caused by corrosion, a hydrophilic and anti-corrosion coating is typically applied to the surface of the heat exchanger's metal substrate. However, during the use of an air conditioner, the coating on the metal heat sink surface will experience aging phenomena such as cracking and edge peeling under complex operating environments. This not only directly affects the performance of the organic coating but also leads to large-scale corrosion of the substrate. Taking aluminum foil substrate as an example, tests have shown that aluminum foil corrosion can reduce the heat exchange performance of an air conditioner by more than 20% and increase energy consumption by 16%.

[0065] To address the aforementioned issues, existing technologies offer solutions such as using high-corrosion-resistance systems or increasing coating thickness. Currently, mainstream high-corrosion-resistance systems primarily employ epoxy or fluorinated systems. Epoxy systems exhibit poor resistance to light aging, leading to a rapid decline in corrosion resistance during service. Fluorinated systems, on the other hand, are costly, hindering large-scale adoption, and suffer from poor compatibility with the hydrophilic topcoat, resulting in poor performance balance. While increasing coating thickness can improve initial corrosion resistance, organic coatings have significantly lower thermal conductivity than metal substrates. Thicker coatings increase air conditioning energy consumption, leading to energy waste, and also present challenges in coating manufacturing and processing. Therefore, existing heat exchanger coatings fail to resolve these technical contradictions, exhibiting a failure to balance corrosion resistance, weather resistance, and thermal conductivity, or presenting difficulties in processing and production.

[0066] One aspect of this application provides an embodiment of a metal matrix composite material. The metal matrix composite material of this application embodiment is described below with reference to Figures 1-5.

[0067] Referring to Figure 1, the metal-based composite material of this embodiment includes a metal substrate 100 and a functional coating 200, wherein the functional coating 200 is disposed on one surface of the metal substrate 100. The functional coating 200 includes an anti-corrosion layer; the anti-corrosion layer includes an organic coating containing graphene and / or its derivatives; the thickness of the cured anti-corrosion layer is 0.8 μm to 1.5 μm; the sheet diameter of the graphene and / or its derivatives is 1 μm to 8 μm; the content of graphene and / or its derivatives in the cured anti-corrosion layer is 0.5 wt% to 4.5 wt%; and the thermal diffusivity of the metal-based composite material in the vertical direction is ≥28 mm. 2 / s. According to embodiments of this application, the anti-corrosion layer of the metal matrix composite material contains graphene and / or its derivatives with specific sheet diameters and contents. The two, combined with an anti-corrosion layer thickness of 0.8 to 1.5 micrometers, can play a synergistic role, which can achieve both corrosion resistance and weather resistance while having excellent thermal conductivity at the same time, even with a thin coating thickness. This makes it easy to process and prepare under the process conditions of existing production equipment.

[0068] The metal matrix composite material uses a graphene high corrosion resistance coating, which can have excellent thermal conductivity with a thin coating thickness, while also taking into account corrosion resistance and weather resistance, and is easy to process and prepare under the process conditions of existing production equipment.

[0069] Furthermore, the anti-corrosion layer of the metal matrix composite contains graphene and / or its derivatives with specific sheet diameters and contents, which can achieve high thermal conductivity, corrosion resistance and high weather resistance with a coating thickness of only 0.8 to 1.5 micrometers, and is easy to process and produce.

[0070] Specifically, by selecting graphene and / or its derivatives with a sheet diameter of 1 to 8 micrometers and a content of 0.5 wt% to 4.5 wt% in the cured anti-corrosion layer, the resulting metal matrix composite material can simultaneously possess high weather resistance, high thermal conductivity, and corrosion resistance. If the sheet diameter of graphene and / or its derivatives is too small or too large, or if the content of graphene and / or its derivatives is too small or too large, it cannot be matched with the thickness of the anti-corrosion layer to simultaneously achieve corrosion resistance, weather resistance, and thermal conductivity. For example, if the sheet diameter of graphene and / or its derivatives is too large, it will penetrate the anti-corrosion layer, affecting corrosion resistance and weather resistance; if the content of graphene and / or its derivatives in the anti-corrosion layer is too small, it cannot exert its function; if the content of graphene and / or its derivatives in the anti-corrosion layer is too large, it is prone to uneven dispersion or agglomeration, which will also affect corrosion resistance and weather resistance.

[0071] In some embodiments of this application, the thickness of the cured anti-corrosion layer can be 0.8 micrometers, 0.9 micrometers, 1.0 micrometers, 1.1 micrometers, 1.2 micrometers, 1.3 micrometers, 1.4 micrometers, or 1.5 micrometers, etc. In some examples, the thickness of the cured anti-corrosion layer can be 0.8 micrometers to 1.4 micrometers. In other examples, the thickness of the cured anti-corrosion layer can be 0.8 micrometers to 1.2 micrometers. In still other examples, the thickness of the cured anti-corrosion layer can be 1 micrometer to 1.2 micrometers.

[0072] In some embodiments of this application, the sheet diameter of graphene and / or its derivatives can be 1 micrometer to 6 micrometers or 3 micrometers to 8 micrometers, etc. In some examples, the sheet diameter of graphene and / or its derivatives can be 1 micrometer to 3 micrometers. In some examples, the sheet diameter of graphene and / or its derivatives can be 3 micrometers to 6 micrometers. In some examples, the sheet diameter of graphene and / or its derivatives can be 3 micrometers to 8 micrometers. Graphene and / or its derivatives can be a mixture of graphene and / or its derivatives with various different sheet diameters, and the sheet diameter of graphene and / or its derivatives can be within a range.

[0073] In some embodiments of this application, the content of graphene and / or its derivatives in the cured anti-corrosion layer can be 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, or 4.5 wt%, etc. In some examples, the content of graphene and / or its derivatives in the cured anti-corrosion layer can be from 0.5 wt% to 3.5 wt%. In some examples, the content of graphene and / or its derivatives in the cured anti-corrosion layer can be from 2 wt% to 3.5 wt%. In other examples, the content of graphene and / or its derivatives in the cured anti-corrosion layer can be from 2.4 wt% to 3 wt%.

[0074] In some embodiments of this application, the thermal diffusivity of the metal matrix composite material in the vertical direction can be 28 mm. 2 / s, 29mm 2 / s, 30mm 2 / s, 31mm 2 / s, 32mm 2 / s, 33mm 2 / s, 34mm 2 / s, 35mm 2 / s or higher. In some examples, the thermal diffusivity of the metal matrix composites in the vertical direction is greater than 29 mm. 2 / s. In some examples, the thermal diffusivity of the metal matrix composite in the vertical direction is greater than 30 mm. 2 / s.

[0075] According to embodiments of this application, the number of graphene and / or its derivatives is 1 to 10 layers. In some embodiments of this application, the number of graphene and / or its derivatives is 1 to 3 layers, or 3 to 10 layers.

[0076] In some specific embodiments of this application, the number of graphene and / or its derivatives is 3 to 10 layers. Such a number of layers in graphene and / or its derivatives makes them easier to disperse and process, enabling the resulting metal-based composite materials to possess corrosion resistance, weather resistance, and thermal conductivity. In some examples, the number of layers in graphene and / or its derivatives is selected from 3, 4, 5, 6, 7, 8, 9, or 10 layers. In some examples, graphene and / or its derivatives can be a mixture of various graphene and / or its derivatives with different numbers of layers, and the number of layers in graphene and / or its derivatives can be within a range.

[0077] In some embodiments of this application, the aspect ratio of graphene and / or its derivatives is 0.1 to 1.

[0078] According to embodiments of this application, the maximum sheet diameter of graphene and / or its derivatives is ≤ 5 times the thickness of the anti-corrosion layer. In some embodiments of this application, the maximum sheet diameter of graphene and / or its derivatives is ≤ 3 times the thickness of the anti-corrosion layer.

[0079] In some specific embodiments of this application, the sheet diameter of graphene and / or its derivatives is 1 micrometer to 3 micrometers. Selecting graphene and / or its derivatives within this sheet diameter range allows for better matching with the thickness of the anti-corrosion layer and the content of graphene and / or its derivatives in the anti-corrosion layer, enabling the resulting metal matrix composite material to possess not only high thermal conductivity but also high corrosion resistance and high weather resistance.

[0080] In some specific embodiments of this application, the thermal diffusivity of the metal matrix composite material in the vertical direction is 28 mm. 2 / s~40mm 2 / s. Metal matrix composites exhibit such a wide range of thermal diffusivity, demonstrating high thermal conductivity. In some examples of this application, the thermal diffusivity of the metal matrix composite in the vertical direction is 30 mm. 2 / s~35mm 2 / s.

[0081] In some embodiments of this application, the thermal diffusivity is measured at 50°C, that is, at 50°C, the thermal diffusivity of the metal matrix composite material in the direction perpendicular to (thickness) is measured. The test method for thermal diffusivity can refer to ASTM E1461-13, "Standard Test Method for Thermal Diffusivity by the Flash Method Test".

[0082] According to embodiments of this application, the organic coating forming the anti-corrosion layer contains graphene and / or its derivatives at a mass percentage of 0.5% to 2%. By adding graphene and / or its derivatives in such a range to the organic coating forming the anti-corrosion layer, the content of graphene and / or its derivatives in the final cured anti-corrosion layer can be 0.5 wt% to 4.5 wt%.

[0083] According to embodiments of this application, the main body of the anti-corrosion layer is an amide-modified acrylic resin coating or an epoxy-modified acrylic resin coating, wherein the amide-modified acrylic resin coating or the epoxy-modified acrylic resin coating contains graphene and / or its derivatives. By using an amide-modified acrylic resin coating or an epoxy-modified acrylic resin coating containing graphene and / or its derivatives as the main body of the anti-corrosion layer, the metal matrix composite material can have good anti-corrosion performance.

[0084] According to embodiments of this application, amide-modified acrylic resin coatings can be made using organic coatings such as amide-modified acrylic resin paints, and epoxy-modified acrylic resin coatings can be made using organic coatings such as epoxy-modified acrylic resin paints. Their formulation and preparation methods are common technical solutions in the art. For example, the raw materials for preparing amide-modified acrylic resin paints may include acrylic monomers, amide monomers, initiators, and optional solvents and additives. Selected additives may include coupling agents, surfactants, or crosslinking agents. The raw materials for preparing epoxy-modified acrylic resin paints may include acrylic monomers, epoxy-based alkenyl monomers, initiators, and optional solvents and additives. Optional acrylic monomers include one or more of acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, propyl methacrylate, butyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxyhexyl acrylate, hydroxyethyl methacrylate, and hydroxypropyl methacrylate. Optional amide monomers include one or more of acrylamide, methacrylamide, N,N-dimethylacrylamide, N-hydroxyethylacrylamide, N-vinylformamide, and N-vinylacetamide. Optional epoxy-based alkenyl monomers include one or more of glycidyl acrylate, glycidyl methacrylate, and allyl alcohol glycidyl ether. Optional initiators include one or a combination of persulfates and azo compounds. In some examples, the amount of amide monomers or epoxy-based alkenyl monomers may be 1% to 30% of the mass of the acrylic monomers, the amount of initiator may be 0.5% to 5% of the sum of the mass of the acrylic monomers and amide monomers (or the sum of the acrylic monomers and the epoxy-based alkenyl monomers), the amount of solvent may be added selectively according to actual conditions, and the amount of other auxiliaries may be 0.1% to 5% of the sum of the mass of the acrylic monomers and amide monomers (or the sum of the acrylic monomers and the epoxy-based alkenyl monomers). Amide-modified acrylic resins or epoxy-modified acrylic resins can improve the crosslinking degree and density of the anti-corrosion layer, thereby improving the corrosion resistance of the coating.

[0085] According to embodiments of this application, graphene derivatives include graphene oxide, reduced graphene oxide, or grafted modified graphene. That is, graphene and / or its derivatives include one or more of graphene, graphene oxide, reduced graphene oxide, and grafted modified graphene. In some embodiments of this application, graphene is used to prepare metal-based composite materials.

[0086] In some embodiments of this application, the overall weight loss rate of the metal matrix composite material in the alkali resistance test is less than 6%. Thus, the metal matrix composite material exhibits good alkali resistance and high corrosion resistance. The alkali resistance test refers to testing the metal matrix composite material in a 100g / L sodium hydroxide solution at a test temperature of 20℃±2℃ for 1 hour. The overall weight loss rate refers to the total weight loss rate of the metal matrix composite material, including the metal substrate and the anti-corrosion layer, in the alkali resistance test. In some examples, the alkali resistance test is conducted in accordance with T / CAS 734-2023 "Technical Specification for Long-lasting Weather-resistant and Corrosion-resistant Coated Aluminum Foil for Air Conditioner Heat Sinks".

[0087] In some embodiments of this application, the corrosion area of ​​the metal matrix composite material is ≤0.02% after 1500 hours of neutral salt spray testing. Thus, the metal matrix composite material exhibits good neutral salt spray resistance and high corrosion resistance. In some examples, the neutral salt spray test is conducted according to GB / T 10125-2021 "Artificial Atmosphere Corrosion Test - Salt Spray Test". In some specific embodiments of this application, the corrosion area of ​​the metal matrix composite material is less than 0.02% after 1500 hours of neutral salt spray testing.

[0088] In some embodiments of this application, the corrosion area rating of the weathering test for the metal matrix composite material is ≥8. Thus, the metal matrix composite material exhibits high weather resistance and excellent aging resistance. The weathering test involves subjecting the metal matrix composite material to 120 hours of ultraviolet light irradiation and 72 hours of neutral salt spray testing sequentially. In some examples, the weathering test is conducted according to T / CAS 734-2023 "Technical Specification for Long-Lasting Weather-Resistant and Corrosion-Resistant Coated Aluminum Foil for Air Conditioner Heat Sinks". In some specific examples of this application, the corrosion area rating of the weathering test for the metal matrix composite material is greater than 8.

[0089] In some specific embodiments of this application, the corrosion area rating of the weathering resistance test for metal matrix composites is grade 8 or 9. According to some examples, in the weathering resistance test of metal matrix composites, the proportion of corrosion ratings of grade 8 or above is ≥85%. According to some specific examples, in the weathering resistance test of metal matrix composites, the proportion of corrosion ratings of grade 8 or above is ≥90%. In some examples, in the weathering resistance test of metal matrix composites, the proportion of corrosion ratings of grade 9 is ≥60%. In some examples, in the weathering resistance test of metal matrix composites, the proportion of corrosion ratings of grade 9 is ≥65%. In some examples, in the weathering resistance test of metal matrix composites, the proportion of corrosion ratings of grade 9 is ≥70%.

[0090] According to embodiments of this application, a functional coating is provided on both surfaces of the metal substrate opposite to each other in the thickness direction, and the functional coating includes an anti-corrosion layer. In some embodiments of this application, the functional coating is provided on the upper and lower surfaces of the metal substrate in the thickness direction, respectively. In some examples, the metal substrate is sheet-like, and its thickness is less than its length and less than its width.

[0091] In some embodiments of this application, the functional coating is an anti-corrosion layer. In some examples, the anti-corrosion layer is an organic coating containing graphene and / or its derivatives.

[0092] According to embodiments of this application, the functional coating further includes a hydrophilic layer disposed on the surface of the anti-corrosion layer away from the metal substrate. The hydrophilic layer enhances the hydrophilicity of the metal-based composite material and improves its detergency.

[0093] In some embodiments of this application, referring to FIG2, the functional coating of the metal matrix composite material includes an anti-corrosion layer 210 and a hydrophilic layer 220; wherein, the anti-corrosion layer 210 is disposed on one surface of the metal substrate 100, and the hydrophilic layer 220 is disposed on the surface of the anti-corrosion layer 210 away from the metal substrate 100.

[0094] According to embodiments of this application, the functional coating further includes a hydrophilic layer and a lubricating layer, wherein the hydrophilic layer is disposed on the surface of the anti-corrosion layer away from the metal substrate; and the lubricating layer is disposed on the surface of the hydrophilic layer away from the metal substrate. The hydrophilic layer can enhance the hydrophilicity of the metal matrix composite material and improve its detergency; the further provision of the lubricating layer can protect the hydrophilic layer and the anti-corrosion layer and improve the stamping performance, thus giving the functional coating better corrosion resistance and hydrophilicity.

[0095] In some embodiments of this application, referring to FIG3, the functional coating of the metal matrix composite material includes an anti-corrosion layer 210, a hydrophilic layer 220, and a lubricating layer 230; wherein, the anti-corrosion layer 210 is disposed on one surface of the metal substrate 100, the hydrophilic layer 220 is disposed on the surface of the anti-corrosion layer 210 away from the metal substrate 100, and the lubricating layer 230 is disposed on the surface of the hydrophilic layer 220 away from the metal substrate 100.

[0096] In some embodiments of this application, referring to FIG4, the functional coating of the metal matrix composite material includes a first anti-corrosion layer 211, a second anti-corrosion layer 212, a first hydrophilic layer 221, and a second hydrophilic layer 222; wherein, the first anti-corrosion layer 211 and the second anti-corrosion layer 212 are respectively disposed on two surfaces of the metal substrate 100; the first hydrophilic layer 221 is disposed on the surface of the first anti-corrosion layer 211 away from the metal substrate 100, and the second hydrophilic layer 222 is disposed on the surface of the second anti-corrosion layer 212 away from the metal substrate 100.

[0097] In some embodiments of this application, referring to FIG5, the functional coating of the metal matrix composite material includes a first anti-corrosion layer 211, a second anti-corrosion layer 212, a first hydrophilic layer 221, a second hydrophilic layer 222, a first lubricating layer 231, and a second lubricating layer 232; wherein, the first anti-corrosion layer 211 and the second anti-corrosion layer 212 are respectively disposed on two surfaces of the metal substrate 100; the first hydrophilic layer 221 is disposed on the surface of the first anti-corrosion layer 211 away from the metal substrate 100, and the second hydrophilic layer 222 is disposed on the surface of the second anti-corrosion layer 212 away from the metal substrate 100; the first lubricating layer 231 is disposed on the surface of the first hydrophilic layer 221 away from the metal substrate 100, and the second lubricating layer 232 is disposed on the surface of the second hydrophilic layer 222 away from the metal substrate 100.

[0098] In some embodiments of this application, when the functional coating further includes a hydrophilic layer, the single-sided coating thickness of the hydrophilic layer is 0.2 micrometers to 0.5 micrometers. In some specific embodiments of this application, the single-sided coating thickness of the hydrophilic layer is 0.2 micrometers to 0.4 micrometers.

[0099] In some embodiments of this application, when the functional coating further includes a lubricating layer, the single-sided coating thickness of the lubricating layer is 0.1 micrometers to 0.5 micrometers. In some specific embodiments of this application, the single-sided coating thickness of the lubricating layer is 0.2 micrometers to 0.4 micrometers.

[0100] Methods for forming hydrophilic or lubricating layers on metal matrix composites are conventional methods in this field. For example, a hydrophilic coating (such as an acrylic resin coating) can be applied and then cured to form a hydrophilic layer; a lubricating material (such as a material containing a lubricant) can be applied and then cured to form a lubricating layer.

[0101] According to embodiments of this application, the metal substrate includes aluminum, copper, iron, or alloys thereof. These substrates all possess good thermal conductivity. In some embodiments of this application, the metal substrate is selected from aluminum alloys, copper alloys, or iron alloys, with stainless steel being an optional iron alloy. In some specific embodiments of this application, the metal substrate is an aluminum alloy. In some examples of this application, when the metal substrate is an aluminum alloy, the resulting metal-based composite material is a coated aluminum foil.

[0102] In some embodiments of this application, the thickness of the metal substrate is 0.02 mm to 0.2 mm. In some specific embodiments of this application, the thickness of the metal substrate is 0.05 mm to 0.12 mm.

[0103] Another aspect of this application provides a method for preparing a metal matrix composite material according to embodiments. According to embodiments of this application, the preparation method includes the following steps: coating at least one surface of a metal substrate with a coating to form a functional coating, thereby obtaining a metal matrix composite material. According to embodiments of this application, the method for preparing the metal matrix composite material is simple to operate, easy to control, and can be processed and prepared under existing production equipment conditions, making it suitable for large-scale industrial production applications.

[0104] In some embodiments of this application, a coating capable of forming a functional coating is applied to at least one surface of a metal substrate to form a functional coating. In some examples, a coating capable of forming a functional coating is applied to two surfaces of the metal substrate that are opposite each other in the thickness direction to form a functional coating.

[0105] In some embodiments of this application, an organic coating containing graphene and / or its derivatives is coated onto at least one surface of a metal substrate and cured to form an anti-corrosion layer. In some specific embodiments of this application, the organic coating containing graphene and / or its derivatives is an amide-modified acrylic resin coating or an epoxy-modified acrylic resin coating, wherein the amide-modified acrylic resin coating or the epoxy-modified acrylic resin coating contains graphene and / or its derivatives.

[0106] In some embodiments of this application, a hydrophilic coating is applied to the surface of the anti-corrosion layer and cured to form a hydrophilic layer. In some specific embodiments of this application, the hydrophilic coating is an acrylic resin coating.

[0107] In some embodiments of this application, a material containing a lubricant is coated on the surface of the hydrophilic layer and cured to form a lubricating layer.

[0108] In some embodiments of this application, the coating method includes roller coating, spray coating, or dip coating.

[0109] In some embodiments of this application, the method for curing to form the functional coating includes thermosetting or photosetting. In other embodiments of this application, the organic coating forming the anti-corrosion layer may contain, in addition to graphene and / or its derivatives, resin and solvent, the solvent being, for example, water, and the method for curing to form the functional coating includes removing the solvent from the coating layer to allow the resin to form a film.

[0110] Another aspect of this application provides a fin embodiment, as shown in FIG6. The fin 300 comprises a metal matrix composite material from the foregoing embodiments of this application, or a metal matrix composite material obtained by the preparation method of the metal matrix composite material from the foregoing embodiments. The thickness of the fin 300 can be 0.05 mm to 0.12 mm. The fin 300 may be provided with through holes and cutouts penetrating the fin in the thickness direction of the fin. The through holes are for heat exchange tubes of the heat exchanger to pass through, and the cutouts, such as bridges or louvers, can be used to improve the heat dissipation effect of the fin. In the metal matrix composite material constituting the fin 300, the metal substrate 100 can be aluminum foil, and the functional coating 200 can be disposed on two opposite surfaces of the metal substrate 100 in the thickness direction. According to the embodiments of this application, the fin can balance corrosion resistance, weather resistance, and thermal conductivity, has good heat dissipation effect, and has a long service life.

[0111] Another aspect of this application provides a heat exchanger embodiment, including the fins of the foregoing embodiments of this application. According to the embodiments of this application, the heat exchanger can balance corrosion resistance, weather resistance, and thermal conductivity, is easy to manufacture, and can significantly improve the reliability, service life, and long-term energy efficiency of the heat exchanger.

[0112] In some embodiments of this application, the heat exchanger further includes heat exchange tubes for the passage of refrigerant, wherein the heat exchange tubes pass through the fins of the aforementioned embodiments or the metal-based composite material of the aforementioned embodiments. In some examples, the heat exchanger is a tube-fin structure.

[0113] Another aspect of this application provides an embodiment of an air handling device, including a metal matrix composite material from the foregoing embodiments of this application, or a metal matrix composite material obtained by the preparation method of the foregoing embodiments of the metal matrix composite material, or fins from the foregoing embodiments, or a heat exchanger from the foregoing embodiments. According to the embodiments of this application, the air handling device can achieve significant improvements in reliability, service life, and long-term energy efficiency.

[0114] According to embodiments of this application, the air handling device is an air conditioner or a dehumidifier.

[0115] According to embodiments of this application, there are no particular limitations on the type of air conditioner; it can be a wall-mounted air conditioner, a floor-standing air conditioner, a window air conditioner, or a ceiling-mounted air conditioner. In addition to the aforementioned heat exchanger, the structure of the air conditioner also includes conventional air conditioner components such as a compressor and a fan.

[0116] The following specific embodiments further illustrate the content of this application in detail. Unless otherwise specified, all raw materials, reagents, and apparatus used herein are available from conventional commercial sources. Unless otherwise specified, the testing or experimental methods are conventional methods in the art.

[0117] Unless otherwise specified, all raw materials used in the following examples / comparative examples are commercially available products and were used directly without further processing.

[0118] The aluminum foil substrates in Examples 1-9 and Comparative Examples 1-2 were made of aluminum alloy grade 3102 (according to GB / T3190-2020) with a thickness of 0.095 mm. The amide-modified acrylic resin coatings used in Examples 1-9 were all the same.

[0119] Example 1

[0120] 0.8 wt% graphene was added to an amide-modified acrylic resin coating, and the mixture yielded an acrylic resin coating containing graphene. The graphene flakes had a diameter of 1–3 μm and consisted of 3–10 layers. This graphene-containing acrylic resin coating was applied to both the upper and lower surfaces of an aluminum foil substrate and cured to form a 1.08 μm thick anti-corrosion layer on one side, resulting in an aluminum foil sample with anti-corrosion coatings on both surfaces. The cured anti-corrosion layer contained 2.4 wt% graphene.

[0121] Acrylic resin coating was applied to the surfaces of the upper and lower anti-corrosion layers of the aluminum foil sample, and cured to form a hydrophilic layer with a single-sided coating thickness of about 0.25 μm, thus obtaining the coated aluminum foil of this embodiment.

[0122] Example 2

[0123] 1 wt% graphene was added to an amide-modified acrylic resin coating, and the mixture yielded an acrylic resin coating containing graphene. The graphene flakes had a diameter of 3–6 μm and consisted of 1–3 layers. This graphene-containing acrylic resin coating was applied to both the upper and lower surfaces of an aluminum foil substrate and cured to form a 1.20 μm thick anti-corrosion layer on one side, resulting in an aluminum foil sample with anti-corrosion coatings on both surfaces. The cured anti-corrosion layer contained 3 wt% graphene.

[0124] Referring to Example 1, acrylic resin coating was applied to the surfaces of the upper and lower anti-corrosion layers of the aluminum foil sample, and cured to form a hydrophilic layer with a single-sided coating thickness of about 0.25 μm, thus obtaining the coated aluminum foil of this example.

[0125] Example 3

[0126] 1 wt% graphene was added to an amide-modified acrylic resin coating, and the mixture yielded an acrylic resin coating containing graphene. The graphene flakes had a diameter of 1–3 μm and consisted of 1–3 layers. This graphene-containing acrylic resin coating was applied to both the upper and lower surfaces of an aluminum foil substrate and cured to form a single-sided coating thickness of 0.80 μm, resulting in an aluminum foil sample with anti-corrosion coatings on both surfaces. The cured anti-corrosion layer contained 3 wt% graphene.

[0127] Referring to Example 1, acrylic resin coating was applied to the surfaces of the upper and lower anti-corrosion layers of the aluminum foil sample, and cured to form a hydrophilic layer with a single-sided coating thickness of about 0.25 μm, thus obtaining the coated aluminum foil of this example.

[0128] Example 4

[0129] 1 wt% graphene was added to an amide-modified acrylic resin coating, and the mixture yielded an acrylic resin coating containing graphene. The graphene flakes had a diameter of 3–6 μm and consisted of 3–10 layers. This graphene-containing acrylic resin coating was applied to both the upper and lower surfaces of an aluminum foil substrate and cured to form a 1.46 μm thick anti-corrosion layer on one side, resulting in an aluminum foil sample with anti-corrosion coatings on both surfaces. The cured anti-corrosion layer contained 3 wt% graphene.

[0130] Referring to Example 1, acrylic resin coating was applied to the surfaces of the upper and lower anti-corrosion layers of the aluminum foil sample, and cured to form a hydrophilic layer with a single-sided coating thickness of about 0.25 μm, thus obtaining the coated aluminum foil of this example.

[0131] Example 5

[0132] 1 wt% graphene was added to an amide-modified acrylic resin coating, and the mixture yielded an acrylic resin coating containing graphene. The graphene flakes had a diameter of 1–3 μm and consisted of 3–10 layers. This graphene-containing acrylic resin coating was applied to both the upper and lower surfaces of an aluminum foil substrate and cured to form a 1.70 μm thick anti-corrosion layer on one side, resulting in an aluminum foil sample with anti-corrosion coatings on both surfaces. The cured anti-corrosion layer contained 3 wt% graphene.

[0133] Referring to Example 1, acrylic resin coating was applied to the surfaces of the upper and lower anti-corrosion layers of the aluminum foil sample, and cured to form a hydrophilic layer with a single-sided coating thickness of about 0.25 μm, thus obtaining the coated aluminum foil of this example.

[0134] Example 6

[0135] 3 wt% graphene was added to an amide-modified acrylic resin coating, and the mixture yielded an acrylic resin coating containing graphene. The graphene flakes had a diameter of 1–3 μm and consisted of 1–3 layers. This graphene-containing acrylic resin coating was applied to both the upper and lower surfaces of an aluminum foil substrate and cured to form a 1.41 μm thick anti-corrosion layer on one side, resulting in an aluminum foil sample with anti-corrosion coatings on both surfaces. The cured anti-corrosion layer contained 9 wt% graphene.

[0136] Referring to Example 1, acrylic resin coating was applied to the surfaces of the upper and lower anti-corrosion layers of the aluminum foil sample, and cured to form a hydrophilic layer with a single-sided coating thickness of about 0.25 μm, thus obtaining the coated aluminum foil of this example.

[0137] Example 7

[0138] 4 wt% graphene was added to an amide-modified acrylic resin coating, and the mixture yielded an acrylic resin coating containing graphene. The graphene flakes had a diameter of 1–3 μm and consisted of 3–10 layers. This graphene-containing acrylic resin coating was coated on both the upper and lower surfaces of an aluminum foil substrate and cured to form a 1.37 μm thick anti-corrosion layer on one side, resulting in an aluminum foil sample with anti-corrosion coatings on both surfaces. The cured anti-corrosion layer contained 12 wt% graphene.

[0139] Referring to Example 1, acrylic resin coating was applied to the surfaces of the upper and lower anti-corrosion layers of the aluminum foil sample, and cured to form a hydrophilic layer with a single-sided coating thickness of about 0.25 μm, thus obtaining the coated aluminum foil of this example.

[0140] Example 8

[0141] 3 wt% graphene was added to an amide-modified acrylic resin coating, and the mixture yielded an acrylic resin coating containing graphene. The graphene flakes had a diameter of 3–8 μm and consisted of 1–3 layers. This graphene-containing acrylic resin coating was coated on both the upper and lower surfaces of an aluminum foil substrate and cured to form a 1.43 μm thick anti-corrosion layer on one side, resulting in an aluminum foil sample with anti-corrosion coatings on both surfaces. The cured anti-corrosion layer contained 9 wt% graphene.

[0142] Referring to Example 1, acrylic resin coating was applied to the surfaces of the upper and lower anti-corrosion layers of the aluminum foil sample, and cured to form a hydrophilic layer with a single-sided coating thickness of about 0.25 μm, thus obtaining the coated aluminum foil of this example.

[0143] Example 9

[0144] 1 wt% graphene was added to an amide-modified acrylic resin coating, and the mixture yielded an acrylic resin coating containing graphene. The graphene flakes had a diameter of 9–12 μm and consisted of 3–10 layers. This graphene-containing acrylic resin coating was applied to both the upper and lower surfaces of an aluminum foil substrate and cured to form a 1.48 μm thick anti-corrosion layer on one side, resulting in an aluminum foil sample with anti-corrosion coatings on both surfaces. The cured anti-corrosion layer contained 3 wt% graphene.

[0145] Referring to Example 1, acrylic resin coating was applied to the surfaces of the upper and lower anti-corrosion layers of the aluminum foil sample, and cured to form a hydrophilic layer with a single-sided coating thickness of about 0.25 μm, thus obtaining the coated aluminum foil of this example.

[0146] Comparative Example 1

[0147] This comparative example is an aluminum foil sample with a common base coating. The common coating conforms to model P11 in YS / T 95.2-2016 "Aluminum Foil for Air Conditioner Heat Sinks Part 2: Coated Aluminum Foil", and is a water-based acrylic system coating. In this example, the thickness of the base coating (common coating) on ​​one side is 1.35 μm, and the hydrophilic layer of the top coating is the same as in Example 1. The anti-corrosion layer of the base coating is mainly formed by coating and curing a thermosetting acrylic emulsion.

[0148] Comparative Example 2

[0149] This comparative example is an aluminum foil sample with a high-corrosion-resistant base coating. The high-corrosion-resistant coating conforms to model P31 in YS / T 95.2-2016 "Aluminum Foil for Air Conditioner Heat Sinks Part 2: Coated Aluminum Foil", and is an epoxy system coating. In this example, the thickness of the base coating (high-corrosion-resistant coating) on ​​one side is 1.89 μm, and the hydrophilic layer of the top coating is the same as in Example 1. The base coating's anti-corrosion layer is mainly formed by coating and curing epoxy resin.

[0150] Table 1 shows a comparison of the coated aluminum foil schemes in Examples 1-9 and Comparative Examples 1-2.

[0151] Table 1 Comparison of Aluminum Foil Coating Schemes in Examples 1-9 and Comparative Examples 1-2

[0152] The structures of the coated aluminum foil samples prepared in Examples 1-9 and Comparative Examples 1-2 are shown in Figure 4. In all cases, an anti-corrosion layer is applied as a base coat and a hydrophilic layer is applied as a top coat on the upper and lower surfaces of the aluminum foil substrate in the thickness direction, thereby forming a double-layer coating structure.

[0153] The coated aluminum foil samples prepared in the examples and comparative examples will be subjected to thermal conductivity tests, alkali resistance tests, salt spray tests, weather resistance tests, and long-term operation tests, respectively.

[0154] I. Thermal conductivity test

[0155] Thermal conductivity of coated aluminum foil was tested according to ASTM E1461-13, "Standard Test Method for Thermal Diffusivity by the Flash Method Test".

[0156] The thermal diffusivity of the coated aluminum foils of Examples 1-9 and Comparative Examples 1-2 in the vertical (thickness) direction at 50°C is shown in Table 2.

[0157] Table 2 Thermal diffusivity of coated aluminum foil in the vertical direction

[0158] Figure 7 shows the thermal diffusivity of the coated aluminum foil sample in the vertical direction at 50°C. Ordinary aluminum foil is the sample of Comparative Example 1, high corrosion resistant aluminum foil is the sample of Comparative Example 2, and graphene aluminum foil is the sample of Example 1. The longitudinal thermal diffusivity is the thermal diffusivity in the vertical direction.

[0159] As can be seen from Table 2 and Figure 7, the graphene aluminum foils of Examples 1-9 exhibit improved thermal conductivity compared to the ordinary aluminum foil and high-corrosion-resistant aluminum foil in the comparative examples, thus contributing to improved overall performance of heat exchangers or air conditioners. Among these, Examples 1-4 show the most significant improvement in thermal conductivity, resulting in better heat exchange efficiency for the heat exchangers or air conditioners. Examples 5 (with a thicker cured anti-corrosion layer), Examples 6-8 (with a higher graphene content in the cured anti-corrosion layer), and Example 9 (with a larger graphene sheet diameter) show less improvement in thermal conductivity than Examples 1-4.

[0160] II. Alkali Resistance Test

[0161] According to Section 5.2.3 of T / CAS 734-2023 "Technical Specification for Long-lasting Weather-resistant and Corrosion-resistant Coated Aluminum Foil for Air Conditioner Heatsinks", the coated aluminum foil samples were tested for alkali resistance in 100g / L NaOH solution, with the test temperature being 20℃±2℃ and the test time being 1 hour.

[0162] Figure 8 shows the overall weight loss percentage of the coated aluminum foil samples in the alkali resistance test. As can be seen from Figure 8, in the alkali resistance test of the ordinary coating in Comparative Example 1, 32.00% of the coatings had a weight loss rate >10%, 52.00% had a weight loss rate of 6%–10%, and 16.00% had a weight loss rate <6%. In contrast, the graphene coating in Example 1 had an overall weight loss rate <6% of 100.00%, which is comparable to the alkali resistance test results of the high-corrosion-resistant coating in Comparative Example 2, demonstrating significantly better alkali corrosion resistance than the ordinary coating samples.

[0163] III. Salt spray test

[0164] According to Sections 5.2.2 and 5.2.3 of GB / T 10125-2021 "Artificial Atmosphere Corrosion Test - Salt Spray Test", the coated aluminum foil was subjected to neutral salt spray test and acetic acid salt spray test respectively.

[0165] The coated aluminum foils of Examples 1-9 and Comparative Examples 1-2 were subjected to acetic acid salt spray tests for 24h, 72h, and 96h, respectively. The corrosion rating results of the acetic acid salt spray tests are shown in Table 3.

[0166] Table 3 Corrosion ratings of coated samples after acetic acid salt spray tests at different times

[0167] Figure 9 shows the corrosion ratings of the coated aluminum foil samples after acetic acid salt spray tests at different times. Figure 9 illustrates the corrosion ratings of the ordinary coated sample in Comparative Example 1, the high-corrosion-resistant coated sample in Comparative Example 2, and the graphene coated sample in Example 1 after 24h, 72h, and 96h acetic acid salt spray tests. Specifically, the corrosion ratings of the ordinary coated sample after 24h, 72h, and 96h acetic acid salt spray tests were 9.8, 9, and 8, respectively; the corrosion ratings of the high-corrosion-resistant coated sample after 24h, 72h, and 96h acetic acid salt spray tests were 9.8, 9.8, and 9, respectively; and the corrosion ratings of the graphene coated sample after 24h, 72h, and 96h acetic acid salt spray tests were 9.8, 9.8, and 9, respectively.

[0168] The coated aluminum foils of Examples 1-9 and Comparative Examples 1-2 were subjected to a 1500-hour neutral salt spray test, and the corrosion rating of the samples is shown in Table 4.

[0169] Table 4. Coating corrosion rating after neutral salt spray test

[0170] Combining the test results in Tables 3-4 and Figure 9, it can be seen that the graphene coating samples of Examples 1-5 exhibited acid and neutral salt spray resistance comparable to the high-corrosion-resistant coating samples, and significantly better than ordinary coating samples of the same thickness. However, the corrosion ratings of Examples 6-8 (with higher graphene content in the cured anticorrosion layer) and Example 9 (with larger graphene flake diameter) in acetic acid salt spray and neutral salt spray tests showed no significant improvement compared to the ordinary coating sample of Comparative Example 1.

[0171] IV. Weather Resistance Test

[0172] The weather resistance test was conducted in accordance with Section 5.3 of the standard T / CAS 734-2023 "Technical Specification for Long-lasting Weather-resistant and Corrosion-resistant Coated Aluminum Foil for Air Conditioner Heatsinks". The test was performed under the conditions of 120h UVB (ultraviolet light irradiation) + 72h NSS (neutral salt spray) after aging.

[0173] The coated aluminum foils of Examples 1-9 and Comparative Examples 1-2 were subjected to weathering resistance tests, and the test results are shown in Table 5. Table 5 shows the proportion of coated aluminum foils in different corrosion ratings.

[0174] Table 5 Weather resistance test results of coated aluminum foil samples

[0175] Figure 10 is a weather resistance rating chart for the coated aluminum foil samples. Figure 10 shows the corrosion rating percentages of the ordinary coated aluminum foil sample in Comparative Example 1, the high-corrosion-resistant coated aluminum foil sample in Comparative Example 2, and the graphene-coated aluminum foil sample in Example 1. As can be seen from Figure 10, after aging and salt spray testing, in Comparative Example 1, 62.00% of the ordinary coated aluminum foil samples were rated as level 6, 38.00% were rated as level 7, and none were rated as level 8 or 9; in Comparative Example 2, 78.00% of the high-corrosion-resistant coated aluminum foil samples were rated as level 6, 22.00% were rated as level 7, and none were rated as level 8 or 9; in Example 1, 4.00% of the graphene-coated aluminum foil samples were rated as level 7, 20.00% were rated as level 8, 76.00% were rated as level 9, and none were rated as level 6.

[0176] As shown in Figure 10 and Table 5, the salt spray test results after aging indicate that the graphene-coated aluminum foil samples of Examples 1-5 have higher ratings and better corrosion resistance than the ordinary aluminum foil and high-corrosion-resistant aluminum foil in the comparative examples, demonstrating excellent weather resistance. However, the weather resistance corrosion ratings of Examples 6-8, which have higher graphene content in the cured anti-corrosion layer, and Example 9, which has larger graphene flake diameter, are not significantly improved compared to the ordinary coated aluminum foil samples.

[0177] V. Long-term operation test

[0178] The coated aluminum foils of Examples 1-9 and Comparative Examples 1-2 were used as fins to make outdoor unit heat exchangers, which were then used to make air conditioning unit prototypes. They were operated in Hainan for a long time to compare and test power consumption and cooling effect.

[0179] The long-haul test method is described below: The environmental adaptability test site for the air conditioning unit is located in Lingao County, Hainan Province. Lingao County is located at 19°34′~20°02′ north latitude and 109°03′~109°53′ east longitude. Lingao County has a tropical monsoon climate, with high temperatures and abundant rainfall, ample sunshine, an average altitude of 306 meters, an average air pressure of 1011.3 hPa, an average annual temperature of 23 to 24℃, an average January temperature of 16.9℃, an average July temperature of 28.3℃, an average relative humidity of 87%, an average of 135.9 rainy days per year, an average rainfall of 1417.8 mm, and an annual total radiation of 5001 MJ / m². 2 The total annual sunshine duration is 2175 hours, the total annual precipitation is 1417.8 mm, and the sea salt particle concentration (gauze method) is 0.107 mg / 100 cm³. 2•d. The Lingao Test Station, a tropical marine climate adaptability testing site for refrigeration products in Lingao County, Hainan Province, is approximately 100 meters from the sea. Following Q / CVC 0035-2020 "General Test Methods for Engineering Sites," the indoor unit of the air conditioning unit was installed in a room, with the outdoor unit facing the ocean. The air conditioning unit was operated in cooling mode for 8 hours daily (9:00 AM to 5:00 PM). Real-time data recordings were made of the unit's power, supply and return air temperature and humidity, and room temperature and humidity, with one set of data recorded every minute.

[0180] The long-term performance test results of the heat exchanger prototypes in Examples 1-9 and Comparative Examples 1-2 are shown in Table 6. Table 6 shows the energy consumption comparison results of different heat exchanger prototypes.

[0181] Table 6 shows the long-term performance test results of the heat exchanger prototypes from Examples 1-9 and Comparative Examples 1-2.

[0182] Figure 11 is a comparison of the performance of the two types of heat exchanger prototypes after the air conditioning unit has been installed for 9 months. Figure 11 shows the energy consumption per unit temperature difference between the graphene-coated heat exchanger prototype and the ordinary-coated heat exchanger prototype. Compared with the prototype using the ordinary-coated heat exchanger of Comparative Example 1, the energy consumption per unit temperature difference of the prototype using the graphene-coated heat exchanger of Example 1 is reduced by approximately 37.8%.

[0183] As can be seen from Table 6 and Figure 11, the prototypes of the graphene-coated heat exchangers in Examples 1-4 of this application have relatively lower energy consumption per unit temperature difference. During long-term operation, their improved corrosion resistance results in slower performance degradation of the entire air conditioning unit, ultimately achieving long-term energy savings. In contrast, the prototypes prepared in Examples 5-9 have relatively higher energy consumption per unit temperature difference, and the comparative prototypes show no significant improvement and do not effectively save energy.

[0184] In summary, the metal matrix composite material embodiments of this application employ a coating containing graphene and / or its derivatives as an anti-corrosion layer. This reduces the impact on thermal conductivity while meeting long-term anti-corrosion requirements, and exhibits good aging resistance. It can be processed and prepared under existing production equipment conditions. Specifically, in the metal matrix composite material embodiments of this application, the graphene and / or its derivatives have a sheet diameter of 1 micrometer to 8 micrometers, and the content of graphene and / or its derivatives in the cured anti-corrosion layer is 0.5 wt% to 4.5 wt%. This allows for high thermal conductivity, corrosion resistance, and high weather resistance even with an anti-corrosion coating thickness as thin as 0.8 to 1.5 micrometers. In embodiments where the anti-corrosion coating thickness, the sheet diameter of graphene and / or its derivatives, or the content of graphene and / or its derivatives in the cured anti-corrosion layer exceeds the above ranges, the thermal conductivity is poor, and the improvement in corrosion resistance and high weather resistance compared to the comparative embodiment using a conventional primer is not significant or even worse. It is evident that graphene and / or its derivatives, when used with specific sheet diameters and contents, combined with specific thicknesses of the anti-corrosion layer, can work synergistically to achieve optimal results. This allows fins and heat exchangers made of metal matrix composites to possess the advantages of high weather resistance, high thermal conductivity, and corrosion resistance. When applied to air handling devices such as air conditioners and dehumidifiers, they can significantly improve the reliability, service life, and energy efficiency of these devices, thereby enhancing their overall performance.

[0185] In the description of this specification, the references to terms such as "some embodiments," "some specific embodiments," "some examples," or "some specific examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0186] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. Metal-based composite materials, including a metal substrate and a functional coating, wherein: The functional coating is disposed on at least one surface of the metal substrate; The functional coating includes at least an anti-corrosion layer; The anti-corrosion layer includes an organic coating containing graphene and / or its derivatives; The thickness of the cured anti-corrosion layer is 0.8 micrometers to 1.5 micrometers; The graphene and / or its derivatives have a sheet diameter of 1 micrometer to 8 micrometers; The content of the graphene and / or its derivatives in the cured anti-corrosion layer is 0.5 wt% to 4.5 wt%; and The metal matrix composite material has a thermal diffusivity ≥28 mm in the vertical direction. 2 / s.

2. The metal matrix composite material according to claim 1, wherein, The number of layers of the graphene and / or its derivatives is 1 to 10.

3. The metal matrix composite material according to claim 1 or 2, wherein, The maximum sheet diameter of the graphene and / or its derivatives is ≤ 5 times the thickness of the anti-corrosion layer.

4. The metal matrix composite material according to any one of claims 1 to 3, wherein, The graphene and / or its derivatives have a sheet diameter of 1 micrometer to 3 micrometers.

5. The metal matrix composite material according to any one of claims 1 to 4, wherein, The thermal diffusivity of the metal matrix composite material in the vertical direction is 28 mm. 2 / s~40mm 2 / s.

6. The metal matrix composite material according to any one of claims 1 to 5, wherein, The thermal diffusivity was measured at 50°C.

7. The metal matrix composite material according to any one of claims 1 to 6, wherein, In the organic coating that forms the anti-corrosion layer, the graphene and / or its derivatives constitute 0.5% to 2% by mass.

8. The metal matrix composite material according to any one of claims 1 to 7, wherein, The anti-corrosion layer is mainly composed of an amide-modified acrylic resin coating or an epoxy-modified acrylic resin coating, wherein the amide-modified acrylic resin coating or the epoxy-modified acrylic resin coating contains graphene and / or its derivatives.

9. The metal matrix composite material according to any one of claims 1 to 8, wherein, The overall weight loss rate of the metal matrix composite material in the alkali resistance test is less than 6%; the alkali resistance test refers to testing the metal matrix composite material in a 100g / L sodium hydroxide solution at a test temperature of 20℃±2℃ for 1 hour.

10. The metal matrix composite material according to any one of claims 1 to 9, wherein, The corrosion area of ​​the metal matrix composite material is ≤0.02% after 1500 hours of neutral salt spray testing.

11. The metal matrix composite material according to any one of claims 1 to 10, wherein, The weather resistance test of the metal matrix composite material has a corrosion area rating of ≥8; the weather resistance test refers to subjecting the metal matrix composite material to 120 hours of ultraviolet light irradiation and 72 hours of neutral salt spray test in sequence.

12. The metal matrix composite material according to any one of claims 1 to 11, wherein, The metal substrate has a functional coating on both surfaces opposite each other in the thickness direction, and the functional coating includes an anti-corrosion layer.

13. The metal matrix composite material according to any one of claims 1 to 12, wherein, The functional coating further includes a hydrophilic layer disposed on the surface of the anti-corrosion layer away from the metal substrate.

14. The metal matrix composite material according to any one of claims 1 to 13, wherein, The functional coating also includes: A hydrophilic layer, wherein the hydrophilic layer is disposed on the surface of the anti-corrosion layer away from the metal substrate; and A lubricating layer is disposed on the surface of the hydrophilic layer away from the metal substrate.

15. The metal matrix composite material according to any one of claims 1 to 14, wherein, The metal substrate includes aluminum, copper, iron, or alloys thereof.

16. A method for preparing a metal matrix composite material according to any one of claims 1 to 15, comprising the following steps: A coating is applied to at least one surface of a metal substrate to form a functional coating, thereby obtaining the metal-based composite material.

17. A fin having a thickness of 0.05 mm to 0.12 mm, comprising a metal matrix composite material according to any one of claims 1 to 15, or a metal matrix composite material obtained by the preparation method according to claim 16.

18. A heat exchanger comprising the fins of claim 17.

19. An air treatment apparatus comprising the metal matrix composite material according to any one of claims 1 to 15, or the metal matrix composite material obtained by the preparation method according to claim 16, or the fins according to claim 17, or the heat exchanger according to claim 18.

20. The air handling device according to claim 19 is an air conditioner or a dehumidifier.

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