Metal-organic framework modified lubricating material, its preparation method, and solid lubricating coating

Abstract

The present disclosure relates to a metal-organic framework modified lubricating material, a preparation method thereof, and a solid lubricating coating, and relates to the technical field of lubricating coatings. The lubricating material includes a first metal-organic framework layer, a two-dimensional layered material layer, and a second metal-organic framework layer that are sequentially stacked; the two-dimensional layered material layer includes a two-dimensional layered material; both the first metal-organic framework layer and the second metal-organic framework layer include a plurality of spherical metal-organic framework materials, and the spherical metal-organic framework materials are all formed on the surface of the two-dimensional layered material layer. During the application process of the metal-organic framework modified lubricating material provided by the present disclosure, the friction coefficient can be significantly reduced, and the service life of the prepared lubricating coating can be improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of lubricating coatings, and in particular, to a metal-organic framework modified lubricating material, a preparation method thereof, and a solid lubricating coating. Background Art

[0002] Friction and wear are the main causes of material failure and mechanical property degradation. According to statistics, about 30% of the world's energy consumption is consumed in friction. Therefore, reducing friction and wear is of great significance for improving the performance and reliability of mechanical equipment. However, traditional lubricating oil and grease systems have certain disadvantages in terms of lubrication failure, environmental adaptability, volatilization, pollution, and performance limitations, and it is difficult to maintain stable lubricating performance under certain special working conditions (such as high temperature, high pressure, strong corrosion, etc.). For example, in the aerospace field, components such as high / low temperature, dry / wet, strongly irradiated, and atmospheric / vacuum alternating extreme environments exist in high-temperature and high-speed bearings, gears, chains, pistons, piston rings, etc. of aerospace vehicles, launch vehicles, and aircraft. These environments pose extremely high requirements on lubricating materials. In the field of mechanical manufacturing, the lubrication of various mechanical components, such as fasteners like bolts, nuts, screws, lead screws, spline shafts, washers, etc., serving under harsh friction conditions such as high temperature, high load, and high speed, all require lubricants with high stability, good lubrication effect, and strong wear resistance. In addition, due to friction heat generation, the contact surface temperature of many sliding components with complex and variable working conditions, as well as components such as automotive engine bearings, pistons, latches, pins, etc., rises significantly, making the wear resistance of traditional lubricating greases decrease and it difficult to achieve an ideal lubrication effect.

[0003] Solid lubricating coatings can significantly reduce the friction coefficient and wear rate, thereby improving the performance and reliability of mechanical equipment. Applying solid lubricating coatings to key components such as engines, transmissions, and bearings can effectively reduce friction and wear, extend the service life of equipment, and reduce maintenance costs. In addition, solid lubricating coatings also have self-lubricating properties and can provide lubrication without an external lubrication source, further improving the reliability and stability of equipment. At the same time, compared with traditional liquid lubricants, solid lubricating coatings have a lower degree of pollution and effectively reduce energy consumption. Therefore, the research and development of new solid lubricating coatings with excellent lubricating performance, high temperature resistance, wear resistance, etc. has become a current research hotspot.

[0004] It should be noted that the information disclosed in the above background art section is only used to enhance the understanding of the background of the present disclosure, and thus may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Invention

[0005] The purpose of the present disclosure is to overcome the deficiencies of the above-mentioned prior art, and to provide a metal-organic framework modified lubricating material, a preparation method thereof, and a solid lubricating coating. By using a metal-organic framework material to modify a two-dimensional layered material, the sliding friction during the friction process is changed into rolling friction, and the friction coefficient is greatly reduced.

[0006] According to one aspect of the present disclosure, there is provided a metal-organic framework modified lubricating material, including a first metal-organic framework layer, a two-dimensional layered material layer, and a second metal-organic framework layer that are sequentially stacked;

[0007] The two-dimensional layered material layer includes a two-dimensional layered material;

[0008] Both the first metal-organic framework layer and the second metal-organic framework layer include a plurality of spherical metal-organic framework materials, and the spherical metal-organic framework materials are all formed on the surface of the two-dimensional layered material layer.

[0009] In an exemplary embodiment of the present disclosure, the length dimension of the two-dimensional layered material is 3 to 5 μm;

[0010] The particle size of the spherical metal-organic framework material is 200 to 500 nm.

[0011] According to another aspect of the present disclosure, there is provided a preparation method of the above-mentioned metal-organic framework modified lubricating material, including the following steps:

[0012] S10. Dispersing the two-dimensional layered material into an ethanol solution of a silane coupling agent for modification to obtain a modified two-dimensional layered material;

[0013] Wherein, the mass ratio of the two-dimensional layered material to the silane coupling agent is (10 to 20):1;

[0014] S20. Mixing the modified two-dimensional layered material obtained in step S10 with nitrate and N,N-dimethylformamide to obtain a first mixed solution;

[0015] Wherein, the molar ratio of the two-dimensional layered material to the nitrate is 10:(1 to 1.5);

[0016] S30. Adding N,N-dimethylformamide containing an organic ligand to the first mixed solution to obtain a second mixed solution;

[0017] Wherein, the molar ratio of the organic ligand to the nitrate is (1 to 2):1;

[0018] S40. After reacting the second mixed solution at 120 to 180 °C for 12 to 24 h, filtering and drying to obtain the metal-organic framework modified lubricating material.

[0019] In an exemplary embodiment of the present disclosure, in step S20, the nitrate is at least one of nickel nitrate hexahydrate, cobalt nitrate hexahydrate, and copper nitrate trihydrate;

[0020] In step S30, the organic ligand is at least one of 3-indolecarboxylic acid and 1,3,5-benzenetricarboxylic acid.

[0021] In an exemplary embodiment of the present disclosure, in step S10, in the ethanol solution of the silane coupling agent, the mass percentage of the silane coupling agent is 2-5%;

[0022] The silane coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570.

[0023] In an exemplary embodiment of the present disclosure, in step S10, the two-dimensional layered material is at least one of molybdenum disulfide, tungsten disulfide, and graphene;

[0024] The length dimension of the two-dimensional layered material is 3-5 μm.

[0025] In an exemplary embodiment of the present disclosure, in step S10, the two-dimensional layered material is tungsten disulfide, and the silane coupling agent is silane coupling agent KH550; the mass ratio of tungsten disulfide to silane coupling agent KH550 is 16.7:1;

[0026] In step S20, the nitrate is nickel nitrate hexahydrate; the molar ratio of tungsten disulfide to nickel nitrate hexahydrate is 10:1.4;

[0027] In step S30, the organic ligand is 3-indolecarboxylic acid, and the molar ratio of 3-indolecarboxylic acid to nickel nitrate hexahydrate is 2:1.

[0028] According to another aspect of the present disclosure, there is provided a solid lubricating coating. By weight, the solid lubricating coating includes 15-25 parts of a composite binder, 3-5 parts of an auxiliary agent, 35-50 parts of a solvent, and 20-35 parts of a metal-organic framework modified lubricating material prepared by the above preparation method;

[0029] The composite binder includes an acrylic acid modified epoxy resin and a polyimide resin;

[0030] The auxiliary agent includes one or more of a dispersant, an antifoaming agent, a leveling agent, and a sediment prevention agent.

[0031] In an exemplary embodiment of the present disclosure, in the composite binder, the mass ratio of the acrylic acid modified epoxy resin to the polyimide resin is 2:(1-1.5).

[0032] In an exemplary embodiment of the present disclosure, it further includes wear-resistant fillers;

[0033] The wear-resistant filler is fibrous calcium sulfate, and the whisker length of the fibrous calcium sulfate is 5-8 μm, and the whisker diameter is 0.5-2 μm.

[0034] In the present disclosure, a spherical metal-organic framework material is used to modify a two-dimensional layered material, so that a metal-organic framework modified lubricating material has a sandwich-like layered structure of a first metal-organic framework layer / a two-dimensional layered material layer / a second metal-organic framework layer. Thus, the spherical metal-organic framework material in the metal-organic framework layer can change the sliding friction during the friction process into rolling friction, significantly reducing the friction coefficient.

[0035] Using the metal-organic framework modified lubricating material, supplemented with a composite binder, additives, etc. to prepare a solid lubricating coating can significantly reduce the friction coefficient during the friction process. The test results of the examples show that using the solid lubricating coating provided by the present disclosure to prepare a solid lubricating coating on the surface of bearing steel GCr15, the average friction coefficient is reduced to 0.054-0.057, and the comprehensive friction coefficient is reduced by 60%.

[0036] The nano-particle metal framework material worn during the friction process can be filled into the micro-defects formed on the friction surface to repair the friction surface, further increasing the lubrication effect and reducing the wear amount. The solid lubricating coating provided by the present disclosure has high heat resistance, thereby improving the lubrication performance under extreme conditions such as high temperature and high pressure. The test results of the examples show that the mass wear amount of the solid lubricating coating is only about 12 mg, and the heat resistance reaches 450 °C.

[0037] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The drawings here are incorporated into the specification and constitute a part of this specification, showing embodiments consistent with the present disclosure, and are used together with the specification to explain the principles of the present disclosure. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and those of ordinary skill in the art can obtain other drawings based on these drawings without creative efforts.

[0039] Figure 1 It is a schematic structural diagram of a metal-organic framework modified lubricating material in an embodiment of the present disclosure.

[0040] Figure 2 It is a schematic process diagram of preparing a metal-organic framework modified lubricating material in an embodiment of the present disclosure.

[0041] Figure 3SEM imaging diagram of the solid lubricating coating formed by the solid lubricating coating prepared in Example 1 of the present disclosure.

[0042] Figure 4 SEM imaging diagram of the solid lubricating coating formed by the solid lubricating coating prepared in Example 2 of the present disclosure.

[0043] Figure 5 Schematic diagram of the friction coefficient test results of the solid lubricating coating formed by the solid lubricating coating prepared in Example 1 of the present disclosure.

[0044] Figure 6 Schematic diagram of the friction coefficient test results of the solid lubricating coating formed by the solid lubricating coating prepared in Example 2 of the present disclosure.

[0045] Figure 7 Schematic diagram of the friction coefficient test results of the solid lubricating coating formed by the solid lubricating coating prepared in Comparative Example 1 of the present disclosure.

[0046] The reference numerals are as follows:

[0047] 10. The first metal-organic framework layer; 20. The two-dimensional layered material layer; 30. The second metal-organic framework layer. Detailed implementation manners

[0048] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the example embodiments to those skilled in the art. Like reference numerals in the figures denote the same or similar structures, and thus their detailed descriptions will be omitted. In addition, the drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale.

[0049] The terms "a", "an", "the", "said" and "at least one" are used to denote the presence of one or more elements / components / etc.; the terms "comprising" and "having" are used to mean an open inclusion and mean that there may be additional elements / components / etc. in addition to the listed elements / components / etc.; the terms "first", "second", etc. are only used as labels and are not a limitation on the quantity of their objects.

[0050] The term "two-dimensional layered material" refers to a crystalline material composed of an ordered stack of single-layer or a few atomic-thickness structural units, with characteristics such as ultra-thin, large surface area, and quantum size effect. The thickness of two-dimensional layered materials is usually between a few nanometers and hundreds of nanometers, and may even reach dozens of nanometers to hundreds of nanometers. The basic structure of two-dimensional layered materials includes two extended planes, in which atoms are arranged in a direction parallel to the surface of the material; the atoms within the layer are bonded by strong covalent bonds, while the layers interact with each other through weak van der Waals forces. Two-dimensional layered materials can overlap with each other in three-dimensional space to form various structural forms, such as single-layer sheets, double-layer sheets, multi-layer sheets, etc.

[0051] Embodiments of the present disclosure provide a metal-organic framework modified lubricating material, as Figure 1 shown, including a first metal-organic framework layer 10, a two-dimensional layered material layer 20, and a second metal-organic framework layer 30 that are stacked in sequence. The two-dimensional layered material layer 20 includes two-dimensional layered materials; both the first metal-organic framework layer 10 and the second metal-organic framework layer 30 include a plurality of spherical metal-organic framework materials, and the spherical metal-organic framework materials are all formed on the surface of the two-dimensional layered material layer 20.

[0052] Metal-organic framework materials (MOFs) are nanoporous materials composed of metal clusters / ions and organic ligands. The diversity of the types and coordination modes of metal elements and organic ligands in MOFs determines that MOFs have rich structures and functionalities. The inorganic-organic hybrid nature of MOFs can fill the blank area between inorganic materials and organic materials in terms of mechanical properties, and can integrate the advantages of inorganic materials and organic materials, spanning traditional "soft" materials and "hard" materials. The metal-organic framework modified lubricating material provided in this embodiment is that metal-organic framework layers are respectively formed on two extended planes of the two-dimensional layered material; the metal-organic framework layer is a layer of spherical metal-organic framework materials. Thus, when the metal-organic framework modified lubricating material is applied, multiple Figure 1 such stacked structures, based on the "ball bearing" effect of the spherical metal-organic framework materials, make the sliding friction transform into rolling friction, which can greatly reduce the friction coefficient. At the same time, the spherical metal-organic framework materials can also fill the worn areas and repair the worn surfaces, further improving the lubrication effect. Therefore, the metal-organic framework modified lubricating material provided in this embodiment can effectively reduce the friction coefficient, reduce wear, and thus extend the service life of the device and reduce the maintenance cost.

[0053] In one example, the length dimension of the two-dimensional layered material is 3 to 5 μm. In this embodiment, the spherical metal-organic framework material at the overlapping contact position of the metal-organic framework modified lubricating material can reduce the friction coefficient through rolling friction. Thus, if the length of the two-dimensional layered material is too large or too small, it will affect the uniform distribution of the spherical metal-organic framework material in the metal-organic framework layer. For example, if the length of the two-dimensional layered material is too small, the area of the overlapping contact position of the metal-organic framework modified lubricating material will decrease, which may lead to the inability to form more effective rolling friction, thereby affecting the friction coefficient and reducing the lubrication performance.

[0054] In one example, the particle size of the spherical metal-organic framework material is 200 to 500 nm. In the metal-organic framework modified lubricating material, the smaller the particle size of the spherical metal-organic framework material, the smaller the friction coefficient generated by rolling friction, thereby improving the lubricity of the metal-organic framework modified lubricating material. At the same time, the spherical metal-organic framework material with a small particle size is more conducive to filling and repairing the worn surface.

[0055] The embodiment of the present disclosure also provides a preparation method of the above metal-organic framework modified lubricating material, as Figure 2 shown, the method includes the following steps:

[0056] S10. Dispersing the two-dimensional layered material into an ethanol solution of a silane coupling agent for modification to obtain a modified two-dimensional layered material. Wherein, the mass ratio of the two-dimensional layered material to the silane coupling agent is (10 to 20):1.

[0057] S20. Mixing the modified two-dimensional layered material obtained in step S10 with nitrate and N,N-dimethylformamide to obtain a first mixed solution. Wherein, the molar ratio of the two-dimensional layered material to the nitrate is 10:(1 to 1.5).

[0058] S30. Adding N,N-dimethylformamide containing an organic ligand to the first mixed solution to obtain a second mixed solution. Wherein, the molar ratio of the organic ligand to the nitrate is (1 to 2):1.

[0059] S40. After reacting the second mixed solution at 120 to 180 °C for 12 to 24 h, filtering and drying to obtain the metal-organic framework modified lubricating material.

[0060] In the preparation method provided by this embodiment, the surface of the two-dimensional layered material is modified with a silane coupling agent, and then nitrate and an organic ligand are added. The spherical metal-organic framework material is prepared by a solvothermal method, and the spherical metal-organic framework material is in-situ grown on the surface of the two-dimensional layered material to form a metal-organic framework layer, thereby forming a sandwich structure of metal-organic framework layer / two-dimensional layered material layer / metal-organic framework layer. That is, as Figure 1As shown, the spherical metal-organic framework material is in-situ grown on the surface of the two-dimensional layered material through the auxiliary modification of a silane coupling agent, and metal-organic framework layers with a layer of spherical metal-organic framework material are formed on both extended surfaces of the two-dimensional layer material. In this way, the "ball bearing" effect of the metal-organic framework modified lubricating material during the friction process can be utilized to transform sliding friction into rolling friction, significantly reducing the friction coefficient. At the same time, during the friction process, after the spherical metal-organic framework layer wears, the exfoliated spherical metal-organic framework material can also fill and repair the micro-defects on the friction surface, further reducing the friction coefficient of the friction surface, realizing the synergistic effect of enhancing lubrication performance and improving self-repairability, reducing environmental pollution, reducing energy consumption, and significantly improving the lubrication performance of the metal-organic framework modified lubricating material under extreme conditions such as high temperature and high pressure.

[0061] In this embodiment, a silane coupling agent is used to assist in modifying the two-dimensional layered material. The silane coupling agent forms a bond between the surface of the two-dimensional layered material and the spherical metal-organic framework material through hydrolysis, enabling the formation of spherical metal-organic framework materials with uniform size and suitable distribution on the surface of the two-dimensional layered material, thereby improving the lubrication performance of the metal-organic framework modified lubricating material.

[0062] In this embodiment, the mass ratio of the two-dimensional layered material to the silane coupling agent is in the range of (10~20):1. The silane coupling agent can uniformly modify the two-dimensional layered material, which is beneficial to the formation of uniform spherical metal-organic framework materials on the surface of the two-dimensional layered material. If the addition amount of the two-dimensional layered material is too small and the concentration of the silane coupling agent is too high, it is easy for the silane coupling agent to agglomerate, which is not conducive to the formation of spherical metal-organic framework materials on the surface of the two-dimensional layered material. If the addition amount of the two-dimensional layered material is too large, the concentration of the silane coupling agent decreases, and the modification of the two-dimensional layered material is incomplete, reducing the formation of spherical metal-organic framework materials on the surface of the two-dimensional layered material, resulting in a reduction in the spherical structure for realizing sliding friction and a decrease in lubrication performance.

[0063] Exemplarily, the mass ratio of the two-dimensional layered material to the silane coupling agent can be, but is not limited to, 10:1 or 11:1 or 12:1 or 14:1 or 15:1 or 16:1 or 16.7:1 or 18:1 or 20:1.

[0064] In this embodiment, by controlling the molar ratio of the organic ligand to the nitrate in the range of (1~2):1, the shape of the prepared metal-organic framework material is spherical and the size is uniform. Through the spherical metal-organic framework material, during the friction process, the sliding friction between the two-dimensional layered material and the friction surface or between adjacent two-dimensional layered materials is changed into the rolling friction of the spherical metal-organic framework material, greatly reducing the friction coefficient and improving the lubricity of the lubricant containing the metal-organic framework modified lubricating material.

[0065] Exemplarily, the molar ratio of the organic ligand to the nitrate may be, but is not limited to, 1:1 or 1.1:1 or 1.2:1 or 1.3:1 or 1.4:1 or 1.5:1 or 1.6:1 or 1.7:1 or 1.8:1 or 1.9:1 or 2:1.

[0066] In this embodiment, the molar ratio of the two-dimensional layered material to the nitrate is limited to be in the range of 10:(1 to 1.5), so as to avoid excessive or insufficient two-dimensional layered material after modification, which may affect the uniformity of the growth of the metal-organic framework material on the surface of the two-dimensional layered material, and further affect the lubricity of the prepared metal-organic framework-modified lubricating material. For example, if the molar ratio of the two-dimensional layered material is too large, the metal-organic framework material grown on the surface of the two-dimensional layered material will be unevenly distributed. For example, there will be local non-growth of spherical metal-organic framework materials on the surface of the two-dimensional layered material, thus affecting the lubrication performance; if the molar ratio of the two-dimensional layered material is too small, it may cause the metal-organic framework materials grown on the surface of the two-dimensional layered material to accumulate and stack, making it impossible to achieve good rolling friction and reducing the lubricity of the metal-organic framework-modified lubricating material.

[0067] Exemplarily, the molar ratio of the two-dimensional layered material to the nitrate may be, but is not limited to, 10:1 or 10:1.1 or 10:1.2 or 10:1.3 or 10:1.4 or 10:1.5.

[0068] Exemplarily, in step S40, the reaction conditions of the second mixed solution may be, but are not limited to, reacting at 120 °C for 16 h, or reacting at 120 °C for 20 h, or reacting at 120 °C for 24 h, or reacting at 120 °C for 12 h, or reacting at 140 °C for 18 h, or reacting at 140 °C for 16 h, or reacting at 140 °C for 22 h, or reacting at 160 °C for 12 h, or reacting at 160 °C for 18 h, or reacting at 160 °C for 20 h, or reacting at 180 °C for 12 h, or reacting at 180 °C for 18 h, or reacting at 180 °C for 22 h, or reacting at 180 °C for 24 h.

[0069] In an embodiment of the present disclosure, the mass percentage of the silane coupling agent in the ethanol solution of the silane coupling agent in step S10 is 2% to 5%. Within this mass percentage range, the silane coupling agent can better modify the surface of the two-dimensional layered material. If the mass percentage of the silane coupling agent is too small, the surface modification of the two-dimensional layered material is incomplete, and then the metal-organic framework material cannot grow well on the surface of the two-dimensional layered material in the subsequent steps. This results in a relatively low density or uneven distribution of the spherical metal-organic framework material formed on the surface of the two-dimensional layered material, reducing the lubrication performance. If the mass percentage of the silane coupling agent is too large and the concentration is too high, the silane coupling agent molecules are prone to agglomeration, hindering the further binding of other functional molecules and preventing effective modification of the two-dimensional layered material. Thus, using a silane coupling agent ethanol solution with a mass percentage of 2% to 5% can avoid the agglomeration of the silane coupling agent itself and can completely modify the surface of the two-dimensional layered material, improving the uniformity of the formed spherical metal-organic framework layer.

[0070] In an embodiment of the present disclosure, the silane coupling agent can be at least one of silane coupling agent KH550, silane coupling agent KH560, or silane coupling agent KH570. Taking silane coupling agent KH550 as an example, silane coupling agent KH550 is an amino silane, and its structural formula is as follows:

[0071]

[0072] When using amino silane to modify the two-dimensional layered material, the three alkoxy groups of the amino silane hydrolyze and bind to the surface of the two-dimensional layered material, and the amino end of the amino silane can couple with the metal ions in the metal-organic framework material to assist in the in-situ growth of the metal-organic framework material on the surface of the two-dimensional layered material.

[0073] In an embodiment of the present disclosure, in step S10, the two-dimensional layered material is one or two of molybdenum disulfide, tungsten disulfide, and graphene.

[0074] In one example, the length of the two-dimensional layered material is 3 to 5 μm. In this way, it is possible to avoid the length dimension of the two-dimensional layered material being too large or too small, which affects the rolling friction effect and thus reduces the lubricity.

[0075] In an embodiment of the present disclosure, in step S20, the nitrate is one or more of nickel nitrate hexahydrate, cobalt nitrate hexahydrate, or copper nitrate trihydrate; in step S30, the organic ligand is one or two of 3-indolecarboxylic acid and 1,3,5-benzenetricarboxylic acid. Thus, by using the solvothermal method to react the above-mentioned nitrate and the above-mentioned ligand in a molar ratio of 1:(1~2) in N,N-dimethylformamide solvent, a uniform and consistent spherical metal-organic framework material can be grown on the surface of the two-dimensional layered material under the action of a silane coupling agent. The spherical metal-organic framework material with high homogeneity and small particle size can further reduce the friction coefficient during the friction process. For example, using copper nitrate trihydrate, 1,3,5-benzenetricarboxylic acid, and the solvent N,N-dimethylformamide, spherical Cu-MOFs can be formed on the surface of the two-dimensional layered material.

[0076] In one example, in step S10, the two-dimensional layered material is tungsten disulfide, and the silane coupling agent is silane coupling agent KH550; the mass ratio of tungsten disulfide to silane coupling agent KH550 is 16.7:1. In step S20, the nitrate is nickel nitrate hexahydrate; the molar ratio of the two-dimensional layered material to nickel nitrate hexahydrate is 10:1.4. In step S30, the organic ligand is 3-indolecarboxylic acid, and the molar ratio of 3-indolecarboxylic acid to nickel nitrate hexahydrate is 2:1.

[0077] The embodiment of the present disclosure also provides a solid lubricating coating, which includes 15~25 parts of a composite binder, 3~5 parts of an additive, 35~50 parts of a solvent, and 20~35 parts of a metal-organic framework modified lubricating material prepared by using the preparation method described in any of the above embodiments. Thus, the metal-organic framework modified lubricating material is mixed with a composite binder, an additive, and a mixed solvent to form a solid lubricating coating. It can transform sliding friction into rolling friction through the "ball bearing" effect during the friction process, significantly reduce the friction coefficient, and can fill and repair the micro-defects on the friction surface to achieve a synergistic effect of enhanced lubrication, and significantly improve the lubrication performance of the solid lubricating coating under extreme conditions such as high temperature and high pressure, effectively reducing friction and wear.

[0078] In one example, the composite binder includes acrylic acid modified epoxy resin and polyimide resin. Exemplarily, in the composite binder, the mass ratio of acrylic acid modified epoxy resin to polyimide resin is 2:(1~1.5).

[0079] In one example, the additive includes one or more of a dispersant, an antifoaming agent, a leveling agent, or an anti-settling agent. Among them, the leveling agent and the anti-settling agent can improve the stability of the solid lubricating coating and extend the storage time. Exemplarily, the additive includes at least a dispersant and an antifoaming agent.

[0080] In one example, the solvent at least includes a solvent capable of dissolving the acrylic modified epoxy resin and the polyimide resin. Exemplarily, the solvent may include xylene, cyclohexanone, N, N-dimethylformamide, and n-butanol; the combined use of the above solvents can fully dissolve the acrylic modified epoxy resin and the polyimide resin, providing a uniform binder for preparing the solid lubricating coating. Exemplarily, the solvent may further include isopropanol and n-butyl acetate. Isopropanol can increase the frost resistance of the solid lubricating coating, and n-butyl acetate can be used as a co-solvent to improve the solubility of each component in the solid lubricating coating, improving the uniformity of the prepared solid lubricating coating.

[0081] In an embodiment of the present disclosure, it further includes wear-resistant fillers. In this way, the obtained lubricating coating can have high lubricating performance and high temperature resistance, and also have wear-resistant performance, further extending the service life of the lubricating coating.

[0082] In one example, the wear-resistant filler may be fibrous calcium sulfate, and the whisker length of the fibrous calcium sulfate is 5-8 μm, and the whisker diameter is 0.5-2 μm. Fibrous calcium sulfate can grow in the form of single crystals, having a uniform cross-section, a complete internal structure, and a stable aspect ratio size, so that fibrous calcium sulfate has excellent mechanical properties, high temperature resistance, compatibility, and wear-resistant performance. As a wear-resistant filler, it can significantly improve the overall performance of the prepared solid lubricating coating.

[0083] The following further illustrates the performance of the lubricating coating provided by the present disclosure in combination with specific embodiments.

[0084] Example 1

[0085] Step 1: Prepare a metal-organic framework modified lubricating material

[0086] S10: Disperse 50 g of tungsten disulfide into an ethanol solution of amino silane (silane coupling agent KH550), and stir at a stirring speed of 600 rpm at room temperature for 4 h for modification. Among them, the total mass of the ethanol solution of amino silane is 150 g, and the mass percentage of amino silane in the ethanol solution of amino silane is 2%. After filtration, washing, and drying, the modified two-dimensional layered material is obtained.

[0087] S20: Add the modified two-dimensional layered material obtained in step S10 and 8.4 g of nickel nitrate hexahydrate to 200 mL of N, N-dimethylformamide solution, and stir until evenly mixed to obtain a first mixed solution.

[0088] S30. Take 9.3 g of 3-indolecarboxylic acid and add it to 50 mL of N,N-dimethylformamide solution. After complete dissolution, slowly add it to the first mixed solution, stir and mix evenly, place it in an oven for reaction, the reaction temperature is 160 °C, and the reaction time is 12 h. After the reaction is completed, filter, wash, and dry the product to obtain the metal-organic framework modified lubricating material 1.

[0089] Step 2. Obtain the raw materials of the lubricating coating

[0090] Weigh 25 g of the metal-organic framework modified lubricating material 1, 12 g of fibrous calcium sulfate, 14 g of acrylic acid modified epoxy resin, 7 g of polyimide resin, 2 g of dispersant BYK-2013 (brand: BYK, model: BYK-2013), 1 g of defoamer BYK-052N (brand: BYK, model: BYK-052N), 0.5 g of leveling agent BYK-333 (brand: BYK, model: BYK-333), 0.5 g of anti-settling agent BYK-410 (brand: BYK, model: BYK-410), 17 g of xylene, 10 g of cyclohexanone, 7 g of N,N-dimethylformamide, 2 g of n-butanol, 1 g of isopropanol, and 1 g of n-butyl acetate respectively.

[0091] Step 3. Prepare the solid lubricating coating

[0092] Prepare the solid lubricating coating according to the amounts weighed in Step 2. The steps are as follows:

[0093] S100. Mix xylene, cyclohexanone, N,N-dimethylformamide, n-butanol, isopropanol, and n-butyl acetate evenly, then add acrylic acid modified epoxy resin and polyimide resin, and stir until completely dissolved to obtain a composite binder solution.

[0094] S200. Add dispersant BYK-2013 to the composite binder solution. After stirring at 600 rpm for 10 min, raise the stirring speed to 1500 rpm. Add the metal-organic framework modified lubricating material 1 and fibrous calcium sulfate in portions while stirring, then stir for 20 min, and then add defoamer BYK-052N and continue to stir for 10 min to obtain a lubricating coating preform solution.

[0095] S300. Use a ball mill tank to ball mill and disperse the lubricating coating preform solution for 2 h, then filter it through a 200-mesh filter screen, add leveling agent BYK-333 and anti-settling agent BYK-410, and mix evenly to obtain a lubricating coating defined as solid lubricating coating 1.

[0096] Example 2

[0097] Step 1. Prepare the metal-organic framework modified lubricating material

[0098] According to the preparation method provided in Step 1 of Example 1, obtain the metal-organic framework modified lubricating material 2.

[0099] Step 2. Obtain the raw materials of the lubricating coating

[0100] Weigh 20 g of the metal-organic framework modified lubricating material 2, 15 g of fibrous calcium sulfate, 14.3 g of acrylic acid modified epoxy resin, 10.7 g of polyimide resin, 2 g of dispersant BYK-2013, 1 g of defoamer BYK-052N, 0.5 g of leveling agent BYK-333, 0.5 g of anti-settling agent BYK-410, 15 g of xylene, 12 g of cyclohexanone, 4 g of N,N-dimethylformamide, 2 g of n-butanol, 2 g of isopropanol, and 1 g of n-butyl acetate respectively.

[0101] Step 3. Prepare the solid lubricating coating

[0102] According to the masses of the respective raw materials weighed in Step 2 of this example, prepare the solid lubricating coating. The steps are the same as those in Step 3 of Example 1, and the obtained lubricating coating is defined as the solid lubricating coating 2.

[0103] Example 3

[0104] Step 1. Prepare the metal-organic framework modified lubricating material

[0105] S10. Disperse 50 g of molybdenum disulfide into an ethanol solution of amino silane, and stir at a stirring speed of 600 rpm at room temperature for 4 h for modification. Among them, the total mass of the ethanol solution of amino silane is 250 g, and the mass percentage of amino silane in the ethanol solution of amino silane is 2%. After filtration, washing, and drying, obtain the modified two-dimensional layered material.

[0106] S20. Add the modified two-dimensional layered material obtained in Step S10 and 9.28 g of nickel nitrate hexahydrate to 200 mL of an N,N-dimethylformamide solution, and stir until evenly mixed to obtain a first mixed solution.

[0107] S30. Take 10.3 g of 3-indolecarboxylic acid and add it to 50 mL of an N,N-dimethylformamide solution. After complete dissolution, slowly add it to the first mixed solution, stir and mix evenly, place it in an oven for reaction, the reaction temperature is 180 °C, and the reaction time is 12 h. After the reaction ends, filter, wash, and dry the product to obtain the metal-organic framework modified lubricating material 3.

[0108] Step 2. Obtain the raw materials of the solid lubricating coating

[0109] Weigh 35 g of the metal-organic framework modified lubricating material 3, 10 g of fibrous calcium sulfate, 12 g of acrylic acid modified epoxy resin, 6 g of polyimide resin, 1 g of dispersant BYK-2013, 1 g of defoamer BYK-052N, 0.5 g of leveling agent BYK-333, 0.5 g of anti-settling agent BYK-410, 12 g of xylene, 10 g of cyclohexanone, 6 g of N,N-dimethylformamide, 3 g of n-butanol, 2 g of isopropanol, and 1 g of n-butyl acetate respectively.

[0110] Step 3: Prepare the solid lubricating coating

[0111] According to the masses of the respective raw materials weighed in Step 2 of this example, prepare the solid lubricating coating. The preparation steps are the same as those in Step 3 of Example 1, and the obtained lubricating coating is defined as solid lubricating coating 3.

[0112] Example 4

[0113] Step 1: Prepare the metal-organic framework modified lubricating material

[0114] S10: Disperse 50 g of tungsten disulfide into the ethanol solution of aminosilane, and stir at a stirring speed of 600 rpm at room temperature for 4 h for modification. Among them, the total mass of the ethanol solution of aminosilane is 125 g, and the mass percentage of aminosilane in the ethanol solution of aminosilane is 2%. After filtration, washing, and drying, the modified two-dimensional layered material is obtained.

[0115] S20: Add the modified two-dimensional layered material obtained in Step S10 and 7.5 g of cobalt nitrate hexahydrate to 200 mL of N,N-dimethylformamide solution, and stir until evenly mixed to obtain the first mixed solution.

[0116] S30: Take 5.4 g of 1,3,5-benzenetricarboxylic acid and add it to 50 mL of N,N-dimethylformamide solution. After complete dissolution, slowly add it to the first mixed solution, stir and mix evenly, place it in an oven for reaction. The reaction temperature is 120 °C, and the reaction time is 20 h. After the reaction ends, filter, wash, and dry the product to obtain the metal-organic framework modified lubricating material 4.

[0117] Step 2: Obtain the raw materials of the solid lubricating coating

[0118] Weigh 30 g of the metal-organic framework modified lubricating material 4, 13 g of fibrous calcium sulfate, 8.6 g of acrylic acid modified epoxy resin, 6.4 g of polyimide resin, 3 g of dispersant BYK-2013, 1 g of defoamer BYK-052N, 0.5 g of leveling agent BYK-333, 0.5 g of anti-settling agent BYK-410, 15 g of xylene, 11 g of cyclohexanone, 6 g of N,N-dimethylformamide, 2 g of n-butanol, 2 g of isopropanol, and 1 g of n-butyl acetate respectively.

[0119] Step 3: Prepare the solid lubricating coating

[0120] Prepare the solid lubricating coating according to the masses of the respective raw materials weighed in Step 2 of this embodiment. The preparation steps are the same as those in Step 3 of Embodiment 1, and the obtained lubricating coating is defined as solid lubricating coating 4.

[0121] Embodiment 5

[0122] Step 1: Prepare the metal-organic framework modified lubricating material

[0123] S10: Disperse 50 g of tungsten disulfide into an ethanol solution of aminosilane, and stir at a stirring speed of 600 rpm at room temperature for 4 h for modification. Among them, the total mass of the ethanol solution of aminosilane is 150 g, and the mass percentage of aminosilane in the ethanol solution of aminosilane is 2%. After filtration, washing, and drying, the modified two-dimensional layered material is obtained.

[0124] S20: Add the modified two-dimensional layered material obtained in Step S10 and 7.2 g of copper nitrate trihydrate to 200 mL of N,N-dimethylformamide solution, and stir until evenly mixed to obtain the first mixed solution.

[0125] S30: Take 6.3 g of 1,3,5-benzenetricarboxylic acid and add it to 50 mL of N,N-dimethylformamide solution. After complete dissolution, slowly add it to the first mixed solution, stir and mix evenly, place it in an oven for reaction, the reaction temperature is 120 °C, and the reaction time is 24 h. After the reaction ends, filter, wash, and dry the product to obtain the metal-organic framework modified lubricating material 5.

[0126] Step 2: Obtain the raw materials of the solid lubricating coating

[0127] Weigh 20 g of the metal-organic framework modified lubricating material 5, 11 g of fibrous calcium sulfate, 10 g of acrylic acid modified epoxy resin, 5 g of polyimide resin, 2 g of dispersant BYK-2013, 1 g of defoamer BYK-052N, 0.5 g of leveling agent BYK-333, 0.5 g of anti-settling agent BYK-410, 20 g of xylene, 16 g of cyclohexanone, 7 g of N,N-dimethylformamide, 3 g of n-butanol, 3 g of isopropanol, and 1 g of n-butyl acetate respectively.

[0128] Step 3: Prepare the solid lubricating coating

[0129] Prepare the solid lubricating coating according to the masses of the respective raw materials weighed in Step 2 of this embodiment. The preparation steps are the same as those in Step 3 of Embodiment 1, and the obtained lubricating coating is defined as solid lubricating coating 5.

[0130] Comparative Example 1

[0131] Step 1: Obtain the raw materials of the solid lubricating coating

[0132] Weigh 25 g of tungsten disulfide, 11 g of fibrous calcium sulfate, 15 g of acrylic modified epoxy resin, 7.5 g of polyimide resin, 2 g of dispersant BYK-2013, 1 g of defoamer BYK-052N, 0.5 g of leveling agent BYK-333, 0.5 g of anti-settling agent BYK-410, 26 g of xylene, 11.5 g of cyclohexanone, 5 g of N, N-dimethylformamide, 3 g of n-butanol, 1 g of isopropanol, and 1 g of n-butyl acetate respectively.

[0133] Step 2: Prepare the solid lubricating coating

[0134] Prepare the solid lubricating coating according to the masses of the respective raw materials weighed in Step 1. The steps are as follows:

[0135] S100: Mix xylene, cyclohexanone, N, N-dimethylformamide, n-butanol, isopropanol, and n-butyl acetate evenly, then add acrylic modified epoxy resin and polyimide resin, and stir until completely dissolved to obtain a composite binder solution.

[0136] S200: Add dispersant BYK-2013 to the composite binder solution, stir at 600 rpm for 10 min, then increase the stirring speed to 1500 rpm. Add tungsten disulfide and fibrous calcium sulfate in portions while stirring, stir for 20 min, then add defoamer BYK-052N and continue to stir for 10 min to obtain a lubricating coating prefabricated liquid.

[0137] S300: Use a ball mill tank to ball mill and disperse the lubricating coating prefabricated liquid for 2 h, then filter it through a 200-mesh filter screen, add leveling agent BYK-333 and anti-settling agent BYK-410, and mix evenly. The obtained lubricating coating is defined as solid lubricating coating 6.

[0138] Comparative Example 2

[0139] Step 1: Obtain the raw materials of the solid lubricating coating

[0140] Weigh 20 g of molybdenum disulfide, 14 g of fibrous calcium sulfate, 16 g of acrylic modified epoxy resin, 8 g of polyimide resin, 2 g of dispersant BYK-2013, 1 g of defoamer BYK-052N, 0.5 g of leveling agent BYK-333, 0.5 g of anti-settling agent BYK-410, 20 g of xylene, 10 g of cyclohexanone, 4 g of N, N-dimethylformamide, 2 g of n-butanol, 1 g of isopropanol, and 1 g of n-butyl acetate respectively.

[0141] Step 2: Prepare the solid lubricating coating

[0142] Prepare the solid lubricating coating according to the masses of the respective raw materials weighed in Step 1. The steps are as follows:

[0143] S100. Mix xylene, cyclohexanone, N, N-dimethylformamide, n-butanol, isopropanol, and n-butyl acetate evenly, then add acrylic modified epoxy resin and polyimide resin, and stir until completely dissolved to obtain a composite binder solution.

[0144] S200. Add dispersant BYK-2013 to the composite binder solution. After stirring at 600 rpm for 10 min, raise the stirring speed to 1500 rpm, and add molybdenum disulfide and fibrous calcium sulfate in portions while stirring. After stirring for 20 min, add defoamer BYK-052N and continue stirring for 10 min to obtain a lubricating coating preform solution.

[0145] S300. Use a ball mill tank to ball mill and disperse the lubricating coating preform solution for 2 h, then filter it through a 200-mesh filter screen. Add leveling agent BYK-333 and anti-settling agent BYK-410, and after mixing evenly, the obtained lubricating coating is defined as solid lubricating coating 7.

[0146] Spray the solid lubricating coatings 1 to 7 prepared in the above Examples 1-5 and Comparative Examples 1-2 respectively on the surface of bearing steel GCr15 to prepare solid lubricating coatings.

[0147] Spraying method: The nozzle diameter used is 1.0 - 1.5 mm, the spraying pressure is set at 0.3 - 0.5 Mpa. During spraying, the distance between the nozzle and bearing steel GCr15 is within the range of 20 - 30 cm. After spraying, first keep it warm at 250 - 270 °C for 20 - 30 min, and then keep it warm at 120 - 150 °C for 15 - 20 min. The thickness of the prepared solid lubricating coating is 20 - 30 μm. Observe the solid lubricating coating prepared on the surface of bearing steel GCr15 by SEM (scanning electron microscope). The SEM results of the solid lubricating coating formed after spraying the solid lubricating coating 1 prepared in Example 1 are shown in Figure 3 The SEM results of the solid lubricating coating formed after spraying the solid lubricating coating 2 prepared in Example 2 are shown in Figure 4 . It can be seen from Figure 3 and Figure 4 that the surface of the solid lubricating coating formed after spraying the solid lubricating coating prepared in the embodiments of the present disclosure is uniform and flat, without bubbles, and has excellent denseness.

[0148] Conduct performance tests on the solid lubricating coatings formed by spraying the solid lubricating coatings 1 to 7 prepared in each example and comparative example. The results are shown in Table 1.

[0149] Table 1. Performance test table of solid lubricating coatings formed by solid lubricating coatings 1 to 7

[0150]

[0151] Adhesion: The adhesion rating was determined by the cross-hatch method, according to ISO classification: 0 (smooth cutting edge, no shedding) to 5 (shedding area exceeds 65%). The results are shown in Table 1, and solid lubricating coatings 1 to 5 are all 0, indicating that the lubricating material prepared by the preparation method provided by the present disclosure can be well adhered to the surface of the device after spraying, and is not easy to fall off, thereby improving the service life and lubrication effect of the formed solid lubricating coating.

[0152] Friction coefficient: The friction coefficient of the coating was tested using the reciprocating module of the friction and wear tester, with a load of 10 N (Newton), a time of 60 min, a test frequency of 0.5 Hz, and a length of 5 mm for the bearing steel GCr15 coated with a solid lubricant coating. Figure 5 , Figure 6 and Figure 7 As shown in Table 1, the friction coefficient of the solid lubricating coatings prepared by solid lubricating coatings 1 to 5 is much lower than the friction coefficient of the solid lubricating coatings prepared by solid lubricating coatings 6 and 7. This is because the solid lubricating coatings 1 to 5 contain the metal organic framework modified lubricating material provided by the present disclosure, and during the friction process, the spherical metal organic framework material converts the sliding friction into rolling friction, thereby greatly reducing the friction coefficient and improving the lubrication performance of the solid lubricating coating.

[0153] Wear amount: Referring to GB / T 1768 standard, a CS-10 rubber grinding wheel was used, loaded with a 1kg weight, the rotation speed was 60 rpm, and the mass loss after 1000 revolutions was recorded. The results are shown in Table 1. The wear amount of the solid lubricating coatings prepared by solid lubricating coatings 1 to 5 is much lower than the wear amount of the solid lubricating coatings prepared by solid lubricating coatings 6 and solid lubricating coatings 7. The metal organic framework nanoparticles in solid lubricating coatings 1 to 5 reduce the friction coefficient due to the "ball bearing" effect, which reduces the wear amount to a certain extent. At the same time, the nanoscale metal organic framework material in the worn solid lubricating coating can be filled into the tiny defects formed on the wear surface, achieving a synergistic effect of enhancing lubrication. In this way, the solid lubricating coating provided in the embodiment of the present disclosure has higher wear resistance than the solid lubricating coating prepared by the two-dimensional layered material without metal organic framework modification in the comparative example, thereby increasing the service life of the solid lubricating coating.

[0154] Heat resistance: Referring to the GB / T 1735 standard, at a preset temperature, if there are no obvious changes in the color and gloss of the coating, and there are no phenomena such as blistering, cracking, and peeling, it is considered that the coating can withstand the preset temperature. The heat resistance test results are shown in Table 1. The heat resistance temperatures of solid lubricating coatings 1-2 and 4-5 are higher than those of solid lubricating coatings 6-7. It shows that using tungsten disulfide as the two-dimensional layered material can improve the heat resistance of the prepared solid lubricating coating.

[0155] Comparing Example 3 with Examples 1 and 2, in Examples 1 and 2, tungsten disulfide was used as the two-dimensional layered material, and spherical Ni-MOFs were grown on the surface of tungsten disulfide. In Example 3, molybdenum disulfide was used as the two-dimensional layered material, and spherical Ni-MOFs were grown on the surface of molybdenum disulfide. Referring to the performance test results in Table 1, the friction coefficient of the solid lubricating coating 3 prepared with molybdenum disulfide as the two-dimensional layered material slightly increases compared with that of solid lubricating coatings 1 and 2; at the same time, the heat resistance of the solid lubricating coating 3 prepared with molybdenum disulfide also decreases. It shows that using tungsten disulfide as the two-dimensional layered material can further enhance the lubrication performance of the prepared solid lubricating coating.

[0156] Therefore, the solid lubricating coating prepared from the metal-organic framework modified lubricating material provided by the present disclosure can significantly reduce the friction coefficient and wear rate of the friction surface, improve the operation efficiency and reliability of mechanical equipment, and can solve the deficiencies of traditional lubricating oil and grease systems in aspects such as lubrication failure, environmental adaptability, volatilization, pollution, and performance limitations under high temperature and high pressure, and has more application scenarios.

[0157] It should be noted that although the steps of the preparation method of the metal-organic framework modified lubricating material in the present disclosure are described in a specific order in the drawings, this does not require or imply that these steps must be executed in this specific order, or that all the shown steps must be executed to achieve the desired result. Additionally or alternatively, some steps can be omitted, multiple steps can be combined into one step for execution, and / or one step can be decomposed into multiple steps for execution, etc.

[0158] Those skilled in the art will readily think of other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure, which follow the general principles of the present disclosure and include common general knowledge or conventional technical means in the technical field not disclosed in the present disclosure. The specification and examples are only regarded as exemplary, and the true scope and spirit of the present disclosure are pointed out by the appended claims.

Claims

1. A metal organic framework modified lubricating material, characterized in that: It comprises a first metal organic framework layer (10), a two-dimensional layered material layer (20) and a second metal organic framework layer (30) which are stacked in sequence; The two-dimensional layered material layer (20) comprises a two-dimensional layered material; The first metal-organic framework layer (10) and the second metal-organic framework layer (30) both comprise a plurality of spherical metal-organic framework materials, and the spherical metal-organic framework materials are both formed on the surface of the two-dimensional layered material layer (20); The spherical metal organic framework material is a spherical metal organic framework material formed by nickel nitrate hexahydrate and 3-indolecarboxylic acid; The length dimension of the two-dimensional layered material is 3-5 μm; The particle size of the spherical metal organic framework material is 200-500 nm; The two-dimensional layered material is tungsten disulfide.

2. A method for preparing the metal organic framework modified lubricating material according to claim 1, characterized in that: The following steps are involved: S10, dispersing the two-dimensional layered material into an ethanol solution of a silane coupling agent for modification to obtain a modified two-dimensional layered material; the two-dimensional layered material is tungsten disulfide; the length of the two-dimensional layered material is 3-5 μm; Wherein, the mass ratio of the two-dimensional layered material to the silane coupling agent is (10-20):1; S20, mixing the modified two-dimensional layered material obtained in step S10 with nickel nitrate hexahydrate and N,N-dimethylformamide to obtain a first mixed solution; Wherein, the molar ratio of the two-dimensional layered material to nickel nitrate hexahydrate is 10:(1-1.5); S30, adding N,N-dimethylformamide containing 3-indolecarboxylic acid to the first mixed solution to obtain a second mixed solution; Wherein, the molar ratio of 3-indolecarboxylic acid to nickel nitrate hexahydrate is (1-2):1; S40, reacting the second mixed solution at 120-180° C. for 12-24 hours, filtering and drying to obtain a metal organic framework modified lubricating material.

3. The method for preparing the metal organic framework modified lubricating material according to claim 2, characterized in that: In step S10, the mass percentage of the silane coupling agent in the ethanol solution of the silane coupling agent is 2-5%; The silane coupling agent is silane coupling agent KH550.

4. The method for preparing the metal organic framework modified lubricating material according to claim 2, characterized in that: In step S10, the silane coupling agent is silane coupling agent KH550; the mass ratio of tungsten disulfide to silane coupling agent KH550 is 16.7:1; In step S20, the molar ratio of tungsten disulfide to nickel nitrate hexahydrate is 10:1.4; In step S30, the molar ratio of 3-indolecarboxylic acid to nickel nitrate hexahydrate is 2:

1.

5. A solid lubricating coating, characterized in that: By weight, it comprises 15-25 parts of a composite binder, 3-5 parts of an additive, 35-50 parts of a solvent, and 20-35 parts of a metal organic framework modified lubricating material prepared by the preparation method according to any one of claims 2 to 4; The composite adhesive comprises acrylic modified epoxy resin and polyimide resin; The auxiliary agent includes one or more of a dispersant, a defoamer, a leveling agent, and an anti-settling agent.

6. The solid lubricating coating according to claim 5, characterized in that: In the composite adhesive, the mass ratio of acrylic modified epoxy resin to polyimide resin is 2:(1-1.5).

7. The solid lubricating coating according to claim 5 or 6, characterized in that: Also included are wear-resistant fillers; The wear-resistant filler is fibrous calcium sulfate, the whisker length of the fibrous calcium sulfate is 5-8 μm, and the whisker diameter is 0.5-2 μm.

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