Low-friction laminated lubricating structure for electrical contact components and method for producing same

Abstract

The application discloses a low-friction laminated lubricating structure for an electrical contact component and a preparation method thereof, relates to the technical field of lubricating material preparation, and comprises the following steps: preparing a GNs ethanol dispersion solution and a PFPE ethanol solution; preparing a substrate; and performing composite coating and polishing forming to prepare a GNs bottom layer and a PFPE top layer. The low-friction laminated lubricating structure for the electrical contact component and the preparation method thereof are adopted, a composite process of synchronous spin coating and polishing is adopted, a GNs solid lubricating bottom layer and a PFPE fluid lubricating top layer are sequentially constructed on the surface of the component, the synergistic lubricating effect of the two layers is realized, and the friction and wear are greatly reduced while the stable electrical contact performance is maintained.

Description

Technical Field

[0001] This invention relates to the field of lubricant preparation technology, and in particular to a low-friction laminated lubricant structure for electrical contact components and its preparation method. Background Technology

[0002] Gold is commonly used as a self-lubricating material and coating material for slip rings and other precision aerospace components. However, gold has limited lubrication properties for gold-to-gold friction pairs, and the plating is easily peeled off during friction. In special environments such as vacuum, where components lack the lubrication of an atmospheric adsorption film, friction and wear problems are more pronounced, necessitating the application of specialized lubricants.

[0003] Solid lubricant coatings (such as GNs) are one effective way to solve this problem. They rely on the material's inherent interlaminar shear properties to provide stable lubrication in a vacuum, avoiding the evaporation of liquid lubricants. GNs also feature high thermal conductivity, high electrical conductivity, and ultra-high strength. Perfluoropolyether (PFPE) is another mature aerospace-grade lubricant with extremely low vapor pressure and a wide liquid lubrication range, but it is an insulator, and forming a film alone may affect the stability of electrical contacts.

[0004] Therefore, combining the excellent fluid lubrication properties of PFPE with the high conductivity, high load-bearing capacity, and solid lubrication properties of GNs to construct a composite lubrication layer with low friction, low wear, and high conductivity stability is of great significance for improving the reliability and lifespan of electrical contact components (such as slip rings and brushes) in high-end equipment such as spacecraft. Summary of the Invention

[0005] The purpose of this invention is to provide a low-friction laminated lubrication structure for electrical contact components and its preparation method, thereby solving the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides a low-friction stacked lubrication structure for electrical contact components, comprising a substrate, a GNs bottom layer, and a PFPE top layer, wherein the PFPE top layer is disposed above the GNs bottom layer, and the GNs bottom layer is disposed above the substrate.

[0007] Preferably, the substrate thickness is set to 0-2 μm, and the thickness of the GNs bottom layer and the PFPE top layer is set to 50-500 nm.

[0008] Preferably, the substrate is made of one of copper, brass, iron, or stainless steel.

[0009] Preferably, the surface of the substrate is coated with a gold or silver coating.

[0010] A method for preparing a low-friction multilayer lubrication structure for electrical contact components includes the following steps: S1. Prepare GNs ethanol dispersion and PFPE ethanol solution; S2. Prepare the substrate; S3. Composite coating and polishing molding to prepare the GNs bottom layer and PFPE top layer.

[0011] Preferably, S1 includes: S11. Disperse GNs powder in ethanol, stir and sonicate to prepare a GNs ethanol dispersion with a concentration of 400-1000 mg / L. S12. Mix and stir perfluoropolyether with ethanol to prepare a PFPE ethanol solution with a concentration of 100-600 mg / L.

[0012] Preferably, step S2 includes: ultrasonically cleaning the substrate for 30 minutes and then drying it.

[0013] Preferably, the step of preparing the GNs underlying layer in S3 includes: S311. The GNs ethanol dispersion is quantitatively applied to the surface of the substrate using the flexible coating head of the coating and polishing device; S312. Start the coating and polishing program, control the glass polishing stone to rotate at a speed of 50-150 rpm while applying a pressure of 0.5-10N, and simultaneously drive the substrate to revolve at a speed of 50-500 rpm. Under this combined motion, spin-coat and polish the lubricant for 0.5-5 minutes to form a uniform and continuous GNs underlayer. S313. Perform the first drying treatment for 2-12 hours.

[0014] Preferably, the step of preparing the PFPE top layer in S3 includes: S321. Apply PFPE ethanol solution quantitatively to the surface of the GNs substrate using a flexible applicator; S322. Control the glass polishing stone to rotate at a speed of 50-100 rpm while applying a pressure of 0.15-5N, and simultaneously drive the substrate to revolve at a speed of 50-300 rpm. Under this combined motion, spin coating and polishing are performed for 1-3 minutes to form a uniform and continuous PFPE top layer. S323. Perform a second drying process for 6-12 hours.

[0015] Preferably, the first drying process and the second drying process in S313 and S323 are both carried out in an insulated box.

[0016] Therefore, the present invention employs the above-mentioned low-friction laminated lubrication structure for electrical contact components and its preparation method, which has the following beneficial effects: This method employs a composite process of simultaneous spin coating and polishing to sequentially construct a GNs solid lubricant underlayer and a PFPE fluid lubricant top layer on the surface of the component, achieving a synergistic lubrication effect between the two. This significantly reduces friction and wear while maintaining stable electrical contact performance.

[0017] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a low-friction stacked lubrication structure for electrical contact components according to the present invention. Figure 2 Optical images of the coating prepared according to the present invention, wherein (a) is an optical image of the BARE structure and (b) is an optical image of the PFPE / GNs coating; Figure 3 The diagram shows the tribological properties of the PFPE / GNs coating and the BARE structure of this invention. Figure 4 The diagram shows a comparison of the electrical contact performance of the PFPE / GNs coating, BARE structure, GNs coating, and PFPE coating of the present invention. In the diagram, (a) is the contact resistance curve of the BARE structure, (b) is the contact resistance curve of the PFPE coating, (c) is the contact resistance curve of the GNs coating, (d) is the contact resistance curve of the PFPE / GNs coating, and (e) is a box plot of the contact resistance of the PFPE / GNs coating, BARE structure, GNs coating, and PFPE coating. Figure 5 The wear performance results of the PFPE / GNs coating and BARE structure of the present invention are shown in (a) and (b), respectively, the wear depth curves of the BARE structure and the PFPE / GNs coating, (c) and (e), respectively, the wear depth optical 2D images of the BARE structure and the PFPE / GNs coating, and (d) is a comparison diagram of the wear rate of the BARE structure and the PFPE / GNs coating. Figure 6 This is a three-dimensional structural diagram of the coating and polishing apparatus of the present invention performing a coating operation on a slip ring with an inner hole positioned by the inner hole. Figure 7 This is a three-dimensional structural diagram of the coating and polishing apparatus of the present invention performing a coating operation on a slip ring positioned on an outer circle. Figure 8 This is a schematic diagram of the application module of the present invention. Figure 1 ; Figure 9 This is a schematic diagram of the application module of the present invention. Figure 2 ; Figure 10 This is a schematic diagram of the overall structure of the quick-change fixture for the lower specimen of the present invention; Figure 11 This is a partial structural diagram of the quick-change fixture for the lower specimen of the present invention. Figure 1 ; Figure 12 This is a partial structural diagram of the quick-change fixture for the lower specimen of the present invention. Figure 2 ; Figure 13 This is a partial structural diagram of the quick-change fixture for the lower specimen of the present invention. Figure 3 ; Figure 14 This is a three-dimensional structural schematic diagram of the coating and polishing apparatus of the present invention for conducting current-carrying friction tests on a slip ring positioned by an inner hole. Figure 15 A three-dimensional structural schematic diagram of the coating and polishing device of the present invention for performing current-carrying friction testing on a slip ring positioned on an outer circle. Figure 16 This is a schematic diagram of the structure of the quick-change fixture for the upper specimen of the present invention, which holds the flexible coating head. Figure 17 This is a schematic diagram of the structure of the quick-change fixture for holding brush filaments in the upper specimen of the present invention; Figure 18 This is a schematic diagram of the structure of the quick-change fixture for the upper specimen of the present invention, which holds the brush bundle. Figure 19 This is a schematic diagram of the structure of the quick-change fixture for the upper specimen of the present invention, which holds the brush block. Figure 20 This is a schematic diagram of the structure of the quick-change fixture for the upper specimen of the present invention, which holds the metal sheet. Reference numerals: 1-1 Vertical support; 1-2 Horizontal base; 2-1 Z-axis linear guide; 2-2 Y-axis linear guide; 2-3 X-axis linear guide; 2-4 Rotating C-axis platform; 3-1 Liquid storage chamber; 3-2 Micro-injection pump; 3-3 Upper specimen connecting plate; 4-1 Miniature digital servo motor; 4-2 Tilting block; 5 Upper specimen quick-change fixture; 6. Coating module; 6-1 Coating head holder; 6-2 Coating head fixing plate; 6-3 Flexible coating head; 7 Lower specimen quick-change fixture; 7-1 Precision three-jaw chuck; 7-2 Expansion mandrel; 7-3. Elastic bushing; 8-1. Brush bristles; 8-2. Brush block; 8-3. Metal sheet; 8-4. Brush bundle; 9-1. Inner hole positioning slip ring; 9-2. Outer circle positioning slip ring; 10-1. Three-dimensional force sensor; 10-2. Accelerometer; 10-3. Temperature sensor; 10-4. Acoustic emission sensor; 10-5. Auxiliary slip ring; 10-6. Circuit test bracket; 11. Glass polishing stone; 12-1. Substrate; 12-2. GNs bottom layer; 12-3. PFPE top layer; 13. Metal to be lubricated; 14. Polishing operation; 15. Spin coating operation. Detailed Implementation

[0019] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0021] Please see Figures 1-20 This invention provides a low-friction multilayer lubrication structure for electrical contact components, comprising a substrate 12-1, a GNs (graphene nanosheets) bottom layer 12-2, and a PFPE (perfluoropolyether) top layer 12-3. The PFPE top layer 12-3 is disposed above the GNs bottom layer 12-2, which is disposed above the substrate 12-1. The thickness of the substrate 12-1 is set to 0-2 μm, and the thicknesses of the GNs bottom layer 12-2 and the PFPE top layer 12-3 are set to 50-500 nm, with a surface coverage of over 80%. The substrate 12-1 is made of copper, brass, iron, or stainless steel, or the surface of the substrate 12-1 is plated with a gold or silver coating, and the substrate 12-1 is also made of copper, brass, iron, or stainless steel. Figure 1 As shown, the stacked lubrication structure is placed on the metal to be lubricated 13, and polishing operation 14 and spin coating operation 15 are performed simultaneously.

[0022] The above-mentioned method for preparing a low-friction laminated lubrication structure for electrical contact components includes the following steps: S1. Prepare GNs ethanol dispersion and PFPE ethanol solution. This includes: S11. Disperse GNs powder in ethanol, stir and sonicate to prepare a GNs ethanol dispersion with a concentration of 400-1000 mg / L. S12. Mix and stir perfluoropolyether with ethanol to prepare a PFPE ethanol solution with a concentration of 100-600 mg / L.

[0023] S2. Prepare substrate 12-1. Clean substrate 12-1 with ultrasonic for 30 minutes and then dry it.

[0024] S3. Composite coating and polishing molding to prepare GNs bottom layer 12-2 and PFPE top layer 12-3.

[0025] The steps for preparing the GNs bottom layer 12-2 include: S311. The GNs ethanol dispersion is quantitatively applied to the surface of the substrate 12-1 through the flexible coating head 6-3 of the coating and polishing device; S312. Start the coating and polishing program to achieve polishing operation 14. Control the glass polishing stone 11 to rotate at a speed of 50-150 rpm while applying a pressure of 0.5-10N, and synchronously drive the substrate 12-1 to revolve at a speed of 50-500 rpm to achieve spin coating operation 15. Under this combined motion, spin coating and polishing of lubricant are performed for 0.5-5 minutes to form a uniform and continuous GNs bottom layer 12-2. S313. Perform the first drying treatment for 2-12 hours.

[0026] The steps for preparing the PFPE top layer 12-3 include: S321. Apply PFPE ethanol solution quantitatively to the surface of GNs bottom layer 12-2 using flexible applicator 6-3; S322, Control the glass polishing stone 11 to rotate at a speed of 50-100 rpm while applying a pressure of 0.15-5N, and synchronously drive the substrate 12-1 to revolve at a speed of 50-300 rpm. Under this combined motion, spin coating and polishing are performed for 1-3 minutes to form a uniform and continuous PFPE top layer 12-3. S323. Perform a second drying process for 6-12 hours.

[0027] The first and second drying processes in S313 and S323 are both carried out in an insulated chamber.

[0028] In this embodiment, the structure of the coating and polishing device used in step S3 is as follows: Figure 6 , Figure 7 As shown, it includes a frame, a power drive module, a quantitative dispensing module, an upper specimen servo adjustment module, an upper specimen quick-change fixture 5, a coating module 6, a lower specimen quick-change fixture 7, a sensing and measurement module, and an information acquisition and processing module.

[0029] The frame consists of a vertical support 1-1 and a horizontal base 1-2, providing a stable installation foundation for each module.

[0030] The power drive module is mounted on the frame and is responsible for all precision movements. Specifically (see...) Figure 6 , Figure 7The Z-axis linear guide 2-1 is installed in the groove of the support; the Y-axis linear guide 2-2 is installed on the Z-axis displacement platform; the X-axis linear guide 2-3 is installed on the base 1-2; and the rotary C-axis platform 2-4 is installed on the X-axis displacement platform. This design of three linear axes and one rotary axis ensures that the paint head or brush can be positioned arbitrarily in space and aligned with the ring track at any angle on the slip ring.

[0031] The linear axis of the power drive module is driven by a servo motor in conjunction with a ball screw and precision linear guides, while the rotary axis is driven by a direct-drive torque motor or a servo motor in conjunction with a harmonic reducer to ensure sufficient thrust, rigidity, and high-precision position and speed control. Depending on cost and accuracy requirements, the linear axis can also be driven by a linear motor or a stepper motor in conjunction with a ball screw. The power drive module provides linear motion in the X, Y, and Z directions and rotational motion around the C-axis. To achieve precise alignment and stable contact between the coating head or brush and the slip ring track, the positioning accuracy of the linear axis is better than ±10μm, and the repeatability is better than ±5μm; the positioning accuracy of the rotary axis is better than ±0.2°, and the repeatability is better than ±0.1°. This accuracy range ensures that during the coating and testing process of multi-track slip rings, positional deviations will not significantly affect the contact pressure and test results, and can be adapted and adjusted according to specific application requirements.

[0032] The quantitative dispensing module is mounted on the Y-axis displacement stage via the upper specimen connecting plate 3-3. For example... Figure 8 , Figure 9 As shown, it includes a liquid storage chamber 3-1, a micro-injection pump 3-2, and pipeline valves. The micro-injection pump 3-2 can be programmed to precisely control the dosage and rate of liquid pumped from the liquid storage chamber 3-1, and the liquid is delivered to the application module 6 through channels in the connecting plate.

[0033] The miniature digital servo 4-1 of the servo adjustment module for the upper specimen is also mounted on the Y-axis displacement stage. (Refer to...) Figure 6 , Figure 7 The servo motor drives the flip block 4-2 to precisely rotate from 0° to 180°. A three-dimensional force sensor 10-1 is mounted on the surface of the flip block 4-2 to provide real-time feedback of the contact force. By flipping the flip block 4-2, in-situ rapid switching and contact angle adjustment between the three workstations of coating, testing, and cleaning can be achieved.

[0034] The upper specimen quick-change fixture 5 is mounted on the three-dimensional force sensor 10-1. A brush, including brush filaments 8-1, brush bundle 8-4, brush block 8-2, or metal sheet 8-3, is mounted on the upper specimen quick-change fixture 5 and moves together with the flipping block 4-2. The upper specimen quick-change fixture 5 can also be used to hold the flexible coating head 6-3 or the glass polishing stone 11. Figure 14As shown, the upper specimen quick-change clamp 5 uses a motor-driven precision clamp. The clamping force is adjusted by controlling the motor output torque, and the clamping force range can be set from 0.5N to 50N. It can also be programmed to adjust according to the material and size requirements of different brushes or coating modules 6. The clamp jaws can be changed manually or automatically (e.g., pneumatic or electromagnetic). The clamp jaws are made of materials that combine insulation and wear resistance, such as ceramics, polyetheretherketone, polytetrafluoroethylene, or metals with an insulating surface, to prevent short circuits during current-carrying tests and ensure long-term stability. By changing different clamp jaws (standard flat jaws for brush blocks or metal sheets, and V-groove jaws for brush filaments, brush bundles, or coating heads), various types of brushes and coating modules 6 can be quickly, stably, and without damage.

[0035] The coating module 6 is held by the upper specimen quick-change fixture 5. For example... Figure 8 , Figure 9 As shown, it includes a coating head holder 6-1, a coating head fixing plate 6-2, and a flexible coating head 6-3. The flexible coating head 6-3 is made of a porous elastic material or fiber material with resilience and liquid adsorption and release capabilities, including one or more of silicone, polyurethane foam, non-woven fabric, brush, and microporous foam plastic; to withstand the chemical corrosion of different types of lubricants and cleaning fluids, the flexible coating head material is selected from oil- and solvent-resistant nitrile rubber foam, fluororubber foam, or polytetrafluoroethylene fiber felt. The coating head holder 6-1 is held by the upper specimen quick-change clamp 5, the coating head fixing plate 6-2 is installed on the coating head holder 6-1, and the flexible coating head 6-3 is fixed on the coating head fixing plate 6-2. The coating head holder 6-1 and the coating head fixing plate 6-2 have flow channels inside, which are connected to the flexible coating head 6-3, for receiving the liquid delivered by the quantitative dispensing module and achieving uniform coating on the slip ring track.

[0036] The quick-change fixture 7 for the lower specimen is mounted on the rotating C-axis platform 2-4 of the power drive module to hold the slip ring rotor 9 to be tested. Figure 10 and Figure 11 As shown, it adopts a modular design: the core is a precision three-jaw chuck 7-1, equipped with a quick-change expansion spindle 7-2 and a flexible bushing 7-3. Specifically, for Figure 6 , Figure 10 , Figure 11 The inner hole positioning slip ring 9-1 shown (such as a column slip ring) is fitted with an expansion mandrel 7-2 of the corresponding size. When the three-jaw chuck tightens, the expansion mandrel expands outward, thus gripping the inner hole of the slip ring; for Figure 7 , Figure 12 , Figure 15The outer circular positioning slip ring 9-2 shown (such as a disc slip ring) is fitted with an elastic bushing 7-3 of the corresponding inner diameter. The slip ring is placed within it, and when the three-jaw chuck tightens, the elastic bushing contracts evenly to grip the outer circle of the slip ring. All clamping components, including the jaws of the three-jaw chuck 7-1, the expansion mandrel 7-2, and the elastic bushing 7-3, are made of materials with good insulation properties and sufficient mechanical strength to prevent leakage or short circuits during current-carrying tests. The insulating material is selected from one or more of polyetheretherketone, ceramic, polyoxymethylene, nylon, polytetrafluoroethylene, or polyimide, depending on the clamping force and wear resistance requirements, or equivalent replacements are used. In this embodiment, nylon material is used.

[0037] The sensing and measurement modules are distributed and integrated within the device to acquire force, heat, vibration, acoustic emission, and electrical signals in real time during the testing process. Specifically, they include: The three-dimensional force sensor 10-1 is mounted on the flip block 4-2 and is used to monitor the normal contact force and tangential friction force in real time.

[0038] Accelerometer 10-2, mounted on flip block 4-2, is used to measure mechanical vibration signals during the test process.

[0039] Temperature sensor 10-3 and acoustic emission sensor 10-4 are installed on the upper specimen quick-change fixture 5 near the brush, and are used to monitor the temperature rise at the contact point and capture stress wave signals generated by micro-deformation and cracking of the material, respectively.

[0040] The auxiliary slip ring 10-5, whose rotor is connected to the quick-change fixture 7 for the lower specimen, is used to extract dynamic electrical signals.

[0041] Circuit test bracket 10-6 is used to fix the test circuit.

[0042] The aforementioned coating and polishing device achieves multi-axis precision motion through a power drive module, and achieves precise control of polishing angle and pressure through an upper specimen servo adjustment module, a sensing and measurement module, and an information acquisition and processing module. By rapidly switching between the flexible coating head 6-3 and the glass polishing stone 11, it integrates "quantitative coating" and "composite coating and polishing" functions, thereby ensuring the uniformity, density, and thickness controllability of the nanoscale lubrication layer.

[0043] Example 1 (1) Solution preparation: Prepare 500 mg / L GNs ethanol dispersion and 400 mg / L PFPE ethanol solution.

[0044] (2) Substrate preparation: A copper substrate with a 30-40nm gold layer on the surface is used, which is ultrasonically cleaned for 30 minutes and then dried.

[0045] (3) Composite coating and polishing preparation: a) Preparation of GNs underlayer 12-2: The substrate is fixed to the coating and polishing device. A flexible coating head 6-3 quantitatively applies the GNs dispersion. Subsequently, the glass polishing stone 11 rotates at 50 rpm with a pressure of 1 N, while the substrate revolves at 200 rpm, for a composite treatment of 3 min. After treatment, it is placed in a drying oven for 6 h.

[0046] b) Preparation of the PFPE top layer 12-3: On the same apparatus, the flexible coating head 6-3 quantitatively applies the PFPE solution. Subsequently, the glass polishing stone 11 rotates at 50 rpm with a pressure of 0.5 N, while the substrate revolves at 50 rpm, for a composite treatment of 2 min. After treatment, it is placed in a drying oven for 4 h.

[0047] The performance test results of the obtained laminated lubrication structure are shown in Table 1.

[0048] Table 1: Performance indicators of the GNs boundary lubrication film samples prepared in Example 1

[0049] Example 2 (1) Solution preparation: Prepare a 600 mg / L GNs ethanol dispersion and a 300 mg / L PFPE ethanol solution.

[0050] (2) Substrate preparation: Same as in Example 1.

[0051] (3) Composite coating and polishing preparation: a) GNs bottom layer 12-2 parameters: polishing force 2N, glass polishing stone 11 rotation 100rpm, substrate revolution 300rpm, time 2min, drying 4h.

[0052] b) PFPE top layer 12-3 parameters: polishing force 0.25N, glass polishing stone 11 rotation 100rpm, substrate revolution 100rpm, time 2.5min, drying 6h.

[0053] The performance test results of the obtained laminated lubrication structure are shown in Table 2.

[0054] Table 2: Performance indicators of the GNs boundary lubrication film samples prepared in Example 2

[0055] Example 3 (1) Solution preparation: Prepare 700 mg / L GNs ethanol dispersion and 100 mg / L PFPE ethanol solution.

[0056] (2) Substrate preparation: Pure copper substrate is used, which is ultrasonically cleaned for 30 minutes and then dried.

[0057] (3) Composite coating and polishing preparation: a) GNs bottom layer 12-2 parameters: polishing force 3N, glass polishing stone 11 rotation 100rpm, substrate revolution 150rpm, time 3min, drying 8h.

[0058] b) PFPE top layer 12-3 parameters: polishing force 0.5N, glass polishing stone 11 rotation 50rpm, substrate revolution 100rpm, time 3min, drying 12h.

[0059] The performance test results of the obtained laminated lubrication structure are shown in Table 3.

[0060] Table 3: Performance indicators of the GNs boundary lubrication film samples prepared in Example 3

[0061] Example 4 (1) Solution preparation: Prepare 500 mg / L GNs ethanol dispersion and 500 mg / L PFPE ethanol solution.

[0062] (2) Substrate preparation: Same as in Example 3.

[0063] (3) Composite coating and polishing preparation: a) GNs bottom layer 12-2 parameters: polishing force 1.5N, glass polishing stone 11 rotation 150rpm, substrate revolution 100rpm, time 2min, drying 6h.

[0064] b) PFPE top layer 12-3 parameters: polishing force 0.15N, glass polishing stone 11 rotation 50rpm, substrate revolution 300rpm, time 1min, drying 12h.

[0065] The performance test results of the obtained laminated lubrication structure are shown in Table 4.

[0066] Table 4: Performance indicators of the GNs boundary lubrication film samples prepared in Example 4

[0067] The PFPE / GNs laminated lubrication structure prepared by the above method achieves a film coverage of 80% (e.g., Figure 2As shown), the thickness is between 80-120 nm. After ball-disk current-carrying tribological wear test (conditions: upper sample is a 5 mm diameter steel ball, lower sample is a gold-plated copper block, normal load 1 N, current 2 A, sliding linear velocity 2 cm / s, 20,000 cycles), it exhibits excellent comprehensive performance: the coefficient of friction is stable at approximately 0.09, significantly lower than the BARE structure (the BARE structure can be a substrate without any coating, the substrate material being one of copper, brass, iron, or stainless steel; or a substrate with gold or silver plating, the substrate material being one of copper, brass, iron, or stainless steel; in this embodiment, the BARE is a brass substrate with the original gold plating), by approximately 0.11. Figure 3 As shown; the contact resistance fluctuation is extremely small, such as Figure 4 As shown; the wear rate is as low as 1.41 × 10⁻⁶. -5 mm 3 / N·m, approximately one-tenth the thickness of the original gold-plated coating, is expected to increase wear resistance by about 10 times. Figure 5 As shown.

[0068] Therefore, the present invention adopts the above-mentioned low-friction multilayer lubrication structure for electrical contact components and its preparation method, and uses a composite process of simultaneous spin coating and polishing to sequentially construct a GNs solid lubrication bottom layer and a PFPE fluid lubrication top layer on the surface of the component, so as to achieve the synergistic lubrication effect of the two, and significantly reduce friction and wear while maintaining stable electrical contact performance.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A low-friction laminated lubrication structure for electrical contact components, characterized in that: It includes a substrate, a GNs bottom layer, and a PFPE top layer, wherein the PFPE top layer is disposed above the GNs bottom layer, and the GNs bottom layer is disposed above the substrate; The substrate thickness is greater than 0 μm and less than or equal to 2 μm, and the thickness of the GNs bottom layer and the PFPE top layer is set to 50-500 nm; The above-mentioned method for preparing a low-friction laminated lubrication structure for electrical contact components includes the following steps: S1. Prepare GNs ethanol dispersion and PFPE ethanol solution; S2. Prepare the substrate; S3. Composite coating and polishing molding to prepare GNs bottom layer and PFPE top layer; In S3, a coating and polishing process is used when preparing the GNs underlayer, including: controlling the glass polishing stone to rotate at a speed of 50-150 rpm while applying a pressure of 0.5-10N, and synchronously driving the substrate to revolve at a speed of 50-500 rpm. Under this combined motion, the lubricant is spin-coated and polished for 0.5-5 minutes to form a uniform and continuous GNs underlayer. In step S3, a coating and polishing process is used when preparing the PFPE top layer, including: controlling the glass polishing stone to rotate at a speed of 50-100 rpm while applying a pressure of 0.15-5N, and synchronously driving the substrate to revolve at a speed of 50-300 rpm. Spin coating and polishing are performed under this combined motion for 1-3 minutes to form a uniform and continuous PFPE top layer.

2. The low-friction laminated lubrication structure for electrical contact components according to claim 1, characterized in that: The substrate is made of one of the following materials: copper, brass, iron, or stainless steel.

3. The low-friction laminated lubrication structure for electrical contact components according to claim 2, characterized in that: The surface of the substrate is coated with a gold or silver coating.

4. The low-friction laminated lubrication structure for electrical contact components according to claim 3, characterized in that, S1 includes: S11. Disperse GNs powder in ethanol, stir and sonicate to prepare a GNs ethanol dispersion with a concentration of 400-1000 mg / L. S12. Mix and stir perfluoropolyether with ethanol to prepare a PFPE ethanol solution with a concentration of 100-600 mg / L.

5. A low-friction laminated lubrication structure for electrical contact components according to claim 4, characterized in that, S2 includes: ultrasonically cleaning the substrate for 30 minutes and then drying it.

6. A low-friction laminated lubrication structure for electrical contact components according to claim 5, characterized in that, The steps for preparing the GNs bottom layer in S3 include: S311. The GNs ethanol dispersion is quantitatively applied to the surface of the substrate using the flexible coating head of the coating and polishing device; S312, Start the coating and polishing program; S313. Perform the first drying treatment for 2-12 hours.

7. A low-friction laminated lubrication structure for electrical contact components according to claim 6, characterized in that, The steps for preparing the PFPE top layer in S3 include: S321. Apply PFPE ethanol solution quantitatively to the surface of the GNs substrate using a flexible applicator; S322, Start the coating and polishing program; S323. Perform a second drying process for 6-12 hours.

8. A low-friction laminated lubrication structure for electrical contact components according to claim 7, characterized in that: The first drying process and the second drying process in S313 and S323 are both carried out in an insulated box.

Images