A coupled coated carbon fiber, its preparation method and application

Abstract

This invention discloses a coupled coated carbon fiber, its preparation method, and its application. A pretreatment process of degumming, roughening, sensitization, activation, and reduction, combined with a post-treatment of chemically deposited calcium-nickel, yields a carbon fiber-calcium-nickel deposited layer coupled with a wear-resistant surface material that can enhance the wear resistance of synchronizing ring surfaces. The carbon fiber composite material with coupled calcium-nickel layer deposition exhibits approximately 60% lower friction coefficient compared to single carbon fiber material, thus improving the wear resistance of the synchronizing ring material surface. During synchronizing ring operation, the harder calcium-nickel coating surface is directly worn first, hindering the wear of the carbon fiber itself. This invention is simple to prepare, low in cost, and applicable to wear protection of metals in various physical environments, covering wear-resistant surfaces of metal parts in numerous fields such as automobiles, ships, and aerospace.

Description

Technical Field

[0001] This invention relates to the field of wear-resistant surface composite materials, and in particular to a coupled coated carbon fiber, its preparation method, and its application. Background Technology

[0002] Synchronizer rings are a key component of automotive transmissions, transmitting engine speed to the output shaft via gear friction, causing the output shaft to rotate synchronously for smooth gear shifting. In practice, the coefficient of friction of the synchronizer ring decreases with the number of gear shifts, eventually leading to shifting failure. Therefore, the coefficient of friction of the synchronizer ring is a crucial factor determining the transmission's lifespan, stability, and safety. Carbon fiber materials, due to their excellent wear resistance and corrosion resistance, are widely used in aerospace, automotive, and nuclear energy applications.

[0003] Chinese patent application CN02158922.4 discloses a method for preparing a phenolic resin composite material for automotive synchronizer gear rings. The method uses a mixture of phenolic resin, urea-formaldehyde resin, and melamine-formaldehyde resin, wherein the phenolic resin comprises 75-90 parts by weight, the urea-formaldehyde resin comprises 5-15 parts by weight, and the melamine-formaldehyde resin comprises 5-10 parts by weight. This mixture is then combined with carbon fiber, glass fiber, cotton fiber, calcium carbonate, zinc stearate, molybdenum disulfide, and oil black. Hexamethylenetetramine is used as a curing agent, resulting in a polymer composite material with excellent comprehensive physical and mechanical properties.

[0004] However, carbon fibers have poor wettability with most metals, making processing difficult when metal matrix composites are involved, and causing voids between composite materials, leading to a decline in material properties. Surface metallization of carbon fibers is an effective method to improve their surface activity and compatibility with other materials, and it is also an effective way to prepare advanced composite materials and obtain various new functional materials. The main methods for surface metallization of carbon fibers include oxidation, physical vapor deposition (PVD), chemical vapor deposition (CVD), plasma spraying, sol-gel method, and chemical deposition. Among these, chemical deposition produces a uniform, smooth, and dense metal coating, and the process is simple, easy to control, and does not cause mechanical damage or fiber damage. Nickel has good wear resistance, and calcium carbonate, as a major component of seashells, effectively resists the erosion and wear of seabed sand. Therefore, chemical deposition is used to fill the gaps in the carbon fibers. During friction, the calcium-nickel coating protects the carbon fibers. The friction pair first contacts the calcium-nickel coating, protecting the inner carbon fibers while reducing the coefficient of friction, greatly reducing the wear rate, and extending the service life of the carbon fibers and the synchronization ring. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a coupled coated carbon fiber, its preparation method, and its application.

[0006] To achieve the above objectives, the present invention is implemented according to the following technical solution:

[0007] The first objective of this invention is to provide a method for preparing coupled-coated carbon fibers, comprising the following steps:

[0008] S1. Degumming treatment of carbon fiber;

[0009] S2. Desizing treatment is performed on the degummed carbon fiber.

[0010] S3. Roughen the carbon fiber after desizing;

[0011] S4. Sensitize the roughened carbon fiber: Place the roughened carbon fiber in SnCl2 solution and stir magnetically to adsorb a layer of easily oxidized substance on the surface of the carbon fiber.

[0012] S5. Activate the sensitized carbon fiber: Place the sensitized carbon fiber in a mixed solution of AgNO3 and NaOH and stir magnetically to generate a catalytically active metal layer on the surface of the carbon fiber.

[0013] S6. Reduce the activated carbon fiber: Place the activated carbon fiber in NaH2PO2 solution and stir magnetically for 60-80 minutes to reduce the silver oxide remaining on the surface of the carbon fiber.

[0014] S7. The reduced carbon fiber is placed in a chemical deposition solution for chemical deposition. The chemical deposition reaction temperature is 80℃, the reaction time is 20-40 min, and after the reaction, it is allowed to stand for 5 min to obtain calcium-nickel-carbon fiber. The chemical deposition solution is composed of the following components: 7 g / L, 14 g / L, or 21 g / L nickel sulfate hexahydrate, 7 g / L, 14 g / L, or 21 g / L calcium carbonate, 30 g / L sodium hypophosphite, 30 g / L sodium acetate, 18 g / L sodium citrate, and the balance is ammonia water. The pH of the chemical deposition solution is 10.

[0015] S8. Place the obtained calcium-nickel-carbon fiber in an acetone solution for 20-40 minutes to reduce it, remove excess impurities from the chemical plating surface, and wash and dry it with deionized water to obtain the coupled coating carbon fiber.

[0016] Further, step S1 specifically involves placing the carbon fiber in a muffle furnace at 400-500°C for 20-40 minutes.

[0017] Further, step S2 specifically involves immersing the degummed carbon fiber in anhydrous ethanol solution for 30 minutes under magnetic stirring, then rinsing it with deionized water until the supernatant is clear and free of milky white sludge.

[0018] Further, step S3 specifically involves placing the carbon fiber in a NaOH solution with a volume fraction of 2.5-3% and stirring magnetically for 20-40 minutes.

[0019] Furthermore, in step S4, the volume fraction of the SnCl2 solution is 3-4%, and the sensitization time is 20-40 min.

[0020] Furthermore, in step S5, the volume fraction of AgNO3 in the mixed solution of AgNO3 and NaOH is 4%, the volume fraction of NaOH is 2.5%, and the activation time is 20-40 min.

[0021] Furthermore, the volume fraction of the NaH2PO2 solution in step S6 is 2%.

[0022] A second objective of this invention is to provide a coupled-coated carbon fiber prepared using the above-described method.

[0023] The third objective of this invention is to provide an application of coupled coated carbon fiber in improving the wear resistance of gearbox synchronizer rings.

[0024] Compared with existing technologies, the composite material prepared by this invention, which combines carbon fiber and calcium-nickel deposited layer to enhance surface wear resistance, can be used to improve the wear resistance of the synchronizing ring surface. Simultaneously, the surface calcium-nickel layer reduces the friction coefficient of the carbon fiber surface; the friction coefficient of the coupled calcium-nickel layer surface is reduced by approximately 60% compared to the surface of a single carbon fiber layer, thereby improving the wear resistance of the synchronizing ring surface. During the operation of the synchronizing ring, the harder calcium-nickel plating surface is directly worn first, hindering the wear of the carbon fiber. This invention is simple to prepare, low in cost, and can be applied to wear protection of metals in various physical environments, covering wear-resistant surfaces of metal parts in many fields such as automobiles, ships, and aviation. Attached Figure Description

[0025] Figure 1 A process flow for preparing a composite material with enhanced surface wear resistance through coupling of carbon fiber and calcium-nickel deposition layer.

[0026] Figure 2 Electron microscopy image of a composite material with carbon fiber and calcium-nickel deposited layer coupled to enhance surface wear resistance.

[0027] Figure 3 Friction coefficient curves were tested on a tribological tester for a gearbox synchro ring material with a composite material bonded with carbon fiber and a calcium-nickel deposit layer to enhance surface wear resistance. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. The specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention.

[0029] In the following embodiments, the fibers used are Toray Group T300 type 1K carbon fibers. However, this invention is not limited to this embodiment, and the matrix material can be any common carbon fiber.

[0030] Example 1

[0031] Reference Figure 1 The carbon fiber coupled chemical deposition process for preparing calcium-nickel coatings includes the following steps:

[0032] (1) Remove glue: Place the carbon fiber in a muffle furnace and hold it at 500°C for 40 minutes;

[0033] (2) Desizing: The degummed carbon fiber is placed in anhydrous ethanol solution for 30 minutes under magnetic stirring. It is then taken out and washed with deionized water until the supernatant is clear and there are no milky white floating threads.

[0034] (3) Roughening: Place the desized carbon fiber in a 3% (v / v) NaOH solution and stir magnetically for 30 min. Take it out, wash it with deionized water until neutral, and dry it for later use.

[0035] (4) Sensitization: The roughened carbon fiber is placed in a SnCl2 solution with a volume fraction of 3% and stirred magnetically for 30 min. It is then taken out, washed with deionized water until neutral, and dried for later use.

[0036] (5) Activation: The sensitized carbon fiber is placed in a mixed solution of 4% AgNO3 and 2.5% NaOH and stirred magnetically for 40 min. It is then taken out, washed with deionized water until neutral, and dried for later use.

[0037] (6) Reduction: Place the activated carbon fiber in a 2% NaH2PO2 solution and stir magnetically for 60 min. Take it out, wash it with deionized water until neutral, and dry it for later use.

[0038] (7) Chemical deposition of calcium-nickel alloy: First, dissolve 21 g / L nickel sulfate hexahydrate, 7 g / L calcium carbonate, 30 g / L sodium hypophosphite, 30 g / L sodium acetate, and 18 g / L sodium citrate in a small amount of deionized water. Next, pour the nickel sulfate solution into the sodium citrate solution while stirring continuously. Then, pour the sodium hypophosphite solution into the solution prepared in the previous step while stirring vigorously. Dilute with deionized water to a volume of 1 L. Finally, adjust the pH value to 10 with ammonia. The magnetic stirring reaction temperature is 80℃, the reaction time is 30 min, and the reaction is allowed to stand for 5 min after reaction to obtain calcium-nickel alloy carbon fiber.

[0039] (8) Reduction: Place the calcium-nickel alloy carbon fiber in an acetone solution and reduce for 20 min. Wash and dry with deionized water to obtain the coupled coating carbon fiber.

[0040] Example 2

[0041] Reference Figure 1 The carbon fiber coupled chemical deposition process for preparing calcium-nickel coatings includes the following steps:

[0042] (1) Remove glue: Place the carbon fiber in a muffle furnace and hold it at 500°C for 40 minutes.

[0043] (2) Desizing: The degummed carbon fiber is placed in anhydrous ethanol solution for 30 minutes under magnetic stirring. It is then taken out and washed with deionized water until the supernatant is clear and there are no milky white floating threads.

[0044] (3) Roughening: Place the desized carbon fiber in a 3% (v / v) NaOH solution and stir magnetically for 30 min. Take it out, wash it with deionized water until neutral, and dry it for later use.

[0045] (4) Sensitization: The roughened carbon fiber is placed in a SnCl2 solution with a volume fraction of 3% and stirred magnetically for 30 min. It is then taken out, washed with deionized water until neutral, and dried for later use.

[0046] (5) Activation: The sensitized carbon fiber is placed in a mixed solution of 4% AgNO3 and 2.5% NaOH and stirred magnetically for 40 min. It is then taken out, washed with deionized water until neutral, and dried for later use.

[0047] (6) Reduction: Place the activated carbon fiber in a 2% NaH2PO2 solution and stir magnetically for 60 min. Take it out, wash it with deionized water until neutral, and dry it for later use.

[0048] (7) Chemical deposition of calcium-nickel alloy: First, dissolve 14 g / L nickel sulfate hexahydrate, 14 g / L calcium carbonate, 30 g / L sodium hypophosphite, 30 g / L sodium acetate, and 18 g / L sodium citrate separately in a small amount of deionized water. Next, pour the nickel sulfate solution into the sodium citrate solution while stirring continuously. Then, pour the sodium hypophosphite solution into the solution prepared in the previous step while stirring vigorously. Dilute with deionized water to a volume of 1 L. Finally, adjust the pH value to 10 with ammonia. The magnetic stirring reaction temperature is 80℃, the reaction time is 30 min, and after the reaction, let it stand for 5 min to obtain calcium-nickel alloy carbon fiber.

[0049] (8) Reduction: Place the calcium-nickel alloy carbon fiber in an acetone solution and reduce for 20 min. Wash and dry with deionized water to obtain the coupled coating carbon fiber.

[0050] Example 3

[0051] Reference Figure 1 The carbon fiber coupled chemical deposition process for preparing calcium-nickel coatings includes the following steps:

[0052] (1) Remove glue: Place the carbon fiber in a muffle furnace and hold it at 500°C for 40 minutes.

[0053] (2) Desizing: The degummed carbon fiber is placed in anhydrous ethanol solution for 30 minutes under magnetic stirring. It is then taken out and washed with deionized water until the supernatant is clear and there are no milky white floating threads.

[0054] (3) Roughening: Place the desized carbon fiber in a 3% NaOH solution and stir magnetically for 30 minutes. Take it out, wash it with deionized water until neutral, and dry it for later use.

[0055] (4) Sensitization: The roughened carbon fiber is placed in a SnCl2 solution with a volume fraction of 3% and stirred magnetically for 30 min. It is then taken out, washed with deionized water until neutral, and dried for later use.

[0056] (5) Activation: The sensitized carbon fiber is placed in a mixed solution of 4% AgNO3 and 2.5% NaOH and stirred magnetically for 40 min. It is then taken out, washed with deionized water until neutral, and dried for later use.

[0057] (6) Reduction: Place the activated carbon fiber in a 2% NaH2PO2 solution and stir magnetically for 60 min. Take it out, wash it with deionized water until neutral, and dry it for later use.

[0058] (7) Chemical deposition of calcium-nickel alloy: First, 7 g / L nickel sulfate hexahydrate, 21 g / L calcium carbonate, 30 g / L sodium hypophosphite, 30 g / L sodium acetate, and 18 g / L sodium citrate were dissolved in a small amount of deionized water. Next, the nickel sulfate solution was poured into the sodium citrate solution while stirring continuously. Then, the sodium acetate solution was poured into the solution while stirring. Subsequently, the sodium hypophosphite solution was poured into the solution prepared in the previous step while stirring vigorously. The solution was diluted with deionized water to a volume of 1 L. Finally, the pH value was adjusted to 10 with ammonia. The magnetic stirring reaction temperature was 80℃, the reaction time was 30 min, and the reaction was allowed to stand for 5 min after reaction to obtain calcium-nickel alloy carbon fiber.

[0059] (8) Reduction: Place the calcium-nickel alloy carbon fiber in an acetone solution and reduce for 20 min. Wash and dry with deionized water to obtain the coupled coating carbon fiber.

[0060] The coupled coated carbon fiber prepared in Example 2 was subjected to electron microscopy, and its electron microscopy image is shown below. Figure 2 As shown, by Figure 2As can be seen, the carbon fiber is coated with a calcium-nickel plating layer. When it comes into contact with other metal surfaces, the calcium-nickel plating layer is directly worn first, which protects the inner carbon fiber layer and reduces the coefficient of friction, thus greatly reducing the wear rate. Therefore, it can be used on the surface of the gearbox synchronizer ring to extend the service life of the carbon fiber and the synchronizer ring.

[0061] Furthermore, to test the wear resistance of the coupled-coated carbon fiber prepared in this invention, the coupled-coated carbon fiber prepared in Examples 1-3 was bonded to the surface of the gearbox synchronizer ring material for friction testing. The test force was 500 N, the relative rotation speed was 9 r / min, and the temperature was 235 °C. The coefficient of friction was tested, and the results are as follows: Figure 3 As shown, the friction coefficient of the single carbon fiber layer surface is 0.418, while the lowest friction coefficient of the coupled calcium-nickel layer surface is 0.123, representing a reduction of approximately 60% in friction coefficient compared to the single carbon fiber layer surface. Figure 3 It can be seen that the coupling coating carbon fibers prepared in Examples 1-3 all have a low coefficient of friction, which can effectively protect the gearbox synchronization ring.

[0062] The technical solutions of the present invention are not limited to the specific embodiments described above. Any technical modifications made in accordance with the technical solutions of the present invention fall within the protection scope of the present invention.

Claims

1. A method for preparing coupled coated carbon fiber, characterized in that, Includes the following steps: S1. Degumming treatment of carbon fiber; S2. Desizing treatment is performed on the degummed carbon fiber. S3. Roughen the carbon fiber after desizing; S4. Sensitize the roughened carbon fiber: Place the roughened carbon fiber in SnCl2 solution and stir magnetically to adsorb a layer of easily oxidized substance on the surface of the carbon fiber. S5. Activate the sensitized carbon fiber: Place the sensitized carbon fiber in a mixed solution of AgNO3 and NaOH and stir magnetically to generate a catalytically active metal layer on the surface of the carbon fiber. S6. Reduce the activated carbon fiber: Place the activated carbon fiber in NaH2PO2 solution and stir magnetically for 60-80 minutes to reduce the silver oxide remaining on the surface of the carbon fiber. S7. The reduced carbon fiber is placed in a chemical deposition solution for chemical deposition. The chemical deposition reaction temperature is 80℃, the reaction time is 20-40 min, and after the reaction, it is allowed to stand for 5 min to obtain calcium-nickel-carbon fiber. The chemical deposition solution is composed of the following components: 7 g / L, 14 g / L, or 21 g / L nickel sulfate hexahydrate, 7 g / L, 14 g / L, or 21 g / L calcium carbonate, 30 g / L sodium hypophosphite, 30 g / L sodium acetate, 18 g / L sodium citrate, and the balance is ammonia. The pH of the chemical deposition solution is 10. S8. Place the obtained calcium-nickel-carbon fiber in an acetone solution for 20-40 minutes to reduce it, remove excess impurities from the chemical plating surface, and wash and dry it with deionized water to obtain the coupled coating carbon fiber.

2. The method for preparing the coupled-coated carbon fiber according to claim 1, characterized in that, Step S1 specifically involves placing the carbon fiber in a muffle furnace at 400-500℃ for 20-40 minutes.

3. The method for preparing the coupled-coated carbon fiber according to claim 1, characterized in that, Step S2 specifically involves immersing the degummed carbon fiber in anhydrous ethanol solution for 30 minutes under magnetic stirring, then rinsing it with deionized water until the supernatant is clear and free of milky white flocculation.

4. The method for preparing the coupled-coated carbon fiber according to claim 1, characterized in that, Step S3 specifically involves placing the carbon fiber in a NaOH solution with a volume fraction of 2.5-3% and stirring magnetically for 20-40 minutes.

5. The method for preparing the coupled-coated carbon fiber according to claim 1, characterized in that: In step S4, the volume fraction of the SnCl2 solution is 3-4%, and the sensitization time is 20-40 min.

6. The method for preparing the coupled-coated carbon fiber according to claim 1, characterized in that: In step S5, the volume fraction of AgNO3 in the mixed solution of AgNO3 and NaOH is 4%, the volume fraction of NaOH is 2.5%, and the activation time is 20-40 min.

7. The method for preparing coupled-coated carbon fiber according to claim 1, characterized in that: The volume fraction of the NaH2PO2 solution in step S6 is 2%.

8. A coupled coated carbon fiber prepared by the method according to any one of claims 1-7.

9. The application of the coupled coated carbon fiber as described in claim 8 in improving the wear resistance of the synchronizer ring of a gearbox.

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