Carbon fiber / Cu-Zn bearing composite material, preparation method and application
By preparing copper-plated carbon fiber/Cu-Zn bearing composite material, the problem of poor bonding between copper-based composite materials and carbon fiber was solved, and the wear resistance and self-lubrication of the material were improved. It is suitable for self-lubricating bearings, brushes, electrical contacts and high-speed printer components.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- JILIN RAILWAY VOCATIONAL & TECH COLLEGE
- Filing Date
- 2023-11-30
- Publication Date
- 2026-05-19
AI Technical Summary
The poor bonding between copper-based composite materials and carbon fibers results in poor wear resistance and makes it difficult to distribute loads evenly on the matrix metal, thus affecting the material properties.
By mixing copper-plated carbon fiber with Cu and Zn powdered raw materials and adding polyethylene wax binder, the distribution direction of the copper-plated carbon fiber strips is controlled to prepare carbon fiber/Cu-Zn bearing composite material, thereby enhancing the integrity and wear resistance of the composite material.
It improves the wear resistance and self-lubrication of composite materials, reduces the wear rate, and enhances the integrity and thermal conductivity of the materials, making it suitable for self-lubricating bearings, brushes, electrical contacts, and high-speed printer components.
Smart Images
Figure CN117721343B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of copper-based composite materials, and particularly to a carbon fiber / Cu-Zn bearing composite material, its preparation method, and its application. Background Technology
[0002] Copper-based composites typically possess excellent thermal conductivity, mechanical properties, and corrosion resistance, making them widely used in many fields. However, their applications are limited by deficiencies in strength, stiffness, and coefficient of thermal expansion. Research often involves strengthening copper-based composites with additives, which, while improving alloy hardness, also introduces problems such as poor wear resistance and poor bonding. Therefore, researching and preparing copper-based composites with good bonding and enhanced wear resistance has become an urgent problem to solve. Carbon fiber materials, with their graphite-like hexagonal lattice crystal structure, possess a series of excellent properties, including high specific strength, high specific modulus, high temperature and corrosion resistance, fatigue resistance, creep resistance, electrical and thermal conductivity, low coefficient of thermal expansion, and excellent self-lubricating and friction-reducing properties. These properties make them one of the most important reinforcing materials in recent years. By improving the electrical and thermal conductivity of carbon fiber-reinforced copper-based composites, the excellent properties of the matrix material, such as resistance to arc erosion and self-lubricating ability, are achieved. Carbon fiber-reinforced self-lubricating composites not only possess the good electrical and thermal conductivity of copper but also the low coefficient of thermal expansion and ultra-low coefficient of friction of carbon fiber, making them a promising new type of functional material. However, adding carbon fiber materials to a Cu-Zn matrix can lead to poor dispersibility and bonding, making it difficult for the matrix material to wet and react with the carbon fibers in both solid and liquid states during the preparation of composite materials. Therefore, it is difficult to form products with excellent dispersibility and bonding. This phenomenon results in the inability to uniformly distribute the load on the matrix metal or transfer it to the supporting fibers when the prepared product is subjected to external loads. Consequently, the added fibers in the matrix cannot function properly and negatively impact the performance of the matrix material. Existing bearings, brushes, electrical contacts, and high-speed printer components, which cannot use ball bearings for sliding parts, suffer from a series of problems with traditional materials, including poor conductivity, poor friction reduction and wear resistance, poor corrosion resistance, poor resistance to arc erosion, and poor resistance to welding. How to combine the excellent friction reduction and wear resistance properties of carbon fiber with the excellent thermal conductivity, mechanical properties, and corrosion resistance of copper-based materials for application in these sliding parts to overcome these problems of traditional materials is the research topic of this invention. Summary of the Invention
[0003] To address the issue of poor wear resistance in copper-based composite materials due to poor bonding between the composite material and carbon fiber, this invention provides a carbon fiber / Cu-Zn bearing composite material, its preparation method, and its application. The composite material is obtained by mixing copper-plated carbon fiber with Cu and Zn powdered raw materials, adding a polyethylene wax binder, mixing thoroughly, pressing, and sintering under a protective atmosphere. The copper-plated carbon fiber exhibits good compatibility with the Cu-Zn matrix, enhancing the overall integrity of the composite material; the ultra-low coefficient of friction of the carbon fiber further enhances the wear resistance of the composite material.
[0004] The present invention provides the following specific solution: a carbon fiber / Cu-Zn bearing composite material, prepared from the following raw materials: 3.6-3.8 wt% carbon fiber, 57-62 wt% Cu (copper), 34-39 wt% Zn (zinc), and 0.2-0.4 wt% binder. The carbon fiber has a minimum length of not less than 1 mm and is copper-plated carbon fiber strips with a continuous surface electroplating of a 20-25 micrometer thick copper layer and cut into lengths of 0.4 mm-1.1 mm. The Cu and Zn are in powder form, both with a size of 200-300 mesh.
[0005] The copper-plated carbon fiber strips consist of 3.6 wt% Cu (copper), 60 wt% Cu (copper), 36 wt% Zn (zinc), and 0.4 wt% binder. The resulting composite material has a density of 7.24 g / cm³. 3 It has a coefficient of friction of 0.13 and a hardness of 171HB.
[0006] The copper-plated carbon fiber strips in the raw material blank formed after the raw materials are mixed evenly and compacted tend to be distributed perpendicular to the workpiece in the direction of strip length.
[0007] In the finished product made of the composite material, the copper-plated carbon fiber strips, which tend to be perpendicular to the workpiece, are distributed on the side of the finished product that bears the sliding friction of the workpiece, while the copper-plated carbon fiber strips are not distributed on the side of the finished product that is away from the sliding friction of the workpiece.
[0008] A method for preparing the carbon fiber / Cu-Zn bearing composite material includes the following steps:
[0009] S1. Copper plating on carbon fiber surface: A copper layer is electroplated on the surface of carbon fiber raw material to obtain copper-plated carbon fiber.
[0010] S2. Cutting copper-plated carbon fiber into segments and mixing with Cu and Zn powder raw materials: Cut the copper-plated carbon fiber into copper-plated carbon fiber strips and mix the copper-plated carbon fiber strips with Cu and Zn powder raw materials by dry mixing method.
[0011] S3. Add adhesive to mixture and compact: Add polyethylene wax adhesive to the mixture obtained in S2, mix evenly, and then compact to obtain raw material blank;
[0012] S4. Sintering preparation: The raw material blank described in S3 is sintered under a protective atmosphere to obtain carbon fiber / Cu-Zn composite material.
[0013] The electroplating solution used in S1 is copper sulfate solution, and the copper plating material is pure copper.
[0014] During the S3 compaction process, the arrangement direction of the copper-plated fiber strips is controlled so that the distribution of copper-plated carbon fiber strips in the raw material blank tends to be perpendicular to the workpiece in terms of strip length direction.
[0015] During the S3 compaction process, the arrangement direction of the copper-plated fiber strips is controlled so that the copper-plated carbon fiber strips in the raw material blank are distributed on the side of the finished product that bears the sliding friction of the workpiece, while the copper-plated carbon fiber strips are not distributed on the side of the finished product that is away from the sliding friction of the workpiece.
[0016] The application of the carbon fiber / Cu-Zn bearing composite material in self-lubricating bearings, brushes, electrical contacts, and high-speed printer components.
[0017] The method produces self-lubricating bearings, brushes, electrical contacts, and high-speed printer components.
[0018] The beneficial effects of this invention are:
[0019] This invention provides a carbon fiber / Cu-Zn bearing composite material, its preparation method, and its application. The bearing composite material uses carbon fiber mixed with copper and zinc in a specific ratio. The carbon fiber is first continuously electroplated to form copper-plated carbon fiber strips of a specific thickness. The copper-plated carbon fiber strips of a specific size are then mixed with Cu and Zn powdered raw materials, and a polyethylene wax binder is added and mixed evenly. After pressing, the mixture is sintered under a protective atmosphere to obtain the carbon fiber / Cu-Zn bearing composite material. The copper-plated carbon fiber has good compatibility with the Cu-Zn matrix, enhancing the overall integrity of the composite material. The ultra-low coefficient of friction of the carbon fiber enhances the wear resistance of the composite material.
[0020] Specifically, the distribution of copper-plated carbon fiber strips in the raw material billet, with the strip length direction perpendicular to the workpiece, helps to form self-lubricating properties. In the bearing material of this invention, during operation, the copper and copper-zinc matrix mainly detaches in the early stages of wear. As the sliding distance increases, the carbon fibers gradually lose the support of the matrix and adhere to the matrix and test ring, forming a carbon film with lubricating properties. Friction transitions from metal-metal wear to carbon-carbon and metal-carbon wear. Due to the addition of carbon fibers, the material possesses self-lubricating properties. Therefore, as the volume content of carbon fibers in the composite material increases, the wear coefficient decreases, and the wear rate also decreases.
[0021] In particular, copper-plated carbon fiber strips are distributed only on the bearing material facing the workpiece, which can save materials and improve processing efficiency. Attached Figure Description
[0022] Figure 1 This is a flowchart of a method for preparing carbon fiber / Cu-Zn bearing composite material provided by the present invention.
[0023] Figure 2 This is a schematic diagram showing the distribution of copper-plated carbon fiber strips on the workpiece-facing side of the bearing made of the carbon fiber / Cu-Zn bearing composite material of the present invention. The copper-plated carbon fiber strips tend to be perpendicular to the length direction of the workpiece, and there are copper-plated carbon fiber strips only on this side, while there are no copper-plated carbon fiber strips on the other side. Detailed Implementation
[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0025] like Figure 2 As shown, a carbon fiber / Cu-Zn bearing composite material is prepared from the following raw materials: 3.6-3.8 wt% carbon fiber, 57-62 wt% Cu (copper), 34-39 wt% Zn (zinc), and 0.2-0.4 wt% binder. The carbon fiber has a minimum length of not less than 1 mm and is copper-plated carbon fiber strips with a continuous surface electroplating of a 20-25 micrometer thick copper layer and cut into lengths of 0.4 mm-1.1 mm. The Cu and Zn are in powder form, both with a size of 200-300 mesh.
[0026] The aforementioned bearing composite material exhibits a monotonically decreasing coefficient of friction and wear rate with increasing carbon fiber content. Within the aforementioned range, the dynamic friction coefficient of the basal surface, measured by a transverse force microscope, is 0.12-0.15. However, the material hardness decreases from 177HB to 155HB with increasing carbon fiber content.
[0027] Preferably, the copper-plated carbon fiber strip comprises 3.6 wt% Cu (copper), 60 wt% Zn (zinc), and 0.4 wt% binder; the composite material prepared under this ratio has a density of 7.24 g / cm³. 3 At that time, the coefficient of friction was 0.13 and the hardness was 171HB. The proportions of each component can be adjusted within the above range according to the needs of different hardness and wear resistance, but they can all be applied to existing bearings, brushes, electrical contacts, and sliding parts of high-speed printer components where ball bearings cannot be used. It has the advantages of good conductivity, strong friction reduction and wear resistance, good corrosion resistance, good resistance to electric arc erosion, and good resistance to welding.
[0028] For example, when preparing the composite material, the proportions of copper-plated carbon fiber strips (3.8 wt%), Cu (copper) (58 wt%), Zn (zinc) (38 wt%), and binder (0.2 wt%) show enhanced friction reduction and wear resistance. With the copper-plated carbon fiber strip content remaining constant, increasing the Zn content (Zn%) in the copper-zinc alloy to 34%-39% results in a relatively small impact on the material's friction coefficient, as shown in Table 1, without significant changes.
[0029] Table 1
[0030] Zn% 34％ 36％ 39％ coefficient of friction 0.128 0.129 0.134
[0031] During the experiment, when the copper-plated carbon fiber strips were randomly distributed in the composite material, their electrical conductivity was low. The thermal conductivity and electrical conductivity of the composite material showed similar trends, with the thermal conductivity gradually decreasing from parallel to perpendicular arrangement of the copper-plated carbon fibers. In this embodiment, the copper-plated carbon fiber strips were perpendicular to the inner contact surface of the bearing to enhance the thermal conductivity of the composite material.
[0032] Preferably, in the raw material blank formed after the raw materials are uniformly mixed and compacted, the copper-plated carbon fiber strips are distributed with their length direction perpendicular to the workpiece. The distribution of the copper-plated carbon fiber strips during the compaction process is easily achieved in existing technologies. In a laboratory setting, the copper-plated carbon fiber strips can be manually arranged in the same direction before compacting the copper-zinc powder. In industrial applications, specialized tools are available for aligning the strips in the same direction, such as electrostatic treatment.
[0033] The distribution of copper-plated carbon fiber strips, with their length direction perpendicular to the workpiece, helps to form self-lubricating properties. In the early stages of wear in bearing composite materials, the copper and copper-zinc matrix mainly detach. As the sliding distance increases, the carbon fibers gradually lose the support of the matrix and adhere to the matrix and test ring, forming a carbon film with lubricating properties. The friction transitions from metal-metal wear to carbon-carbon and metal-carbon wear. Due to the addition of carbon fibers, the material has self-lubricating properties. Therefore, as the volume content of carbon fibers in the composite material increases, the wear coefficient decreases and the wear rate also decreases.
[0034] Preferably, in the finished product made of the composite material, the copper-plated carbon fiber strips, which tend to be perpendicular to the workpiece, are distributed on the side of the finished product that bears the sliding friction of the workpiece, while the copper-plated carbon fiber strips are not distributed on the side of the finished product away from the side that bears the sliding friction of the workpiece. Figure 2 As shown, the bearing made of the composite material has copper-plated carbon fiber strips distributed on the inner side of the bearing (i.e. the side subjected to sliding friction), with the strip length direction perpendicular to the inner side of the bearing. The copper-plated carbon fiber strips are only distributed on the inner side, and there are no copper-plated carbon fiber strips on the outer side.
[0035] like Figure 1As shown, a method for preparing the carbon fiber / Cu-Zn bearing composite material includes the following steps:
[0036] S1. Copper plating on carbon fiber surface: A copper layer is electroplated on the surface of carbon fiber raw material to obtain copper-plated carbon fiber; wherein the electroplating solution used is copper sulfate solution, and the copper plating material is pure copper.
[0037] S2. Cutting copper-plated carbon fiber into segments and mixing with Cu and Zn powder raw materials: Cut the copper-plated carbon fiber into copper-plated carbon fiber strips and mix the copper-plated carbon fiber strips with Cu and Zn powder raw materials by dry mixing.
[0038] S3. Adding adhesive to the mixture and compacting: Add polyethylene wax adhesive to the mixture obtained in S2, mix evenly, and then compact to obtain a raw material blank. During the compaction process, control the arrangement direction of the copper-plated fiber strips so that the distribution of the copper-plated carbon fiber strips in the raw material blank tends to be perpendicular to the workpiece in terms of strip length. During the compaction process, control the arrangement direction of the copper-plated carbon fiber strips so that the copper-plated carbon fiber strips in the raw material blank are distributed on the side of the finished product that bears the sliding friction of the workpiece, and the side of the finished product away from the sliding friction of the workpiece does not have the copper-plated carbon fiber strips distributed.
[0039] S4. Sintering preparation: The raw material blank described in S3 is sintered under a protective atmosphere to obtain carbon fiber / Cu-Zn composite material.
[0040] The application of the carbon fiber / Cu-Zn bearing composite material in self-lubricating bearings, brushes, electrical contacts, and high-speed printer components.
[0041] The method produces self-lubricating bearings, brushes, electrical contacts, and high-speed printer components.
[0042] It should be noted that the specific embodiments described above enable those skilled in the art to more fully understand the present invention, but do not limit the present invention in any way. Therefore, although the present invention has been described in detail with reference to the accompanying drawings and embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the present invention. In short, all technical solutions and improvements that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the present invention patent.
Claims
1. A carbon fiber / Cu-Zn bearing composite material, characterized in that, It is prepared from the following raw materials: carbon fiber 3.6-3.8wt%, Cu (copper) 57-62wt%, Zn (zinc) 34-39wt%, binder 0.2-0.4wt%. The carbon fiber has a minimum length of not less than 1mm and is copper-plated carbon fiber strips with a continuous surface electroplating of a 20-25 micrometer thick copper layer and cut into lengths of 0.4mm-1.1mm. The Cu and Zn are in powder form, both with a size of 200-300 mesh. The copper-plated carbon fiber strips in the raw material blank formed after the raw materials are mixed evenly and compacted tend to be distributed perpendicular to the workpiece in the direction of strip length. In the finished product made of the composite material, the copper-plated carbon fiber strips, which tend to be perpendicular to the workpiece, are distributed on the side of the finished product that bears the sliding friction of the workpiece, while the copper-plated carbon fiber strips are not distributed on the side of the finished product that is away from the sliding friction of the workpiece.
2. The carbon fiber / Cu-Zn bearing composite material according to claim 1, characterized in that, The copper-plated carbon fiber strip consists of 3.6 wt% copper, 60 wt% copper, 36 wt% zinc, and 0.4 wt% binder.
3. The carbon fiber / Cu-Zn bearing composite material according to claim 2, characterized in that, The density of the composite material is 7.24 g / cm³. 3 Its coefficient of friction is 0.13 and its hardness is 171HB.
4. A method for preparing the carbon fiber / Cu-Zn bearing composite material according to any one of claims 1-3, characterized in that, Includes the following steps: S1. Copper plating on carbon fiber surface: A copper layer is electroplated on the surface of carbon fiber raw material to obtain copper-plated carbon fiber. S2. Cutting copper-plated carbon fiber into segments and mixing with Cu and Zn powder raw materials: Cut the copper-plated carbon fiber into copper-plated carbon fiber strips and mix the copper-plated carbon fiber strips with Cu and Zn powder raw materials by dry mixing method. S3. Add adhesive to mixture and compact: Add polyethylene wax adhesive to the mixture obtained in S2, mix evenly, and then compact to obtain raw material blank; S4. Sintering preparation: The raw material blank described in S3 is sintered under a protective atmosphere to obtain carbon fiber / Cu-Zn composite material.
5. The method for preparing a carbon fiber / Cu-Zn bearing composite material according to claim 4, characterized in that, In S1, the electroplating solution used is copper sulfate solution, and the electroplating copper material is pure copper. In the S3 compaction process, the arrangement direction of the copper-plated fiber strips is controlled so that the distribution of copper-plated carbon fiber strips in the raw material blank tends to be perpendicular to the workpiece in the length direction.
6. A method for preparing a carbon fiber / Cu-Zn bearing composite material as described in claim 4 or 5, characterized in that... During the S3 compaction process, the arrangement direction of the copper-plated fiber strips is controlled so that the copper-plated carbon fiber strips in the raw material blank are distributed on the side of the finished product that bears the sliding friction of the workpiece, while the copper-plated carbon fiber strips are not distributed on the side of the finished product that is away from the sliding friction of the workpiece.
7. The application of a carbon fiber / Cu-Zn bearing composite material as described in any one of claims 1-3 in self-lubricating bearings, brushes, electrical contacts, and high-speed printer components.
8. Self-lubricating bearings, brushes, electrical contacts, and high-speed printer components prepared by the method according to any one of claims 4-6.