Copper-based wear-resistant antifriction material and preparation method thereof

Abstract

The invention discloses a copper-based wear-resistant antifriction material which comprises the following components in parts by mass: 5-20 parts of a wear-resistant component, 5-20 parts of a lubricating component and 60-90 parts of corrosion-resistant copper alloy powder, wherein the wear-resistant component comprises at least one of the following components: SiO2 particles, Al2O3 particles and SiC particles; the lubricating component comprises at least one of graphite powder, silver powder and lead powder; the corrosion-resistant copper alloy powder comprises at least one of copper tin powder, copper aluminum powder and copper zinc powder. The copper-tin powder, the copper-aluminum powder and the copper-zinc powder are used as base materials, a base body of the prepared composite material has good corrosion resistance, meanwhile, the follow-up machining performance of the composite material is excellent, and the composite material has good corrosion resistance and lower corrosion rate in a saline water or salt mist environment.

Description

Technical Field

[0001] The present invention relates to the technical field of friction materials, and particularly relates to a copper-based wear-resistant and friction-reducing material and a preparation method thereof. Background Art

[0002] The friction materials commonly used in braking systems mainly include copper-based, iron-based, and copper-iron-based materials. The most traditional and economical brake pads are still iron-based powder metallurgy brake pad materials. However, with the improvement of braking requirements and different braking environments, and the kinetic energy that the braking device needs to absorb and convert heat energy increasing exponentially, in order to reduce the surface temperature of the brake disc and brake pads, the requirement for the heat conduction of the braking material is getting higher and higher. During the use of iron-based powder metallurgy brake pads, they are prone to adhesion with iron-based brake discs, the friction coefficient varies greatly with temperature, and the instantaneous braking power fluctuates greatly during the full braking process, resulting in heat spots on the brake disc, and heat spots are the source of brake disc cracking. At the same time, due to the huge changes in the working environment of modern braking systems, especially in environments such as coastal railways and offshore wind power where there is a high salt mist environment with a high chloride ion concentration, the corrosion of the composite materials exposed outside the brake pad material of the braking system is very serious. Therefore, a braking material with good heat conduction performance, high braking stability, high corrosion resistance, good wear resistance, and a small adhesion tendency with the brake disc has become a research hotspot.

[0003] On this basis, copper-based powder metallurgy friction materials have been widely used in the clutch and braking devices of aerospace, high-speed trains, onshore wind power, and ships due to their outstanding characteristics of good high-temperature friction performance, thermal conductivity, wear resistance, and maintaining friction stability under different dry and wet conditions. However, at present, the wear amount of copper-based powder metallurgy friction materials is relatively high, and their hardness and compressive strength are relatively low. Summary of the Invention

[0004] The purpose of the present invention is to provide a copper-based wear-resistant and friction-reducing material and a preparation method thereof to solve the above technical problems.

[0005] To achieve the above purpose, the present invention provides a copper-based wear-resistant and friction-reducing material, which comprises the following components in parts by mass: 5 - 20 parts of wear-resistant components, 5 - 20 parts of lubricating components, and 60 - 90 parts of corrosion-resistant copper alloy powder;

[0006] Among them, the wear-resistant components include at least one of the following: SiO2 particles, Al2O3 particles, SiC particles; the lubricating components include at least one of the following: graphite powder, silver powder, lead powder; the corrosion-resistant copper alloy powder includes at least one of the following: copper-tin powder, copper-aluminum powder, and copper-zinc powder.

[0007] The present invention also provides a preparation method of a copper-based wear-resistant and friction-reducing material, and the method comprises:

[0008] Mix wear-resistant components, lubricating components, and corrosion-resistant copper alloy powder to obtain mixed powder;

[0009] Load the dried mixed powder into a copper tube for compaction and sealing to obtain a cold-pressed green body;

[0010] Perform hot isostatic pressing on the cold-pressed green body to obtain the copper-based wear-resistant and friction-reducing material.

[0011] The present invention also provides an application of the copper-based wear-resistant and friction-reducing material, and the application of the copper-based wear-resistant and friction-reducing material in a braking device in a coastal high-salt fog environment.

[0012] The technical effects and advantages of the present invention:

[0013] 1. The present invention uses copper-tin powder, copper-aluminum powder, and copper-zinc powder as matrix materials. The matrix of the prepared composite material has good corrosion resistance, and at the same time, its subsequent processing performance is excellent. In a saline water or salt fog environment, it has good corrosion resistance and a lower corrosion rate.

[0014] 2. The preparation method of the present invention first adopts mechanical mixing, cold pressing of the green body, and then hot isostatic pressing, so that the matrix components, wear-resistant components, and lubricating components of the obtained composite material are evenly dispersed and the material properties are stable.

[0015] Other features and advantages of the present invention will be described in the following specification, and, in part, will become obvious from the specification, or will be understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the structures pointed out in the specification and the drawings. Brief Description of the Drawings

[0016] Figure 1 It is a flow chart of the preparation method of the copper-based wear-resistant and friction-reducing material;

[0017] Figure 2 It is a scanning electron microscope photograph of the mixed powder prepared in Example 1;

[0018] Figure 3 It is a scanning electron microscope photograph of the copper-based composite material in Example 1. Detailed Description of the Invention

[0019] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the drawings provided by the present invention. Moreover, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the protection scope of the present invention.

[0020] It should be noted that the structures, proportions, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the implementation conditions of the present invention. Therefore, they do not have substantial technical significance. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle", and "one" cited in this specification are only for the convenience of clear narration and are not used to limit the scope of implementation of the present invention. The change or adjustment of their relative relationship, without substantial change in the technical content, should also be regarded as the scope of implementation of the present invention.

[0021] To better understand this solution, a general description of the concept of this solution is given first: By adding uniformly dispersed wear-resistant components (such as SiO2, Al2O3, SiC particles, etc.) to the corrosion-resistant copper alloy powder, the hardness and strength of the material can be significantly improved, and excellent wear resistance can be exhibited. Moreover, SiO2, Al2O3, and SiC can inhibit grain growth and reduce grain size during the sintering process. At the same time, copper-tin powder, copper-aluminum powder, and copper-zinc powder are selected as the matrix materials. Such powder materials have good corrosion resistance and excellent subsequent processing performance. In addition, the lubricating components are graphite powder, silver powder, lead powder, etc. The friction coefficient is very low, they can coexist with salt water, and have good dispersibility in salt water. Therefore, even when the friction material is in a salt spray environment, it can maintain its good lubricating performance and corrosion resistance. Therefore, in summary, the high-temperature-resistant and high-corrosion-resistant copper-based wear-resistant and friction-reducing material obtained by reasonably selecting component compositions and controlling the addition amounts in this technical solution has good physical properties, especially excellent wear resistance and corrosion resistance, and has broad application prospects in the field of braking devices for coastal rail transit, offshore wind power, offshore cruise ships, etc. The following details the copper-based wear-resistant and friction-reducing material and the preparation method of the copper-based wear-resistant and friction-reducing material.

[0022] The present invention provides a copper-based wear-resistant and friction-reducing material, which includes the following components in parts by mass: 5 - 20 parts of wear-resistant components, 5 - 20 parts of lubricating components, and 60 - 90 parts of corrosion-resistant copper alloy powder; wherein, the wear-resistant components include at least one of the following: SiO2 particles, Al2O3 particles, SiC particles; the lubricating components include at least one of the following: graphite powder, silver powder, lead powder; the corrosion-resistant copper alloy powder includes at least one of the following: copper-tin powder, copper-aluminum powder, and copper-zinc powder.

[0023] Among them, the wear-resistant components include but are not limited to: SiO2 particles, Al2O3 particles, SiC particles; the lubricating components include but are not limited to: graphite powder, silver powder, lead powder; the corrosion-resistant copper alloy powder includes but is not limited to: copper-tin powder, copper-aluminum powder, and copper-zinc powder.

[0024] Specifically, the particle size of the wear-resistant component is 100 - 500 μm. The particle size of the lubricating component is 125 - 500 μm. The particle size of the corrosion-resistant copper alloy powder is 10 - 500 μm.

[0025] The present invention also provides a preparation method of a copper-based wear-resistant and friction-reducing material, as Figure 1 shown, the method includes:

[0026] Mixing the wear-resistant component, the lubricating component, and the corrosion-resistant copper alloy powder to obtain a mixed powder;

[0027] Loading the dried mixed powder into a copper tube for compaction and sealing to obtain a cold-pressed blank;

[0028] Performing hot isostatic pressing on the cold-pressed blank to obtain the copper-based wear-resistant and friction-reducing material.

[0029] Among them, the mixing includes: mechanical mixing; among them, the forms of the mechanical mixing include: ball milling, stirring, vibration, bottom blowing, and rotation. It should be noted that solvents such as alcohol, soap, and methanol can be added during the mixing process, but if the above organic solvents are added, subsequent baking at a low temperature of 200 - 500 °C is required to remove the organic substances introduced during the mixing process.

[0030] Among them, the copper tube is a white copper tube, and the shapes of the copper tube include: round tube, square tube, and cuboid.

[0031] Among them, the conditions of the hot isostatic pressing include: the temperature is 700 - 1050 °C, and the pressure holding time is 1 - 4 h.

[0032] The present invention also provides an application of the copper-based wear-resistant and friction-reducing material, and the application of the copper-based wear-resistant and friction-reducing material in a braking device in a coastal high-salt fog environment.

[0033] To make the present solution more substantial, the present invention also provides embodiments, specifically as follows:

[0034] Example 1

[0035] The high heat-resistant and high corrosion-resistant copper-based wear-resistant and friction-reducing material of this example includes the following mass components: 5 parts of wear-resistant component SiO2, 5 parts of lubricating component graphite powder, 50 parts of copper-tin powder, 40 parts of copper-aluminum powder, etc.

[0036] The preparation method of the high heat-resistant and high corrosion-resistant copper-based wear-resistant and friction-reducing material of this example includes the following steps:

[0037] (1) Select 5 wt.% wear-resistant component SiO2 (average particle size is 100 μm, purity is 99.5%), 5 wt.% lubricating component graphite powder (average particle size is 125 μm, purity is 99.5%), 50 wt.% copper-tin powder (average particle size is 125 μm, purity is 99.5%), and 40 wt.% copper-aluminum powder (average particle size is 125 μm, purity is 99.5%) as raw materials. Add the above raw material powders into a device with a mixing function respectively, then add 5% anhydrous ethanol, etc. as process control agents, and then carry out sufficient mixing. After mixing, bake at 200 °C for 1 hour to remove the organic matter introduced during the mixing process. Among them, Figure 2 is the scanning electron microscope photo of the mixed powder. It can be seen from the figure that the matrix component, wear-resistant component and lubricating component in the mixed powder are evenly dispersed.

[0038] (2) Load the evenly mixed and fully dried powder into a white copper tube for compaction and sealing. The shape of the white copper tube is a round tube, and the sealing method is vacuum electron beam welding.

[0039] (3) Carry out hot isostatic pressing and densification on the sealed cold-pressed blank at a temperature of 700 °C for a holding time of 4 hours to obtain a high heat-resistant and high corrosion-resistant copper-based wear-resistant and friction-reducing material. Among them, Figure 3 is the scanning electron microscope photo of the high heat-resistant and high corrosion-resistant copper-based wear-resistant and friction-reducing material. It can be seen from the figure that the matrix component, wear-resistant component and lubricating component in the composite material are evenly dispersed, ensuring the stability of the material performance.

[0040] Example 2

[0041] The high heat-resistant and high corrosion-resistant copper-based wear-resistant and friction-reducing material of this example includes the following mass components: 10 parts of wear-resistant component Al2O3, 10 parts of lubricating component silver powder, and 80 parts of copper-aluminum powder.

[0042] The preparation method of the high heat-resistant and high corrosion-resistant copper-based wear-resistant and friction-reducing material of this example includes the following steps:

[0043] (1) Select 10 wt.% wear-resistant component Al2O3 (average particle size is 200 μm, purity is 99.5%), 10 wt.% lubricating component silver powder (average particle size is 200 μm, purity is 99.5%), and 80 wt.% copper-aluminum powder (average particle size is 125 - 500 μm, purity is 99.5%) as raw materials. Add the above raw material powders into a device with a mixing function respectively, then add 5% anhydrous ethanol as a process control agent, and then carry out sufficient mixing. After mixing, bake at 300 °C for 2 hours to remove the organic matter introduced during the mixing process.

[0044] (2) Load the evenly mixed and fully dried powder into a white copper tube for compaction and sealing. The shape of the white copper tube is a round tube, and the sealing method is vacuum electron beam welding.

[0045] (3) Hot isostatic pressing densification is carried out on the sealed cold-pressed green body at a temperature of 900 °C for a holding pressure time of 2 hours.

[0046] Example 3

[0047] The high heat-resistant and high corrosion-resistant copper-based wear-resistant and friction-reducing material of this example includes the following mass components: 20 parts of wear-resistant component SiC, 5 parts of lubricating component lead powder, and 75 parts of copper-zinc powder.

[0048] The preparation method of the high heat-resistant and high corrosion-resistant copper-based wear-resistant and friction-reducing material of this example includes the following steps:

[0049] (1) Select 20 wt.% of wear-resistant component SiC (average particle size is 300 μm, purity 99.5%), 5 wt.% of lubricating component lead powder (average particle size is 125 μm, purity 99.5%), and 75 wt.% of copper-zinc powder (particle size is 125 μm, purity 99.5%) as raw materials. Add the above raw material powders into a device with a mixing function respectively, then add 5% of methanol, etc. as a process control agent, and then carry out sufficient mixing. After mixing, bake at 200 °C for 1 hour to remove the organic matter introduced during the mixing process.

[0050] (2) Load the uniformly mixed and fully dried powder into a white copper tube for compaction and sealing. The shape of the white copper tube is a square tube, and the sealing method is vacuum electron beam welding.

[0051] (3) Hot isostatic pressing densification is carried out on the sealed cold-pressed green body at a temperature of 750 °C for a holding pressure time of 1.5 hours.

[0052] Example 4

[0053] The high heat-resistant and high corrosion-resistant copper-based wear-resistant and friction-reducing material of this example includes the following mass components: 20 parts of wear-resistant components SiO2 and Al2O3, 10 parts of lubricating components graphite powder and silver powder, and 70 parts of copper-tin powder and copper-aluminum powder.

[0054] The preparation method of the high heat-resistant and high corrosion-resistant copper-based wear-resistant and friction-reducing material of this example includes the following steps:

[0055] (1) Select 10 wt.% wear-resistant component SiO2 (average particle size of 150 μm, purity of 99.5%), 10 wt.% wear-resistant component Al2O3 (average particle size of 150 μm, purity of 99.5%), 5 wt.% lubricating component graphite powder (average particle size of 120 μm, purity of 99.5%), 5 wt.% lubricating component silver powder (average particle size of 120 μm, purity of 99.5%), 40 wt.% copper-tin powder (particle size of 200 μm, purity of 99.5%), and 30 wt.% copper-aluminum powder (particle size of 200 μm, purity of 99.5%) as raw materials. Add the above raw material powders into a device with a mixing function respectively, then add 5% of absolute ethanol, methanol, etc. as process control agents, and then carry out sufficient mixing. After mixing, bake at 300 °C for 2 hours to remove the organic substances introduced during the mixing process.

[0056] (2) Load the uniformly mixed and fully dried powder into a white copper tube for compaction and sealing. The shape of the white copper tube is a rectangular tube, and the sealing method is vacuum electron beam welding.

[0057] (3) Perform hot isostatic pressing densification on the sealed cold-pressed compact at a temperature of 900 °C for a holding time of 2 hours.

[0058] Example 5

[0059] The high heat-resistant and high corrosion-resistant copper-based wear-resistant and friction-reducing material of this example includes the following mass components: 15 parts of wear-resistant components SiO2, Al2O3, and SiC, 10 parts of lubricating components graphite powder and silver powder, and 75 parts of corrosion-resistant copper alloy powder copper-tin powder, copper-aluminum powder, and copper-zinc powder.

[0060] The preparation method of the high heat-resistant and high corrosion-resistant copper-based wear-resistant and friction-reducing material of this example includes the following steps:

[0061] (1) Select 5 wt.% wear-resistant component SiO2 (average particle size of 500 μm, purity of 99.5%), 5 wt.% wear-resistant component Al2O3 (average particle size of 125 μm, purity of 99.5%), 5 wt.% wear-resistant component SiC (average particle size of 300 μm, purity of 99.5%), 5 wt.% lubricating component graphite powder, 5 wt.% silver powder (average particle size of 125 μm, purity of 99.5%), 15 wt.% copper-tin powder (average particle size of 500 μm, purity of 99.5%), 30 wt.% copper-aluminum powder (average particle size of 200 μm, purity of 99.5%), and 30 wt.% copper-zinc powder (average particle size of 150 μm, purity of 99.5%) as raw materials. Add the above raw material powders into a device with a mixing function respectively, then add 5% of methanol, etc. as process control agents, and then carry out sufficient mixing. After mixing, bake at 500 °C for 23 hours to remove the organic substances introduced during the mixing process.

[0062] (2) The uniformly mixed and fully dried powder is filled into a white copper tube for compaction and sealing. The shape of the white copper tube is a round tube, and the sealing method is vacuum electron beam welding.

[0063] (3) The sealed cold-pressed green body is densified by hot isostatic pressing at a temperature of 850 °C for a holding time of 4 hours.

[0064] Example 6

[0065] The high heat-resistant and high corrosion-resistant copper-based wear-resistant and friction-reducing material of this example includes the following mass components: 20 parts of wear-resistant components SiO2 and SiC, 20 parts of lubricating components graphite powder and lead powder, and 60 parts of corrosion-resistant copper alloy powder copper-tin powder, copper-aluminum powder and copper-zinc powder.

[0066] The preparation method of the high heat-resistant and high corrosion-resistant copper-based wear-resistant and friction-reducing material of this example includes the following steps:

[0067] (1) Select 10 wt.% of wear-resistant component SiO2, 10 wt.% of wear-resistant component SiC (average particle size of 150 μm, purity of 99.5%), 10 wt.% of lubricating component graphite powder (average particle size of 180 μm, purity of 99.5%), 10 wt.% of lubricating component lead powder (average particle size of 250 μm, purity of 99.5%), 20 wt.% of copper-tin powder (average particle size of 250 μm, purity of 99.5%), 20 wt.% of copper-aluminum powder (average particle size of 450 μm, purity of 99.5%) and 20 wt.% of copper-zinc powder (average particle size of 350 μm, purity of 99.5%) as raw materials. The above raw material powders are respectively added into a device with a mixing function, then 2.5% of anhydrous ethanol and 2.5% of methanol, etc. are added as process control agents, and then sufficient mixing is carried out. After mixing, it is baked at 300 °C for 3 hours to remove the organic matter introduced during the mixing process.

[0068] (2) The uniformly mixed and fully dried powder is filled into a white copper tube for compaction and sealing. The shape of the white copper tube is a round tube, and the sealing method is vacuum electron beam welding.

[0069] (3) The sealed cold-pressed green body is densified by hot isostatic pressing at a temperature of 1050 °C for a holding time of 1 hour.

[0070] Comparative Example 1

[0071] The high heat-resistant and high corrosion-resistant copper-based wear-resistant and friction-reducing material of this example includes the following mass components: 10 parts of wear-resistant component Al2O3, 10 parts of lubricating component silver powder; 80 parts of copper powder.

[0072] The preparation method of the high heat-resistant and high corrosion-resistant copper-based wear-resistant and friction-reducing material of this example includes the following steps:

[0073] (1) Select 10 wt.% wear-resistant component Al2O3 (average particle size is 200 μm, purity 99.5%), 10 wt.% lubricating component silver powder (average particle size is 200 μm, purity 99.5%), and 80 wt.% copper powder (average particle size is 125 - 500 μm, purity 99.5%) as raw materials. Add the above raw material powders into a device with a mixing function respectively, then add 5% anhydrous ethanol as a process control agent, and then carry out sufficient mixing. After mixing, bake at 300 °C for 2 hours to remove the organic substances introduced during the mixing process.

[0074] (2) Load the uniformly mixed and fully dried powder into a white copper tube for compaction and sealing. The shape of the white copper tube is a round tube, and the sealing method is vacuum electron beam welding.

[0075] (3) Carry out hot isostatic pressing densification on the sealed cold-pressed blank, with the temperature being 900 °C and the holding pressure time being 2 hours.

[0076] Perform performance tests on the copper-based wear-resistant and friction-reducing materials prepared in the above embodiments. The test data are shown in Table 1.

[0077] Table 1 Performance parameter table of the copper-based wear-resistant and friction-reducing materials prepared in the embodiments

[0078]

[0079] As can be seen from Table 1, by adopting the materials and their preparation methods in the above invention, the hardness, yield strength, friction coefficient, and high-temperature anti-lubrication temperature of the composite materials prepared in the embodiments are significantly higher than those of the related materials in the comparative examples; while its wear rate and corrosion rate are lower than those of the materials in the comparative examples.

[0080] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A copper-based wear-resistant and friction-reducing material, characterized in that, It comprises components in the following parts by mass: 5 - 20 parts of wear - resistant components, 5 - 20 parts of lubricating components, and 60 - 90 parts of corrosion - resistant copper alloy powder; Among them, the wear - resistant components include at least one of the following: SiO2 particles, Al2O3 particles, SiC particles; the lubricating components include at least one of the following: graphite powder, silver powder, lead powder; the corrosion - resistant copper alloy powder includes at least one of the following: copper - tin powder, copper - aluminum powder, and copper - zinc powder.

2. The copper-based wear-resistant and friction-reducing material according to claim 1, characterized in that, The particle size of the wear - resistant components is 100 - 500 μm.

3. The copper-based wear-resistant and friction-reducing material according to claim 1, characterized in that, The particle size of the lubricating components is 125 - 500 μm.

4. The copper-based wear-resistant and friction-reducing material according to claim 1, characterized in that, The particle size of the corrosion - resistant copper alloy powder is 10 - 500 μm.

5. A preparation method of a copper-based wear-resistant and friction-reducing material based on any one of claims 1-4, characterized in that, The method comprises: Mixing the wear - resistant components, lubricating components, and corrosion - resistant copper alloy powder to obtain a mixed powder; Loading the dried mixed powder into a copper tube for compaction and sealing to obtain a cold - pressed green body; Performing hot isostatic pressing on the cold - pressed green body to obtain the copper - based wear - resistant and friction - reducing material.

6. The method according to claim 5, characterized in that, The mixing includes: mechanical mixing; among them, the forms of the mechanical mixing include: ball milling, stirring, vibration, bottom blowing, rotation.

7. The method according to claim 5, characterized in that, The copper tube is a white copper tube, and the shape of the copper tube includes: round tube, square tube, cuboid.

8. The method according to claim 5, characterized in that, The conditions of the hot isostatic pressing include: temperature of 700 - 1050 °C and holding pressure time of 1 - 4 h.

9. The method according to claim 5, characterized in that, An organic solvent is added during the mixing process; among them, the organic solvent includes at least one of the following: alcohol, soap, methanol.

10. An application of a copper-based wear-resistant and friction-reducing material, characterized in that, The application of the copper - based wear - resistant and friction - reducing material in a braking device in a coastal high - salt - fog environment.

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