A copper-based friction material and a preparation method and application thereof

Abstract

The application discloses a copper-based friction material and a preparation method and application thereof, and belongs to the technical field of friction material preparation. Raw materials include a base component, a lubricating component and a friction component. The base component is copper, the lubricating component is graphite, metal selenide and antimony sulfide, and the friction component is titanium-aluminum alloy, kyanite and zirconium dioxide. The copper-based friction material prepared by the application is well matched with a Co-based coating brake disc, has good mechanical properties, high high-temperature resistance, good thermal recession resistance, a high and stable friction coefficient and a low wear rate under extreme high temperature, is easy to prepare and low in price.

Description

Technical Field

[0001] This invention belongs to the field of friction material preparation technology, and in particular relates to a copper-based friction material, its preparation method and application. Background Technology

[0002] The braking system is crucial in determining the braking capability of high-speed trains in emergency situations, and is directly related to the safety of high-speed train operation. As high-speed trains continue to develop towards higher speeds and heavier loads, the braking energy that the braking system needs to absorb during emergency braking has increased significantly, placing new demands on the system. The friction pair, composed of the brake disc and brake pads, is a key component of the high-speed train braking system and serves as the last line of defense for ensuring the safe operation of high-speed trains. The International Union of Railways (UIC) and other regulations stipulate that, in the absence of other braking methods, the brake friction pair must ensure that the high-speed train can stop within a specified distance.

[0003] Steel-based brake discs (such as cast steel and forged steel) possess high strength and toughness, as well as good heat dissipation, heat resistance, and wear resistance. Therefore, high-speed trains currently in service with speeds of 200-350 km / h primarily use steel-based brake discs paired with powder metallurgy brake pads as the braking friction pair. However, as the speed and load of high-speed trains further increase, the instantaneous temperature of the friction pair surface during emergency braking will exceed 800℃. Steel-based brake discs often exhibit problems such as hot spots, hot cracks, and abnormal wear, making them unsuitable for the evolving requirements of high-speed trains.

[0004] Enhancing the surface properties of brake discs is crucial. Wear-resistant coatings can improve the friction performance of brake discs, stabilize the coefficient of friction, and effectively extend their lifespan. Co-based coatings, due to their excellent high-temperature resistance and wear resistance, can effectively improve the high-temperature friction and wear performance of brake discs and have broad application prospects. Chinese patent document CN115058627 discloses a laser-clad Co-based coating for high-speed train brake discs. The Co-based coating has good high-temperature resistance, excellent oxidation resistance and thermal fatigue resistance, low crack sensitivity, good compatibility with steel-based brake disc substrates, and outstanding overall strength and toughness, which can meet the stringent requirements of brake disc service.

[0005] Copper-based friction materials possess stable friction coefficients, excellent wear resistance, temperature resistance, and good environmental adaptability, and are widely used in high-speed train brake pads. Chinese patent document CN113118434 provides a high-speed train brake pad, comprising the following raw material components by weight: 35-45 parts copper, 5-10 parts nano-copper, 6-13 parts iron, 10-15 parts ferrochrome, 3-10 parts zirconium sand, 1-5 parts ferromolybdenum, 1-5 parts ferroboron, 1.5-5 parts silicon carbide, 0.5-3 parts molybdenum disulfide, 5-15 parts natural granular graphite, 1-8 parts natural flake graphite, and 1-5 parts artificial granular graphite. Chinese patent document CN112899520 discloses a powder metallurgy friction material, comprising the following raw material components by weight: 51-63 parts copper, 10-17 parts iron, 1-3 parts tin, 0.5-1 part molybdenum disulfide, 2-3 parts aluminum oxide, 3-5 parts zircon, 0.5-1.5 parts boron carbide, 7-10 parts ferrochrome, 5-7 parts flake graphite, and 4-6 parts granular graphite. Chinese patent document CN106399743 discloses a simplified component powder metallurgy friction material for high-speed train brake pads, comprising, by weight percentage: 40-55% copper, 8-20% iron, 1-10% zirconium dioxide, 6-15% ferrochrome, 16-22% graphite, and 1-4% molybdenum disulfide.

[0006] As mentioned above, existing copper-based friction materials are all developed to match the friction pairs of steel-based brake discs and are used in high-speed trains with speeds of 350 km / h and below. Because the materials involved in friction differ between steel-based brake discs and Co-coated brake discs, the requirements for the frictional and mechanical properties of copper-based friction materials differ. Especially to adapt to the high-speed and heavy-load development of high-speed trains, copper-based friction materials are required to have good high-temperature tribological properties, good temperature resistance, and good compatibility with Co-coated brake discs. Currently, there is no mature product in China specifically designed for Co-coated brake discs. Therefore, there is an urgent need for a copper-based friction material specifically designed for Co-coated brake discs. Summary of the Invention

[0007] The purpose of this invention is to provide a copper-based friction material, its preparation method, and its application, to solve the problems existing in the prior art. This invention uses novel lubricating and friction components with high thermal stability to prepare a copper-based friction material that is well-matched with brake discs coated with a Co-based coating. The copper-based friction material exhibits good mechanical properties, strong high-temperature resistance, and good resistance to thermal degradation. It possesses a high and stable coefficient of friction and a low wear rate at extreme high temperatures, making it suitable for the high-speed, heavy-load service conditions of high-speed trains.

[0008] One of the technical solutions provided by this invention:

[0009] A copper-based friction material, comprising a matrix component, a lubricating component, and a friction component, wherein the matrix component is copper, the lubricating component is graphite, metal selenide, and antimony sulfide, and the friction component is titanium-aluminum alloy, kyanite, and zirconium dioxide.

[0010] This invention uses copper as a framework to ensure the friction material has excellent thermal conductivity, effectively dissipating the frictional heat generated during friction. Antimony sulfide is used to improve the wear resistance, anti-fading properties, high-temperature friction stability, and noise reduction of the friction material. Metal selenides are not only lubricants but also friction stabilizers, possessing high thermal stability and non-hygroscopic properties, which improve the temperature resistance, thermal stability, and wear resistance of the friction material, while also providing sound absorption and noise reduction. High-content graphite and thermally stable antimony sulfide and metal selenides are used as lubricating components, providing excellent anti-galling properties under high-temperature conditions and improving the friction material's resistance to thermal fading, friction stability, and wear resistance. Kyanite, a triclinic island-structure high-alumina mineral, has strong chemical corrosion resistance, high thermal shock mechanical strength, high refractoriness, and moderate hardness, playing a role in increasing friction and wear resistance at high temperatures, improving the material's thermal shock resistance, wear resistance, and frictional resistance. Titanium-aluminum alloys possess characteristics such as low density, high strength, strong resistance to high-temperature creep and oxidation, excellent specific elastic modulus, and high hardness. Using titanium-aluminum alloys can significantly improve the oxidation resistance and high-temperature wear resistance of friction materials. High-temperature stable titanium-aluminum alloys also bond tightly with the copper matrix, forming a good interface and improving the creep resistance and strength of the friction material. Adding large-particle zirconium dioxide can further provide a suitable coefficient of friction. Using kyanite, titanium-aluminum alloys, and zirconium dioxide, which have excellent thermal stability and moderate hardness, as friction components can improve the strength, oxidation resistance, and other physicochemical properties of the friction material. This ensures that the friction material has a suitable coefficient of friction, protecting the mating parts from damage while maintaining a stable coefficient of friction itself.

[0011] Preferably, the raw materials comprise, by weight percentage: 52-70% copper, 10-18% graphite, 1-4% metal selenide, 0.5-2% antimony sulfide, 8-15% kyanite, 4-8% titanium-aluminum alloy, and 1-4% zirconium dioxide, wherein the titanium-aluminum alloy contains 40-50% aluminum and the balance is titanium.

[0012] More preferably, the raw materials comprise, by weight percentage: 55-65% copper, 12-16% graphite, 2-3% metal selenide, 1-2% antimony sulfide, 9-13% kyanite, 5-7% titanium-aluminum alloy, and 2-3% zirconium dioxide, wherein the titanium-aluminum alloy contains 42-48% aluminum and the balance is titanium.

[0013] More preferably, the raw materials comprise, by weight percentage: 60% copper, 15% graphite, 3% metal selenide, 2% antimony sulfide, 12% kyanite, 6% titanium-aluminum alloy, and 2% zirconium dioxide, wherein the titanium-aluminum alloy contains 46% aluminum and 54% titanium, and the metal selenide is composed of molybdenum diselenide and niobium diselenide in equal proportions.

[0014] Preferably, the metal selenide includes one or more of molybdenum diselenide and niobium diselenide.

[0015] Preferably, the raw materials of the matrix component, lubrication component, and friction component are all in powder form, and the particle sizes of the raw materials are as follows: copper powder 37-74 μm, graphite powder 180-354 μm, metal selenide powder 2.5-10 μm, antimony sulfide powder 1-5 μm, kyanite powder 74-150 μm, titanium-aluminum alloy powder 25-53 μm, and zirconium dioxide powder 100-250 μm.

[0016] The second technical solution provided by this invention:

[0017] The raw materials were weighed according to the weight percentage, mixed with kerosene, stirred evenly, and then filled into a mold, pressed into shape, and sintered under a hydrogen atmosphere to prepare copper-based friction material.

[0018] Preferably, the unit pressing pressure of the compression molding is 400-500 MPa, and the holding time is 3-4 seconds.

[0019] Preferably, the sintering temperature is 950–980℃, the unit sintering pressure is 2.5–2.9 MPa, and the holding time is 3–4 h.

[0020] Preferably, the ratio of the kerosene to the total mass of all raw materials is (9-12) mL: 1 kg.

[0021] The third technical solution provided by this invention:

[0022] Application of the aforementioned copper-based friction material in matching with a brake disc coated with a Co-based coating.

[0023] The beneficial effects of this invention are:

[0024] (1) The copper-based friction material provided by the present invention does not contain harmful substances. It selects novel lubricating and friction components with high thermal stability. Copper is used as the matrix component, graphite, metal selenide and antimony sulfide are used as lubricating components, and titanium aluminum alloy, kyanite and zirconium dioxide are used as friction components. The three types of components work synergistically. Through the reasonable ratio of each component, a copper-based friction material that matches well with the brake disc coated with Co-based coating can be obtained. It effectively overcomes the problems of obvious friction coefficient decay, large wear and damage to the brake disc that exist in copper-based friction materials during high temperature friction.

[0025] (2) The copper-based friction material prepared by the present invention is well matched with the brake disc coated with Co-based coating. It has good mechanical properties, strong high temperature resistance, good heat fading resistance, high and stable friction coefficient and low wear rate under extreme high temperature. It is easy to prepare and inexpensive.

[0026] (3) The metal selenide in this invention has a strong synergistic effect with the titanium-aluminum alloy, which further ensures that the friction material has good mechanical properties, strong high temperature resistance, good heat fading resistance, high and stable friction coefficient and low wear rate at extreme high temperature, and is well matched with the brake disc coated with Co-based coating. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 Metallographic photograph of the copper-based friction material prepared in Example 1 of this invention;

[0029] Figure 2 The friction curve of the copper-based friction material prepared in Example 1 of the present invention against a brake disc coated with a Co-based coating at 800°C;

[0030] Figure 3 The friction curve of the copper-based friction material prepared for Comparative Example 1 of the present invention at 800°C is shown when it rubs against a brake disc coated with a Co-based coating. Detailed Implementation

[0031] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0032] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0033] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0034] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be obvious to those skilled in the art. This application specification and embodiments are merely exemplary.

[0035] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0036] All raw materials used in this invention embodiment were purchased. The particle size distribution of the raw materials used is as follows: copper powder: 37-74 μm, graphite powder: 180-354 μm, metal selenide powder: 2.5-10 μm, antimony sulfide powder: 1-5 μm, kyanite powder: 74-150 μm, titanium aluminum alloy powder: 25-53 μm, and zirconium dioxide powder: 100-250 μm.

[0037] Example 1: A method for preparing a copper-based friction material

[0038] The copper-based friction material in this embodiment comprises the following raw materials by weight percentage: 60% copper, 15% graphite, 1.5% molybdenum diselenide, 1.5% niobium diselenide, 2% antimony sulfide, 12% kyanite, 6% titanium-aluminum alloy, and 2% zirconium dioxide, wherein the titanium-aluminum alloy contains 46% aluminum and 54% titanium.

[0039] According to the weight percentage of each component mentioned above, the raw material components of the copper-based friction material were weighed, and kerosene was added. The raw material powders were then stirred evenly (the ratio of kerosene to the total mass of all raw materials was 10 mL: 1 kg). The mixture was then put into a three-dimensional mixer for mixing for 5 hours. The evenly mixed material was filled into a mold and pressed into shape using a powder hydraulic press. The unit pressing pressure was 500 MPa, and the pressure was held for 3 seconds. The pressed blank was sintered in a pressure sintering furnace under hydrogen protection at a sintering temperature of 970℃, a unit sintering pressure of 2.7 MPa, and a holding time of 3 hours to obtain the copper-based friction material.

[0040] Figure 1Here are metallographic images of the copper-based friction material prepared in this embodiment. Figure 1 It can be seen that graphite, kyanite, metal selenide, titanium-aluminum alloy and zirconium dioxide are evenly distributed in the copper matrix, the material is relatively dense and there are no defects such as pores.

[0041] Example 2:

[0042] By weight percentage, the copper-based friction material in this embodiment comprises the following raw materials: 62% copper, 15% graphite, 1% molybdenum diselenide, 2% antimony sulfide, 12% kyanite, 6% titanium-aluminum alloy, and 2% zirconium dioxide, wherein the titanium-aluminum alloy contains 42% aluminum and 58% titanium.

[0043] According to the weight percentage of each component mentioned above, the raw material components of the copper-based friction material were weighed, and kerosene was added. The raw material powders were then stirred evenly (the ratio of kerosene to the total mass of all raw materials was 9 mL: 1 kg). The mixture was then put into a three-dimensional mixer for mixing for 4 hours. The evenly mixed material was filled into a mold and pressed into shape using a powder hydraulic press. The unit pressing pressure was 400 MPa, and the pressure was held for 4 seconds. The pressed blank was sintered in a pressure sintering furnace under hydrogen protection at a sintering temperature of 950℃, a unit sintering pressure of 2.9 MPa, and a holding time of 3 hours to obtain the copper-based friction material.

[0044] Example 3:

[0045] By weight percentage, the copper-based friction material in this embodiment comprises the following raw materials: 59% copper, 15% graphite, 4% niobium diselenide, 2% antimony sulfide, 12% kyanite, 6% titanium-aluminum alloy, and 2% zirconium dioxide, wherein the titanium-aluminum alloy contains 48% aluminum and 52% titanium.

[0046] According to the weight percentage of each component mentioned above, the raw material components of the copper-based friction material were weighed, and kerosene was added. The raw material powders were then stirred evenly (the ratio of kerosene to the total mass of all raw materials was 12 mL: 1 kg). The mixture was then put into a three-dimensional mixer for mixing for 5 hours. The evenly mixed material was filled into a mold and pressed into shape using a powder hydraulic press. The unit pressing pressure was 400 MPa, and the pressure was held for 3 seconds. The pressed blank was sintered in a pressure sintering furnace under hydrogen protection at a sintering temperature of 980℃, a unit sintering pressure of 2.5 MPa, and a holding time of 4 hours to obtain the copper-based friction material.

[0047] Example 4:

[0048] By weight percentage, the copper-based friction material in this embodiment comprises the following raw materials: 58% copper, 15% graphite, 1.5% molybdenum diselenide, 1.5% niobium diselenide, 2% antimony sulfide, 12% kyanite, 8% titanium-aluminum alloy, and 2% zirconium dioxide, wherein the titanium-aluminum alloy contains 48% aluminum and 52% titanium.

[0049] According to the weight percentage of each component mentioned above, the raw material components of the copper-based friction material were weighed, and kerosene was added. The raw material powders were then stirred evenly (11 mL of kerosene was added for every 1 kg of total raw materials). The mixture was then put into a three-dimensional mixer for mixing for 5 hours. The evenly mixed material was filled into a mold and pressed into shape using a powder hydraulic press. The unit pressing pressure was 500 MPa, and the pressure was held for 4 seconds. The pressed blank was sintered in a pressure sintering furnace under hydrogen protection at a sintering temperature of 980℃, a unit sintering pressure of 2.9 MPa, and a holding time of 4 hours to obtain the copper-based friction material.

[0050] Example 5:

[0051] The copper-based friction material in this embodiment comprises the following raw materials by weight percentage: 59% copper, 15% graphite, 4% molybdenum diselenide, 2% antimony sulfide, 12% kyanite, 6% titanium-aluminum alloy, and 2% zirconium dioxide, wherein the titanium-aluminum alloy contains 46% aluminum and 54% titanium.

[0052] According to the weight percentage of each component mentioned above, the raw material components of the copper-based friction material were weighed, and kerosene was added. The raw material powders were then stirred evenly (12 mL of kerosene was added for every 1 kg of total raw materials). The mixture was then put into a three-dimensional mixer for mixing for 4 hours. The evenly mixed material was filled into a mold and pressed into shape using a powder hydraulic press. The unit pressing pressure was 500 MPa, and the pressure was held for 3 seconds. The pressed blank was sintered in a pressure sintering furnace under hydrogen protection at a sintering temperature of 970℃, a unit sintering pressure of 2.7 MPa, and a holding time of 3 hours to obtain the copper-based friction material.

[0053] Example 6:

[0054] By weight percentage, the copper-based friction material in this embodiment comprises the following raw materials: 64% copper, 15% graphite, 1% niobium diselenide, 2% antimony sulfide, 12% kyanite, 4% titanium-aluminum alloy, and 2% zirconium dioxide, wherein the titanium-aluminum alloy contains 42% aluminum and 58% titanium.

[0055] According to the weight percentage of each component mentioned above, the raw material components of the copper-based friction material were weighed, and kerosene was added. The raw material powders were then stirred evenly (9 mL of kerosene was added per 1 kg of total raw material). The mixture was then put into a three-dimensional mixer for mixing for 4 hours. The evenly mixed material was filled into a mold and pressed into shape using a powder hydraulic press. The unit pressing pressure was 400 MPa, and the pressure was held for 4 seconds. The pressed blank was sintered in a pressure sintering furnace under hydrogen protection at a sintering temperature of 950℃, a unit sintering pressure of 2.5 MPa, and a holding time of 3 hours to obtain the copper-based friction material.

[0056] Comparative Example 1:

[0057] Same as Example 1, except that no metal selenide and titanium-aluminum alloy were added. At the same time, the weight percentage of the original metal selenide and titanium-aluminum alloy was included in the copper. According to the weight percentage, it includes the following raw materials: 69% copper, 15% graphite, 2% antimony sulfide, 12% kyanite, and 2% zirconium dioxide.

[0058] According to the weight percentage of each component mentioned above, weigh each raw material component of the copper-based friction material, add kerosene, and stir the raw material powder evenly (the ratio of kerosene to the total mass of all raw materials is 10 mL: 1 kg). Then, put it into a three-dimensional mixer for mixing for 5 hours. Fill the uniformly mixed material into a mold and press the mixture into shape using a powder hydraulic press. The unit pressing pressure is 500 MPa, and the pressure is held for 3 seconds. The pressed blank is sintered in a pressure sintering furnace under hydrogen protection. The sintering temperature is 970℃, the unit sintering pressure is 2.7 MPa, and the holding time is 3 hours.

[0059] Comparative Example 2

[0060] Similar to Example 1, except that no metal selenide was added, and the weight percentage of the original metal selenide was included in the copper. According to the weight percentage, it includes the following raw materials: 63% copper, 15% graphite, 2% antimony sulfide, 12% kyanite, 6% titanium-aluminum alloy, and 2% zirconium dioxide, wherein the titanium-aluminum alloy contains 46% aluminum and 54% titanium.

[0061] According to the weight percentage of each component mentioned above, weigh each raw material component of the copper-based friction material, add kerosene, and stir the raw material powder evenly (the ratio of kerosene to the total mass of all raw materials is 10 mL: 1 kg). Then, put it into a three-dimensional mixer for mixing for 5 hours. Fill the uniformly mixed material into a mold and press the mixture into shape using a powder hydraulic press. The unit pressing pressure is 500 MPa, and the pressure is held for 3 seconds. The pressed blank is sintered in a pressure sintering furnace under hydrogen protection. The sintering temperature is 970℃, the unit sintering pressure is 2.7 MPa, and the holding time is 3 hours.

[0062] Comparative Example 3

[0063] Similar to Example 1, except that no titanium-aluminum alloy was added, and the weight percentage of the original titanium-aluminum alloy was included in the copper. According to the weight percentage, it includes the following raw materials: 66% copper, 15% graphite, 1.5% molybdenum diselenide, 1.5% niobium diselenide, 2% antimony sulfide, 12% kyanite, and 2% zirconium dioxide.

[0064] According to the weight percentage of each component mentioned above, weigh each raw material component of the copper-based friction material, add kerosene, and stir the raw material powder evenly (the ratio of kerosene to the total mass of all raw materials is 10 mL: 1 kg). Then, put it into a three-dimensional mixer for mixing for 5 hours. Fill the uniformly mixed material into a mold and press the mixture into shape using a powder hydraulic press. The unit pressing pressure is 500 MPa, and the pressure is held for 3 seconds. The pressed blank is sintered in a pressure sintering furnace under hydrogen protection. The sintering temperature is 970℃, the unit sintering pressure is 2.7 MPa, and the holding time is 3 hours.

[0065] Performance testing

[0066] The copper-based friction materials prepared in Examples 1-6 and the copper-based friction materials prepared in Comparative Examples 1-3 were subjected to physical and mechanical properties and tribological properties tests, and the test results are shown in Table 2.

[0067] The surface hardness of the copper-based friction material was tested using a 310HBS-3000 digital Brinell hardness tester; the compressive strength and shear strength of the copper-based friction material were tested using an Instron 3369 universal testing machine.

[0068] The tribological properties of copper-based friction materials, such as friction curves, friction coefficients, and wear rates, were tested using a pin-disc friction testing machine. The disc was a Co-based coated brake disc with dimensions of Ф130mm × 20mm; the pin was a copper-based friction material with dimensions of Ф12mm × 10mm. Test parameters were: operating speed 4.71m / s, applied pressure 0.8MPa, test time 120min, and temperature 800℃.

[0069] During the experiment, the coefficient of friction (μ) was determined by the formula Therefore, F is the frictional force (N), and P is the working pressure (N).

[0070] Wear rate (V) (mm) of copper-based friction materials 3 / km) from the formula The results show that m1 is the mass (g) of the copper-based friction material before the test, m2 is the mass (g) of the copper-based friction material after the test, and ρ is the density (g / mm³) of the copper-based friction material. 3 ), where L is the total friction distance of the pin sample (km).

[0071] Table 2

[0072]

[0073]

[0074] Comparing Examples 1-6 with Comparative Examples 1-3, it can be seen that adding appropriate amounts of metal selenide and titanium-aluminum alloy can exert a synergistic effect, significantly improving the hardness, compressive strength, and shear strength of copper-based friction materials.

[0075] Figure 2 The friction curves of the copper-based friction material prepared in Example 1 against a brake disc coated with a Co-based coating at 800°C are shown. Figure 3 The friction curves of the copper-based friction material prepared for Comparative Example 1 against a brake disc coated with a Co-based coating at 800°C are shown. Figure 2 and Figure 3 It can be seen that the copper-based friction material obtained in the examples exhibits significantly better frictional stability than the comparative example when rubbing against a brake disc coated with a Co-based coating under high-temperature conditions. This demonstrates that the novel copper-based friction material provided by this invention has a high and stable coefficient of friction, strong resistance to high temperatures and thermal fading, high strength, stable operation, low noise, and is less affected by the environment, thus ensuring the safety of high-speed train operation under high-speed and heavy-load conditions. Therefore, using the novel copper-based friction material provided by this invention provides greater assurance for the operation of high-speed trains, greatly improves the service life of brake pads, and saves manpower, financial resources, and materials. The materials used in this invention have relatively simple compositions, low economic costs, and relatively easy preparation processes.

[0076] Furthermore, during the tribological tests of the copper-based friction materials prepared in Examples 1-6 and Comparative Examples 1-3 using a pin-disc friction testing machine, it was found that the copper-based friction materials prepared in Examples 1-6 did not exhibit cracks or defects in the friction pair materials during high-temperature friction with the Co-coated brake discs, and there were no sharp noises or sparks, demonstrating good matching and excellent frictional stability. In contrast, the copper-based friction materials prepared in Comparative Examples 1-3 showed defects in the friction materials during high-temperature friction with the Co-coated brake discs, and there were sharp noises and sparks, indicating lower frictional stability.

[0077] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A copper-based friction material, characterized in that, The raw materials include a matrix component, a lubricating component, and a friction component. The matrix component is copper, the lubricating component is graphite, metal selenide, and antimony sulfide, and the friction component is titanium-aluminum alloy, kyanite, and zirconium dioxide. The copper-based friction material comprises, by weight percentage, the following raw materials: 52-70% copper, 10-18% graphite, 1-4% metal selenide, 0.5-2% antimony sulfide, 8-15% kyanite, 4-8% titanium-aluminum alloy, and 1-4% zirconium dioxide. The titanium-aluminum alloy contains 40-50% aluminum, with the balance being titanium.

2. The copper-based friction material according to claim 1, characterized in that, The raw materials comprise, by weight percentage, the following: 55-65% copper, 12-16% graphite, 2-3% metal selenide, 1-2% antimony sulfide, 9-13% kyanite, 5-7% titanium-aluminum alloy, and 2-3% zirconium dioxide, wherein the titanium-aluminum alloy contains 42-48% aluminum and the balance is titanium.

3. The copper-based friction material according to claim 1, characterized in that, The raw materials comprise, by weight percentage, the following: 60% copper, 15% graphite, 3% metal selenide, 2% antimony sulfide, 12% kyanite, 6% titanium-aluminum alloy, and 2% zirconium dioxide. The titanium-aluminum alloy contains 46% aluminum and 54% titanium. The metal selenide is composed of molybdenum diselenide and niobium diselenide in equal proportions.

4. The copper-based friction material according to claim 1, characterized in that, The metal selenide includes one or more of molybdenum diselenide and niobium diselenide.

5. The copper-based friction material according to claim 1, characterized in that, The raw materials of the matrix component, lubrication component, and friction component are all in powder form, and the particle sizes of the raw materials are as follows: copper powder 37~74 μm, graphite powder 180~354 μm, metal selenide powder 2.5~10 μm, antimony sulfide powder 1~5 μm, kyanite powder 74~150 μm, titanium aluminum alloy powder 25~53 μm, and zirconium dioxide powder 100~250 μm.

6. A method for preparing a copper-based friction material according to any one of claims 1 to 5, characterized in that, The raw materials were weighed according to the weight percentage, mixed with kerosene, stirred evenly, and then filled into a mold, pressed into shape, and sintered under a hydrogen atmosphere to prepare copper-based friction material.

7. The preparation method according to claim 6, characterized in that, The unit pressing pressure for the pressing molding is 400~500MPa, and the holding time is 3~4s.

8. The preparation method according to claim 6, characterized in that, The sintering temperature is 950~980℃, the unit sintering pressure is 2.5~2.9 MPa, and the holding time is 3~4h.

9. The application of the copper-based friction material according to any one of claims 1 to 5 in matching with a brake disc coated with a Co-based coating.

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