A race track brake pad and a method of manufacturing the same

Abstract

The application discloses a race track brake pad and a preparation method thereof, and belongs to the technical field of brake pads. The race track brake pad comprises, from bottom to top, a titanium alloy steel back, a combined buffer layer, a friction bottom layer and a friction surface layer. The combined buffer layer comprises short fibers, elastic particles and boron-modified phenolic resin. The friction bottom layer comprises short fibers, copper-tin alloy powder and boron-modified phenolic resin. The friction surface layer comprises steel fibers, tungsten steel particles, a lubricating phase and polyamide-imide resin. The race track brake pad has high interlayer bonding strength, excellent heat decay resistance and wear resistance, and the reliability and safety of the race track brake pad under continuous high-frequency braking conditions are improved.

Description

Technical Field

[0001] This invention belongs to the field of brake pad technology, specifically a racing brake pad and its preparation method. Background Technology

[0002] In motorsports, brake pads are a core component ensuring vehicle braking safety, handling stability, and continuous racing performance. Track conditions are characterized by short-duration, high-intensity, and high-frequency repetitive braking, where a single braking action can cause the brake pad surface temperature to rise rapidly. Under these harsh conditions, brake pads must simultaneously withstand severe thermal shock, cyclic mechanical loads, and complex environmental corrosion, placing far higher demands on them than on civilian braking components.

[0003] The steel backing and friction material are often bonded by a common resin-based buffer layer, relying solely on physical adhesion for bonding, resulting in poor interfacial compatibility. Under high-temperature conditions, the resin rapidly decomposes and fails, easily causing the friction layer to crack and detach, posing serious safety hazards. The friction layer is mostly a dense, homogeneous structure with a lack of heat dissipation channels, leading to a large accumulation of braking heat. This causes rapid thermal decomposition, oxidation, and even ignition of the organic components in the friction material, while also resulting in significant thermal degradation, a sharp drop in the coefficient of friction, and a substantial decrease in continuous braking performance. Furthermore, the interlayer bonding reliability is low, and under the combined action of high-temperature thermal stress and alternating loads, interlayer separation, peeling, and flaking are prone to failure. Summary of the Invention

[0004] To overcome the aforementioned technical problems, this invention provides a racing brake pad and its manufacturing method. The racing brake pad is composited from top to bottom, consisting of a titanium alloy steel backing, a bonding buffer layer, a friction underlayer, and a friction surface layer. The bonding buffer layer uses high-temperature resistant boron-modified phenolic resin as the matrix, combined with reinforcing fibers and elastic particles, providing high-strength adhesion and stress buffering. The friction underlayer is rich in thermally conductive metal powder and has a porous structure, forming heat dissipation channels. The friction surface layer uses polyamide-imide resin as the matrix and ultra-hard tungsten carbide particles as the wear-resistant skeleton, ensuring frictional stability under high-temperature conditions. This racing brake pad possesses high interlayer bonding strength, excellent resistance to thermal fading, and wear resistance, improving reliability and safety under continuous high-frequency braking conditions.

[0005] The present invention solves the above-mentioned technical problems through the following technical solutions.

[0006] This invention discloses a racetrack brake pad, which consists of, from bottom to top, a titanium alloy steel backing, a combined buffer layer, a friction bottom layer, and a friction surface layer; The combined buffer layer comprises chopped fibers, elastic particles, and boron-modified phenolic resin; The friction substrate comprises chopped fibers, copper-tin alloy powder, and boron-modified phenolic resin; The friction surface layer comprises steel fibers, tungsten carbide particles, a lubricating phase, and polyamide-imide resin.

[0007] According to some embodiments of the present invention, the combined buffer layer comprises the following raw materials in weight percentages: 0.1-15% ceramic fiber, 8-18% chopped fiber, 0.1-5% PTFE powder, 10-25% thermally conductive filler, 3-9% elastic particles and 23-78% boron-modified phenolic resin.

[0008] In some preferred embodiments, the combined buffer layer comprises the following raw materials by weight percentage: 3-10% ceramic fiber, 8-15% chopped fiber, 2-4% PTFE powder, 11-19% thermally conductive filler, 4-8% elastic particles, and 39-71% boron-modified phenolic resin.

[0009] The buffer layer, while ensuring interfacial bonding strength, also alleviates thermal stress and provides corrosion resistance and temperature resistance. Boron-modified phenolic resin, compared to traditional phenolic resin, exhibits superior high-temperature resistance and bonding strength, forming the basis for interlayer bonding. Ceramic fibers and chopped fibers form a fiber-reinforced network, enhancing the structural strength of the transition layer and preventing brittleness at high temperatures; furthermore, the deformation of elastic particles absorbs thermal stress and mechanical impact during braking. PTFE imparts corrosion resistance, hydrophobicity, and friction-reducing properties to the transition layer. Thermally conductive fillers facilitate the initial transfer of braking heat from the friction layer to the steel backing, preventing heat accumulation at the interface.

[0010] According to some embodiments of the present invention, the friction underlayer comprises the following raw materials by mass percentage: 18-45% copper-tin alloy powder, 5-14% chopped fibers, 5-12% thermally conductive filler, 2-10% polycarbonate microspheres, 5-10% wear-resistant phase, and 4-61% boron-modified phenolic resin.

[0011] In some preferred embodiments, the friction substrate comprises the following raw materials by weight percentage: 20-40% copper-tin alloy powder, 6-12% chopped fibers, 6-9% thermally conductive filler, 4-8% polycarbonate microspheres, 5-8% wear-resistant phase, and 17-55% boron-modified phenolic resin.

[0012] The friction layer serves as a rapid heat dissipation channel for braking heat. Copper-tin alloy powder is used as the base filler to conduct heat, and polycarbonate microspheres are added as a pore-forming agent. During the hot-pressing and curing process, the microspheres decompose to form an interconnected porous structure, which greatly increases the heat dissipation area and enables rapid heat dissipation. At the same time, the porous structure can buffer braking impact and reduce braking noise.

[0013] According to some embodiments of the present invention, the friction surface comprises the following raw materials in weight percentages: 25-45% polyamide-imide resin, 5-10% steel fiber, 10-20% polycrystalline alumina, 3-9% lubricating phase and 10-54% tungsten carbide particles.

[0014] In some preferred embodiments, the friction surface layer comprises the following raw materials by mass percentage: 30-45% polyamide-imide resin, 6-9% steel fiber, 11-17% polycrystalline alumina, 4-8% lubricating phase, and 15-46% tungsten carbide particles.

[0015] The friction surface has stable friction performance at high temperatures. The friction surface uses polyamide-imide resin as the matrix and tungsten carbide particles as the main filler to improve wear resistance. Steel fibers are used as fiber reinforcement network to improve the crack resistance of the surface.

[0016] According to some embodiments of the present invention, the thermally conductive filler is flake graphite and aluminum nitride; the mass ratio of flake graphite to aluminum nitride is 1 / 5 to 10; and the particle size of the thermally conductive filler is ≤20 μm.

[0017] According to some embodiments of the present invention, the chopped fiber is at least one of chopped aramid fiber, chopped carbon fiber and copper fiber; the length of the chopped fiber is 1~50mm.

[0018] According to some embodiments of the present invention, the ceramic fiber is alumina fiber or aluminum silicate fiber.

[0019] According to some embodiments of the present invention, the elastic particles are nitrile rubber powder or polyacrylonitrile powder; Furthermore, the acrylonitrile content of the nitrile rubber is 30~40wt%.

[0020] According to some embodiments of the present invention, the wear-resistant phase is at least one of synthetic diamond micron powder and silicon carbide; the wear-resistant phase enhances the wear resistance of the friction substrate and prevents the substrate from failing rapidly after the surface layer wears down.

[0021] According to some embodiments of the present invention, the copper-tin alloy powder is made of CuSn10, CuSn6, CuSn15 or CuSn8Zn.

[0022] According to some embodiments of the present invention, the steel material of the steel fiber is 304 steel, 310 steel, 330 steel, 430 steel or 446 steel; the diameter of the steel fiber is ≤0.08mm.

[0023] According to some embodiments of the present invention, the D50 of the polycrystalline alumina is 10~80μm.

[0024] According to some embodiments of the present invention, the lubricating phase is molybdenum disulfide and graphene, and the mass ratio of molybdenum disulfide to graphene is 2 to 5 / 1.

[0025] According to some embodiments of the present invention, the chemical composition of the tungsten carbide particles is WC and Co.

[0026] According to some embodiments of the present invention, the titanium alloy steel backing is made of TC4, TC6, TC11 or TC16.

[0027] According to some embodiments of the present invention, the thickness of the titanium alloy steel backing is 5~7mm.

[0028] According to some embodiments of the present invention, the inner wall of the front side of the titanium alloy steel back is provided with a spiral groove with a groove depth of 0.08mm to 0.12mm, and the groove is filled with thermally conductive graphite paste.

[0029] According to some embodiments of the present invention, the front side of the titanium alloy steel back is provided with a nesting component, which is a coaxial nesting structure of hollow copper and Ni-Ti shape memory alloy wire.

[0030] According to some embodiments of the present invention, the diameter of the hollow copper is 2~4mm.

[0031] According to some embodiments of the present invention, the back of the titanium alloy steel back is provided with a honeycomb structure, and the honeycomb area accounts for 30-50%.

[0032] This invention also discloses a method for preparing the aforementioned racetrack brake pads, comprising the following steps: S1. Mix the raw materials for the preparation of the combined buffer layer, the friction bottom layer, and the friction surface layer to obtain the combined buffer layer slurry, the friction bottom layer slurry, and the friction surface layer dry powder, respectively. S2. The buffer layer slurry and the friction underlayer slurry are sequentially coated on the front side of the titanium alloy steel backing, and then the friction surface dry powder is laid on top, and cured after hot pressing.

[0033] In S1, after the composite bonding buffer layer slurry is coated, it needs to be pre-baked at 120°C for 1 hour before the friction underlayer slurry is sprayed; after the friction underlayer slurry is coated, it needs to be pre-baked at 120°C for 1 hour before the friction surface dry powder is laid.

[0034] In S2, the hot pressing is performed under conditions of 20~35MPa and 180~220℃ for 15~25min.

[0035] In S2, the curing is carried out at 150~220℃ for 0.5~3 hours, preferably at 160~180℃ for 1~2 hours.

[0036] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present invention.

[0037] Compared with the prior art, the beneficial effects of the present invention are: This invention achieves bonding between the titanium alloy steel backing and the friction substrate by combining a buffer layer. In the fiber-reinforced system, elastic particles are added to absorb thermal stress and mechanical impact. Simultaneously, thermally conductive fillers are used to initially conduct the braking heat from the friction layer to the steel backing, preventing heat accumulation at the interface. The friction substrate uses copper-tin alloy powder as the base thermally conductive filler, combined with polycarbonate microsphere pore-forming agents to form an interconnected porous structure. This allows for rapid conduction of braking heat generated on the friction surface to the steel backing and dissipation, preventing heat accumulation and reducing the thermal degradation rate. The friction surface uses high-temperature resistant polyamide-imide resin as the matrix, with tungsten carbide particles as the main wear-resistant component. Steel fibers act as a fiber reinforcement network to suppress surface cracks and prevent material spalling and flaking at high temperatures. The lubrication phase balances low-temperature lubrication and noise reduction with high-temperature friction stability.

[0038] The hollow copper and Ni-Ti shape memory alloy wire-controlled structure of the titanium alloy steel backing of this invention can generate radial preload through shape memory effect at high temperature, actively suppress thermal expansion deformation of the steel backing, ensure uniform adhesion between the friction material and the brake disc, and avoid fluctuations in braking performance.

[0039] The track brake pads of this invention are less prone to delamination and detachment under high-frequency, high-intensity braking conditions, and their structural stability and braking reliability are greatly improved. Attached Figure Description

[0040] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0041] Figure 1 This is a schematic diagram of the layers of a racetrack brake pad.

[0042] Figure 2 This is a front view of the titanium alloy steel back.

[0043] Figure 3 This is a view of the back of the titanium alloy steel backing.

[0044] Figure 4 This is a schematic diagram of a nested component structure.

[0045] Figure 5 Friction coefficient test data graph for Example 1.

[0046] Explanation of reference numerals in the attached drawings: 1. Titanium alloy steel backing; 2. Composite buffer layer; 3. Friction bottom layer; 4. Friction surface layer; 110. Front side of titanium alloy steel backing; 111. Nested component; 100. Back side of titanium alloy steel backing; 101. Honeycomb; 1111. Ni-Ti shape memory alloy wire; 1112. Hollow copper. Detailed Implementation

[0047] To facilitate understanding of the present invention, the present invention will be described more fully and in detail below with reference to preferred embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments.

[0048] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0049] The raw material information used in the following examples is as follows: The aramid chopped strand fiber is from DuPont, USA, and its specific surface area is 5.5 ± 0.5 m². 2 / g, average length is 3~23mm; The grade of short-cut carbon fiber is Toray T1100 from Japan; The average fiber length of copper fiber is 3~4mm; Boron-modified phenolic resin was purchased from Greenlink Chemical Technology Co., Ltd. The modified phenolic resin from butyl rubber latex was purchased from Jining Huakai Resin Co., Ltd. (HK-9016). The chemical composition of alumina fiber cotton is 72wt% Al2O3 and 28wt% SiO2; its fiber diameter is 5~7μm; Nitrile rubber powder was purchased from Anhui Donggao Technology Co., Ltd. (PNBR-03B), with a bound acrylonitrile content of 35-40 wt%. The polyacrylonitrile powder is branded by DuPont, USA, and has a molecular weight of 100,000. The average particle size of silicon carbide is 5 μm; The diameter of the steel fibers is ≤0.08mm; The tungsten carbide particles were purchased from Zhuzhou Jinzhou Hard Alloy Co., Ltd., YG8, with a particle size of 25μm and a chemical composition of 92wt%WC and 8wt%Co. Polyamide-imide resin (PAI powder) grade: Solvay Torlon® 4203 (USA); This includes, but is not limited to, the models from the above manufacturers.

[0050] By mass fraction, the raw materials for preparing the combined buffer layer also contain 0.5-3% silane coupling agent, 0.5-3% dispersant, etc. as processing aids.

[0051] By mass fraction, the raw materials for preparing the friction underlayer also contain 0.5-3% silane coupling agent, 1-2% zinc stearate, 0.5-3% dispersant, and 0.1-0.8% anti-scorching agent as processing aids; By mass fraction, the raw materials for preparing the friction surface layer also contain 0.5-3% fluorine-modified acrylate hydrophobic agent and 2-5% sintering aid as processing aids.

[0052] Further in S1, the pretreatment process of the titanium alloy steel backing is sandblasting roughening treatment, so that the surface roughness Ra of the bonding surface reaches 6.3~12.5μm, followed by alkaline washing to remove oil and acid washing to activate, and drying for later use.

[0053] Further in S1, the preparation process of the combined buffer layer slurry is as follows: boron-modified phenolic resin is dissolved in ethanol to prepare a resin slurry with a solid content of 60-75 wt%; under stirring, silane coupling agent, PTFE powder, thermally conductive filler, elastic particles and other processing aids are added sequentially, and the mixture is stirred at high speed of 700-1000 rpm for 20-40 min; finally, chopped fibers and ceramic fibers are added, and the mixture is stirred at low speed of 200-500 rpm for 10-20 min to obtain the combined buffer layer slurry.

[0054] Further in S1, the preparation process of the friction underlayer slurry is as follows: Boron-modified phenolic resin is dissolved in an appropriate amount of ethanol to prepare a resin slurry with a solid content of 65-80 wt%; under stirring, silane coupling agent, thermally conductive filler, polycarbonate microspheres, wear-resistant phase and other processing aids are added in sequence, and dispersed at high speed of 700-1000 rpm for 20-40 min; finally, short-cut fibers and copper-tin alloy powder are added, and stirred at low speed for 10-20 min to obtain the friction underlayer slurry.

[0055] Further in S1, the preparation process of the friction surface dry powder is as follows: polyamide-imide resin powder, steel fiber, tungsten steel particles, polycrystalline alumina, lubricating phase and processing aid are mixed and sheared at 1500~2000rpm for 10~40min.

[0056] Racing brake pads The schematic diagram of each layer structure of the track brake pad of the present invention is shown below. Figure 1 From bottom to top, it consists of a titanium alloy steel backing 1, a combined buffer layer 2, a friction bottom layer 3, and a friction surface layer 4. See Figure 2 The front view of the titanium alloy steel backing shows a spiral groove (0.10mm deep) inside the front 110, into which the nesting piece 111 is embedded. The spiral groove is filled with thermally conductive graphite paste. The nesting piece 111 is a coaxial nesting structure of hollow copper 1112 (3mm in diameter) covered with Ni-Ti shape memory alloy wire 1111. See [reference needed]. Figure 4 ; See Figure 3 The back of the titanium alloy steel back is shown in the figure. The back surface 100 of the titanium alloy steel back is provided with honeycomb 101, and the area of ​​honeycomb 101 accounts for 40%.

[0057] Example 1 The race car brake pads in this embodiment are as follows: The buffer layer is composed of the following raw materials by mass percentage: 7.1% ceramic fiber (alumina fiber), 10.5% chopped aramid fiber, 3.8% PTFE powder, 15.9% thermally conductive filler (flake graphite / aluminum nitride mass ratio of 1 / 5), 5.6% elastic particles (nitrile rubber powder), 1.3% silane coupling agent (KH560), 1.0% dispersant (glyceryl monostearate), and the balance boron-modified phenolic resin; The friction substrate is composed of the following raw materials by mass percentage: 35.3% copper-tin alloy powder (CuSn10), 8.2% chopped carbon fiber, 8.7% thermally conductive filler (flake graphite / aluminum nitride mass ratio of 1 / 5), 6.4% polycarbonate microspheres, 6.9% wear-resistant phase (silicon carbide), 1.2% silane coupling agent KH550, 1.5% zinc stearate, 1.0% dispersant (glyceryl tristearate), and 0.5% anti-scorching agent (CTP). N -Cyclohexylthiophthalimide) and the balance boron-modified phenolic resin; The friction surface layer is composed of the following raw materials by mass percentage: 30.7% polyamide-imide resin, 7.1% steel fiber, 15.4% polycrystalline alumina (D50=40μm), 5.9% lubricating phase (MoS2 / graphene mass ratio of 3 / 1), 2.6% fluorine-modified acrylate hydrophobic agent, 2.9% sintering aid (aluminum dihydrogen phosphate), and the balance tungsten carbide particles.

[0058] Its preparation method is as follows: Pretreatment: The TC4 titanium alloy steel backing surface is roughened by sandblasting, and the roughness Ra is controlled at 8.0μm; alkaline washing, acid washing, water washing and drying are performed; 15 hollow copper beads are installed on the front side of the steel backing, and Ni-Ti shape memory alloy wires are embedded and welded and fixed; the back side of the steel backing is filled with paraffin-expanded graphite material and then sealed with a porous ceramic cover plate. S1. Raw material preparation (prepare raw materials according to the above formula): Preparation of the combined buffer layer slurry: Boron-modified phenolic resin was dissolved in ethanol to prepare a resin slurry with a solid content of 70 wt%; under stirring, silane coupling agent, PTFE powder, thermally conductive filler, elastic particles and dispersant were added in sequence, and the mixture was stirred at high speed of 800 rpm for 30 min; finally, chopped fibers and ceramic fibers were added, and the mixture was stirred at low speed of 300 rpm for 15 min to obtain the combined buffer layer slurry.

[0059] Preparation of friction underlayer slurry: Boron-modified phenolic resin was dissolved in ethanol to prepare a resin slurry with a solid content of 70 wt%; silane coupling agent, thermally conductive filler, polycarbonate microspheres, diamond micro powder, zinc stearate, dispersant, and anti-scorching agent were added in sequence, and the mixture was stirred at high speed of 800 rpm for 30 min; short-cut carbon fibers and copper-tin alloy powder were added, and the mixture was stirred at low speed of 300 rpm for 15 min to obtain the friction underlayer slurry; Preparation of dry powder for friction surface: Polyamide-imide resin, steel fiber, tungsten steel particles, polycrystalline alumina, lubricating phase, hydrophobic agent, and sintering aid are mixed and sheared at 1800 rpm for 20 min to obtain dry powder for friction surface.

[0060] S2. Apply the bonding buffer layer slurry to the bonding surface of the titanium alloy steel backing and pre-bake at 120℃ for 1 hour; then apply the friction underlayer slurry and pre-bake at 120℃ for 1 hour; evenly spread the friction surface dry powder on the friction underlayer surface; hot press at 30MPa and 200℃ for 20 minutes; then cure at 160℃ for 2 hours.

[0061] Example 2 The difference between this embodiment and Embodiment 1 is as follows: Replace nitrile rubber powder with polyacrylonitrile powder; The other raw materials, steps and parameters are the same as in Example 1.

[0062] Example 3 The difference between this embodiment and Embodiment 1 is as follows: The buffer layer is composed of the following raw materials by mass percentage: 9.7% chopped carbon fiber, 5.1% chopped copper fiber, 2.3% PTFE powder, 15.7% thermally conductive filler, 4.3% elastic particles, 2.1% coupling agent, 1.8% dispersant and balance boron-modified phenolic resin. The other raw materials, steps and parameters are the same as in Example 1.

[0063] Example 4 The difference between this embodiment and Embodiment 1 is as follows: In this embodiment, no PTFE powder is added to the raw materials used to prepare the buffer layer. The other raw materials, steps and parameters are the same as in Example 1.

[0064] Example 5 The difference between this embodiment and Embodiment 1 is as follows: The friction substrate is composed of the following raw materials by mass percentage: 22.6% copper-tin alloy powder (CuSn6), 8.3% chopped aramid fiber, 7.4% thermally conductive filler, 2.8% polycarbonate microspheres, 6.7% wear-resistant phase (silicon carbide), 1.2% silane coupling agent KH550, 1.7% zinc stearate, 2.4% dispersant, 0.5% anti-scorching agent, and the balance boron-modified phenolic resin; The other raw materials, steps and parameters are the same as in Example 1.

[0065] Example 6 The difference between this embodiment and Embodiment 1 is as follows: The friction surface layer is composed of the following raw materials by mass percentage: 40% polyamide-imide resin, 8.8% steel fiber, 12.5% ​​polycrystalline alumina, 6.8% lubricating phase (MoS2 / graphene mass ratio is 1 / 1), 2.4% fluorine-modified acrylate hydrophobic agent, 1.8% sintering aid and balance tungsten carbide particles.

[0066] The other raw materials, steps and parameters are the same as in Example 1.

[0067] Comparative Example 1 The difference between this comparative example and Example 1 is as follows: The brake pads in this comparative example do not contain a friction underlayer. Accordingly, in S2, the bonding buffer layer slurry is coated on the bonding surface of the titanium alloy steel backing and pre-baked at 120°C for 1 hour; then the friction surface dry powder is evenly spread on the surface of the friction underlayer and hot-pressed to obtain the racing brake pads of this comparative example. The other raw materials, steps and parameters are the same as in Example 1.

[0068] Comparative Example 2 The difference between this comparative example and Example 1 is as follows: Replace the boron-modified phenolic resin in the raw materials with butylated latex-modified phenolic resin. The other raw materials, steps and parameters are the same as in Example 1.

[0069] Comparative Example 3 The difference between this comparative example and Example 1 is as follows: The raw materials used to prepare the buffer layer do not contain elastic particles; The other raw materials, steps and parameters are the same as in Example 1.

[0070] Comparative Example 4 The difference between this comparative example and Example 1 is as follows: The raw materials used to prepare the friction surface layer do not contain tungsten carbide particles; The other raw materials, steps and parameters are the same as in Example 1.

[0071] [Racing Brake Pad Performance Test] The racetrack brake pads prepared in the above embodiments and comparative examples were used as samples for the following tests.

[0072] Test Example 1—Interfacial Shear Strength Referring to ASTM D1002, the sample is fixed on a special fixture, and a shear force parallel to the bonding surface is applied to the friction material layers until interlayer failure occurs. The maximum failure load is recorded, and the shear strength is calculated.

[0073]

[0074] Test Example 2—Thermal Attenuation Performance The coefficient of friction μ was tested at 150℃, 400℃, and 600℃ using a LINK 3000 passenger car brake test bench; the initial braking velocity was 100 kph, and the deceleration value was 0.4g (i.e., 0.4 × 9.8 m / s²). 2 ); For example, the friction coefficient γ test data for Example 1 can be found here. Figure 5 The data for the remaining embodiments and comparative examples are summarized in Table 2.

[0075]

[0076] Test Example 3 – Wear Resistance Test Referring to GB / T 5763, a friction and wear testing machine is used to rub the specimen against a rotating disk under load, speed, and temperature. The wear rate is calculated based on the experimental results, and is usually expressed as K = V / (F × S), where V is the volumetric wear amount (mm). 3 F is the normal load (N), and S is the total sliding distance (m). The smaller the K value, the better the wear resistance of the material.

[0077]

[0078] Unless otherwise specified, all raw materials, reagents, instruments, and equipment used in this invention can be purchased commercially or prepared using existing methods. The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this invention. It should be understood that the above descriptions are merely specific embodiments of this invention and are not intended to limit the invention. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A racing car brake pad, characterized in that, From bottom to top, the layers are: titanium alloy steel backing, combined buffer layer, friction base layer, and friction surface layer. The combined buffer layer comprises chopped fibers, elastic particles, and boron-modified phenolic resin; The friction substrate comprises chopped fibers, copper-tin alloy powder, and boron-modified phenolic resin; The friction surface layer comprises steel fibers, tungsten carbide particles, a lubricating phase, and polyamide-imide resin.

2. The racetrack brake pad as described in claim 1, characterized in that, The combined buffer layer comprises the following raw materials by mass percentage: 0.1-15% ceramic fiber, 8-18% chopped fiber, 0.1-5% PTFE powder, 10-25% thermally conductive filler, 3-9% elastic particles and 23-78% boron-modified phenolic resin. And / or, the friction substrate comprises the following raw materials by mass percentage: 18-45% copper-tin alloy powder, 5-14% chopped fibers, 5-12% thermally conductive filler, 2-10% polycarbonate microspheres, 5-10% wear-resistant phase and 4-61% boron-modified phenolic resin. And / or, the friction surface comprises the following raw materials by mass percentage: 25-45% polyamide-imide resin, 5-10% steel fiber, 10-20% polycrystalline alumina, 3-9% lubricating phase and 10-54% tungsten carbide particles.

3. The racetrack brake pad as described in claim 2, characterized in that, The thermally conductive filler is flake graphite and aluminum nitride; And / or, the chopped fiber is at least one of chopped aramid fiber, chopped carbon fiber and copper fiber.

4. The racetrack brake pad as described in claim 2, characterized in that, The wear-resistant phase is at least one of synthetic diamond micro powder and silicon carbide; And / or, the ceramic fiber is alumina fiber or aluminosilicate fiber; And / or, the elastic particles are nitrile rubber powder or polyacrylonitrile powder.

5. The racetrack brake pad as described in claim 2, characterized in that, The copper-tin alloy powder is made of CuSn10, CuSn6, CuSn15 or CuSn8Zn. And / or, the steel material of the steel fiber is 304 steel, 310 steel, 330 steel, 430 steel or 446 steel; And / or, the lubricating phase is molybdenum disulfide and graphene; And / or, the chemical composition of the tungsten carbide particles is WC and Co.

6. The racetrack brake pad as described in claim 1, characterized in that, The titanium alloy steel backing is made of TC4, TC6, TC11 or TC16. And / or, the thickness of the titanium alloy steel backing is 5~7mm.

7. The racetrack brake pad as described in claim 6, characterized in that, The inner wall of the front side of the titanium alloy steel back is provided with a spiral groove; the front side of the titanium alloy steel back is provided with a nesting component, which is a coaxial nesting structure of hollow copper and Ni-Ti shape memory alloy wire. And / or, the back of the titanium alloy steel back is provided with a honeycomb structure.

8. The method for preparing racetrack brake pads according to any one of claims 1 to 7, characterized in that, Includes the following steps: S1. Mix the raw materials for the preparation of the combined buffer layer, the friction bottom layer, and the friction surface layer to obtain the combined buffer layer slurry, the friction bottom layer slurry, and the friction surface layer dry powder, respectively; S2. The buffer layer slurry and the friction underlayer slurry are sequentially coated on the front side of the titanium alloy steel backing, and then the friction surface dry powder is laid on top, and cured after hot pressing.

9. The preparation method according to claim 8, characterized in that, In S1, after the composite bonding buffer layer slurry is coated, it needs to be pre-baked at 120°C for 1 hour before the friction underlayer slurry is sprayed; after the friction underlayer slurry is coated, it needs to be pre-baked at 120°C for 1 hour before the friction surface dry powder is laid.

10. The preparation method according to claim 8, characterized in that, In S2, the hot pressing is performed under conditions of 20~35MPa and 180~220℃ for 15~25min; And / or, in S2, the curing is carried out at 150~220℃ for 0.5~3h.

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