Three-matrix collaborative optimization long-life composite friction material as well as preparation method and application thereof

Abstract

The invention discloses a three-matrix collaborative optimization long-life composite friction material as well as a preparation method and application thereof. A preparation method of the long-life composite friction material belongs to the technical field of friction materials, and comprises the following steps: mixing a matrix, an inorganic filler and a fiber reinforced phase, performing hot-pressing curing, performing two-stage heat treatment, and cooling to room temperature to obtain the long-life composite friction material with synergistically optimized matrix, the matrix consists of thermosetting resin, rubber and an inorganic adhesive; according to the long-service-life composite friction material with synergic optimization of the three matrixes, the shear strength ranges from 12.4 MPa to 18.7 MPa; the compression strength is 135 to 202 Mpa; and at the temperature of 200 DEG C to 350 DEG C, the friction coefficient is 0.40 to 0.62. The problems that an existing brake shoe is large in high-temperature abrasion rate, low in compressive strength, low in friction coefficient and unstable are remarkably solved, the safety of a brake system is improved, the service life of the brake system is prolonged, and the brake shoe adapts to the severe high-speed and heavy-load working environment of railway wagons. And the inorganic adhesive is introduced as a matrix, so that the high-temperature adhesive property of the friction material is enhanced, and the harsh long-life service requirement of the railway wagon is met.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of friction materials, and particularly relates to a long-service-life composite friction material with three matrix synergistic optimization and a preparation method and application thereof. BACKGROUND

[0002] With the rapid development of railway heavy-haul transportation, the performance requirements of friction materials in the braking system are increasingly improved. Railway heavy-haul freight cars need to maintain stable braking performance under high load and frequent braking conditions. However, most existing friction materials adopt a double-matrix structure formed by thermosetting resin and rubber. Although this material combines the high strength of thermosetting resin and the elasticity of rubber to some extent, it still has obvious deficiencies in high-temperature resistance. Under high-temperature, high-load and frequent braking conditions, the double-matrix material is prone to thermal degradation, with unstable friction coefficient, accelerated wear and shortened service life. These problems not only seriously affect the safety and reliability of the braking system, but also lead to a high wear rate. High wear rate requires frequent replacement of brake shoes, which not only increases maintenance costs, but also brings many inconveniences to railway operation. Frequent replacement of brake shoes requires a large amount of manpower, material resources and time, and may also lead to an increase in train downtime, affecting the efficiency and economic benefits of railway transportation. Therefore, developing a new type of friction material that can maintain stable performance and has a low wear rate under high-temperature and high-load conditions is of great significance to improving the overall performance of the braking system of railway heavy-haul freight cars and reducing operating costs.

[0003] Chinese patent application CN114957867A discloses "A friction body composition for synthetic brake shoe of heavy truck and a synthetic brake shoe of heavy truck prepared by the composition", which uses ternary ethylene-propylene rubber copolymer blend as the matrix, zinc oxide, stearic acid, 4,4'-dithiodimorpholine (DTDM), hollow ceramic microspheres, dipentaerythritol and hydrotalcite as inorganic fillers and reinforcing bodies of friction material, and adopts mixing, banburying, vulcanization and other processes to prepare the brake shoe material. Although the friction coefficient of the brake shoe material prepared by the invention is reduced at high and low braking speeds, the friction stability at high and low braking speeds is improved, but the service life of the brake shoe is 16.9-18.2 million kilometers, corresponding to 5-7 months of use time, which is still lower than the industry leading level. Chinese patent application CN102191015A discloses a "hybrid fiber reinforced friction material for train braking and a preparation method thereof", which provides a friction material for train braking with excellent quality and can avoid heat recession and thermal cracking, and a preparation method thereof. The friction material is prepared by mixing, molding and heat treatment, etc. by using modified phenolic resin and rubber as the matrix, hybrid fiber as the reinforcing body, and graphite, mica, carbon black, aluminum oxide, silicon carbide, cuprous oxide, barium oxide, wollastonite, silicon dioxide, etc. as the friction modifier. Although the invention overcomes the heat recession problem of traditional phenolic resin matrix friction material, the wear rate is 0.57-0.69 cm 3 / MJ, which is difficult to meet the long-life application requirements of train brake shoes.

[0004] At present, most of the existing brake shoe friction materials on the market are prepared by different raw materials and proportions, and their performance can only meet the use requirements of ordinary railway freight cars. However, under high temperature conditions, the friction coefficient of these materials is generally low and fluctuates greatly, the wear rate increases significantly, and the compressive strength is also not ideal. These defects make it difficult for existing brake shoe friction materials to adapt to the higher requirements of high-speed heavy-load railway freight cars on braking performance. Therefore, it is urgent to develop a new type of brake shoe friction material with high strength and excellent high-temperature friction and wear performance, and to explore a corresponding efficient preparation method to meet the braking requirements of high-speed heavy-load railway freight cars and ensure the safety and efficiency of railway transportation. SUMMARY

[0005] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present application is to provide a long-life composite friction material with three matrix synergistic optimization and a preparation method and application, to solve the technical problem of high wear rate of existing brake shoe at high temperature.

[0006] In order to achieve the above-mentioned purpose, the following technical solutions are adopted in the present application: The application discloses a preparation method of a long-service-life composite friction material with three matrix synergistic optimization, and comprises the following steps: mixing a matrix, inorganic fillers and a fiber reinforced phase, performing heat pressing and solidification, performing two-stage heat treatment, and cooling to room temperature to obtain the long-service-life composite friction material with matrix synergistic optimization. The matrix is composed of a thermosetting resin, rubber and an inorganic adhesive. The long-service-life composite friction material with three matrix synergistic optimization has a shear strength of 12.4-18.7 MPa, a compression strength of 135-202 MPa, and a friction coefficient of 0.40-0.62 at 200 DEG C.-350 DEG C.

[0007] Preferably, the mass percentage of the matrix, the inorganic fillers and the fiber reinforced phase is (15%-30%):(40%-60%):(10%-30%).

[0008] Preferably, the mass percentage of the thermosetting resin, the rubber and the inorganic adhesive in the matrix is (11%-26%):(2%-8%):(2%-8%).

[0009] Preferably, the thermosetting resin comprises one or more of cashew nut shell oil modified phenolic resin, boron modified phenolic resin, bisphenol A type epoxy resin, polyimide resin, benzoxazine resin, unsaturated polyester resin, bismaleimide resin, cyanate ester resin, phenolic epoxy resin and melamine formaldehyde resin. The rubber comprises one or more of silicone rubber, nitrile rubber, styrene butadiene rubber, butadiene rubber, fluorine rubber, black rubber powder, natural rubber, chloroprene rubber, ethylene propylene diene rubber, cis-butadiene rubber and butyl rubber. The inorganic adhesive comprises one or more of alumina-based high-temperature adhesive, phosphate high-temperature adhesive, borate high-temperature adhesive, silicate high-temperature adhesive, aluminum hydroxide-based high-temperature adhesive and zirconia-based high-temperature adhesive.

[0010] Preferably, the inorganic fillers comprise one or more of corundum, barium sulfate, calcium carbonate, zinc oxide, graphite, carbon black, chromite, fluorite and sublimed sulfur. The fiber reinforced phase comprises one or more of polyacrylonitrile-based carbon fiber, pitch-based carbon fiber, aramid fiber, calcium sulfate whisker, mineral fiber, basalt fiber, glass fiber and steel fiber.

[0011] Preferably, the mixing conditions comprise the following steps: the speed is 8000-12000 rpm, the mixing time is 2-5 s each time, the next mixing is performed after an interval of 4-6 min, and the mixing is performed for 3 times. The fiber reinforced phase is pre-mixed before mixing, and the pre-mixing conditions comprise the following steps: the speed is 8000-12000 rpm, the mixing time is 2-5 s each time, the next mixing is performed after an interval of 4-6 min, and the mixing is performed for 3 times.

[0012] Preferably, the heat-pressing curing conditions include a temperature of 150-180℃, a pressure of 4-8 MPa, and a time of 600-1200 s, with the pressure being released every 30-50 s during the pressing process.

[0013] Preferably, the two-stage heat treatment conditions include a temperature of 110-150℃ for 150-180 min and a temperature of 150-190℃ for 150-180 min.

[0014] The application further discloses a long-service-life composite friction material with three matrixes synergistically optimized, which is prepared by the preparation method of the long-service-life composite friction material with three matrixes synergistically optimized. 3 / MJ.

[0015] The application further discloses an application of the long-service-life composite friction material with three matrixes synergistically optimized in a railway heavy-load freight car.

[0016] Compared with the prior art, the application has the following beneficial effects: The application discloses a preparation method of a long-service-life composite friction material with three matrixes synergistically optimized, which is prepared from a ternary system of a matrix, inorganic fillers and a fiber reinforced phase through mixing, heat-pressing curing and two-stage heat treatment. The matrix provides adhesion, the inorganic fillers adjust the friction coefficient, and the fiber reinforced phase improves the mechanical strength, so that the three matrixes synergistically improve the comprehensive performance of the material. The low-temperature stage promotes the preliminary curing of the resin, the high-temperature stage eliminates internal stress, optimizes the microstructure, and improves the thermal stability and durability of the material. In brake shoe friction materials, although the addition of a proper amount of thermosetting resin and rubber as the matrix can make the adhesion strength of the material reach a moderate level, the thermosetting resin and rubber are prone to decomposition under high-temperature conditions, which leads to a significant decrease in the performance of the material, such as weakened adhesion strength and reduced wear resistance, and even harmful gases may be generated, thereby affecting the braking effect and safety. To solve this problem, the introduction of inorganic adhesives as the matrix material is an effective improvement measure. The inorganic adhesives have a unique secondary adhesion effect under high-temperature environments, which can effectively compensate for the problem of a significant increase in the wear rate caused by the softening and decomposition of the thermosetting resin and rubber under high temperatures, thereby significantly prolonging the service life of the brake shoe and improving the overall performance of the brake shoe friction material, including the strength, thermal stability and friction stability. The optimized long-service-life friction material with three matrixes synergistically enhanced has a volume wear rate of 0.015-0.072 cm 3The compression strength is 135-202 MPa, increased by 42%-260%, and the compression modulus is 2307-3151 MPa, increased by 68%-289%. The friction coefficient at 200-350℃ is 0.40-0.62. The problems of high wear rate, low compression strength, and low and unstable friction coefficient at high temperature of the existing brake shoe are significantly improved, and the safety and service life of the braking system are improved to adapt to the harsh working environment of high-speed and heavy-load railway freight cars. By introducing inorganic binder as the matrix, the high-temperature bonding performance of the brake shoe friction material is enhanced, and by reasonably adjusting the types and proportions of raw materials, the problems of high wear rate, low compression strength, and low and unstable friction coefficient at high temperature of the existing brake shoe are improved. The brake shoe friction material has the advantages of high and stable friction coefficient at high temperature, good compression resistance, and low wear rate at high temperature, and meets the harsh requirements of long service life of railway freight cars.

[0017] Further, the long-life composite friction material optimized by the synergistic effect of the three matrices includes, in mass percentage, 15%-30% of the matrix, 40%-60% of the inorganic filler, and 10%-30% of the fiber reinforced phase. The high proportion of inorganic filler provides a stable friction coefficient and reduces wear at high temperature; the fiber reinforced phase forms a skeleton structure to prevent material cracking and improve impact resistance.

[0018] Further, the matrix includes, in mass percentage, 11%-26% of thermosetting resin, 2%-8% of rubber, and 2%-8% of inorganic binder. By accurately adjusting the composition ratio of thermosetting resin, rubber, and inorganic binder, the synergistic effect among the three can be achieved. The thermosetting resin provides high-temperature bonding force to ensure that the material does not fall off; the rubber improves the toughness of the material and reduces crack propagation during friction; the inorganic binder improves the thermal stability of the material above 350℃ to prevent decomposition of the matrix.

[0019] Further, the thermosetting resin includes one or more of cashew shell oil modified phenolic resin, boron modified phenolic resin, bisphenol A type epoxy resin, polyimide resin, benzoxazine resin, unsaturated polyester resin, bismaleimide resin, cyanate ester resin, phenolic epoxy resin, and melamine formaldehyde resin. By selecting these different types of thermosetting resins, the performance of the brake shoe friction material can be adjusted according to specific application requirements, such as wear resistance, heat resistance, and mechanical strength.

[0020] Further, the rubber includes one or more of silicone rubber, nitrile rubber, styrene butadiene rubber, butadiene rubber, fluororubber, black rubber powder, natural rubber, chloroprene rubber, ethylene propylene diene rubber, cis-butadiene rubber, and butyl rubber. By selecting these different types of rubber, the elasticity, wear resistance, and friction performance of the brake shoe friction material can be optimized to adapt to different working conditions.

[0021] Further, the inorganic binder includes one or more of alumina-based high-temperature binder, phosphate high-temperature binder, borate high-temperature binder, silicate high-temperature binder, aluminum hydroxide-based high-temperature binder, and zirconia-based high-temperature binder; by selecting different types of inorganic binders, the high-temperature wear resistance, friction coefficient stability, and high-temperature mechanical properties of the brake shoe can be optimized to adapt to the use of the brake shoe under high-temperature conditions.

[0022] Further, the inorganic filler includes one or more of corundum, barium sulfate, calcium carbonate, zinc oxide, graphite, carbon black, chromite, fluorite, and sublimed sulfur; wherein the mass fraction of SiO2 in the fluorite is 10% to 15%. The graphite provides self-lubricity to reduce the low-temperature friction coefficient; the corundum and zinc oxide improve wear resistance and inhibit high-temperature wear.

[0023] Further, the fiber reinforced phase includes one or more of polyacrylonitrile-based carbon fiber, pitch-based carbon fiber, aramid fiber, calcium sulfate whisker, mineral fiber, basalt fiber, glass fiber, and steel fiber. The carbon fiber can improve strength and electrical conductivity to prevent static electricity accumulation; the steel fiber enhances impact resistance to adapt to high load impact of heavy-duty trucks.

[0024] Further, the high-speed shearing force uniformly disperses the filler and the fiber to avoid agglomeration and improve material homogeneity; short-time mixing reduces mechanical shear damage to the fiber, and the premixing process ensures that the fiber forms a uniform network structure in the matrix.

[0025] Further, the medium-temperature high-pressure condition promotes complete crosslinking of the resin to form a dense network structure and improve compressive strength; the interval degassing eliminates air introduced during the mixing process and small molecules generated during resin curing, reduces internal pores of the material, and improves shear strength.

[0026] Further, slow curing at a low temperature reduces internal stress, further crosslinking at a high temperature improves heat resistance, high-temperature treatment promotes interfacial reaction between the inorganic binder and the resin to form an interpenetrating network structure and reduce volume wear rate. The three-matrix synergistically optimized long-life friction material can maintain a stable friction coefficient of 0.40 to 0.62 in the temperature range of 200 to 350°C, which can ensure sufficient braking force, thereby effectively shortening the braking distance and enhancing the response capability of the train in an emergency braking situation, significantly improving the driving safety and reliability. At the same time, the stable friction coefficient helps to reduce the instability of braking caused by insufficient or fluctuating braking force, further ensuring the smooth operation of the braking system, especially under complex working conditions such as high temperature and heavy load, which can better demonstrate its advantages.

[0027] The application also discloses a three-matrix synergistically optimized long-life friction material prepared by the preparation method, which has a volume wear rate of 0.015 to 0.072 cm3 / g in the temperature range of 200 to 350°C.3 The lower wear rate indicates that the material has excellent wear resistance, can maintain a long service life under high temperature working conditions, and significantly reduces the replacement frequency and maintenance cost of the brake shoe. At the same time, the lower wear rate also means that the material has better dimensional stability during use, can maintain stable braking performance, and further guarantees the reliability and safety of the braking system.

[0028] The application also discloses application of the three-matrix synergistically optimized long-life composite friction material prepared by the preparation method in a heavy load freight train, the high compression strength (135-202 MPa) and the shear strength (12.4-18.7 MPa) can withstand the high braking pressure and impact force of the heavy load freight train; the replacement frequency of the friction plate is reduced, the dust emission is reduced, and the environmental protection and cost control requirements of railway transportation are met. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 Room temperature mechanical properties of the three-matrix synergistically optimized long-life composite friction material prepared in the examples 1-9 of the application and the double-matrix friction material prepared in the comparative examples 1-2; wherein (a) is a compression strength and compression modulus diagram; (b) is a shear strength diagram; Figure 2 Volume wear rate diagrams of the three-matrix synergistically optimized long-life composite friction material prepared in the examples 1-9 of the application and the double-matrix friction material prepared in the comparative examples 1-2 at 200-350 DEG C; wherein (a) is the volume wear rate at 200 DEG C; (b) is the volume wear rate at 250 DEG C; (c) is the volume wear rate at 300 DEG C; (d) is the volume wear rate at 350 DEG C. DETAILED DESCRIPTION

[0030] The technical solutions of the present application will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0031] In the present application, all the embodiments and preferred implementation methods mentioned in the present application can be combined to form new technical solutions, if not specifically stated.

[0032] In the present application, all the technical features and preferred features mentioned in the present application can be combined to form new technical solutions, if not specifically stated.

[0033] In the present application, percentage (%) or part refers to the weight percentage or weight part of the composition, if not specifically stated.

[0034] In the present application, each component or its preferred component involved can be combined with each other to form a new technical solution, unless otherwise specified.

[0035] In the present application, unless otherwise specified, the numerical range "a~b" represents a shorthand notation for any real number combination between a and b, wherein a and b are both real numbers. For example, the numerical range "6~22" represents that all real numbers between "6~22" have been listed herein, and "6~22" is only a shorthand notation for these numerical combinations.

[0036] The lower limit and upper limit of the range disclosed in the present application can be one or more lower limits and one or more upper limits, respectively.

[0037] In the present application, the term "and / or" used herein means any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0038] In the present application, unless otherwise specified, each reaction or operation step can be carried out sequentially or according to the sequence. Preferably, the reaction method herein is carried out sequentially.

[0039] Unless otherwise specified, the professional and scientific terms used herein have the same meaning as those familiar to those skilled in the art. In addition, any method or material similar or equivalent to that described can also be applied in the present application.

[0040] The present application provides a long-life composite friction material with three matrix synergistic optimization, which comprises, in mass percentage, a matrix 15%~30%, an inorganic filler 40%~60% and a fiber reinforced phase 10%~30%, and the weight ratio of each component is 100%. The matrix comprises, in mass percentage, a thermosetting resin 11%~26%, a rubber 2%~8% and an inorganic adhesive 2%~8%, and the percentages involved are mass percentages.

[0041] The thermosetting resin comprises one or more of cashew nut shell oil modified phenolic resin, boron modified phenolic resin, bisphenol A type epoxy resin, polyimide resin, benzoxazine resin, unsaturated polyester resin, bismaleimide resin, cyanate ester resin, phenolic epoxy resin and melamine formaldehyde resin.

[0042] The rubber comprises one or more of silicone rubber, nitrile rubber, styrene butadiene rubber, butadiene rubber, fluororubber, black rubber powder, natural rubber, chloroprene rubber, ethylene propylene diene rubber, cis-butadiene rubber and butyl rubber.

[0043] The inorganic adhesive comprises one or more of alumina-based high-temperature adhesive, phosphate high-temperature adhesive, borate high-temperature adhesive, silicate high-temperature adhesive, aluminum hydroxide-based high-temperature adhesive and zirconia-based high-temperature adhesive.

[0044] The inorganic filler includes one or more of corundum, barium sulfate, calcium carbonate, zinc oxide, graphite, carbon black, chromite, fluorite and sublimed sulfur; wherein the mass fraction of SiO2 in the fluorite is 10% to 15%.

[0045] The fiber reinforced phase includes one or more of polyacrylonitrile-based carbon fiber, pitch-based carbon fiber, aramid fiber, calcium sulfate whisker, mineral fiber, basalt fiber, glass fiber and steel fiber.

[0046] The volume wear rate of the three-matrix synergistically optimized long-life composite friction material is 0.015 to 0.072 cm 3 / MJ at 200 to 350℃.

[0047] The application further discloses a preparation method of the three-matrix synergistically optimized long-life composite friction material, which comprises the following steps: 1) preparation of mixed powder; 11) powder weighing: the fiber reinforced phase, the matrix and the inorganic filler are weighed respectively for use; 12) premixing of the fiber reinforced phase: the fiber reinforced phase is added into a high-speed mixer, the mixing speed is 8000 to 12000 rpm, the mixing time is 2 to 5 s each time, the next mixing is carried out after an interval of 4 to 6 min, and the total mixing is 3 times, to obtain the fiber reinforced phase premixing material; 13) mixing of the fiber reinforced phase and other powders: the matrix, the inorganic filler and the fiber reinforced phase premixing material are added into a high-speed mixer, the mixing speed is 8000 to 12000 rpm, the mixing time is 2 to 5 s, the next mixing is carried out after an interval of 4 to 6 min, and the total mixing is 3 times, to obtain the mixed powder.

[0048] 2) preparation of a composite preform from the mixed powder; 21) mixing and filling of the powder: the mixed powder is filled into a preheated mold; 22) hot pressing and curing: the filled mold is subjected to hot pressing and curing, the hot pressing and curing temperature is 150 to 180℃, the pressure is 4 to 8 MPa, and the time is 600 to 1200 s, and the pressure is released once every 30 to 50 s during the pressing process; 23) demolding: the hot pressing and curing product is placed into an ejector for demolding, to obtain the composite preform.

[0049] 3) preparation of the three-matrix synergistically optimized long-life composite friction material from the composite preform; 31) heat treatment: the composite preform is placed in an oven for heat treatment, the heat treatment is a multi-stage heat treatment, and the temperature-time conditions are: 110-150 DEG C for 150-180 min; 150-190 DEG C for 150-180 min, and then cooled to room temperature.

[0050] 32) mechanical processing: the heat-treated composite preform is mechanically processed according to the size requirements to obtain a three-matrix synergistically optimized long-life composite friction material.

[0051] The three-matrix synergistically optimized long-life composite friction material is prepared by mixing raw materials using a gradient mixing method, and then sequentially performing processes such as filling, hot pressing and curing, heat treatment, and mechanical processing. By introducing an inorganic adhesive with strong bonding ability at high temperatures as a matrix, and synergizing with a thermosetting resin matrix and a rubber matrix, the performance of the material is optimized, the friction performance of the brake shoe is stable under high temperature conditions, the wear resistance is significantly enhanced, and the service life is greatly extended. Compared with traditional thermosetting resin and rubber double-matrix friction materials, the wear rate of this material is reduced by 71% to 186% at 350 DEG C.

[0052] The application also discloses application of the three-matrix synergistically enhanced long-life friction material in railway heavy haul wagons. In actual application, the friction material can significantly prolong the service life of the brake shoe, reduce the maintenance workload and cost caused by frequent replacement of the brake shoe. Especially in high temperature environment, the friction coefficient of the brake shoe remains stable and does not decrease significantly due to temperature rise. This not only effectively reduces the braking distance of the heavy haul wagon, but also significantly improves the braking efficiency, thereby ensuring the braking safety and reliability of the heavy haul wagon under complex working conditions. In addition, the excellent performance of the friction material can also reduce the braking failure caused by uneven wear or performance degradation of the brake shoe, and further improve the safety and economy of railway transportation.

[0053] To make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0054] Embodiment 1 A preparation method of a three-matrix synergistically enhanced long-life friction material comprises the following steps: Step 1, preparation of mixed powder: first, 30% of the fiber reinforced phase (including 6% of polyacrylonitrile-based carbon fiber, 2% of pitch-based carbon fiber, 8% of aramid fiber, 6% of calcium sulfate whisker and 8% of mineral fiber) is added to a high-speed mixer, the rotation speed is set to 10000 rpm, each stirring for 2s and then standing for 5min, repeating for 3 times. Then, 24% of the matrix (including 13% of phenolic resin, 3% of silicone rubber and 8% of alumina-based high-temperature secondary adhesive) and 40% of inorganic filler (including 4% of corundum, 8% of chromite, 4% of zinc oxide, 2% of graphite, 1% of carbon black, 2% of sulfur and 19% of calcium carbonate) are added to the above mixed fibers, and the rotation speed is continued to be 10000 rpm, each stirring for 2s and then standing for 5min, repeating for 3 times, to complete the mixing of the powder.

[0055] Step 2, preparation of composite preform: the mixed powder is filled into a mold for heat pressing and curing. The heat pressing temperature is set to 160℃, the pressure is 5MPa, and the time is 900s, and the pressure is released every 40s during the pressing process. After curing, the mold is removed to obtain a preform.

[0056] Step 3, preparation of three-matrix synergistically reinforced long-life friction material: the preform is placed in an oven for heat treatment. The temperature is raised to 130℃ and kept for 150min; then the temperature is raised to 170℃ and kept for 180min. After completion, cool to room temperature, and then mechanically process to obtain a three-matrix synergistically optimized long-life composite friction material.

[0057] Example 2 A method for preparing a three-matrix synergistically reinforced long-life friction material, comprising the following steps: Step 1, preparation of mixed powder: first, 26% of the fiber reinforced phase (including 4% of polyacrylonitrile-based carbon fiber, 2% of pitch-based carbon fiber, 8% of aramid fiber, 6% of calcium sulfate whisker and 6% of mineral fiber) is added to a high-speed mixer, the rotation speed is set to 8000 rpm, each stirring for 2s and then standing for 5min, repeating for 3 times. Then, 30% of the matrix (including 26% of phenolic resin, 2% of silicone rubber and 2% of alumina-based high-temperature secondary adhesive) and 44% of inorganic filler (including 4% of corundum, 8% of chromite, 8% of zinc oxide, 2% of graphite, 1% of carbon black, 2% of sulfur and 19% of calcium carbonate) are added to the above mixed fibers, and the rotation speed is continued to be 8000 rpm, each stirring for 2s and then standing for 5min, repeating for 3 times, to complete the mixing of the powder.

[0058] Step 2, preparation of composite preform: the mixed powder is filled into a mold for heat pressing and curing. The heat pressing temperature is set to 150℃, the pressure is 4MPa, and the time is 1200s, and the pressure is released every 35s during the pressing process. After curing, the mold is removed to obtain a preform.

[0059] Step 3, preparation of the three-matrix synergistically enhanced long-life friction material: place the preform into an oven for heat treatment. Increase the temperature to 120°C and maintain for 150 min; then increase the temperature to 180°C and maintain for 150 min. After completion, cool to room temperature, and then mechanically process to obtain the three-matrix synergistically optimized long-life composite friction material.

[0060] Example 3 A method for preparing a three-matrix synergistically enhanced long-life friction material, comprising the following steps: Step 1, preparation of mixed powder: first, add 30% of the fiber reinforcement phase (including 6% of polyacrylonitrile-based carbon fiber, 2% of asphalt-based carbon fiber, 8% of aramid fiber, 6% of calcium sulfate whisker, and 8% of mineral fiber) into a high-speed mixer, set the rotation speed to 9000 rpm, stir for 2 s each time, then rest for 5 min, repeat for 3 times. Then, add 29% of the matrix (including 23% of phenolic resin, 3% of silicone rubber, and 3% of alumina-based high-temperature secondary adhesive) and 41% of inorganic filler (including 5% of corundum, 8% of chromite, 4% of zinc oxide, 2% of graphite, 1% of carbon black, 2% of sulfur, and 19% of calcium carbonate) into the mixed fibers, continue to use a rotation speed of 9000 rpm, stir for 2 s each time, then rest for 5 min, repeat for 3 times, and complete the mixing of the powder.

[0061] Step 2, preparation of the composite preform: fill the mixed powder into a mold and perform heat pressing and curing. Set the heat pressing temperature to 150°C, the pressure to 4 MPa, and the time to 12000 s, and release the pressure every 40 s during the pressing process. After curing, remove the mold to obtain the preform.

[0062] Step 3, preparation of the three-matrix synergistically enhanced long-life friction material: place the preform into an oven for heat treatment. Increase the temperature to 110°C and maintain for 150 min; then increase the temperature to 180°C and maintain for 180 min. After completion, cool to room temperature, and then mechanically process to obtain the three-matrix synergistically optimized long-life composite friction material.

[0063] Example 4 A method for preparing a three-matrix synergistically enhanced long-life friction material, comprising the following steps: Step 1, preparation of mixed powder: First, add 30% of the fiber reinforcement phase (including 6% polyacrylonitrile-based carbon fiber, 2% pitch-based carbon fiber, 8% aramid fiber, 6% calcium sulfate whisker, and 8% mineral fiber) to a high-speed mixer, set the speed to 8000 rpm, stir for 3 seconds each time, let it stand for 4 minutes, and repeat three times. Next, add 30% of the matrix (including 20% ​​phenolic resin, 8% silicone rubber, and 2% alumina-based high-temperature secondary adhesive) and 40% of the inorganic filler (including 40% chromite) to the above mixed fiber, continue to use the speed of 8000 rpm, stir for 3 seconds each time, let it stand for 4 minutes, and repeat three times to complete the powder mixing.

[0064] Step 2, Preparation of Composite Preform: The mixed powder is placed in a mold and hot-pressed for curing. The hot-pressing temperature is set at 160°C, the pressure at 5 MPa, and the pressing time is 800 seconds. During the pressing process, air is released every 50 seconds. After curing is complete, the preform is removed from the mold to obtain the final product.

[0065] Step 3: Preparation of a three-matrix synergistically reinforced long-life friction material: Place the preform in an oven for heat treatment. Heat to 150°C and hold for 150 minutes; then heat to 180°C and hold for 180 minutes. After cooling to room temperature, the preform is machined to obtain a three-matrix synergistically optimized long-life composite friction material.

[0066] Example 5 A method for preparing a three-matrix synergistically reinforced long-life friction material comprises the following steps: Step 1, preparation of mixed powder: First, add 24% fiber reinforcement phase (including 6% polyacrylonitrile-based carbon fiber, 8% aramid fiber, 6% calcium sulfate whisker and 4% mineral fiber) to a high-speed mixer, set the speed to 9000 rpm, stir for 4 seconds each time, let it stand for 4 minutes, repeat three times. Next, add 30% matrix (including 20% ​​phenolic resin, 2% silicone rubber and 8% alumina-based high-temperature secondary adhesive) and 46% inorganic filler (including 6% corundum, 10% chromite, 6% zinc oxide, 2% graphite, 1% carbon black, 2% sublimated sulfur and 19% calcium carbonate) to the above mixed fiber, continue to use the speed of 9000 rpm, stir for 4 seconds each time, let it stand for 4 minutes, repeat three times to complete the powder mixing.

[0067] Step 2, Preparation of Composite Preform: The mixed powder is placed in a mold and hot-pressed for curing. The hot-pressing temperature is set at 170°C, the pressure at 6 MPa, and the pressing time is set at 600 seconds. During the pressing process, air is released every 45 seconds. After curing is complete, the preform is removed from the mold to obtain the final product.

[0068] Step 3, preparation of the three-matrix synergistically enhanced long-life friction material: the preform is placed in an oven for heat treatment. The temperature is raised to 110°C and kept for 160 min; then the temperature is raised to 150°C and kept for 180 min. After completion, it is cooled to room temperature, and then mechanical processing is performed to obtain the three-matrix synergistically optimized long-life composite friction material.

[0069] Example 6 A method for preparing a three-matrix synergistically enhanced long-life friction material, comprising the following steps: Step 1, preparation of mixed powder: first, 25% of the fiber reinforcement phase (including 9% of polyacrylonitrile-based carbon fiber, 2% of asphalt-based carbon fiber, 6% of calcium sulfate whisker, and 8% of mineral fiber) is added to a high-speed mixer, and the rotation speed is set to 12000 rpm. After each stirring for 5 s, it is left for 6 min, and the process is repeated for 3 times. Then, 15% of the matrix (including 11% of phenolic resin, 2% of silicone rubber, and 2% of alumina-based high-temperature secondary adhesive) and 60% of inorganic filler (including 4% of corundum, 8% of chromite, 4% of zinc oxide, 2% of graphite, 1% of carbon black, 2% of sulfur, and 39% of calcium carbonate) are added to the mixed fibers, and the rotation speed is continued to be set to 12000 rpm. After each stirring for 5 s, it is left for 6 min, and the process is repeated for 3 times to complete the mixing of the powder.

[0070] Step 2, preparation of the composite preform: the mixed powder is filled into a mold for heat pressing and curing. The heat pressing temperature is set to 170°C, the pressure is set to 8 MPa, and the time is set to 1000 s. During the pressing process, the pressure is released every 30 s. After curing, the mold is removed to obtain the preform.

[0071] Step 3, preparation of the three-matrix synergistically enhanced long-life friction material: the preform is placed in an oven for heat treatment. The temperature is raised to 140°C and kept for 170 min; then the temperature is raised to 160°C and kept for 150 min. After completion, it is cooled to room temperature, and then mechanical processing is performed to obtain the three-matrix synergistically optimized long-life composite friction material.

[0072] Example 7 A method for preparing a three-matrix synergistically enhanced long-life friction material, comprising the following steps: Step 1, preparation of mixed powder: first, 18% of the fiber reinforced phase (including 8% aramid fiber, 6% calcium sulfate whisker and 4% mineral fiber) is added to a high-speed mixer, the rotation speed is set to 12000 rpm, each stirring for 5 s and then standing for 6 min, repeating for 3 times. Then, 23% of the matrix (including 10% phenolic resin, 5% polyimide resin, 4% silicone rubber and 4% alumina-based high-temperature secondary adhesive) and 59% of the inorganic filler (including 4% corundum, 8% chromite, 4% zinc oxide, 2% graphite, 1% carbon black, 2% sulfur and 38% calcium carbonate) are added to the above mixed fibers, and the rotation speed is continued to be 12000 rpm, each stirring for 5 s and then standing for 6 min, repeating for 3 times, to complete the mixing of the powder.

[0073] Step 2, preparation of composite preform: the mixed powder is filled into a mold for hot pressing and curing. The hot pressing temperature is set to 180℃, the pressure is 8MPa, and the time is 900s. During the pressing process, the pressure is released every 35s. After curing, the mold is removed to obtain a preform.

[0074] Step 3, preparation of three-matrix synergistically reinforced long-life friction material: the preform is placed in an oven for heat treatment. The temperature is raised to 130℃ and kept for 180min; then the temperature is raised to 170℃ and kept for 170min. After completion, cool to room temperature, then mechanical processing, to obtain a three-matrix synergistically optimized long-life composite friction material.

[0075] Example 8 A method for preparing a three-matrix synergistically reinforced long-life friction material, comprising the following steps: Step 1, preparation of mixed powder: first, 10% of the fiber reinforced phase (including 10% polyacrylonitrile-based carbon fiber) is added to a high-speed mixer, the rotation speed is set to 9000 rpm, each stirring for 4 s and then standing for 4.5 min, repeating for 3 times. Then, 30% of the matrix (including 15% phenolic resin, 4% silicone rubber, 4% nitrile rubber and 7% alumina-based high-temperature secondary adhesive) and 60% of the inorganic filler (including 4% corundum, 8% chromite, 4% zinc oxide, 2% graphite, 1% carbon black, 2% sulfur and 39% calcium carbonate) are added to the above mixed fibers, and the rotation speed is continued to be 9000 rpm, each stirring for 4 s and then standing for 4.5 min, repeating for 3 times, to complete the mixing of the powder.

[0076] Step 2, preparation of composite preform: the mixed powder is filled into a mold for hot pressing and curing. The hot pressing temperature is set to 150℃, the pressure is 4MPa, and the time is 600s. During the pressing process, the pressure is released every 50s. After curing, the mold is removed to obtain a preform.

[0077] Step 3: Preparation of a three-matrix synergistically reinforced long-life friction material: The preform is placed in an oven for heat treatment. The temperature is raised to 120°C and held for 150 minutes, then raised to 190°C and held for 170 minutes. After cooling to room temperature, the preform is machined to obtain a three-matrix synergistically optimized long-life composite friction material.

[0078] Example 9 A method for preparing a three-matrix synergistically reinforced long-life friction material comprises the following steps: Step 1, Preparation of Mixed Powder: First, add 10% of the fiber reinforcement phase (including 10% aramid fiber) to a high-speed mixer at 9000 rpm. Stir for 3 seconds each time, then let it stand for 5.5 minutes. Repeat three times. Next, add 30% of the matrix (including 20% ​​phenolic resin, 4% silicone rubber, 4% alumina-based high-temperature secondary adhesive, and 2% silicate high-temperature adhesive) and 60% of the inorganic filler (including 4% corundum, 8% chromite, 4% zinc oxide, 2% graphite, 1% carbon black, 2% sublimed sulfur, and 39% calcium carbonate) to the mixed fiber. Continue to use a speed of 9000 rpm. Stir for 3 seconds each time, then let it stand for 5.5 minutes. Repeat three times to complete the powder mixing.

[0079] Step 2, Preparation of Composite Preform: The mixed powder is placed in a mold and hot-pressed for curing. The hot-pressing temperature is set at 160°C, the pressure at 5 MPa, and the pressing time is set at 900 seconds. During the pressing process, air is released every 40 seconds. After curing is complete, the preform is removed from the mold to obtain the final product.

[0080] Step 3: Preparation of a three-matrix synergistically reinforced long-life friction material: Place the preform in an oven for heat treatment. Heat to 120°C and hold for 180 minutes; then heat to 180°C and hold for 160 minutes. After cooling to room temperature, the preform is machined to obtain a three-matrix synergistically optimized long-life composite friction material.

[0081] Example 10 The difference from Example 1 is that: The fiber reinforcement phase is 6% basalt fiber, 2% asphalt-based carbon fiber, 8% glass fiber, 6% calcium sulfate whisker and 8% steel fiber; the thermosetting resin is 13% boron-modified phenolic resin; the rubber is 3% styrene-butadiene rubber; the inorganic adhesive is 8% phosphate high-temperature adhesive; the inorganic filler is 4% corundum, 8% fluorite, 4% zinc oxide, 2% graphite, 1% carbon black, 2% barium sulfate and 19% calcium carbonate.

[0082] Example 11 The difference from Example 1 is that: The thermosetting resin is 13% bisphenol A epoxy resin; the rubber is 3% butadiene rubber; and the inorganic adhesive is 8% borate high-temperature adhesive.

[0083] Example 12 The difference from Example 1 is that: The thermosetting resin is 13% benzoxazine resin; the rubber is 3% fluororubber; and the inorganic adhesive is 8% aluminum hydroxide-based high-temperature adhesive.

[0084] Example 13 The difference from Example 1 is that: The thermosetting resin is 13% unsaturated polyester resin; the rubber is 3% black rubber powder; and the inorganic adhesive is 8% zirconia-based high-temperature adhesive.

[0085] Example 14 The difference from Example 1 is that: The thermosetting resin is 13% bismaleimide resin; the rubber is 3% natural rubber.

[0086] Example 15 The difference from Example 1 is that: The thermosetting resin is 13% cyanate ester resin; the rubber is 3% chloroprene rubber.

[0087] Example 16 The difference from Example 1 is that: The thermosetting resin is 13% phenolic epoxy resin; the rubber is 3% EPDM rubber.

[0088] Example 17 The difference from Example 1 is that: The thermosetting resin is 13% melamine formaldehyde resin; the rubber is 3% butadiene rubber.

[0089] Example 18 The difference from Example 1 is that: The rubber is 3% butyl rubber.

[0090] Comparative Example 1 A method for preparing a dual-matrix friction material comprises the following steps: Step 1, preparation of mixed powder: first, 30% of the fiber reinforced phase (6% of polyacrylonitrile-based carbon fiber, 2% of pitch-based carbon fiber, 8% of aramid fiber, 6% of calcium sulfate whisker and 8% of mineral fiber) is added to a high-speed mixer, the rotation speed is set to 10000 rpm, each stirring for 2 s and then standing for 5 min, repeating for 3 times. Then, 30% of the matrix (including 10% of phenolic resin, 20% of silicone rubber) and 40% of inorganic filler (including 4% of corundum, 8% of chromite, 4% of zinc oxide, 2% of graphite, 1% of carbon black, 2% of sulfur and 19% of calcium carbonate) are added to the above mixed fibers, and the rotation speed is continued to be 10000 rpm, each stirring for 2 s and then standing for 5 min, repeating for 3 times, to complete the mixing of the powder.

[0091] Step 2, preparation of composite preform: the mixed powder is filled into a mold for hot pressing and curing. The hot pressing temperature is set to 160℃, the pressure is 5MPa, and the time is 900s, and the pressure is released every 40s during the pressing process. After curing, the mold is removed to obtain a preform.

[0092] Step 3, preparation of double friction material: the preform is placed in an oven for heat treatment. The temperature is raised to 130℃ and kept for 150 min, and then raised to 170℃ and kept for 180 min. After completion, it is cooled to room temperature, and then mechanically processed to obtain a double-matrix friction material.

[0093] Comparative Example 2 A method for preparing a double-matrix friction material, comprising the following steps: Step 1, preparation of mixed powder: first, 30% of the fiber reinforced phase (6% of polyacrylonitrile-based carbon fiber, 2% of pitch-based carbon fiber, 8% of aramid fiber, 6% of calcium sulfate whisker and 8% of mineral fiber) is added to a high-speed mixer, the rotation speed is set to 10000 rpm, each stirring for 2 s and then standing for 5 min, repeating for 3 times. Then, 30% of the matrix (including 15% of phenolic resin, 15% of silicone rubber) and 40% of inorganic filler (including 4% of corundum, 8% of chromite, 4% of zinc oxide, 2% of graphite, 1% of carbon black, 2% of sulfur and 19% of calcium carbonate) are added to the above mixed fibers, and the rotation speed is continued to be 10000 rpm, each stirring for 2 s and then standing for 5 min, repeating for 3 times, to complete the mixing of the powder.

[0094] Step 2, preparation of composite preform: the mixed powder is filled into a mold for hot pressing and curing. The hot pressing temperature is set to 160℃, the pressure is 5MPa, and the time is 900s, and the pressure is released every 40s during the pressing process. After curing, the mold is removed to obtain a preform.

[0095] Step 3, preparation of the double friction material: the preform is placed in an oven for heat treatment. The temperature is raised to 130°C and kept for 150 min; then the temperature is raised to 170°C and kept for 180 min. After completion, it is cooled to room temperature, and then mechanical processing is performed to obtain the double matrix friction material.

[0096] In order to verify the effect of the present application, the compression performance, shear performance and friction and wear performance tests are carried out to compare the performance of the three-matrix synergistically enhanced long-life friction material prepared in the examples with the double-matrix friction material prepared in the comparative examples.

[0097] Figure 1 The room temperature mechanical properties of the three-matrix synergistically optimized long-life composite friction materials prepared in Examples 1-9 and the double-matrix friction materials prepared in Comparative Examples 1-2 are shown in (a) and (b). (a) is a graph of compression strength and compression modulus, and (b) is a graph of shear strength. The compression strength and compression modulus of the examples and the comparative examples are shown in the (a) graph. The compression strength of the comparative examples is 56-95 MPa, while the compression strength of the examples is significantly improved to 135-202 MPa, with an improvement of 42%-260%. This shows that the examples significantly improve the compression resistance of the friction material at room temperature. In addition, the compression modulus of the comparative examples is 810-1372 MPa, while the compression modulus of the examples is 2307-3151 MPa, with an improvement of 68%-289%. This shows that the examples also perform well in improving the rigidity of the material, further optimizing the mechanical properties of the friction material. The significant improvement in strength and rigidity of the examples shows that they can better withstand complex mechanical environments in practical applications, reducing deformation and damage caused by external forces and greatly extending the service life of the friction material. The shear strength of the examples and the comparative examples is shown in the (b) graph. The shear strength of the examples is 12.4-18.7 MPa, and the shear strength of the comparative examples is 5.4-11.5 MPa. It can be seen that the shear strength of the examples is higher than that of the comparative examples, with an improvement of 8%-346%. This shows that the material of the examples has significantly improved shear performance, which can better resist shear force and thus improve the structural stability and service life of the brake shoe.

[0098] Figure 2 The volume wear rate of the three-matrix synergistically optimized long-life composite friction materials prepared in Examples 1-9 and the double-matrix friction materials prepared in Comparative Examples 1-2 at 200-350°C is shown in (a)-(d). (a) is the volume wear rate at 200°C; (b) is the volume wear rate at 250°C; (c) is the volume wear rate at 300°C; (d) is the volume wear rate at 350°C. It can be seen from the graph that the volume wear rate of the examples does not change significantly with temperature, while the volume wear rate of the comparative examples increases significantly with temperature. The volume wear of the examples at 200-350°C is 0.015-0.072 cm3 The compression strength of the comparative example is 0.245-0.469 cm 3 The wear rate is much lower than that of the comparative example, reduced by 71%-186%. The high-temperature wear resistance of the friction material is significantly enhanced, the problem of high wear rate of the brake shoe at high temperature is improved, and the service life of the brake shoe is improved.

[0099] Table 1 Comparison of the mass percentage of each component of the 30% matrix selected in Examples 1-9 and Comparative Examples 1-2

[0100] Table 2 Comparison of the friction coefficient of the three-matrix synergistically optimized long-life composite friction material prepared in Examples 1-9 and the double-matrix friction material prepared in Comparative Examples 1-2 at 200-350°C

[0101] Table 1 is a comparison of the mass percentage of each component of the 30% matrix selected in Examples 1-9 and Comparative Examples 1-2. It can be seen that under the condition that the matrix components account for 30% of the total composition of the friction material, the matrix used in Examples 1-9 is added with an inorganic binder as a matrix synergistic phase, which is expected to effectively enhance the high-temperature bonding performance of the friction material. Table 2 is a comparison of the friction coefficient of the three-matrix synergistically optimized long-life composite friction material prepared in Examples 1-9 and the double-matrix friction material prepared in Comparative Examples 1-2 at 200-350°C. The average friction coefficient of the three-matrix synergistically optimized long-life composite friction material prepared in Examples 1-9 at 200-350°C is 0.40-0.62, and the average friction coefficient of the comparative example at 200-350°C is 0.36-0.48. It can be seen that the average friction coefficient of the example is higher than that of the comparative example, increased by 2%-61%. The larger friction coefficient can significantly improve the braking effect and braking force of the brake shoe, thereby improving the braking performance and safety of the vehicle. In practical application, this means that the vehicle can complete braking in a shorter distance, especially when driving at high speed or emergency braking, which can effectively reduce the braking distance and reduce the risk of accidents. At the same time, the higher friction coefficient can also ensure the stable braking performance of the brake shoe in high-temperature environment, avoiding the decrease of friction coefficient due to temperature rise, thereby further enhancing the braking reliability of the vehicle under complex working conditions. This is crucial for ensuring the safe operation of the vehicle.

[0102] In summary, the long-life composite friction material with three matrix synergistic optimization, preparation method and application of the application, by using thermosetting resin, rubber and inorganic adhesive composition of three matrix and inorganic filler, fiber reinforced phase synergistic system, combined with specific mixing, hot pressing curing and two stage heat treatment process, the three matrix synergistic optimization of long-life composite friction material has excellent mechanical properties and friction stability, its shear strength is 12.4~18.7 MPa, the compression strength is 135~202 MPa, the friction coefficient is stable at 0.40~0.62 at 200~350℃, the volume wear rate is as low as 0.015~0.072 cm 3 / MJ, not only through the synergistic effect of multiple components to enhance the impact resistance and high temperature resistance of the material, but also to optimize the microstructure by means of gradient process, effectively improve the durability of the material in high frequency braking scene of railway heavy haul vehicle, reduce the wear and tear and maintenance cost, realize the synergistic optimization of mechanical properties, friction performance and long life. By increasing the inorganic adhesive as the matrix of the composite friction material, the thermal decomposition of thermosetting resin and rubber matrix at high temperature is effectively slowed down, and the performance advantages of thermosetting resin and rubber matrix are synergized, which significantly improves the friction coefficient and enhances the mechanical properties. This makes the brake performance of the brake shoe more stable in high temperature environment, greatly prolongs the service life, significantly improves the reliability and durability of the brake shoe, and provides a strong guarantee for the safe operation of the vehicle.

[0103] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the application, and not to limit them; although the application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the application.

Claims

1. A method for preparing a long-life composite friction material with coordinated optimization of three substrates, characterized in that: include: After the matrix, inorganic filler and fiber reinforcement phase are mixed, hot pressing and curing are carried out, two-stage heat treatment is carried out, and after cooling to room temperature, a long-life composite friction material with synergistic optimization of the matrix is ​​obtained; The matrix is ​​composed of thermosetting resin, rubber and inorganic adhesive; The long-life composite friction material with coordinated optimization of the three matrices has a shear strength of 12.4-18.7 MPa, a compressive strength of 135-202 MPa, and a friction coefficient of 0.40-0.62 at 200-350°C.

2. The method for preparing a three-matrix synergistically optimized long-life composite friction material according to claim 1, characterized in that: The mass percentages of the matrix, inorganic filler and fiber reinforcement phase are (15%-30%): (40%-60%): (10%-30%).

3. The method for preparing a long-life composite friction material with three-matrix coordinated optimization according to claim 1, characterized in that: In the matrix, the mass percentages of thermosetting resin, rubber and inorganic adhesive are (11%~26%): (2%~8%): (2%~8%).

4. The method for preparing a three-matrix synergistically optimized long-life composite friction material according to claim 1, characterized in that: The thermosetting resin includes one or more of cashew nut shell liquid modified phenolic resin, boron modified phenolic resin, bisphenol A epoxy resin, polyimide resin, benzoxazine resin, unsaturated polyester resin, bismaleimide resin, cyanate resin, phenolic epoxy resin and melamine formaldehyde resin; The rubber includes one or more of silicone rubber, nitrile rubber, styrene-butadiene rubber, butadiene rubber, fluororubber, black rubber powder, natural rubber, chloroprene rubber, EPDM rubber, butadiene rubber and butyl rubber; The inorganic adhesive includes one or more of an alumina-based high-temperature adhesive, a phosphate-based high-temperature adhesive, a borate-based high-temperature adhesive, a silicate-based high-temperature adhesive, an aluminum hydroxide-based high-temperature adhesive, and a zirconium oxide-based high-temperature adhesive.

5. The method for preparing a three-matrix synergistically optimized long-life composite friction material according to claim 1, characterized in that: The inorganic filler includes one or more of corundum, barium sulfate, calcium carbonate, zinc oxide, graphite, carbon black, chromite, fluorite and sublimated sulfur; The fiber reinforcement phase includes one or more of polyacrylonitrile-based carbon fibers, pitch-based carbon fibers, aramid fibers, calcium sulfate whiskers, mineral fibers, basalt fibers, glass fibers, and steel fibers.

6. The method for preparing a three-matrix synergistically optimized long-life composite friction material according to claim 1, characterized in that: The mixing conditions include: a speed of 8000-12000 rpm, a mixing time of 2-5 seconds per mixing, an interval of 4-6 minutes before the next mixing, and a total of 3 mixing times; The fiber reinforcement phase is premixed before mixing. The premixing conditions include: a speed of 8000-12000 rpm, a mixing time of 2-5 seconds each time, an interval of 4-6 minutes before the next mixing, and a total of 3 mixing times.

7. The method for preparing a three-matrix synergistically optimized long-life composite friction material according to claim 1, characterized in that: The conditions for hot pressing curing include: temperature of 150-180° C., pressure of 4-8 MPa, time of 600-1200 s, and air release every 30-50 s during the pressing process.

8. The method for preparing a three-matrix synergistically optimized long-life composite friction material according to claim 1, characterized in that: The conditions of the two-stage heat treatment include: keeping the temperature at 110-150° C. for 150-180 minutes; and keeping the temperature at 150-190° C. for 150-180 minutes.

9. A three-matrix synergistically optimized long-life composite friction material, characterized in that: The method for preparing a long-life composite friction material with three-matrix synergistic optimization according to any one of claims 1 to 8 is adopted, wherein the volume wear rate of the long-life composite friction material with three-matrix synergistic optimization is 0.015-0.072 cm at 200-350°C. 3 / MJ.

10. Use of the three-matrix synergistically optimized long-life composite friction material prepared by the preparation method of the three-matrix synergistically optimized long-life composite friction material according to any one of claims 1 to 8 in railway heavy-duty freight cars.

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