Method for manufacturing a high-strength carbon ceramic brake disc with a ceramic functional layer

Abstract

The present invention relates to a high-strength carbon / ceramic brake disc with a ceramic functional layer, which belongs to the technical field of vehicle brake parts. First, a carbon / carbon green body with a binary carbon matrix is ​​graphitized at high temperature, and then the carbon / carbon green body with a binary carbon matrix is ​​graphitized by liquid silicon infiltration reaction to produce a carbon / ceramic brake disc green body, and then a ceramic precursor paste is reacted in situ on the surface of the carbon / ceramic brake disc green body to form a ceramic functional layer, thereby obtaining the brake disc. The carbon / carbon green body with a binary carbon matrix can effectively protect the carbon fiber from the erosion by silicon liquid and reduce the proportion of residual silicon, and the ceramic functional layer formed by the in situ reaction has good binding force with the matrix and can be adjusted in thickness. The brake disc has the characteristics of high mechanical strength, high friction coefficient, low wear rate, excellent oxidation resistance, and long life, and has great future application prospects.

Description

[Technical Field]

[0001] The present invention relates to a high-strength carbon / ceramic brake disc with a ceramic functional layer, which belongs to the technical field of vehicle brake components. [Background technology]

[0002] Carbon / ceramic composites, which are made of carbon fiber reinforced carbon and a silicon carbide ceramic matrix, first appeared in the 1980s as a thermostructural material. They are new high-temperature structural and functional materials with low density, good oxidation resistance, corrosion resistance, and excellent high-temperature mechanical and thermophysical properties, capable of use at temperatures up to 1650°C. As a brake material, carbon / ceramic composites have advantages such as wear resistance, high-temperature resistance, low density, large heat capacity, stable wet friction properties, and a high-temperature friction coefficient that does not decay, making them ideal brake materials for new-generation automobiles, high-speed trains, aircraft, tanks, and more.

[0003] German Patent DE 19727585 A1 discloses a combination of a chopped fiber-reinforced C / SiC ceramic brake disc, which is made by pressing chopped carbon fibers and then ceramicizing them, and a brake lining made of a sintered metal material or a non-organic adhesive material having a ceramic adhesive phase and metal particles. Chinese Patent CN113548902 A discloses a method for producing a carbon fiber-reinforced silicon carbide brake disc, which involves first heat-treating chopped carbon fibers, then homogeneously mixing chopped carbon fibers of various lengths with resin and additives, then pressing them into a mold press, decomposing them at high temperature under a protective atmosphere of nitrogen gas or inert gas, and finally infiltrating them with silicon in a vacuum infiltration furnace to obtain a carbon fiber-reinforced silicon carbide brake disc. Carbon / ceramic brake discs produced by this method lack mechanical strength and are prone to cracking when hit by a hard object during use.

[0004] U.S. Patent US7445095, "Brake system having a composite-material brake disc," discloses a combination of a carbon / ceramic brake disc with a friction layer and a composite brake pad, which has a friction coefficient of 0.4 to 0.48 and excellent friction characteristics. The surface friction layer contains a large amount of chopped carbon fibers. When the temperature of the friction surface of the brake disc rises rapidly during braking, the carbon fibers oxidize at high temperatures and lose strength, resulting in increased wear and a shortened service life of the brake disc.

[0005] Chinese Patent CN105565839 A discloses a method for manufacturing a carbon / ceramic brake material and a carbon / ceramic brake disc. Ceramic powder is added to a phenolic resin solution to obtain a mixture, which is then impregnated into a carbon fiber green body and carbonized to obtain a porous carbon / carbon-ceramic powder composite. This mixture is then machined and silicon-infiltrated in a vacuum furnace to obtain a carbon / ceramic brake disc. The porous carbon / carbon-ceramic powder composite is difficult to machine, and the surface protection of the carbon fiber reinforcement is insufficient. Silicon erodes and damages the fibers during silicon infiltration, resulting in poor mechanical strength of the brake disc.

[0006] Chinese Patent CN111892416 A discloses a method for producing a carbon / ceramic brake material, in which a low-density carbon / carbon green body is placed in a silicon powder impregnation slurry, dried after impregnation, and then the silicon powder-impregnated carbon / carbon green body is placed in a siliconization furnace, where the silicon powder in the carbon green body and the carbon deposited on the surface of the green body are melted and chemically reacted in situ at high temperature to form a SiC ceramic phase. After impregnation with the silicon powder impregnation slurry, the silicon powder in the carbon / carbon green body is concentrated in the outer layer, and the silicon powder content gradually decreases from the center to the outside, resulting in a non-uniform brake disc material after ceramization, with excessive silicon remaining in the outer layer and an excessively low SiC ceramic content in the inner layer, which affects braking performance.

[0007] Chinese Patent CN113277869 A discloses a carbon / ceramic brake disc with a wear-resistant and oxidation-resistant coating, and a manufacturing method thereof, in which a wear-resistant slurry containing 60% SiC particles is brush-painted into pre-drilled grooves in a carbon / carbon green body, and then coated using a vapor deposition silicon infiltration process, where the silicon powder does not come into contact with the carbon / carbon composite disc body, and the distance between the silicon powder and the carbon / carbon composite disc body is 100 mm or more. The coating applied by the vapor deposition process is thin and cannot provide long-term wear resistance, only antioxidant properties. The high proportion of SiC particles in the slurry is not produced by in-situ reaction, so the bonding strength with the matrix is ​​weak and they are easily detached during friction, making it impossible to form a stable friction film on the friction surface, resulting in relatively high wear rates for the brake disc and dual brake pad.

[0008] Chinese Patent CN108299002 A discloses a manufacturing process for a C / C-SiC ventilated brake disc with a silicon carbide friction functional layer. This patent describes using a trichloromethylsilane (CH3SiCl3) vapor-phase silicon infiltration method to react silicon vapor with a carbon / carbon green body to produce silicon carbide, obtaining a carbon / ceramic composite brake disc green body, and then depositing a layer of pure silicon carbide on the surface of the carbon / ceramic brake disc green body using a CVI process to form the friction functional layer. Carbon / ceramic brake discs manufactured using this method have high raw material costs, a long manufacturing period, and poor cost performance for the brake disc product.

[0009] Chinese Patent CN110131343 A discloses a method for manufacturing automobile brake discs, which first employs a one-piece press molding process to produce a pair of automobile brake preforms, then uses a polyazosilane solution and a polycarbosilane solution as ceramic precursors, and obtains a ceramic matrix through repeated impregnation and high-temperature decomposition, finally producing a carbon fiber reinforced carbon / ceramic composite material. This method has low manufacturing efficiency, high costs, and is difficult to industrialize. Summary of the Invention [Problem to be solved by the invention]

[0010] To address the problems of conventional brake discs, the present invention provides a high-strength carbon / ceramic brake disc with a ceramic functional layer. This involves introducing pyrolytic carbon coated on carbon fiber and pore-filled resin carbon or pitch carbon into a carbon fiber preform to form a carbon / carbon green body with a binary carbon matrix. During the subsequent liquid silicon infiltration process, silicon preferentially reacts with the resin carbon or pitch carbon to produce SiC. The pyrolytic carbon effectively protects the carbon fiber from erosion by the silicon liquid, thereby increasing the strength retention rate of the carbon fiber and ensuring high mechanical strength of the brake disc. The ceramic functional layer formed by the in-situ reaction has good bonding strength with the matrix, is adjustable in thickness, and can effectively achieve the comprehensive functions of improving wear resistance, oxidation resistance, and friction coefficient. As a result, the brake disc has the characteristics of high mechanical strength, a high friction coefficient, low wear rate, good oxidation resistance, and a long service life. This brake disc can be used not only in conventional automobiles, airplanes, and high-speed trains, but also in the extreme braking environments of high-performance racing cars, large trucks, and tanks. [Means for solving the problem]

[0011] The object of the present invention is achieved by the following technical solutions:

[0012] A high-strength carbon / ceramic brake disc with a ceramic functional layer, First, a carbon / carbon green body with a dual carbon matrix is ​​graphitized at high temperature, and then the graphitized carbon / carbon green body with a dual carbon matrix is ​​manufactured into a carbon / ceramic brake disc green body by a liquid silicon infiltration reaction. Then, a ceramic precursor paste is reacted in situ on the surface of the carbon / ceramic brake disc green body to form a ceramic functional layer, thereby obtaining the brake disc; The carbon / carbon green body with a binary carbon matrix is ​​manufactured by first coating the surface of the carbon fiber of a carbon fiber preform with pyrolytic carbon using a chemical vapor deposition process, and then filling the pores of the carbon fiber preform with resin carbon or pitch carbon using an impregnation carbonization process. The carbon fiber preform is formed by needle punching carbon fiber and a carbon mesh tire, and has a density of 0.4 to 0.6 g / cm. 3 The density after coating with pyrolytic carbon is 0.8 to 1.3 g / cm 3 After filling with resin carbon or pitch carbon, the density remains at 1.0-1.5g / cm 3 and the density of the carbon / ceramic brake disc green body increased to 1.9-2.4 g / cm. 3 and The ceramic precursor paste is a mixture of a thermosetting resin, polymethylsilane, and silicon powder in a mass ratio of 30:(15-40):(30-55), and the thermosetting resin is preferably a phenolic resin, an epoxy resin, or a furfural acetone resin. After mixing the thermosetting resin, polymethylsilane, and silicon powder, the mixture is preferably stirred and mixed for 0.5 to 2 hours.

[0013] The carbon fiber preform is manufactured by spreading carbon fiber and pre-needle-punching it with a carbon mesh tire to form a carbon fiber-carbon mesh tire unit layer, laying a plurality of carbon fiber-carbon mesh tire unit layers flat layer by layer in a flat needle-punching machine, and successively needle-punching them to form a 2.5D carbon fiber flat felt, which is then cut according to the size of the brake disc to obtain a carbon fiber preform; The carbon fiber is preferably 12 to 48K carbon fiber, where K represents the number of tows in thousands. In the needle-punching process of the carbon fiber-carbon mesh tire unit layer, the stacking direction is adjusted to alternately stack and needle-punch at 0° / 90°, and the needle-punching density is 16 to 30 needles / cm. 2 Let's say.

[0014] The steps for preparing the carbon / carbon green body with a dual carbon matrix are as follows: Density 0.4~0.6g / cm 3 The carbon fiber preform is placed in a chemical vapor deposition furnace, and a carbon source gas and a dilution gas are introduced to perform chemical vapor deposition under conditions of a high temperature of 900 to 1200°C and a vacuum degree of 500 to 4000 Pa, to form pyrolytic carbon coating the carbon fiber on the surface of the carbon fiber preform, and the density is 0.80 to 1.3 g / cm. 3 To obtain a carbon / carbon green body with a unit carbon matrix, The carbon source gas is natural gas or propylene (C3H6), the diluent gas is nitrogen gas (N2) or hydrogen (H2), and the volume ratio of the carbon source gas to the diluent gas is (1 to 3):1; The carbon / carbon green body of the unit carbon matrix is ​​placed in a vacuum-pressure impregnation and hardening furnace, heated until the impregnating agent is softened, and then impregnated using a vacuum or pressure method to drive the impregnating agent into the internal pores of the carbon / carbon green body of the unit carbon matrix. After the remaining impregnating agent is discharged, the temperature is increased to 170-220°C and kept at this temperature for 1-4 hours to harden the impregnating agent in the carbon / carbon green body of the unit carbon matrix. After that, the carbonization furnace is placed in a carbonization furnace, where the carbonization temperature is controlled to 850-1000°C and the carbonization time is controlled to 2-6 hours, resulting in a density of 1.0-1.5 g / cm. 3 to obtain a carbon / carbon green body with a binary carbon matrix of The impregnating agent is a furfural acetone resin, a phenolic resin or pitch, and the pressure inside the furnace during pressurized impregnation is 1.5 MPa or more.

[0015] The step of graphitizing the carbon / carbon green body of the binary carbon matrix at high temperature specifically includes: The carbon / carbon green body with a dual carbon matrix is ​​placed in a high-temperature treatment furnace, and nitrogen gas or inert gas is introduced into the furnace. The temperature is raised to 1800-2400°C under a protective atmosphere, and the temperature is maintained for 1-6 hours to complete the high-temperature graphitization treatment of the carbon / carbon green body with a dual carbon matrix.

[0016] The steps of producing a carbon / ceramic brake disc green body specifically include: First, the graphitized carbon / carbon green body is mechanically processed according to the final product drawing to produce a molded body. Then, the molded body is placed in a graphite crucible, and silicon powder is added according to the volume of the final product. After filling is complete, the graphite crucible is placed in a high-temperature furnace, heated to 1600-2000°C, and kept at that temperature for 1-4 hours. The vacuum is controlled to 200-2000 Pa to melt the solid silicon material into silicon liquid. The silicon liquid enters the pores of the molded body through the capillary effect, and Si and C come into contact with each other and undergo a chemical reaction at the silicon-carbon interface to produce SiC, with a density of 1.9-2.4 g / cm. 3 Carbon / ceramic brake disc green body is obtained.

[0017] Silicon powder is spread evenly on the bottom of the crucible, and 5 to 8 spacers made of porous silicon carbide material are placed among the silicon powder to support the compact and prevent the silicon powder from coming into contact with the compact.

[0018] The step of producing a ceramic functional layer on the surface of the carbon / ceramic brake disc green body by in-situ reaction specifically includes: The prepared ceramic precursor paste is applied to the surface of the carbon / ceramic brake disc green body with a brush, or the carbon / ceramic brake disc green body is impregnated with the prepared ceramic precursor paste, and then dried. After that, the body is placed in a high-temperature furnace, heated to 1600 to 2000°C, and kept at that temperature for 1 to 3 hours to form a ceramic functional layer on the surface of the carbon / ceramic brake disc green body. After that, the required metal parts are polished and attached to obtain a high-strength carbon / ceramic brake disc with a ceramic functional layer.

[0019] The thickness of the ceramic functional layer is preferably 0.5 to 3 mm. [Effects of the Invention]

[0020] The beneficial effects are as follows: (1) In the present invention, a carbon / carbon green with a binary carbon matrix is ​​used, and pyrolytic carbon coating the carbon fiber and resin carbon or pitch carbon filling the pores are introduced into the carbon fiber preform. During the subsequent liquid silicon infiltration process, silicon reacts preferentially with the resin carbon or pitch carbon to produce SiC. The pyrolytic carbon coating on the carbon fiber surface effectively protects the carbon fiber from erosion by the silicon liquid, maximizing the strength and toughness of the carbon fiber and ensuring the high mechanical strength of the brake disc. (2) In this invention, when resin carbon or pitch carbon is introduced into a carbon fiber preform, the introduced impregnating agent is carbonized and then shrunk to form pores, creating channels for the subsequent silicon liquid to enter. This stores the carbon source for the silicon-carbon reaction after the silicon liquid enters the pores, effectively reducing the proportion of residual silicon and controlling the mass ratio of residual silicon to within 5%. Because the melting point of silicon (approximately 1420°C) is much lower than that of silicon carbide (approximately 2700°C), this invention can significantly improve the high-temperature stability of brake discs. (3) In the present invention, in order to effectively achieve the purpose of protecting the carbon fibers from erosion by silicon by covering the carbon fibers with pyrolytic carbon, the thickness of the introduced pyrolytic carbon is set to about 1 to 3 μm, that is, the density is set to 0.4 to 0.6 g / cm. 3 The carbon fiber preform is 0.8~1.3g / cm 3 In order to fully react the resin carbon / pitch carbon with the liquid silicon, the weight ratio of the introduced resin carbon / pitch carbon is 25-35%, i.e., 1.0-1.5 g / cm 3 By scientifically blending the pyrolytic carbon and resin / pitch carbon content in the dual matrix carbon, the residual silicon content can be effectively reduced, significantly increasing the strength retention rate of carbon fibers and improving the mechanical performance of carbon / ceramic brake discs by 10-20%. (4) In the present invention, when pyrolytic carbon is introduced into a carbon fiber preform, the microstructure of the pyrolytic carbon formed is controlled by controlling the volume ratio of the carbon source gas to the dilution gas, the deposition temperature, the degree of vacuum, and other conditions, thereby forming coarse-layered pyrolytic carbon and avoiding isotropic layered pyrolytic carbon. This is because coarse-layered pyrolytic carbon has a higher friction coefficient, is more easily graphitized, and is more easily pore-forming than isotropic pyrolytic carbon, which is advantageous for the later ceramicization reaction and allows the brake disc to maintain stable tribological performance. (5) In this invention, a ceramic functional layer with good bonding strength with the matrix and adjustable thickness is produced on the surface of the brake disc through an in-situ reaction. To better utilize the advantages of SiC ceramics—high friction coefficient, high hardness, and oxidation resistance—the ceramic functional layer is scientifically designed so that the SiC content in the produced ceramic functional layer exceeds 92% by mass, much higher than the SiC content in the brake disc body (40-70% by mass). This effectively improves the friction coefficient, wear resistance, and oxidation resistance of the brake disc, significantly extending the service life of the brake disc. (6) The brake disc according to the present invention has the characteristics of high mechanical strength, high friction coefficient, low wear rate, excellent oxidation resistance, and long service life. It can be used not only in conventional automobiles, airplanes, and high-speed trains, but also in high-performance racing cars, large trucks, tanks, and other vehicles that are subjected to extreme braking conditions. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a scanning electron microscope (SEM) image of coarse-layered pyrolytic carbon deposited on the surface of the carbon fiber preform in step (2) of Example 1. [Figure 2] 1 is a scanning electron microscope (SEM) image of isotropic pyrolytic carbon deposited on the surface of the carbon fiber preform in step (2) of Comparative Example 4. DETAILED DESCRIPTION OF THE INVENTION

[0022] The present invention will now be further described with reference to certain embodiments, wherein the processes are conventional unless otherwise specified, and the raw materials are available from public commercial sources unless otherwise specified.

[0023] Example 1 (1) SYT49S-12K carbon fiber manufactured by China Fu Shenying Co., Ltd. is used. The carbon fiber and carbon mesh tire are pre-needle-punched to produce carbon fiber-carbon mesh tire unit layers. Multiple carbon fiber-carbon mesh tire unit layers are laid flat on a flat needle-punching machine and needle-punched one by one. The layers are alternately stacked at 0° / 90° in the planar direction, and the needle-punching density in the thickness direction is 16 needles / cm. 2 The 2.5D carbon fiber flat felt is then cut to fit the size of the brake disc, with an outer diameter of 390mm, a thickness of 38mm, and a density of 0.4g / cm. 3 A carbon fiber preform of 1000 .mu.m was obtained. (2) The carbon fiber preform produced in step (1) was placed in a chemical vapor deposition furnace, and the temperature inside the furnace was increased to 900°C. When the vacuum in the furnace reached a stabilized pressure of 500 Pa, carbon source gas C3H6 and dilution gas N2 were introduced in a volume ratio of 1:1, and chemical vapor deposition was carried out for 150 hours, resulting in a density of 0.91 g / cm. 3 A carbon / carbon green body with a unit carbon matrix was obtained, and when observed under a polarizing microscope, it was found that the material deposited on the surface of the carbon fiber preform was coarse-layered pyrolytic carbon, and its microstructure was as shown in Figure 1. (3) The carbon / carbon green body of the unit carbon matrix produced in step (2) was placed in a vacuum-pressure impregnation and curing furnace, and phenolic resin was used as the impregnating agent. The phenolic resin was heated and pressurized to 1.5 MPa in the vacuum-pressure impregnation and curing furnace to allow the phenolic resin to enter the pores inside the product. After the residual phenolic resin was expelled under pressure, the temperature inside the furnace was slowly raised to 180°C to cause a curing reaction. After 3 hours of curing reaction, the product was removed and placed in a carbonization furnace, where it was carbonized at a temperature of 850°C for 5 hours, resulting in a density of 1.18 g / cm. 3Carbon / carbon green with a binary carbon matrix was prepared. (4) The carbon / carbon green body with a dual carbon matrix prepared in step (3) was placed in a high-temperature treatment furnace, protected by nitrogen gas, and slowly heated to 1800°C and kept at that temperature for 6 hours to complete the high-temperature graphitization treatment of the carbon / carbon green body with a dual carbon matrix. (5) The carbon / carbon green body with a binary carbon matrix that had been subjected to high-temperature graphitization in step (4) was mechanically processed according to the drawings of the final product, and the inner diameter, outer diameter, and thickness were processed as specified, and ventilation holes were drilled to produce a compact. (6) 2500 g of silicon powder is spread evenly on the bottom of the graphite crucible, and five spacers made of porous silicon carbide material are placed among the silicon powder. The molded body produced in step (5) is placed on the spacers to prevent the silicon powder from contacting the molded body. Then, the graphite crucible is placed in a high-temperature furnace, the vacuum level is controlled to 200 Pa, the temperature is slowly raised to 1600 °C, and the temperature is maintained for 4 hours. The silicon powder is melted into a silicon liquid, which then enters the pores of the molded body through the capillary effect. The reaction between Si and C produces SiC, with a density of 2.26 g / cm. 3 Carbon / ceramic brake green bodies were obtained. (7) Phenolic resin, polymethylsilane, and silicon powder were mixed in a mass ratio of 30:15:55 and mixed by mechanical stirring for 0.5 hours to prepare a ceramic precursor paste. The prepared ceramic precursor paste was then brushed onto the surface of the carbon / ceramic brake disc green body produced in step (6). After drying and hardening, the body was placed in a high-temperature furnace, slowly heated to 1600°C, and kept at that temperature for 3 hours to form a 0.5 mm thick ceramic functional layer on the surface of the carbon / ceramic brake disc green body. (8) The carbon / ceramic brake disc green body with a ceramic functional layer on its surface produced in step (7) was polished, and the required metal parts were attached to obtain a high-strength carbon / ceramic brake disc with a ceramic functional layer.

[0024] Example 2 (1) SYT49S-12K carbon fiber manufactured by China Fu Shenying Co., Ltd. is used. The carbon fiber and carbon mesh tire are pre-needle-punched to produce carbon fiber-carbon mesh tire unit layers. Multiple carbon fiber-carbon mesh tire unit layers are laid flatly in a flat needle-punching machine and needle-punched sequentially, resulting in alternating stacking at 0° / 90° in the planar direction, with a needle-punching density of 30 needles / cm in the thickness direction. 2 The 2.5D carbon fiber flat felt is then cut to fit the size of the brake disc, with an outer diameter of 390mm, a thickness of 38mm, and a density of 0.6g / cm. 3 A carbon fiber preform of 1000 .mu.m was obtained. (2) The carbon fiber preform produced in step (1) was placed in a chemical vapor deposition furnace, and the temperature inside the furnace was increased to 1200°C. When the vacuum in the furnace reached a stabilized pressure of 4000 Pa, CH4 as a carbon source gas and H2 as a dilution gas were introduced in a volume ratio of 3:1. Chemical vapor deposition was carried out for 200 hours, resulting in a density of 1.22 g / cm3. 3 A carbon / carbon green body with a unit carbon matrix of 1000 was obtained, and when observed under a polarizing microscope, it was found that the material deposited on the surface of the carbon fiber preform was coarse-layered pyrolytic carbon. (3) The carbon / carbon green body of the unit carbon matrix produced in step (2) was placed in a vacuum-pressure impregnation and curing furnace, and furfural acetone resin was used as the impregnating agent. The furfural acetone resin was heated and pressurized to 2.5 MPa in the vacuum-pressure impregnation and curing furnace, allowing the furfural acetone resin to enter the pores inside the product. After the residual furfural acetone resin was discharged under pressure, the temperature inside the furnace was slowly raised to 220°C to cause a curing reaction. After 2 hours of curing reaction, the product was removed and placed in a carbonization furnace, where it was carbonized at a temperature of 1000°C for 4 hours, resulting in a density of 1.45 g / cm. 3 Carbon / carbon green with a binary carbon matrix was prepared. (4) The carbon / carbon green body with a dual carbon matrix prepared in step (3) was placed in a high-temperature treatment furnace, protected by nitrogen gas, and slowly heated to 2200°C and kept at that temperature for 1 hour to complete the high-temperature graphitization treatment of the carbon / carbon green body with a dual carbon matrix. (5) The carbon / carbon green body with a binary carbon matrix that had been subjected to high-temperature graphitization in step (4) was mechanically processed according to the drawings of the final product, and the inner diameter, outer diameter, and thickness were processed as specified, and ventilation holes were drilled to produce a compact. (6) 2500 g of silicon powder is spread evenly on the bottom of the graphite crucible, and eight spacers made of porous silicon carbide material are placed among the silicon powder. The molded body produced in step (5) is placed on the spacers to prevent the silicon powder from contacting the molded body. Then, the graphite crucible is placed in a high-temperature furnace, the vacuum level is controlled to 2000 Pa, the temperature is slowly raised to 2000 °C, and the temperature is maintained for 1 hour. The silicon powder is melted into a silicon liquid, which then enters the pores of the molded body through the capillary effect. The reaction between Si and C produces SiC, with a density of 2.09 g / cm. 3 Carbon / ceramic brake green bodies were obtained. (7) Furfural acetone resin, polymethylsilane, and silicon powder were mixed in a mass ratio of 30:28:42 and mixed for 2 hours by mechanical stirring to prepare a ceramic precursor paste. The ceramic precursor paste was then brushed onto the surface of the carbon / ceramic brake disc green body produced in step (6), which was then dried and cured. After that, the body was placed in a high-temperature furnace, slowly heated to 2000°C, and kept at that temperature for 1 hour to form a 3 mm-thick ceramic functional layer on the surface of the carbon / ceramic brake disc green body. (8) The carbon / ceramic brake disc green body with a ceramic functional layer on its surface produced in step (7) was polished, and the required metal parts were attached to obtain a high-strength carbon / ceramic brake disc with a ceramic functional layer.

[0025] Comparative Example 1 (1) SYT49S-24K carbon fiber manufactured by China Fu Shenying Co., Ltd. is used. Nonwoven fabric and carbon mesh tires are alternately layered and needle-punched. The angle between adjacent nonwoven fabrics is 0° / 90°, and the needle-punching density in the thickness direction is 20 needles / cm. 2 The sheet is then needle-punched layer by layer and cut to an outer diameter of 390 mm, a thickness of 40 mm, and a density of 0.50 g / cm. 3 A 2.5D preform was manufactured. (2) A chemical vapor deposition process similar to step (2) of Example 2 was performed to obtain a 1.28 g / cm 3 A carbon / carbon green body with a carbon matrix of 1000 units was obtained. (3) The carbon / carbon green body of the unit carbon matrix produced in step (2) was subjected to high temperature treatment in the same manner as in step (4) of Example 2. (4) The carbon / carbon green body of the unit carbon matrix treated at high temperature in step (3) was mechanically processed according to the drawing of the final product to process the inner diameter, outer diameter, and thickness as required, and air holes were drilled to obtain a molded body. (5) The green body produced in step (4) was subjected to a ceramic treatment in the same manner as in step (6) of Example 2, and the volume density was accordingly 2.05 g / cm 3 A carbon / ceramic brake disc green body was obtained. (6) The carbon / ceramic brake disc green body produced in step (5) was polished, and required metal parts were attached to obtain a carbon / ceramic brake disc having no ceramic functional layer.

[0026] Comparative Example 2 (1) SYT49S-24K carbon fiber manufactured by China Fu Shenying Co., Ltd. is used. Nonwoven fabric and carbon mesh tires are alternately layered and needle-punched. The angle between adjacent nonwoven fabrics is 0° / 90°, and the needle-punch density in the thickness direction is 20 needles / cm. 2 The sheet is then needle-punched layer by layer and cut to an outer diameter of 390 mm, a thickness of 40 mm, and a density of 0.50 g / cm. 3 A 2.5D preform was manufactured. (2) The carbon fiber preform produced in step (1) was subjected to a resin impregnation and carbonization treatment in the same manner as in step (3) of Example 2. The resin impregnation and carbonization treatment was repeated four times to obtain a carbon fiber preform having a density of 1.26 g / cm3, in which the matrix carbon was resin carbon. 3 A carbon / carbon green body with a carbon matrix of 1000 units was obtained. (3) The carbon / carbon green body of the unit carbon matrix produced in step (2) was subjected to high temperature treatment in the same manner as in step (4) of Example 2. (4) The carbon / carbon green body of the unit carbon matrix that had been subjected to high-temperature treatment in step (3) was mechanically processed according to the drawings of the final product to process the inner diameter, outer diameter, and thickness as required, and air holes were drilled to produce a compact. (5) The green body produced in step (4) was subjected to a ceramic treatment in the same manner as in step (6) of Example 2, and the volume density was accordingly 2.07 g / cm 3 A carbon / ceramic brake disc green body was obtained. (6) The carbon / ceramic brake disc green body produced in step (5) was polished, and required metal parts were attached to obtain a carbon / ceramic brake disc having no ceramic functional layer.

[0027] Comparative Example 3 (1) SYT49S-24K carbon fiber manufactured by China Fu Shenying Co., Ltd. is used. Nonwoven fabric and carbon mesh tires are alternately layered and needle-punched. The angle between adjacent nonwoven fabrics is 0° / 90°, and the needle-punch density in the thickness direction is 20 needles / cm. 2 The sheet is then needle-punched layer by layer and cut to an outer diameter of 390 mm, a thickness of 40 mm, and a density of 0.60 g / cm. 3 A 2.5D preform was manufactured. (2) The carbon fiber preform produced in step (1) was subjected to chemical vapor deposition for 300 hours in the same manner as in step (2) of Example 2, and the density was 1.49 g / cm 3 A carbon / carbon green body with a carbon matrix of 1000 units was obtained. (3) The carbon / carbon green body of the unit carbon matrix produced in step (2) was impregnated and carbonized in the same manner as in step (3) of Example 2 to obtain a carbon-carbon green body with a density of 1.70 g / cm. 3 Carbon / carbon green bodies with a binary carbon matrix were prepared. (4) The carbon / carbon green body with a dual carbon matrix prepared in step (3) was subjected to high temperature treatment in the same manner as in step (4) of Example 2. (5) The carbon / carbon green body with a binary carbon matrix that had been subjected to high-temperature treatment in step (4) was mechanically processed according to the drawings of the final product, and the inner diameter, outer diameter, and thickness were processed as specified, and ventilation holes were drilled to produce a compact. (6) The green body produced in step (4) was subjected to a ceramic treatment in the same manner as in step (6) of Example 2, and the volume density was accordingly 1.89 g / cm 3 A carbon / ceramic brake disc green body was obtained. (7) The carbon / ceramic brake disc green body produced in step (6) was polished, and required metal parts were attached to obtain a carbon / ceramic brake disc having no ceramic functional layer.

[0028] Comparative Example 4 (1) SYT49S-24K carbon fiber manufactured by China Fu Shenying Co., Ltd. is used. Nonwoven fabric and carbon mesh tires are alternately layered and needle-punched. The angle between adjacent nonwoven fabrics is 0° / 90°, and the needle-punch density in the thickness direction is 20 needles / cm. 2 The sheet was then needle-punched layer by layer and cut to an outer diameter of 390 mm, a thickness of 40 mm, and a density of 0.60 g / cm. 3 A 2.5D preform was manufactured. (2) The carbon fiber preform produced in step (1) was placed in a chemical vapor deposition furnace, the temperature inside the furnace was raised to 1100°C, and when the degree of vacuum inside the furnace reached a stabilized pressure of 2000 Pa, CH4 as a carbon source gas and H2 as a dilution gas were introduced so that the volume ratio of CH4 to H2 was 1:2. Chemical vapor deposition was carried out for 200 hours, resulting in a density of 1.02 g / cm3. 3A carbon / carbon green body with the unit carbon matrix was obtained and observed under a polarizing microscope. The produced pyrolytic carbon had an isotropic structure, as shown in FIG. (3) The carbon / carbon green body of the unit carbon matrix produced in step (2) was placed in a vacuum-pressure impregnation and curing furnace, and furfural acetone resin was used as the impregnating agent. The furfural acetone resin was heated and pressurized to 2.5 MPa in the vacuum-pressure impregnation and curing furnace to be introduced into the pores inside the product. After the residual furfural acetone resin was removed under pressure, the temperature inside the furnace was slowly raised to 220°C to carry out a curing reaction. After 2 hours of curing reaction, the product was removed and placed in a carbonization furnace, where it was carbonized at a temperature of 1000°C for 4 hours, resulting in a density of 1.24 g / cm. 3 Carbon / carbon green bodies with a binary carbon matrix were prepared. (4) The carbon / carbon green body with a dual carbon matrix prepared in step (3) was subjected to high temperature treatment in the same manner as in step (4) of Example 2. (5) The high-temperature treated carbon / carbon green body of the dual carbon matrix produced in step (4) was mechanically processed according to the drawings of the final product, and the inner diameter, outer diameter, and thickness were processed as required, and ventilation holes were drilled to produce a compact. (6) The green body produced in step (4) was subjected to a ceramic treatment in the same manner as in step (6) of Example 2, and the volume density was accordingly 1.78 g / cm 3 A carbon / ceramic brake disc green body was obtained. (7) The carbon / ceramic brake disc green body produced in step (5) was polished, and required metal parts were attached to obtain a carbon / ceramic brake disc having no ceramic functional layer.

[0029] In order to further study and evaluate the mechanical properties and friction and wear properties of the carbon / ceramic brake discs manufactured in the examples and comparative examples, the carbon / ceramic brake discs manufactured in the examples and comparative examples were each combined with imported brake pads designed specifically for carbon / ceramic discs, and subjected to ground bench tests in accordance with the SAEJ2522-AK Master test standard using a LINK3000 bench tester. The strength and test results are shown in Table 1 below.

[0030] [Table 1]

[0031] In Comparative Example 1, a carbon / ceramic brake disc containing only a unit carbon matrix (pyrolytic carbon), the absence of resin carbon to consume the silicon source resulted in a residual silicon mass ratio of 15.3%, which adversely affected mechanical properties and high-temperature friction characteristics. In Comparative Example 2, a carbon / ceramic brake disc containing only a unit carbon matrix (resin carbon), the lack of protection from pyrolytic carbon on the carbon fiber surface led to reactive erosion of the carbon fibers by liquid silicon, significantly reducing the bending strength of the carbon / ceramic brake disc. Comparative Example 3 contained a binary carbon matrix, but the ratios of the two were unbalanced, resulting in a high matrix carbon content, which led to a low green body perforation rate and poor silicon infiltration flow paths. This resulted in a low SiC ceramic content in the carbon / ceramic brake disc, resulting in low product density and low compressive strength. In Comparative Example 4, due to unreasonable process parameters, the pyrolytic carbon microstructure did not have a coarse layer structure and was mainly isotropic carbon, which was unfavorable for high-temperature graphitization and perforation. The poor silicon infiltration flow path resulted in a low SiC ceramic content in the carbon / ceramic brake disc, resulting in low product density and poor performance. Because no ceramic functional layer was formed in Comparative Examples 1 to 4, the friction coefficients were generally lower than those of the Examples, and the wear rates were generally higher than those of the Examples. The test results in the table above demonstrate that the high-strength carbon / ceramic brake disc with a ceramic functional layer manufactured according to the present invention maximizes the strength and toughness of the carbon fiber by incorporating a dual matrix carbon (pyrolytic carbon and resin carbon / pitch carbon), effectively reducing the proportion of residual silicon and significantly improving the mechanical strength of the material. The ceramic functional layer introduced by in situ reaction significantly improved the friction coefficient and reduced the wear rate.

[0032] As mentioned above, the above is only a preferred embodiment of the present invention, and does not limit the protection scope of the present invention. Any amendments, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall all be included within the protection scope of the present invention.

[0033] (Addendum) (Appendix 1) A high-strength carbon / ceramic brake disc with a ceramic functional layer, First, a carbon / carbon green body with a binary carbon matrix is ​​graphitized at high temperature, and then the graphitized carbon / carbon green body with a binary carbon matrix is ​​manufactured into a carbon / ceramic brake disc green body by liquid silicon infiltration reaction. Then, a ceramic precursor paste is reacted in situ on the surface of the carbon / ceramic brake disc green body to form a ceramic functional layer, thereby obtaining the brake disc; The carbon / carbon green body with a binary carbon matrix is ​​manufactured by first coating the surface of the carbon fiber of a carbon fiber preform with pyrolytic carbon using a chemical vapor deposition process, and then filling the pores of the carbon fiber preform with resin carbon or pitch carbon using an impregnation carbonization process. The carbon fiber preform is formed by needle punching carbon fiber and a carbon mesh tire, and has a density of 0.4 to 0.6 g / cm. 3 The density after coating with pyrolytic carbon is 0.8 to 1.3 g / cm 3 After filling with resin carbon or pitch carbon, the density remains at 1.0-1.5g / cm 3 and the density of the carbon / ceramic brake disc green body increased to 1.9-2.4 g / cm. 3 and The ceramic precursor paste is a mixture of thermosetting resin, polymethylsilane, and silicon powder in a mass ratio of 30:(15-40):(30-55). A high-strength carbon / ceramic brake disc with a ceramic functional layer characterized by:

[0034] (Appendix 2) The carbon fiber preform is manufactured by spreading carbon fiber and pre-needle-punching it with a carbon mesh tire to form a carbon fiber-carbon mesh tire unit layer, laying a plurality of carbon fiber-carbon mesh tire unit layers flat layer by layer in a flat needle-punching machine, and successively needle-punching them to form a 2.5D carbon fiber flat felt, which is then cut according to the size of the brake disc to obtain a carbon fiber preform. A high-strength carbon / ceramic brake disc having a ceramic functional layer according to claim 1.

[0035] (Appendix 3) In the process of needle-punching the carbon fiber-carbon mesh tire unit layer, the stacking direction is adjusted to alternately stack at 0° / 90° and needle-punch, and the needle-punch density is set to 16~30 needles / cm 2 The carbon fiber is 12~48K. A high-strength carbon / ceramic brake disc having a ceramic functional layer according to claim 2.

[0036] (Appendix 4) The steps for preparing the carbon / carbon green body with a dual carbon matrix are as follows: Density 0.4~0.6g / cm 3 The carbon fiber preform is placed in a chemical vapor deposition furnace, and a carbon source gas and a dilution gas are introduced to perform chemical vapor deposition under conditions of a high temperature of 900 to 1200°C and a vacuum degree of 500 to 4000 Pa, to form pyrolytic carbon coating the carbon fiber on the surface of the carbon fiber preform, and the density is 0.80 to 1.3 g / cm. 3 To obtain a carbon / carbon green body with a unit carbon matrix, The carbon / carbon green body of the unit carbon matrix is ​​placed in a vacuum-pressure impregnation and hardening furnace, heated until the impregnating agent is softened, and then impregnated using a vacuum or pressure method to drive the impregnating agent into the internal pores of the carbon / carbon green body of the unit carbon matrix. After the remaining impregnating agent is discharged, the temperature is increased to 170-220°C and kept at this temperature for 1-4 hours to harden the impregnating agent in the carbon / carbon green body of the unit carbon matrix. After that, the carbonization furnace is placed in a carbonization furnace, where the carbonization temperature is controlled to 850-1000°C and the carbonization time is controlled to 2-6 hours, resulting in a density of 1.0-1.5 g / cm. 3 to obtain a carbon / carbon green body with a binary carbon matrix of The carbon source gas is natural gas or propylene, the diluent gas is nitrogen gas or hydrogen, the volume ratio of the carbon source gas to the diluent gas is (1 to 3):1, the impregnating agent is furfural acetone resin, phenol resin or pitch, and the pressure in the furnace during pressurized impregnation is 1.5 MPa or more. 4. A high-strength carbon / ceramic brake disc comprising the ceramic functional layer according to any one of appendices 1 to 3.

[0037] (Appendix 5) The step of graphitizing the carbon / carbon green body of the binary carbon matrix at high temperature specifically includes: The carbon / carbon green body with a dual carbon matrix is ​​placed in a high-temperature treatment furnace, and nitrogen gas or inert gas is introduced into the furnace to heat the body to 1800-2400°C under a protective atmosphere. The temperature is kept at 1-6 hours to complete the high-temperature graphitization of the carbon / carbon green body with a dual carbon matrix. A high-strength carbon / ceramic brake disc having a ceramic functional layer according to claim 1.

[0038] (Appendix 6) The steps of producing a carbon / ceramic brake disc green body specifically include: First, a graphitized carbon / carbon green body with a binary carbon matrix is ​​mechanically processed according to the drawing of the final product to produce a compact. Then, the compact is placed in a graphite crucible, and silicon powder is added according to the amount calculated from the volume of the final product. After the filling is complete, the graphite crucible is placed in a high-temperature furnace, heated to 1600-2000°C, and kept at that temperature for 1-4 hours. The degree of vacuum is controlled to 200-2000 Pa, and the density is set to 1.9-2.4 g / cm. 3 Carbon / ceramic brake disc green body obtained, A high-strength carbon / ceramic brake disc having a ceramic functional layer according to claim 1.

[0039] (Appendix 7) Silicon powder is spread evenly on the bottom of the crucible, and 5 to 8 spacers made of porous silicon carbide material are placed in the silicon powder to support the compact, preventing the silicon powder from coming into contact with the compact. 7. A high-strength carbon / ceramic brake disc having a ceramic functional layer according to claim 6.

[0040] (Appendix 8) The thermosetting resin in the ceramic precursor paste is a phenolic resin, an epoxy resin, or a furfural acetone resin; A high-strength carbon / ceramic brake disc having a ceramic functional layer according to claim 1.

[0041] (Appendix 9) The step of producing a ceramic functional layer on the surface of the carbon / ceramic brake disc green body by in-situ reaction specifically includes: The prepared ceramic precursor paste is applied to the surface of the carbon / ceramic brake disc green body by brushing, or the carbon / ceramic brake disc green body is impregnated with the prepared ceramic precursor paste, and then dried. After that, the carbon / ceramic brake disc green body is placed in a high-temperature furnace, heated to 1600-2000°C, and kept at that temperature for 1-3 hours to form a ceramic functional layer on the surface of the carbon / ceramic brake disc green body. A high-strength carbon / ceramic brake disc having a ceramic functional layer according to claim 1.

[0042] (Appendix 10) The thickness of the ceramic functional layer is 0.5~3mm. 10. A high-strength carbon / ceramic brake disc comprising a ceramic functional layer according to claim 1, 8 or 9.

Claims

1. 1. A method for manufacturing a high-strength carbon ceramic brake disc with a ceramic functional layer, comprising: First, a green body of carbon and carbon with a binary carbon matrix is ​​graphitized at high temperature, and then the graphitized green body of carbon and carbon with a binary carbon matrix is ​​manufactured into a green body of a carbon ceramic brake disc by a liquid silicon infiltration reaction. Then, a ceramic precursor paste is reacted in situ on the surface of the green body of the carbon ceramic brake disc to form a ceramic functional layer, thereby obtaining the brake disc; The carbon and carbon green bodies of the binary carbon matrix are manufactured by first coating the carbon fiber surface of a carbon fiber preform with pyrolytic carbon using a chemical vapor deposition process, and then filling the pores of the carbon fiber preform with resin carbon or pitch carbon using an impregnation carbonization process. The carbon fiber preform is formed by needle punching carbon fibers and a carbon mesh tire, and has a density of 0.4 to 0.6 g / cm. ３ and the density after coating with pyrolytic carbon is 0.8 to 1.3 g / cm ３ After filling with resin carbon or pitch carbon, the density remains at 1.0 to 1.5 g / cm ３ and correspondingly, the density of the green body of the carbon ceramic brake disc increases to 1.9-2.4 g / cm ３ and The ceramic precursor paste is a mixture of a thermosetting resin, polymethylsilane, and silicon powder in a mass ratio of 30:(15-40):(30-55). A method for manufacturing a high-strength carbon ceramic brake disc having a ceramic functional layer, characterized by:

2. The carbon fiber preform is manufactured by spreading carbon fiber and pre-needle-punching it with a carbon mesh tire to form a carbon fiber-carbon mesh tire unit layer, laying a plurality of carbon fiber-carbon mesh tire unit layers flat layer by layer in a flat needle-punching machine, and successively needle-punching them to form a 2.5D carbon fiber flat felt, which is then cut according to the size of a brake disc to obtain a carbon fiber preform. A method for manufacturing a high-strength carbon ceramic brake disc having a ceramic functional layer according to claim 1.

3. In the process of needle-punching the carbon fiber-carbon mesh tire unit layer, the stacking direction is adjusted to alternately stack and needle-punch at 0° and 90°, and the needle-punch density is set to 16 to 30 needles / cm ２ and uses 12 to 48K carbon fiber as the carbon fiber.

3. A method for manufacturing a high-strength carbon ceramic brake disc having a ceramic functional layer according to claim 2.

4. The steps for preparing the carbon and carbon green body of the binary carbon matrix are as follows: Density is 0.4 to 0.6 g / cm ３ The carbon fiber preform is placed in a chemical vapor deposition furnace, and a carbon source gas and a dilution gas are introduced to perform chemical vapor deposition under conditions of a high temperature of 900 to 1200°C and a vacuum degree of 500 to 4000 Pa, to form pyrolytic carbon covering the carbon fiber on the surface of the carbon fiber preform, and the density is 0.80 to 1.3 g / cm. ３ To obtain a carbon matrix carbon and carbon green body, The unit carbon matrix carbon and carbon green bodies are placed in a vacuum-pressure impregnation and curing furnace, heated until the impregnating agent is softened, and impregnated using a vacuum or pressure method into the unit carbon matrix carbon and carbon green bodies. The impregnating agent is forced into the internal pores of the unit carbon matrix carbon and carbon green bodies. After the remaining impregnating agent is discharged, the temperature is raised to 170-220°C and kept at that temperature for 1-4 hours to allow the impregnating agent in the unit carbon matrix carbon and carbon green bodies to undergo a curing reaction. The unit carbon matrix carbon and carbon green bodies are then placed in a carbonization furnace, and the carbonization temperature is controlled to 850-1000°C and the carbonization time is controlled to 2-6 hours, resulting in a density of 1.0-1.5 g / cm. ３ To obtain a green body of carbon and carbon in a binary carbon matrix, the carbon source gas is natural gas or propylene, the diluent gas is nitrogen gas or hydrogen, the volume ratio of the carbon source gas to the diluent gas is (1 to 3):1, the impregnating agent is furfural acetone resin, phenol resin or pitch, and the pressure inside the furnace during pressurized impregnation is 1.5 MPa or more; A method for manufacturing a high-strength carbon ceramic brake disc provided with the ceramic functional layer according to any one of claims 1 to 3.

5. The step of graphitizing the carbon and carbon green body of the binary carbon matrix at high temperature specifically includes: The carbon and carbon green body with a binary carbon matrix are placed in a high-temperature treatment furnace, and nitrogen gas or inert gas is introduced into the furnace to heat the carbon to 1800-2400°C under a protective atmosphere, and the temperature is maintained for 1-6 hours to complete the high-temperature graphitization treatment of the carbon and carbon green body with a binary carbon matrix. A method for manufacturing a high-strength carbon ceramic brake disc having a ceramic functional layer according to claim 1.

6. The steps of producing a green body of a carbon ceramic brake disc specifically include: First, the graphitized carbon of the binary carbon matrix and the carbon green body are mechanically processed according to the drawing of the final product to produce a molded body. Then, the molded body is placed in a graphite crucible, and the filling amount is calculated from the volume of the final product and silicon powder is added. After filling is complete, the graphite crucible is placed in a high-temperature furnace, heated to 1600-2000°C, and kept at that temperature for 1-4 hours. The degree of vacuum is controlled to 200-2000 Pa, and the density is set to 1.9-2.4 g / cm. ３ To obtain the green body of the carbon ceramic brake disc, A method for manufacturing a high-strength carbon ceramic brake disc having a ceramic functional layer according to claim 1.

7. Silicon powder is spread evenly on the bottom of the crucible, and 5 to 8 spacers made of porous silicon carbide material are placed in the silicon powder to support the molded body and prevent the silicon powder from coming into contact with the molded body. A method for manufacturing a high-strength carbon ceramic brake disc having a ceramic functional layer according to claim 6.

8. The thermosetting resin in the ceramic precursor paste is a phenolic resin, an epoxy resin, or a furfural acetone resin; A method for manufacturing a high-strength carbon ceramic brake disc having a ceramic functional layer according to claim 1.

9. The step of producing a ceramic functional layer on the surface of the carbon ceramic brake disc green body by in-situ reaction specifically includes: The prepared ceramic precursor paste is applied to the surface of the carbon ceramic brake disc green body by a brush, or the carbon ceramic brake disc green body is impregnated with the prepared ceramic precursor paste, and then dried. After that, the carbon ceramic brake disc green body is placed in a high-temperature furnace, heated to 1600 to 2000°C, and kept at that temperature for 1 to 3 hours, thereby forming a ceramic functional layer on the surface of the carbon ceramic brake disc green body. A method for manufacturing a high-strength carbon ceramic brake disc having a ceramic functional layer according to claim 1.

10. The thickness of the ceramic functional layer is 0.5 to 3 mm; 10. A method for manufacturing a high-strength carbon ceramic brake disc provided with a ceramic functional layer according to claim 1, 8 or 9.

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