Carbon ceramic brake disc with multiple friction layers and method for manufacturing thereof

Abstract

The application provides a carbon ceramic brake disc with multiple friction layers, which comprises a base layer and friction layers, wherein the friction layers comprise a first friction layer, a second friction layer and a third friction layer, and the first friction layer, the second friction layer and the third friction layer are sequentially arranged from the base layer outward; the thickness of the first friction layer is 0.05-0.4 mm, and the first friction layer at least contains silicon carbide particles with a size of 2-40 μm; the thickness of the second friction layer is 0.1-0.4 mm, and the second friction layer at least contains silicon carbide particles with a size of 35-85 μm; the thickness of the third friction layer is 0.4-5 mm, and the third friction layer at least contains silicon carbide particles with a size of 75-150 μm. By arranging the three layers of friction layers, the thermal expansion coefficients of each layer of friction layers gradually increase, the comprehensive performance of the carbon ceramic brake disc is greatly improved, and the falling off of the friction layers is greatly avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of brake disc manufacturing, in particular to a carbon ceramic brake disc with multiple friction layers and a preparation method thereof. BACKGROUND

[0002] The brake disc is an essential part of all vehicle braking systems, which is fixed on the axle and rotates with the wheel. When braking, the brake block is pressed onto the brake disc under the push of the clamping piston, and the friction between the brake block and the brake disc reduces the wheel speed, achieving the purpose of vehicle deceleration. With the acceleration of the vehicle, the brake disc will bear the increasing pressure and friction of the brake block, and wear during relative motion, especially when there are sand and other debris on the working surface, the wear is more serious, greatly shortening the service life of the brake disc. Therefore, the material for making the brake disc should not only have high mechanical strength, but also have good wear resistance. Cf / SiC composite material can be used as a brake part in the aviation and high-end automobile industry due to its high hardness, superior friction performance and significant reduction in the mass of friction braking material. The carbon ceramic brake disc combines the physical properties of carbon fiber and polycrystalline silicon carbide. The elongation at break of C / SiC material is from 0.1% to 0.3%, which is a very high value for ceramic materials. At the same time, due to the characteristics of light weight, good hardness, stability under high pressure and high temperature conditions, thermal shock resistance and shear fracture characteristics, the service life of the brake disc is prolonged, and most of the problems caused by load are avoided.

[0003] The current preparation process of carbon ceramic brake disc is needle punching-carbonization-high temperature treatment-chemical vapor deposition-high temperature treatment-applying friction layer-processing-silicon infiltration-processing, wherein the application of the friction layer is to improve the wear resistance of the brake disc and stabilize the friction coefficient. The friction layer and the silicon carbide content and fiber content of the brake disc are very different. Due to the high wear resistance requirement of the friction layer, it often does not contain carbon fiber and the silicon carbide content is more than 80%, which leads to a large difference in the thermal expansion coefficient between the friction layer and the matrix. During the cooling process, the friction layer has a large residual stress, which causes the friction layer to easily peel off during use. To this end, a carbon ceramic brake disc with multiple friction layers is proposed to improve the bonding problem between the friction layer and the matrix layer. SUMMARY

[0004] The present application aims to provide a carbon ceramic brake disc with multiple friction layers and a preparation method thereof. By setting three layers of friction layers, the thermal expansion coefficients of different friction layers change in turn, effectively improving the bonding strength between the friction layer and the matrix layer and the wear resistance of the brake disc.

[0005] To achieve the purpose, the application provides a carbon ceramic brake disc with multiple friction layers, which comprises a base layer and friction layers, the friction layers comprising a first friction layer, a second friction layer and a third friction layer, the first friction layer, the second friction layer and the third friction layer being sequentially arranged outward from the base layer. The thickness of the first friction layer is 0.05-0.4mm, and the first friction layer contains at least 2-40μm silicon carbide particles; the thickness of the second friction layer is 0.1-0.4mm, and the second friction layer contains at least 35-85μm silicon carbide particles; the thickness of the third friction layer is 0.4-5mm, and the third friction layer contains at least 75-150μm silicon carbide particles.

[0006] Preferably, the silicon carbide content v1 of the first friction layer is 55-85vol%, and the silicon content is 15-45vol%; the silicon carbide content v2 of the second friction layer is 65-90vol%, and the silicon content is 10-35vol%; the silicon carbide content v3 of the third friction layer is 70-95vol%, and the silicon content is 5-30vol%.

[0007] Preferably, the silicon carbide contents of the first friction layer, the second friction layer and the third friction layer satisfy v3>v2>v1.

[0008] Preferably, the silicon carbide of the first friction layer, the second friction layer and the third friction layer is composed of α phase and β phase, wherein the α phase accounts for 60-100% of the total silicon carbide content. The α phase silicon carbide is obtained after crushing, has irregular morphology and relatively coarse particle size, is generally added in the form of raw material in the friction layer, has better roughness of the friction surface during friction, and is beneficial to improving the friction coefficient. The β silicon carbide is obtained by the reaction of carbon and silicon during silicon infiltration, has smaller particle size and relatively regular morphology, and too much β silicon carbide can easily lead to insufficient roughness of the friction surface. However, the β silicon carbide plays a role in sticking the initial α silicon carbide, and if the β silicon carbide is too little, the α silicon carbide has insufficient bonding force in the friction layer and is easily "planed out" by the friction pair during friction, resulting in peeling and low friction coefficient. Therefore, the reasonable ratio of α phase and β phase silicon carbide is of great significance to improving the friction resistance of the friction layer.

[0009] Preferably, the first friction layer contains 20-500μm free silicon, the second friction layer contains 10-300μm free silicon, and the third friction layer contains 5-200μm free silicon.

[0010] The application further provides a preparation method of the carbon ceramic brake disc with multiple friction layers, which is used for preparing the carbon ceramic brake disc with multiple friction layers and comprises the following steps.

[0011] S1: repeatedly overlap carbon fiber unidirectional cloth and carbon fiber tire to obtain a carbon fiber preform, each layer of carbon fiber unidirectional cloth and each layer of carbon fiber tire are subjected to needle punching treatment after being overlapped, the needle punching density is 50-200 needles / cm 2 , the carbon fiber directions of the two carbon fiber unidirectional cloths adjacent to each other on each carbon fiber tire are at a 90° angle;

[0012] S2: immerse the carbon fiber preform in a 40wt% concentration of phenolic resin alcohol solution, dry the immersed body until the alcohol is completely volatilized to obtain an impregnated body, the impregnation time is generally 2-5h, preferably 3-4h;

[0013] S3: carbonize the impregnated body to obtain a carbonized body, the carbonization temperature is 800-1100℃, and the holding time is 4-6h;

[0014] S4: perform low-temperature graphitization treatment on the carbonized body in nitrogen to obtain a graphitized body, the treatment temperature is 1400-1800℃, and the holding time is 2h;

[0015] S5: uniformly mix silicon carbide powder and phenolic powder to obtain first friction layer pressing powder, uniformly lay the first friction layer pressing powder on the surface of the graphitized body, and press for 30min at a temperature of 90℃ to obtain a first body, the pressure is greater than 10MPa;

[0016] S6: uniformly mix silicon carbide powder and phenolic powder to obtain second friction layer pressing powder, uniformly lay the second friction layer pressing powder on the surface of the first body, and press for 30min at a temperature of 90℃ to obtain a second body, the pressure is greater than 10MPa;

[0017] S7: uniformly mix silicon carbide powder and phenolic powder to obtain third friction layer pressing powder, uniformly lay the third friction layer pressing powder on the surface of the second body, and press for 60min at a temperature of 150℃ to completely solidify to obtain a third body, the pressure is greater than 10MPa;

[0018] S8: mechanically process the third body to obtain a brake disc body;

[0019] S9: place the brake disc body into a boron nitride crucible and then into a high-temperature vacuum furnace to perform silicon infiltration treatment, after the silicon infiltration treatment is completed, perform surface grinding and size processing to obtain the carbon ceramic brake disc with multiple friction layers, the boron nitride crucible is pre-filled with pure silicon powder with a mass of 1.1 times the mass of the body, the silicon infiltration treatment temperature is 1600-1700℃, the holding time is 2-4h, and the furnace pressure is less than 1000Pa.

[0020] Preferably, steps S2 and S3 are performed at least once, so that the density of the carbonized body reaches 1.25-1.45g / cm3 .

[0021] Preferably, the first friction layer pressing powder has a silicon carbide particle size of 2-40 μm, a silicon carbide powder content of 45-75 vol%, and a phenolic powder of 25-55 vol%.

[0022] Preferably, the second friction layer pressing powder has a silicon carbide particle size of 35-85 μm, a silicon carbide powder content of 55-80 vol%, and a phenolic powder of 20-45 vol%.

[0023] Preferably, the third friction layer pressing powder has a silicon carbide particle size of 75-150 μm, a silicon carbide powder content of 60-85 vol%, and a phenolic powder of 5-40 vol%.

[0024] Beneficial effects: The carbon ceramic brake disc with multiple friction layers provided by the application aims at the problems of residual stress between the friction layer and the substrate and low bonding force of the friction layer, and sets three friction layers, the first friction layer close to the substrate layer has a lower thermal expansion coefficient, avoiding excessive residual stress in the interface layer; the second friction layer is located between the first friction layer and the third friction layer, and has a moderate thermal expansion coefficient, playing a good buffering role; the third friction layer is located in the outermost layer and needs to have high wear resistance, so the third friction layer has the largest thickness, the silicon carbide particles have a larger particle size and the content of wear-resistant particles is increased, and the third friction layer has a higher thermal expansion coefficient, greatly improving the comprehensive performance of the carbon ceramic brake disc.

[0025] The application further provides a preparation method of the carbon ceramic brake disc with multiple friction layers, and the carbonization treatment is followed by three-step pressing, and different contents of the mixed pressing powder of the silicon carbide powder and the phenolic powder are used in each pressing, so as to realize the manufacturing of the three friction layers. The whole preparation process has a simple manufacturing method, does not need chemical vapor deposition treatment, adopts low-temperature graphite conversion, has a lower process difficulty, and is easy to scale production. DETAILED DESCRIPTION

[0026] The embodiments described below are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application.

[0027] The embodiment provides a carbon ceramic brake disc with multiple friction layers, which comprises a base layer and friction layers, the friction layers comprising a first friction layer, a second friction layer and a third friction layer, the first friction layer, the second friction layer and the third friction layer being sequentially arranged from the base layer outwards. The thickness of the first friction layer is 0.05-0.4mm, and the first friction layer at least contains silicon carbide particles with a size of 2-40um; the thickness of the second friction layer is 0.1-0.4mm, and the second friction layer at least contains silicon carbide particles with a size of 35-85um; the thickness of the third friction layer is 0.4-5mm, and the third friction layer at least contains silicon carbide particles with a size of 75-150um.

[0028] The silicon carbide content v1 of the first friction layer is 55-85vol%, and the silicon content is 15-45vol%; the silicon carbide content v2 of the second friction layer is 65-90vol%, and the silicon content is 10-35vol%; the silicon carbide content v3 of the third friction layer is 70-95vol%, and the silicon content is 5-30vol%.

[0029] The silicon carbide contents of the first friction layer, the second friction layer and the third friction layer satisfy v3>v2>v1.

[0030] The silicon carbide of the first friction layer, the second friction layer and the third friction layer is composed of alpha phase and beta phase, and the alpha phase accounts for 60-100% of the total silicon carbide content.

[0031] The first friction layer contains free silicon with a size of 20-500um, the second friction layer contains free silicon with a size of 10-300um, and the third friction layer contains free silicon with a size of 5-200um.

[0032] The embodiment further provides a preparation method of the carbon ceramic brake disc with multiple friction layers, which comprises the following steps.

[0033] S1: carbon fiber unidirectional cloth and carbon fiber tire are repeatedly overlapped to obtain a carbon fiber preform, and each layer of carbon fiber unidirectional cloth and each layer of carbon fiber tire are subjected to needle punching treatment after being overlapped, and the needle punching density is 50-200 needles / cm 2 , and the carbon fiber directions of the two adjacent carbon fiber unidirectional cloths of each carbon fiber tire are at a 90° angle;

[0034] S2: the carbon fiber preform is immersed in a 40wt% concentration of phenolic resin alcohol solution, and after being immersed, the preform is subjected to drying treatment until the alcohol is completely volatilized to obtain an impregnated body;

[0035] S3: the impregnated body is subjected to carbonization treatment to obtain a carbonized body, and the carbonization temperature is 800-1100℃, and the holding time is 4-6h;

[0036] S4: the carbonized body is subjected to low-temperature graphitization treatment in nitrogen to obtain a graphitized body, the treatment temperature is 1400-1800℃, and the holding time is 2h;

[0037] S5: silicon carbide powder and phenolic powder are uniformly mixed to obtain first friction layer pressing powder, the first friction layer pressing powder is uniformly laid on the surface of the graphitized body, and pressing is performed at a temperature of 90℃ for 30min to obtain a first body, the pressure is greater than 10MPa;

[0038] S6: silicon carbide powder and phenolic powder are uniformly mixed to obtain second friction layer pressing powder, the second friction layer pressing powder is uniformly laid on the surface of the first body, and pressing is performed at a temperature of 90℃ for 30min to obtain a second body, the pressure is greater than 10MPa;

[0039] S7: silicon carbide powder and phenolic powder are uniformly mixed to obtain third friction layer pressing powder, the third friction layer pressing powder is uniformly laid on the surface of the second body, and pressing is performed at a temperature of 150℃ for 60min to completely solidify to obtain a third body, the pressure is greater than 10MPa;

[0040] S8: the third body is subjected to mechanical processing to obtain a brake disc body;

[0041] S9: the brake disc body is placed into a boron nitride crucible and then placed into a high-temperature vacuum furnace for siliconizing treatment, after the siliconizing treatment is completed, surface grinding and size processing are performed to obtain the carbon ceramic brake disc with multiple friction layers, the boron nitride crucible is pre-filled with pure silicon powder with a mass of 1.1 times the mass of the body, the siliconizing treatment temperature is 1600-1700℃, the holding time is 2-4h, and the furnace pressure is less than 1000Pa.

[0042] S2 and S3 are performed at least once, so that the density of the carbonized body reaches 1.25-1.45g / cm 3 .

[0043] In the first friction layer pressing powder, the particle size of silicon carbide is 2-40μm, the content of silicon carbide powder is 45-75vol%, and the content of phenolic powder is 25-55vol%.

[0044] In the second friction layer pressing powder, the particle size of silicon carbide is 35-85μm, the content of silicon carbide powder is 55-80vol%, and the content of phenolic powder is 20-45vol%.

[0045] In the third friction layer pressing powder, the particle size of silicon carbide is 75-150μm, the content of silicon carbide powder is 60-85vol%, and the content of phenolic powder is 5-40vol%.

[0046] Example 1

[0047] The embodiment provides a carbon ceramic brake disc with multiple friction layers, and preparation steps of the carbon ceramic brake disc with multiple friction layers are as follows.

[0048] S1: carbon fiber unidirectional cloth and carbon fiber tire are repeatedly overlapped to obtain a carbon fiber preform, and each layer of carbon fiber unidirectional cloth and each layer of carbon fiber tire are subjected to needle punching treatment after being overlapped, and the needle punching density is 150 needles / cm 2 , and the carbon fiber directions of the two carbon fiber unidirectional cloths adjacent to each other on each carbon fiber tire are at an angle of 90°.

[0049] S2: the carbon fiber preform is immersed in a 40wt% concentration of phenolic resin alcohol solution, and after immersion, drying treatment is performed until alcohol is completely volatilized to obtain an impregnated body;

[0050] S3: the impregnated body is subjected to carbonization treatment to obtain a carbonized body, the carbonization temperature is 900 DEG C, and the holding time is 6h, and the steps of S2 and S3 are repeatedly performed until the density of the carbonized body reaches 1.35g / cm 3 .

[0051] S4: the carbonized body is subjected to low-temperature graphitization treatment in nitrogen to obtain a graphitized body, the treatment temperature is 1800 DEG C, and the holding time is 2h;

[0052] S5: silicon carbide powder and phenolic powder are uniformly mixed to obtain first friction layer pressing powder, the particle size of the silicon carbide in the first friction layer pressing powder is 5μm, the content of the silicon carbide powder is 55vol%, and the content of the phenolic powder is 45vol%; the first friction layer pressing powder is uniformly laid on the surface of the graphitized body, and first body is obtained by pressing at a temperature of 90 DEG C for 30min, the pressure is 12MPa, and the pressing thickness is 0.2mm;

[0053] S6: silicon carbide powder and phenolic powder are uniformly mixed to obtain second friction layer pressing powder, the particle size of the silicon carbide in the second friction layer pressing powder is 40μm, the content of the silicon carbide powder is 60vol%, and the content of the phenolic powder is 40vol%; the second friction layer pressing powder is uniformly laid on the surface of the first body, and second body is obtained by pressing at a temperature of 90 DEG C for 30min, the pressure is 15MPa, and the pressing thickness is 0.2mm;

[0054] S7: silicon carbide powder and phenolic powder are uniformly mixed to obtain third friction layer pressing powder, the particle size of the silicon carbide in the third friction layer pressing powder is 100μm, the content of the silicon carbide powder is 65vol%, and the content of the phenolic powder is 35vol%; the third friction layer pressing powder is uniformly laid on the surface of the second body, and third body is obtained by pressing at a temperature of 150 DEG C for 60min to completely solidify, the pressure is 20MPa, and the pressing thickness is 0.6mm;

[0055] S8: machining the third blank to obtain a brake disc blank, and preparing a product with a vent channel and other features;

[0056] S9: placing the brake disc blank into a boron nitride crucible, and then into a high-temperature vacuum furnace for siliconizing treatment; after the siliconizing treatment, surface grinding and size processing are performed to obtain the carbon ceramic brake disc with multiple friction layers, the boron nitride crucible is pre-filled with pure silicon powder with a mass of 1.1 times that of the blank, the siliconizing treatment temperature is 1650°C, the holding time is 3h, and the furnace pressure is less than 1000Pa.

[0057] Example 2

[0058] The present embodiment provides a carbon ceramic brake disc with multiple friction layers, and the preparation steps of the carbon ceramic brake disc with multiple friction layers are as follows:

[0059] S1: repeatedly stacking carbon fiber unidirectional cloth and carbon fiber web to obtain a carbon fiber preform, and performing needle punching treatment after stacking each layer of carbon fiber unidirectional cloth and each layer of carbon fiber web, the needle punching density is 150 needles / cm 2 , and the carbon fibers of the upper and lower two carbon fiber unidirectional cloths in each carbon fiber web are arranged at a 90° angle;

[0060] S2: immersing the carbon fiber preform in a 40wt% concentration of phenolic resin alcohol solution, and drying until the alcohol is completely volatilized to obtain an impregnated body;

[0061] S3: carbonizing the impregnated body to obtain a carbonized body, the carbonization temperature is 900°C, and the holding time is 6h, and the steps of S2 and S3 are repeated until the density of the carbonized body reaches 1.35g / cm 3 ;

[0062] S4: performing low-temperature graphitization treatment on the carbonized body in nitrogen to obtain a graphitized blank, the treatment temperature is 1800°C, and the holding time is 2h;

[0063] S5: uniformly mixing silicon carbide powder and phenolic powder to obtain first friction layer pressing powder, the particle size of silicon carbide in the first friction layer pressing powder is 5μm, the content of silicon carbide powder is 55vol%, and the content of phenolic powder is 45vol%; uniformly laying the first friction layer pressing powder on the surface of the graphitized blank, and pressing at a temperature of 90°C for 30min to obtain a first blank, the pressure is 12MPa, and the pressing thickness is 0.3mm;

[0064] S6: mixing silicon carbide powder and phenolic powder uniformly to obtain a second friction layer pressing powder, the particle size of silicon carbide in the second friction layer pressing powder is 40 μm, the content of silicon carbide powder is 60 vol%, and the content of phenolic powder is 40 vol%; the second friction layer pressing powder is uniformly laid on the surface of the first compact, and the second compact is obtained by pressing at a temperature of 90°C for 30 min, the pressure is 15 MPa, and the pressing thickness is 0.3 mm;

[0065] S7: mixing silicon carbide powder and phenolic powder uniformly to obtain a third friction layer pressing powder, the particle size of silicon carbide in the third friction layer pressing powder is 100 μm, the content of silicon carbide powder is 65 vol%, and the content of phenolic powder is 35 vol%; the third friction layer pressing powder is uniformly laid on the surface of the second compact, and the third compact is obtained by pressing at a temperature of 150°C for 60 min to completely solidify, the pressure is 20 MPa, and the pressing thickness is 0.6 mm;

[0066] S8: the third compact is machined to obtain a brake disc compact, and the product is prepared to have a ventilation channel and other characteristics;

[0067] S9: the brake disc compact is placed into a boron nitride crucible, and then placed into a high-temperature vacuum furnace for siliconizing treatment; after the siliconizing treatment is completed, surface grinding and size processing are performed to obtain the carbon ceramic brake disc with multiple friction layers, the boron nitride crucible is pre-filled with pure silicon powder with a mass of 1.1 times that of the compact, the siliconizing treatment temperature is 1650°C, the holding time is 3 h, and the furnace pressure is less than 1000 Pa.

[0068] Example 3

[0069] The embodiment provides a carbon ceramic brake disc with multiple friction layers, and the preparation steps of the carbon ceramic brake disc with multiple friction layers are as follows:

[0070] S1: repeatedly stacking carbon fiber unidirectional cloth and carbon fiber tire to obtain a carbon fiber preform, after each layer of carbon fiber unidirectional cloth and each layer of carbon fiber tire are stacked, needle punching treatment is performed, the needle punching density is 150 needles / cm 2 , and the carbon fiber directions of the upper and lower two carbon fiber unidirectional cloths of each carbon fiber tire are at an angle of 90°;

[0071] S2: immersing the carbon fiber preform in a 40 wt% concentration of phenolic resin alcohol solution, and performing drying treatment until the alcohol is completely volatilized to obtain an impregnated body;

[0072] S3: performing carbonization treatment on the impregnated body to obtain a carbonized body, the carbonization temperature is 900°C, and the holding time is 6 h, and the steps of S2 and S3 are repeatedly performed until the density of the carbonized body reaches 1.35 g / cm 3 ;

[0073] S4: the carbonized body is subjected to low-temperature graphitization treatment in nitrogen to obtain a graphitized body, the treatment temperature is 1800℃, and the holding time is 2h;

[0074] S5: the silicon carbide powder and the phenolic powder are uniformly mixed to obtain first friction layer pressing powder, the particle size of the silicon carbide in the first friction layer pressing powder is 10μm, the content of the silicon carbide powder is 55vol%, and the content of the phenolic powder is 45vol%; the first friction layer pressing powder is uniformly laid on the surface of the graphitized body, and first body is obtained by pressing at a temperature of 90℃ for 30min, the pressure is 12MPa, and the pressing thickness is 0.2mm;

[0075] S6: the silicon carbide powder and the phenolic powder are uniformly mixed to obtain second friction layer pressing powder, the particle size of the silicon carbide in the second friction layer pressing powder is 60μm, the content of the silicon carbide powder is 60vol%, and the content of the phenolic powder is 40vol%; the second friction layer pressing powder is uniformly laid on the surface of the first body, and second body is obtained by pressing at a temperature of 90℃ for 30min, the pressure is 15MPa, and the pressing thickness is 0.2mm;

[0076] S7: the silicon carbide powder and the phenolic powder are uniformly mixed to obtain third friction layer pressing powder, the particle size of the silicon carbide in the third friction layer pressing powder is 120μm, the content of the silicon carbide powder is 65vol%, and the content of the phenolic powder is 35vol%; the third friction layer pressing powder is uniformly laid on the surface of the second body, and third body is obtained by pressing at a temperature of 150℃ for 60min to completely solidify, the pressure is 20MPa, and the pressing thickness is 0.6mm;

[0077] S8: the third body is subjected to mechanical processing to obtain brake disc body, and the product is prepared to have features such as ventilation channels;

[0078] S9: the brake disc body is placed into a boron nitride crucible, and then is placed into a high-temperature vacuum furnace to perform silicon infiltration treatment, after the silicon infiltration treatment is completed, surface grinding and size processing are performed to obtain the carbon ceramic brake disc with multiple friction layers, the boron nitride crucible is pre-filled with pure silicon powder with a mass of 1.1 times the mass of the body, the silicon infiltration treatment temperature is 1650℃, the holding time is 3h, and the furnace pressure is less than 1000Pa.

[0079] Example 4

[0080] The embodiment provides a carbon ceramic brake disc with multiple friction layers, and the preparation steps of the carbon ceramic brake disc with multiple friction layers are as follows:

[0081] S1: carbon fiber unidirectional cloth and carbon fiber tire are repeatedly overlapped to obtain a carbon fiber preform, after each layer of carbon fiber unidirectional cloth and each layer of carbon fiber tire are overlapped, needle punching treatment is performed, and the needle punching density is 150 needles / cm 2, each carbon fiber net tire upper and lower adjacent two carbon fiber unidirectional cloth carbon fiber direction 90 ° angle;

[0082] S2: the carbon fiber preform is immersed in a 40wt% concentration of phenolic resin alcohol solution, and after immersion, drying treatment is performed until the alcohol is completely volatilized to obtain an impregnated body;

[0083] S3: the impregnated body is subjected to carbonization treatment to obtain a carbonized body, the carbonization temperature is 900°C, and the holding time is 6h, and the steps of S2 and S3 are repeated until the density of the carbonized body reaches 1.35g / cm 3 ;

[0084] S4: the carbonized body is subjected to low-temperature graphitization treatment in nitrogen to obtain a graphitized body, the treatment temperature is 1800°C, and the holding time is 2h;

[0085] S5: the silicon carbide powder and the phenolic powder are uniformly mixed to obtain first friction layer pressing powder, the particle size of the silicon carbide in the first friction layer pressing powder is 5μm, the content of the silicon carbide powder is 60vol%, and the content of the phenolic powder is 40vol%; the first friction layer pressing powder is uniformly laid on the surface of the graphitized body, and the first body is obtained by pressing at a temperature of 90°C for 30min, the pressure is 12MPa, and the pressing thickness is 0.2mm;

[0086] S6: the silicon carbide powder and the phenolic powder are uniformly mixed to obtain second friction layer pressing powder, the particle size of the silicon carbide in the second friction layer pressing powder is 40μm, the content of the silicon carbide powder is 65vol%, and the content of the phenolic powder is 35vol%; the second friction layer pressing powder is uniformly laid on the surface of the first body, and the second body is obtained by pressing at a temperature of 90°C for 30min, the pressure is 15MPa, and the pressing thickness is 0.2mm;

[0087] S7: the silicon carbide powder and the phenolic powder are uniformly mixed to obtain third friction layer pressing powder, the particle size of the silicon carbide in the third friction layer pressing powder is 100μm, the content of the silicon carbide powder is 70vol%, and the content of the phenolic powder is 30vol%; the third friction layer pressing powder is uniformly laid on the surface of the second body, and the third body is obtained by pressing at a temperature of 150°C for 60min to completely solidify, the pressure is 20MPa, and the pressing thickness is 0.6mm;

[0088] S8: the third body is subjected to mechanical processing to obtain a brake disc body, and the product has a ventilation channel and other characteristics;

[0089] S9: placing the brake disc blank into a boron nitride crucible, then into a high-temperature vacuum furnace for siliconizing treatment, and after the siliconizing treatment, polishing and size processing are performed to obtain the carbon ceramic brake disc with multiple friction layers, pure silicon powder with a mass 1.1 times that of the blank is pre-placed in the boron nitride crucible, the siliconizing treatment temperature is 1650℃, the holding time is 3h, and the furnace chamber pressure is less than 1000Pa.

[0090] Example 5

[0091] The present embodiment provides a carbon ceramic brake disc with multiple friction layers, and the preparation steps of the carbon ceramic brake disc with multiple friction layers are as follows:

[0092] S1: repeatedly overlapping carbon fiber unidirectional cloth and carbon fiber tire to obtain a carbon fiber preform, and after each layer of carbon fiber unidirectional cloth and each layer of carbon fiber tire are overlapped, needle punching treatment is performed, the needle punching density is 150 needles / cm 2 , and the carbon fiber directions of the two carbon fiber unidirectional cloths adjacent to each other on each carbon fiber tire are at a 90° angle;

[0093] S2: immersing the carbon fiber preform in a 40wt% concentration of phenolic resin alcohol solution, and after immersion, drying treatment is performed until the alcohol is completely volatilized to obtain an impregnated body;

[0094] S3: performing carbonization treatment on the impregnated body to obtain a carbonized body, the carbonization temperature is 900℃, and the holding time is 6h, and the steps of S2 and S3 are repeatedly performed until the density of the carbonized body reaches 1.35g / cm 3 ;

[0095] S4: performing low-temperature graphitization treatment on the carbonized body in nitrogen to obtain a graphitized blank, the treatment temperature is 1800℃, and the holding time is 2h;

[0096] S5: uniformly mixing silicon carbide powder and phenolic powder to obtain first friction layer pressing powder, the particle size of the silicon carbide in the first friction layer pressing powder is 5μm, the content of the silicon carbide powder is 55vol%, and the content of the phenolic powder is 45vol%; uniformly laying the first friction layer pressing powder on the surface of the graphitized blank, and pressing for 30min at a temperature of 90℃ to obtain a first blank, the pressure is 12MPa, and the pressing thickness is 0.4mm;

[0097] S6: uniformly mixing silicon carbide powder and phenolic powder to obtain second friction layer pressing powder, the particle size of the silicon carbide in the second friction layer pressing powder is 40μm, the content of the silicon carbide powder is 60vol%, and the content of the phenolic powder is 40vol%; uniformly laying the second friction layer pressing powder on the surface of the first blank, and pressing for 30min at a temperature of 90℃ to obtain a second blank, the pressure is 15MPa, and the pressing thickness is 0.4mm;

[0098] S7: uniformly mixing silicon carbide powder and phenolic powder to obtain third friction layer pressing powder, the particle size of silicon carbide in the third friction layer pressing powder is 100 μm, the content of silicon carbide powder is 65 vol%, and the content of phenolic powder is 35 vol%; uniformly laying the third friction layer pressing powder on the surface of the second compact, and completely curing the third friction layer pressing powder by pressing at a temperature of 150 °C for 60 min to obtain a third compact, the pressure is 20 MPa, and the pressing thickness is 5 mm;

[0099] S8: machining the third compact to obtain a brake disc compact, and preparing a product having a ventilation channel and other features;

[0100] S9: placing the brake disc compact into a boron nitride crucible, and then placing the brake disc compact into a high-temperature vacuum furnace for siliconizing treatment; after the siliconizing treatment is completed, surface grinding and size processing are performed to obtain the carbon ceramic brake disc with multiple friction layers, the boron nitride crucible is pre-filled with pure silicon powder with a mass of 1.1 times the mass of the compact, the siliconizing treatment temperature is 1650 °C, the holding time is 3 h, and the furnace pressure is less than 1000 Pa.

[0101] Example 6

[0102] The embodiment provides a carbon ceramic brake disc with multiple friction layers, and preparation steps of the carbon ceramic brake disc with multiple friction layers are as follows:

[0103] S1: repeatedly stacking carbon fiber unidirectional cloth and carbon fiber tire to obtain a carbon fiber preform, needle punching is performed after each layer of carbon fiber unidirectional cloth and each layer of carbon fiber tire are stacked, the needle punching density is 150 needles / cm 2 , and the carbon fiber directions of the two adjacent carbon fiber unidirectional cloths on each carbon fiber tire are at an angle of 90°.

[0104] S2: immersing the carbon fiber preform in a 40 wt% concentration of phenolic resin alcohol solution, and performing drying treatment until the alcohol is completely volatilized to obtain an impregnated body;

[0105] S3: performing carbonization treatment on the impregnated body to obtain a carbonized body, the carbonization temperature is 900 °C, and the holding time is 6 h, the steps S2 and S3 are repeatedly performed until the density of the carbonized body reaches 1.35 g / cm 3 ;

[0106] S4: performing low-temperature graphitization treatment on the carbonized body in nitrogen to obtain a graphitized compact, the treatment temperature is 1800 °C, and the holding time is 2 h;

[0107] S5: uniformly mixing silicon carbide powder and phenolic powder to obtain first friction layer pressing powder, the particle size of silicon carbide in the first friction layer pressing powder is 30 μm, the content of silicon carbide powder is 55 vol%, and the content of phenolic powder is 45 vol%; uniformly laying the first friction layer pressing powder on the surface of the graphitized compact, pressing for 30 min at a temperature of 90 ℃ to obtain a first compact, the pressure is 12 MPa, and the pressing thickness is 0.2 mm;

[0108] S6: uniformly mixing silicon carbide powder and phenolic powder to obtain second friction layer pressing powder, the particle size of silicon carbide in the second friction layer pressing powder is 70 μm, the content of silicon carbide powder is 60 vol%, and the content of phenolic powder is 40 vol%; uniformly laying the second friction layer pressing powder on the surface of the first compact, pressing for 30 min at a temperature of 90 ℃ to obtain a second compact, the pressure is 15 MPa, and the pressing thickness is 0.2 mm;

[0109] S7: uniformly mixing silicon carbide powder and phenolic powder to obtain third friction layer pressing powder, the particle size of silicon carbide in the third friction layer pressing powder is 150 μm, the content of silicon carbide powder is 65 vol%, and the content of phenolic powder is 35 vol%; uniformly laying the third friction layer pressing powder on the surface of the second compact, pressing for 60 min at a temperature of 150 ℃ to obtain a third compact, the pressure is 20 MPa, and the pressing thickness is 0.6 mm;

[0110] S8: machining the third compact to obtain a brake disc compact, and the product has a ventilation channel and other characteristics;

[0111] S9: placing the brake disc compact into a boron nitride crucible, and then placing the brake disc compact into a high-temperature vacuum furnace for siliconizing treatment; after the siliconizing treatment is completed, surface grinding and size processing are performed to obtain the carbon ceramic brake disc with multiple friction layers, the boron nitride crucible is pre-filled with pure silicon powder with a mass of 1.1 times the mass of the compact, the siliconizing treatment temperature is 1650 ℃, the holding time is 3 h, and the furnace pressure is less than 1000 Pa.

[0112] Comparative Example 1

[0113] The present comparative example provides a carbon ceramic brake disc, which is different from the carbon ceramic brake disc with multiple friction layers in Example 1 in that the pressing thickness of the second friction layer in S6 is 0.08 mm.

[0114] Comparative Example 2

[0115] The comparative example provides a carbon ceramic brake disc, which is compared with the carbon ceramic brake disc with multiple friction layers in Example 1, and the difference is that the carbon ceramic brake disc substrate is only provided with a first friction layer and a second friction layer, and the first friction layer is prepared by pressing the powder with a silicon carbide particle size of 5 μm, a silicon carbide powder content of 55 vol%, a phenolic powder of 45 vol%, and a pressing thickness of 0.2 mm; the second friction layer is prepared by pressing the powder with a silicon carbide particle size of 100 μm, a silicon carbide powder content of 65 vol%, a phenolic powder of 35 vol%, and a pressing thickness of 0.8 mm.

[0116] The brake discs prepared in Examples 1-6 and Comparative Examples 1-2 are tested, and the dynamic friction coefficient and wear rate of the carbon ceramic brake disc samples are tested by using an MM-1000 friction tester, the effective friction surface of the test ring is D75mm / D55mmx10mm, the specific pressure is 98N / cm 2 , the inertia is 3kgf·cm·s 2 , and the linear speed is 25m / s. The phase content of each friction layer is analyzed by grinding the sample with friction layer to the corresponding thickness of each layer and using X-ray diffraction.

[0117] The test data is shown in Table 1.

[0118] Table 1 Test data of carbon ceramic brake discs prepared in Examples 1-6 and Comparative Examples 1-2

[0119] Scheme Friction layer 1 thickness mm Friction layer 1 added silicon carbide particle size Friction layer 1 silicon carbide content Friction layer 2 thickness mm Friction layer 2 added silicon carbide particle size Friction layer 2 silicon carbide content Friction layer 3 thickness mm Friction layer 3 added silicon carbide particle size Friction layer 3 silicon carbide content Wear amount μm / surface·time Friction test whether the friction layer peeled off Example 1 0.2 5 μm 76% 0.2 40 μm 82% 0.6 100 μm 89% 0.72 No Example 2 0.3 5 μm 76% 0.3 40 μm 82% 0.6 100 μm 89% 0.73 No Example 3 0.2 10 μm 76% 0.2 60 μm 82% 0.6 120 μm 89% 0.68 No Example 4 0.2 5 μm 81% 0.2 40 μm 85% 0.6 100 μm 92% 0.64 No Example 5 0.4 5 μm 76% 0.4 40 μm 82% 5 mm 100 μm 89% 0.74 No Example 6 0.2 30 μm 76% 0.2 70 μm 82% 0.6 150 μm 89% 0.73 No Comparative Example 1 0.2 5 μm 76% 0.08 40 μm 82% 0.6 100 μm 89% 1.9 Yes Comparative Example 2 0.2 5 μm 76% 0.8 100 μm 89% / / / 2.4 Yes

[0120] From the above example and comparative example data, by setting three layers of friction layer, the content of silicon carbide of each layer is different, so that the thermal expansion coefficient of each layer is continuously increasing, the thermal expansion coefficient of the friction layer close to the substrate layer is small, which can avoid the interface residual stress too large causing the friction layer to fall off, the content of silicon carbide of the outermost friction layer is higher, which can effectively improve the wear resistance of carbon ceramic brake disc and prolong the service life of brake disc. As can be seen from example 3 and example 1, with the increase of the particle size of silicon carbide in the third friction layer, the wear resistance of the sample increases. As can be seen from example 4 and example 1, increasing the ratio of silicon carbide and phenolic powder when preparing the friction layer powder can increase the content of silicon carbide in the friction layer after siliconizing, and further improve the friction performance. It shows that the particle size and content of silicon carbide will affect the wear resistance of brake disc. In example 6, the particle size of the third friction layer increases, and the wear resistance of silicon carbide itself is improved, but too large particle size will increase the probability of peeling of silicon carbide during friction, so the wear rate increases compared with example 3. As can be seen from comparative example 1 and example 1, when the thickness of the second friction layer is low, the thermal stress between the third friction layer and the first friction layer is large due to the difference in the content of silicon carbide, and the second friction layer is too thin to effectively let the stress produce too much, so the third friction layer is easy to appear the whole peeling, and the wear rate also increases. As can be seen from comparative example 2 and example 1, when the friction layer has only two layers, the interface produces a large thermal stress due to the difference in the content of the two layers, and the whole peeling during friction is intensified, and the wear rate is further improved.

[0121] The above disclosure is only several preferred embodiments of the present application, which cannot limit the scope of the present application, and the equivalent changes made according to the patent scope of the present application still fall within the scope of the present application.

Claims

1. A carbon-carbide brake disc having a plurality of friction layers, characterized in that, The carbon ceramic brake disc comprises a base layer and friction layers, the friction layers comprise a first friction layer, a second friction layer and a third friction layer, the first friction layer, the second friction layer and the third friction layer are sequentially arranged from the base layer outward; the thickness of the first friction layer is 0.05-0.4mm, the first friction layer at least contains 2-40μm silicon carbide particles; the thickness of the second friction layer is 0.1-0.4mm, the second friction layer at least contains 35-85μm silicon carbide particles; the thickness of the third friction layer is 0.4-5mm, the third friction layer at least contains 75-150μm silicon carbide particles, the silicon carbide content v1 of the first friction layer is 55-85vol%, the silicon content is 15-45vol%; the silicon carbide content v2 of the second friction layer is 65-90vol%, the silicon content is 10-35vol%; the silicon carbide content v3 of the third friction layer is 70-95vol%, the silicon content is 5-30vol%, the silicon carbide content of the first friction layer, the second friction layer and the third friction layer satisfies v3>v2>v1.

2. The carbon-carbon brake disc with multi-friction layers according to claim 1, wherein, The silicon carbide of the first friction layer, the second friction layer and the third friction layer is composed of α phase and β phase, wherein the α phase accounts for 60-100% of the total silicon carbide content.

3. The carbon-ceramic brake disc with multiple friction layers according to claim 1, wherein: The first friction layer contains 20-500μm free silicon, the second friction layer contains 10-300μm free silicon, and the third friction layer contains 5-200μm free silicon.

4. A method for manufacturing a carbon-carbon brake disc with a multi-friction layer, for manufacturing a carbon-carbon brake disc with a multi-friction layer according to any one of claims 1 to 3, characterized in that The method comprises the following steps: S1: repeatedly overlap carbon fiber unidirectional cloth and carbon fiber tire to obtain a carbon fiber preform, each layer of carbon fiber unidirectional cloth and each layer of carbon fiber tire are subjected to needle punching treatment after being overlapped, the needle punching density is 50-200 needles / cm 2 , the carbon fiber directions of the upper and lower two carbon fiber unidirectional cloths adjacent to each carbon fiber tire are at a 90° angle. S2: the carbon fiber preform is immersed in a 40wt% concentration of phenolic resin alcohol solution, and after immersion, drying treatment is performed until the alcohol is completely volatilized to obtain an impregnated body; S3: the impregnated body is subjected to carbonization treatment to obtain a carbonized body, the carbonization temperature is 800-1100℃, and the holding time is 4-6h; S4: the carbonized body is subjected to low-temperature graphitization treatment in nitrogen to obtain a graphitized blank, the treatment temperature is 1400-1800℃, and the holding time is 2h; S5: the silicon carbide powder and the phenolic powder are uniformly mixed to obtain first friction layer pressing powder, the first friction layer pressing powder is uniformly laid on the surface of the graphitized blank, and pressing is performed at a temperature of 90℃ for 30min to obtain a first blank, the pressure is greater than 10MPa; S6: the silicon carbide powder and the phenolic powder are uniformly mixed to obtain second friction layer pressing powder, the second friction layer pressing powder is uniformly laid on the surface of the first blank, and pressing is performed at a temperature of 90℃ for 30min to obtain a second blank, the pressure is greater than 10MPa; S7: the silicon carbide powder and the phenolic powder are uniformly mixed to obtain third friction layer pressing powder, the third friction layer pressing powder is uniformly laid on the surface of the second blank, and pressing is performed at a temperature of 150℃ for 60min to completely solidify to obtain a third blank, the pressure is greater than 10MPa; S8: the third blank is subjected to mechanical processing to obtain a brake disc blank. S9: the brake disc blank is put into a boron nitride crucible, and then into a high-temperature vacuum furnace for silicon infiltration treatment, and after the silicon infiltration treatment is completed, surface grinding and size processing are performed to obtain the carbon ceramic brake disc with multiple friction layers.

5. The method for preparing a carbon-ceramic brake disc with multiple friction layers according to claim 4, characterized in that: S2 and S3 steps are performed at least once to bring the density of the carbonized body to 1.25-1.45 g / cm3 3 .

6. The method for preparing a carbon-ceramic brake disc with multiple friction layers according to claim 4, wherein: The silicon carbide particle size in the first friction layer pressing powder is 2-40 microns, the silicon carbide powder content is 45-75 vol%, and the phenolic powder is 25-55 vol%.

7. The method for preparing a carbon-ceramic brake disc with multiple friction layers according to claim 4, wherein: The silicon carbide particle size in the second friction layer pressing powder is 35-85 microns, the silicon carbide powder content is 55-80 vol%, and the phenolic powder is 20-45 vol%.

8. The method for preparing a carbon-ceramic brake disc with multiple friction layers according to claim 4, wherein: The silicon carbide particle size in the third friction layer pressing powder is 75-150 microns, the silicon carbide powder content is 60-85 vol%, and the phenolic powder is 5-40 vol%.