Carbon-ceramic composite material, preparation method thereof, brake disc and vehicle

Abstract

The invention relates to a carbon-ceramic composite material and a preparation method thereof, a brake disc and a vehicle, and relates to the technical field of carbon-ceramic composites.The carbon-ceramic composite material comprises a carbon-ceramic matrix, at least part of the surface of the carbon-ceramic matrix is provided with a friction layer, and the friction layer comprises a silicon carbide matrix and SiC whiskers distributed in the silicon carbide matrix; the length direction of at least part of the SiC whiskers extends in the thickness direction of the friction layer. According to the friction layer of the carbon-ceramic composite material, a continuous heat conduction channel in the thickness direction of the friction layer can be constructed, and the heat transport capacity of the friction layer to the base body is effectively improved.

Description

[0001] The present application is a divisional application, the original application number is 202410978839.6, the original application date is July 19, 2024, and the entire contents of the original application are incorporated herein by reference. TECHNICAL FIELD

[0002] The present disclosure relates to the technical field of carbon ceramic composite materials, in particular, to a carbon ceramic composite material, a preparation method thereof, a brake disc and a vehicle. BACKGROUND

[0003] Carbon fiber reinforced carbon / silicon carbide ceramic matrix composite (C / C-SiC, referred to as carbon ceramic) has the characteristics of high strength and high toughness of carbon fiber and high wear resistance of silicon carbide ceramic material, and has low density, which can replace existing metal materials to become the preferred brake disc material for future lightweight electric vehicles, and has huge market potential. However, the existing brake disc has poor thermal stability, low friction coefficient, and poor thermal decay resistance. In particular, during the braking process of the automobile, the surface temperature of the brake disc will rise sharply, and the carbon fibers or matrix carbon exposed on the surface of the carbon ceramic matrix are prone to oxidation under high temperature conditions, and if the heat dissipation is poor, thermal decay is prone to occur, which prolongs the braking distance and reduces the safety factor.

[0004] The Si / SiC composite ceramic layer has excellent friction and wear performance, and can be applied to the surface of the carbon ceramic brake disc to protect the carbon fibers or matrix carbon exposed on the surface of the carbon ceramic matrix from oxidation, and can well meet the requirements of the carbon ceramic brake disc on braking performance. At present, the friction layer of the carbon ceramic disc is prepared by slurry method, and silicon carbide ceramic layer is generated by pyrolysis or silicon infiltration. The ceramic layer generated by this method is a block, and the heat dissipation direction is relatively dispersed, which causes the heat generated by the disc surface braking to be unable to be conducted to the matrix direction, thereby causing thermal decay. SUMMARY

[0005] The purpose of the present disclosure is to provide a carbon ceramic composite material, a preparation method thereof, a brake disc and a vehicle, which can construct a continuous heat conduction channel in the thickness direction in the friction layer of the carbon ceramic composite material, improve the heat transport capacity of the friction layer to the matrix, and avoid the occurrence of thermal decay.

[0006] To achieve the above purpose, the first aspect of the present disclosure provides a carbon ceramic composite material, comprising a carbon ceramic matrix, at least part of the surface of the carbon ceramic matrix having a friction layer, the friction layer comprising a silicon carbide matrix and SiC whiskers distributed in the silicon carbide matrix; at least part of the length direction of the SiC whiskers extends along the thickness direction of the friction layer.

[0007] Optionally, an angle between a length direction of the SiC whisker and a thickness direction of the friction layer is taken as a growth angle of the SiC whisker; and based on a total volume of the friction layer, a volume percentage of the SiC whisker with a growth angle of 0-15° is 3-10%, a volume percentage of the SiC whisker with a growth angle of 15-30° is 1-3%, and a volume percentage of the SiC whisker with a growth angle of 30-90° is 1-2%.

[0008] Optionally, a diameter of the single SiC whisker is 100-600 nm, and a length of the single SiC whisker is 5-50 μm.

[0009] Optionally, one end of at least part of the SiC whisker extends to a contact surface between the friction layer and the carbon-toughened matrix.

[0010] Optionally, the friction layer further comprises carbon fiber filaments and silicon, and the carbon fiber filaments and silicon are dispersed in the silicon carbide matrix.

[0011] Optionally, the friction layer is embedded in the carbon-toughened matrix, and a surface of the friction layer and a surface of the carbon-toughened matrix are in the same plane; and a thickness of the friction layer is 1-4 mm.

[0012] Optionally, the carbon-toughened matrix is formed in a disc shape, a thickness of the carbon-toughened matrix is 25-36 mm, and the friction layer is embedded in each of two circular main surfaces of the carbon-toughened matrix, the friction layer is formed in an annular shape, and is coaxial with the disc-shaped carbon-toughened matrix; and a ring width of the friction layer is 110-120 mm.

[0013] Optionally, based on a total volume of the friction layer, a volume fraction of silicon carbide in the friction layer is 74-92%, a volume fraction of the SiC whisker is 5-15%, a volume fraction of carbon is 2-5%, and a volume fraction of silicon is 1-6%.

[0014] Optionally, the carbon-toughened matrix of the carbon-toughened composite material comprises silicon carbide, carbon and silicon.

[0015] Based on a total volume of the carbon-toughened composite material, a volume fraction of silicon carbide in the carbon-toughened composite material is 54-76%, a volume fraction of carbon is 22-40%, and a volume fraction of silicon is 2-6%.

[0016] Optionally, a thermal conductivity of the carbon-toughened composite material in a thickness direction is 100-150 Wm -1 k -1 .

[0017] The second aspect of the present disclosure provides a method for preparing a carbon ceramic composite material, comprising the following steps: S1, performing a first chemical vapor deposition treatment on a carbon fiber preform under carbon deposition conditions to obtain a densified preform; performing a slotting treatment on at least part of the surface of the densified preform to obtain a slotted substrate; S2, placing a second carbon fiber preform into the slots of the slotted substrate to obtain a first intermediate body, wherein the second carbon fiber preform comprises a laminated carbon fiber unidirectional cloth, and the multiple layers of the carbon fiber unidirectional cloth have the same carbon fiber monofilament arrangement direction, and the length direction of the carbon fiber monofilament is parallel to the depth direction of the slots; S3, performing a second chemical vapor deposition treatment on the first intermediate body under SiC deposition conditions to obtain a second intermediate body; and S4, performing a silicon infiltration treatment on the second intermediate body.

[0018] Optionally, in step S1, the conditions of the first chemical vapor deposition treatment include: a deposition temperature of 900-1300℃, a deposition pressure of 0.5-5kPa, a deposition time of 250-500h, and a process gas selected from one or more of methane, propane and propylene, wherein the flow rate of the process gas is 10-50L / min.

[0019] The density of the densified preform obtained in step S1 is 1.25-1.45g / cm 3 .

[0020] Optionally, in step S2, the number of layers of the carbon fiber unidirectional cloth in the second carbon fiber preform is 350-900 layers. The conditions of the second chemical vapor deposition treatment include: continuously supplying a deposition gas source and a dilution gas, a deposition temperature of 800-1300℃, a deposition time of 2-8h, a furnace pressure of 300-1000Pa, a flow rate ratio of the deposition gas source to the dilution gas of 1: (1.1-2), and a flow rate of the deposition gas source of 250-950mL / min; wherein the deposition gas source comprises trichloromethylsilane, and the dilution gas comprises hydrogen.

[0021] Optionally, in the second intermediate body obtained in step S3, the SiC whiskers grow from the bottom of the slots in a direction away from the bottom of the slots; the volume fraction of the SiC whiskers is 5-15% based on the total volume of the deposited substances in the slots; wherein the growth angle of the SiC whiskers is the angle between the length direction of the SiC whiskers and the depth direction of the slots, the volume fraction of the SiC whiskers with a growth angle of 0°-15° is 3-10%, the volume fraction of the SiC whiskers with a growth angle of 15°-30° is 1-3%, and the volume fraction of the SiC whiskers with a growth angle of 30°-90° is 1-2%; the diameter of a single SiC whisker is 100-600nm; and the length is 5-50μm.

[0022] Optionally, in step S4, the conditions of the siliconizing treatment include: the weight ratio of the silicon powder to the second intermediate body is (1-4): 1, the siliconizing reaction temperature is 1500-1900°C, the siliconizing reaction time is 1-6h, and the siliconizing reaction pressure is 0.5-3kPa.

[0023] The third aspect of the present disclosure provides a carbon-ceramic composite material prepared by the method according to the second aspect of the present disclosure.

[0024] The fourth aspect of the present disclosure provides a brake disc comprising the carbon-ceramic composite material according to the first aspect or the third aspect of the present disclosure.

[0025] The fifth aspect of the present disclosure provides a vehicle comprising the brake disc according to the fourth aspect of the present disclosure.

[0026] By the above technical solution, the present disclosure provides a carbon-ceramic composite material, a preparation method thereof, a brake disc, and a vehicle. The carbon-ceramic composite material has a friction layer on at least part of the surface, has SiC whiskers in the silicon carbide matrix of the friction layer, and at least part of the SiC whiskers extend in the length direction along the thickness direction of the friction layer, i.e., the SiC whiskers are vertically arranged in the friction layer. A continuous heat conduction channel in the thickness direction of the friction layer can be formed in the friction layer, heat conduction is concentrated in the thickness direction, the friction layer has excellent heat conduction coefficient in the thickness direction, and the heat transport capacity of the friction layer to the matrix is improved. In the application of the brake disc, the high temperature generated by braking can be rapidly conducted to the matrix layer through the disc surface (i.e., the friction layer) for heat dissipation, the disc surface temperature is rapidly reduced, heat decay is avoided, and braking safety is improved.

[0027] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF DRAWINGS

[0028] The accompanying drawings are included to provide a further understanding of the present disclosure and constitute a part of the specification, and are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation on the present disclosure. In the drawings: Figure 1 A product structure schematic diagram of the carbon-ceramic composite material provided by the present disclosure before siliconizing (i.e., after deposition of SiC whiskers); Figure 2 A flowchart of the method for preparing the carbon-ceramic composite material provided by the present disclosure.

[0029] Reference signs: 1. SiC whisker; 2. Carbon fiber monofilament; 3. Laminated body (second carbon fiber preform); 4. Grooved matrix. DETAILED DESCRIPTION

[0030] The detailed description of the present disclosure is described below. It should be understood that the detailed description described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

[0031] The first aspect of the present disclosure provides a carbon-ceramic composite material, comprising a carbon-ceramic matrix, at least part of the surface of the carbon-ceramic matrix having a friction layer, the friction layer comprising a silicon carbide matrix and SiC whiskers distributed in the silicon carbide matrix; at least part of the SiC whiskers extend in the length direction along the thickness direction of the friction layer.

[0032] The present disclosure provides a carbon-ceramic composite material, at least part of the surface of the carbon-ceramic composite material having a friction layer, the friction layer having SiC whiskers in the silicon carbide matrix of the friction layer, and at least part of the SiC whiskers extending in the length direction along the thickness direction of the friction layer, i.e. the SiC whiskers are vertically arranged in the friction layer, which can form a continuous heat conduction channel in the thickness direction of the friction layer, and the heat conduction is concentrated in the thickness direction, so that the friction layer has excellent heat conductivity coefficient in the thickness direction, and the heat transport capacity of the friction layer to the matrix is improved; in the application of the carbon-ceramic composite material in the brake disc, the high temperature generated by braking can be quickly conducted to the matrix layer through the disc surface (i.e. the friction layer) to dissipate heat, quickly reduce the disc surface temperature, avoid the occurrence of thermal decay, and improve the braking safety.

[0033] In a preferred embodiment, the growth angle of the SiC whisker is the angle between the length direction of the SiC whisker and the thickness direction of the friction layer; the volume percentage of the SiC whisker with a growth angle of 0-15° is 3-10% by volume, the volume percentage of the SiC whisker with a growth angle of 15-30° is 1-3% by volume, and the volume percentage of the SiC whisker with a growth angle of 30-90° is 1-2% by volume, based on the total volume of the friction layer; preferably, the volume percentage of the SiC whisker with a growth angle of 0-15° is 5-10% by volume, the volume percentage of the SiC whisker with a growth angle of 15-30° is 2-3% by volume, and the volume percentage of the SiC whisker with a growth angle of 30-90° is 1.5-2% by volume. The volume fraction of the SiC whisker affects the heat conduction effect of the friction layer and the carbon ceramic composite material. When the volume fraction of the SiC whisker with different growth angles in the friction layer is within the range of the embodiment, especially within the preferred range, the heat conduction direction of the friction layer is more concentrated, and the heat conduction coefficient in the thickness direction is higher. In the present disclosure, the growth angle of the SiC whisker refers to the SiC whisker that may grow in a direction around the thickness direction, so the growth angle of the SiC whisker in the friction layer in the present disclosure does not mean that all the SiC whiskers grow in the same direction. In the present disclosure, the SiC whisker with a growth angle of 15° is included in the range of 0°-15°, and the SiC whisker with a growth angle of 30° is included in the range of 15°-30°.

[0034] In a specific embodiment, the diameter of a single SiC whisker is 100-600 nm, and the length is 5-50 μm. In the present disclosure, the volume fraction and structural parameters of the SiC whisker in the friction layer are tested by an electron microscope photograph method.

[0035] In a more preferred embodiment, the volume fraction of the SiC whisker in the friction layer is 10% by volume, based on the total volume of the friction layer, wherein the volume percentage of the SiC whisker with a growth angle of 30°-90° is 2% by volume, the diameter is 200-250 nm, and the length is 6-8 μm; the volume percentage of the SiC whisker with a growth angle of 15°-30° is 3% by volume, the diameter is 300-400 nm, and the length is 10-16 μm; and the volume percentage of the SiC whisker with a growth angle of 0°-15° is 5% by volume, the diameter is 300-400 nm, and the length is 20-40 μm. The volume fraction and whisker structure of the SiC whisker with different growth angles in the friction layer provided by the present embodiment can achieve a more optimal heat transfer effect in the friction layer, thereby improving the heat conduction coefficient of the friction layer in the thickness direction.

[0036] In a preferred embodiment, at least part of the SiC whiskers extend to the contact surface between the friction layer and the carbon ceramic matrix, which can further improve the heat conduction effect of the friction layer, so that the heat generated on the surface of the friction layer can be quickly conducted to the carbon ceramic matrix.

[0037] In a specific embodiment, the friction layer further comprises carbon fiber filaments and silicon; the carbon fiber filaments and silicon are dispersed in the silicon carbide matrix. The friction layer provided in the present disclosure can also comprise a small amount of residual carbon fiber filaments and silicon that do not react after the silicon infiltration process.

[0038] In an embodiment, the friction layer is embedded in the carbon ceramic matrix, and the surface of the friction layer is in the same plane as the surface of the carbon ceramic matrix; the thickness of the friction layer is 1-4 mm. The friction layer provided in the present embodiment has a suitable thickness and is embedded in the carbon ceramic matrix, which can maintain good contact with the ceramic matrix and improve the heat conduction effect.

[0039] In an embodiment, the carbon ceramic matrix is formed in a disc shape, the thickness of the carbon ceramic matrix is 25-36 mm; the friction layer is embedded on each of the two circular main surfaces of the carbon ceramic matrix, the friction layer is formed in an annular shape and coaxial with the disc-shaped carbon ceramic matrix, and the ring width of the friction layer is 110-120 mm. In the present embodiment, the friction layer is provided on both main surfaces of the ceramic matrix, which can achieve a better heat conduction effect.

[0040] In an embodiment, the volume fraction of silicon carbide in the friction layer is 74-92 vol%, the volume fraction of SiC whiskers is 5-15 vol%, the volume fraction of carbon is 2-5 vol%, and the volume fraction of silicon is 1-6 vol% based on the total volume of the friction layer; the composite material with the composition of the friction layer provided in the present embodiment has excellent heat conduction performance in the thickness direction; preferably, the volume fraction of silicon carbide in the friction layer is 81-88 vol%, the volume fraction of SiC whiskers is 9-12 vol%, the volume fraction of carbon is 2-4 vol%, and the volume fraction of silicon is 1-3 vol% based on the total volume of the friction layer; further preferably, the volume fraction of silicon carbide in the friction layer is 85 vol%, the volume fraction of SiC whiskers is 10 vol%, the volume fraction of carbon is 3 vol%, and the volume fraction of elemental silicon is 2 vol% based on the total volume of the friction layer; the carbon ceramic composite material with the preferred volume composition of the friction layer provided in the present embodiment can have more excellent heat conduction performance.

[0041] The composition of the carbon ceramic matrix in the present disclosure is a conventional composition in the art, for example, comprising silicon carbide, carbon and silicon.

[0042] In one embodiment, the volume fraction of silicon carbide in the carbon ceramic composite material is 54-76 vol%, the volume fraction of carbon is 22-40 vol%, and the volume fraction of silicon is 2-6 vol%, based on the total volume of the carbon ceramic composite material; the silicon carbide in the carbon ceramic composite material includes silicon carbide formed with carbon in the silicon infiltration process, and also includes SiC whiskers in the friction layer; the carbon ceramic composite material with the volume composition within the range of this embodiment can have excellent thermal conductivity; preferably, the volume fraction of silicon carbide is 60-68 vol%, the volume fraction of carbon is 30-36 vol%, and the volume fraction of silicon is 2-4 vol%, based on the total volume of the carbon ceramic composite material; further preferably, the volume fraction of silicon carbide is 62 vol%, the volume fraction of carbon is 35 vol%, and the volume fraction of elemental silicon is 3 vol%, based on the total volume of the carbon ceramic composite material; the carbon ceramic composite material with the preferred volume composition provided in this embodiment can have more excellent thermal conductivity.

[0043] In the present disclosure, the volume fractions of the components in the carbon ceramic composite material and the friction layer are tested by the electron microscope photograph method.

[0044] In one specific embodiment, the carbon ceramic composite material provided in the present disclosure has a thermal conductivity of 100-150 Wm -1 k -1 in the thickness direction; the thermal conductivity of a conventional carbon ceramic disc in the thickness direction is about 80 Wm -1 k -1 , and the thermal conductivity of the carbon ceramic composite material provided in the present disclosure is significantly higher than that of the conventional carbon ceramic disc.

[0045] The second aspect of the present disclosure provides a method for preparing a carbon ceramic composite material, comprising the following steps: S1, performing first chemical vapor deposition treatment on a carbon fiber preform under carbon deposition conditions to obtain a densified preform; performing slotting treatment on at least part of the surface of the densified preform to obtain a slotted substrate.

[0046] S2, placing a second carbon fiber preform into the slots of the slotted substrate to obtain a first intermediate body, wherein the second carbon fiber preform comprises a laminated carbon fiber unidirectional cloth, and the multiple layers of carbon fiber unidirectional cloth have the same arrangement direction of carbon fiber filaments, and the length direction of the carbon fiber filaments is parallel to the depth direction of the slots.

[0047] S3, performing second chemical vapor deposition treatment on the first intermediate body under SiC deposition conditions to obtain a second intermediate body.

[0048] S4, performing silicon infiltration treatment on the second intermediate body.

[0049] The present disclosure provides a method for preparing a carbon ceramic composite material, which comprises the following steps: a first carbon fiber preform is subjected to chemical vapor deposition to obtain a densified preform; a surface of the densified preform is subjected to slotting treatment; a second carbon fiber preform comprising a plurality of layers of carbon fiber unidirectional cloth is placed in the slot of the densified preform in the length direction of the carbon fiber monofilament; then chemical vapor deposition is performed to grow SiC whiskers in the gap between the carbon fiber monofilaments, and the SiC whiskers can grow in the gap in a direction away from the bottom surface of the slot (i.e. grow upward from the bottom of the slot in the depth direction of the slot), so that the SiC whiskers grow in the thickness direction of the substrate, thereby controlling the growth direction of the SiC whiskers and constructing a continuous heat conduction channel in the thickness direction; and finally, silicon infiltration treatment is performed to form silicon carbide from carbon in the densified preform and the second carbon fiber preform, and the silicon infiltration treatment can also bond the parts together, thereby improving the bonding force of the entire composite material (such as the bonding force between the friction layer and the carbon ceramic substrate).

[0050] In the present disclosure, the first carbon fiber preform can be prepared by a conventional method.

[0051] In one specific embodiment, the first carbon fiber preform used in step S1 can be prepared by a method comprising the following steps: The carbon fiber unidirectional cloth is alternately layered with the net tire, a green body is obtained by using a step pin, and the preform is obtained by cutting with a mold knife. The grade of the carbon fiber in the carbon fiber unidirectional cloth is one or more of T300, T700 and T800, and the specification is preferably 3-12K. The preferred grade is T700, and the specification is 6K. When the carbon fiber unidirectional cloth and the net tire are alternately layered, they can be layered according to the angles of 0° / 45° / 90° / 135°. The first carbon fiber preform prepared by this embodiment has more excellent performance after the carbon-based composite material is prepared.

[0052] In one specific embodiment, in step S1, the densified preform is formed into a disc shape; the surface slotting treatment comprises slotting the upper surface and the lower surface of the densified preform, and the shape of the slot is a circular ring; the width of the slot is 110-120mm, preferably 112-118mm, and further preferably 115mm; the depth of the slot is 1-4mm, preferably 2-3mm, and further preferably 2.5mm. The slot shape provided by this embodiment matches the shape of the densified preform, and can form a friction layer with excellent heat conduction performance in the subsequent process.

[0053] In one embodiment, in step S1, the carbon deposition conditions include: in a carbon carbon deposition furnace, the deposition temperature is 900-1300℃, the deposition pressure is 0.5-5kPa, the deposition time is 250-500h, and the process gas is selected from one or more of methane, propane and propylene, and the flow rate of the process gas is 10-50L / min; preferably, the deposition temperature is 1000-1200℃, the deposition pressure is 1.2-4.2kPa, the deposition time is 280-460h, and the flow rate of the process gas is 25-40L / min; further preferably, the deposition temperature is 1100℃, the deposition pressure is 3kPa, the deposition time is 400h, the process gas is methane, and the flow rate is 35L / min. Carbon deposition densification of the first carbon fiber preform is carried out according to the preferred carbon deposition conditions in this embodiment, which can obtain better densification effect and is beneficial to obtaining carbon ceramic composite material with better heat conduction effect in the subsequent step.

[0054] In one embodiment, the density of the first carbon fiber preform is 0.3-1.0g / cm 3 , preferably 0.4-0.9g / cm 3 ; and the density of the densified preform obtained in step S1 is 1.25-1.45g / cm 3 , preferably 1.3-1.4g / cm 3 . The preform with the density in this embodiment can be used to prepare carbon ceramic composite material with better effect.

[0055] In one embodiment, the second carbon fiber preform used in step S2 can be prepared by a method comprising the following steps: stacking multiple layers of carbon fiber unidirectional cloth, and then performing resin impregnation and curing treatment to obtain a stack of carbon fiber unidirectional cloth, i.e. the second carbon fiber preform; wherein the carbon fiber filaments in the multiple layers of carbon fiber unidirectional cloth are parallel to each other along the length direction of the carbon fiber filaments.

[0056] In one embodiment, the number of stacked layers of the carbon fiber unidirectional cloth in the second carbon fiber preform is 350-900 layers, preferably 400-800 layers, and further preferably 500 layers. Stacking multiple layers of carbon fiber unidirectional cloth according to the preferred stacking mode in this embodiment can have a suitable filament spacing.

[0057] In one embodiment, the resin impregnation and curing treatment comprises: impregnating the stacked multiple layers of carbon fiber unidirectional cloth in a first resin; and pressurizing and curing the impregnated multiple layers of carbon fiber unidirectional cloth; and the number of stacked layers of the carbon fiber unidirectional cloth is 350-900 layers.

[0058] The first resin is selected from one or more of phenol resin, epoxy resin and furan resin; the impregnation time is 60-300 min; the pressure curing conditions include a pressure of 10-30 kg, a curing temperature of 150-230°C and a curing time of 2-4 h; preferably, the impregnation time is 200-240 min, the pressure is 15-25 kg, the curing temperature is 200-230°C and the curing time is 2.5-3 h.

[0059] The distance between the adjacent two layers of the unidirectional carbon fiber cloth in the obtained stack is 1-10 μm, preferably 2-6 μm, and further preferably 4 μm; and the density of the obtained stack is 1.0-1.7 g / cm 3 , preferably 1.2-1.6 g / cm 3 , and further preferably 1.4 g / cm 3 . The stack obtained by the preferred resin impregnation and curing treatment conditions in this embodiment has the effects of high bonding strength and low deformation.

[0060] In one specific embodiment, step S2 further comprises: cutting the second carbon fiber prepreg into a shape matching the slot shape; coating the bottom of the slot with a second resin, and vertically placing the cut second carbon fiber prepreg in the slot; and then curing at 150-250°C for 2-4 h; preferably, curing at 160-230°C for 2.5-3 h; the second resin is selected from one or more of phenol resin, furan resin and epoxy resin; and the length of the fibers in the second carbon fiber prepreg is 1-4 mm. The second carbon fiber prepreg is cut into a shape corresponding to the circular ring slot on the substrate, and the length of the carbon fiber filaments in the cut second carbon fiber prepreg is the same as the depth of the slot, so that when the second carbon fiber prepreg is placed vertically in the slot, the bottom of the carbon fiber filaments in the second carbon fiber prepreg contacts the bottom of the slot, and the upper surface of the stack is in the same plane as the top of the slot.

[0061] In one specific embodiment, the structure of the product obtained after the SiC whisker deposition process is as shown in Figure 1 , wherein in the slot on the surface of the slot substrate 4, the stack 3 (second carbon fiber prepreg) including the unidirectional cloth of fibers placed vertically along the length direction of the carbon fiber filaments, and in the slot, in the gap between the carbon fiber filaments 2 of the stack, there are SiC whiskers extending along the depth direction of the slot in the length direction; and the SiC whiskers grow upward from the bottom surface of the slot.

[0062] In one embodiment, in step S3, the SiC deposition conditions include: In the vapor deposition furnace, the deposition gas source and the dilution gas are continuously supplied, the deposition temperature is 800-1300°C, the deposition time is 2-8h, the pressure in the furnace is 300-1000Pa, the flow ratio of the deposition gas source to the dilution gas is 1:(1.1-2), and the flow rate of the deposition gas source is 250-950mL / min; preferably, in the vapor deposition furnace, the deposition gas source and the dilution gas are continuously supplied, the deposition temperature is 900-1100°C, the deposition time is 4-7h, the pressure in the furnace is 500-900Pa, the flow ratio of the deposition gas source to the dilution gas is 1:(1.1-1.8), and the flow rate of the deposition gas source is 300-900mL / min; further preferably, the deposition temperature is 1000°C, the deposition time is 6h, the pressure in the furnace is 800Pa, the flow ratio of the deposition gas source to the dilution gas is 1:1.3, and the flow rate of the deposition gas source is 600mL / min. According to the preferred SiC deposition conditions in this embodiment, SiC whiskers with more optimal arrangement in the thickness direction can be obtained, and the concentrated heat conduction performance in the thickness direction is improved.

[0063] In a preferred embodiment, in the second intermediate obtained in step S3, the SiC whiskers grow from the slotted bottom in a direction away from the slotted bottom; the volume fraction of the SiC whiskers is 5-15% by volume based on the total volume of the deposited substance in the slot; wherein the angle between the length direction of the SiC whiskers and the depth direction of the slot is taken as the growth angle of the SiC whiskers, and the volume fraction of the SiC whiskers with a growth angle of 0°-15° is 3-10% by volume, preferably 5-10% by volume; the volume fraction of the SiC whiskers with a growth angle of 15°-30° is 1-3% by volume, preferably 2-3% by volume; the volume fraction of the SiC whiskers with a growth angle of 30°-90° is 1-2% by volume, preferably 1.5-2% by volume. When the volume fraction of the SiC whiskers in each growth angle range is within the range of this embodiment, especially within the preferred range, the friction layer obtained by the present disclosure is more concentrated in the heat conduction direction, and has a higher thermal conductivity in the thickness direction. The SiC whiskers with a growth angle of 15° are included in the range of 0°-15°, and the SiC whiskers with a growth angle of 30° are included in the range of 15°-30°. In the present disclosure, the growth angle and volume fraction of the SiC whiskers in the friction layer of the carbon-ceramic composite product prepared are substantially the same as the data of the growth angle and volume fraction of the SiC whiskers in the deposited substance obtained in the slot during the SiC vapor deposition process in the preparation process, and the growth angle and volume fraction of the SiC whiskers in the second intermediate in step S3 are taken as the growth angle and volume fraction of the SiC whiskers in the final product.

[0064] In one specific embodiment, the diameter of the single SiC whisker is 100-600 nm, and the length is 5-50 μm.

[0065] In a more preferred embodiment, the volume fraction of the SiC whisker is 10% by volume, the volume fraction of the SiC whisker with a growth angle of 30-90° is 2% by volume, the diameter is 200-250 nm, and the length is 6-8 μm; the volume fraction of the SiC whisker with a growth angle of 15-30° is 3% by volume, the diameter is 300-400 nm, and the length is 10-16 μm; and the volume fraction of the SiC whisker with a growth angle of 0-15° is 5% by volume, the diameter is 300-400 nm, and the length is 20-40 μm. The volume fraction and structural performance of the SiC whisker with different growth angles provided by the embodiment can achieve a more optimal heat transfer effect, and improve the thermal conductivity of the carbon ceramic composite material in the thickness direction. The growth angle, volume fraction, length, and diameter of the SiC whisker are obtained according to the electron microscope photograph.

[0066] In one embodiment, step S4 comprises: In the second intermediate body, silicon powder is arranged on the upper surface and the lower surface, and is placed in a silicon infiltration furnace for silicon infiltration treatment. The present disclosure forms silicon carbide by melting and infiltrating silicon in the densification preform and the carbon in the second carbon fiber preform, to obtain a carbon ceramic composite material. After the silicon infiltration, each part (for example, between the preform and the second carbon fiber preform, and between the carbon fiber filaments and the SiC whiskers in the second carbon fiber preform, etc.) is combined to form an integral structure, thereby improving the bonding force between the matrix and the friction layer in the composite material.

[0067] In one embodiment, in step S4, the purity of the silicon powder is 99.0% or higher, the particle size of the silicon powder is 50-300 mesh, the weight ratio of the silicon powder to the second intermediate body is (1-4):1, preferably (2-3):1, the silicon infiltration reaction temperature is 1500-1900°C, preferably 1550-1700°C, and more preferably 1600°C, the silicon infiltration reaction time is 1-6 h, preferably 2-5 h, and more preferably 4 h, and the silicon infiltration reaction pressure is 0.5-3 kPa, preferably 0.8-1.5 kPa, and more preferably 1 kPa. According to the preferred conditions in the embodiment, a carbon ceramic composite material with better performance can be obtained.

[0068] In one specific embodiment, as shown in Figure 2 The method for preparing the carbon ceramic composite material comprises the following steps: (1) Carbon fiber unidirectional cloth is alternately laid in the directions of 0° / 45° / 90° / 135° with a web tire, a green body is obtained by using a step pin, and a first carbon fiber preform is obtained by cutting with a mold knife.

[0069] (2) The preform is placed in a carbon-carbon deposition furnace for chemical vapor deposition (first chemical vapor deposition treatment), and process gas is introduced to densify the substrate to obtain a carbon-carbon disk.

[0070] (3) After machining the brake disc according to the dimensions of the drawing in step (2), the disc surface is then grooved (the groove is circular) to obtain the base disc.

[0071] (4) After the carbon fiber unidirectional cloth is laid in the same direction, it is then immersed in resin, taken out and cured under pressure.

[0072] (5) The cured carbon fiber unidirectional fabric laminate obtained in step (4) is cut along the fiber axis using a cutting machine. Then the cut laminate (i.e. the second carbon fiber preform) is placed vertically along the fiber axis and cut into corresponding annular sheets according to the size of the matrix disk. Then resin is applied to the bottom of the matrix disk groove and the annular sheets are embedded into the matrix disk groove for curing.

[0073] (6) Then it is placed in a vapor deposition furnace. During the heating process, the glue is removed first, and then the deposition gas source and dilution gas are continuously introduced to carry out the second chemical vapor deposition treatment to obtain a friction layer blank disk containing SiC whiskers.

[0074] (7) Then place the friction layer blank in a graphite crucible, spread silicon powder on the top and bottom of the blank, and put it into a silicon infiltration furnace for silicon infiltration treatment to finally obtain a carbon ceramic plate.

[0075] This disclosure provides a third aspect of a carbon-ceramic composite material as described in the second aspect of this disclosure.

[0076] This disclosure provides a fourth aspect of a brake disc, comprising the carbon-ceramic composite material described in the first or third aspect of this disclosure.

[0077] The fifth aspect of this disclosure provides a vehicle that includes the brake disc described in the fourth aspect of this disclosure.

[0078] The present disclosure is further described in detail below through examples. All raw materials used in the examples are commercially available.

[0079] Example 1 (1) T700-6K carbon fiber unidirectional fabric is alternately laid with the mesh in the directions of 0° / 45° / 90° / 135° (based on the mesh), and then a preform is obtained by step-by-step needle punching. The preform (first carbon fiber preform) is then cut with a die cutter. The overall density of the preform is 0.4 g / cm³. 3 .

[0080] (2) The preform was placed in a carbon-carbon deposition furnace for chemical vapor deposition (first chemical vapor deposition treatment). Methane gas was introduced at a flow rate of 35 L / min, the deposition temperature was 1100℃, the deposition pressure was 3 kPa, and the deposition time was 400 h to densify the substrate. After 400 h of deposition, a carbon-carbon disk (densified preform) was obtained. The overall density of the carbon-carbon disk was 1.4 g / cm³. 3 The thickness is 32mm.

[0081] (3) The deposited densified body is machined. According to the hole size requirements of the brake disc, bolt holes and positioning holes are machined on the surface, and cooling channels are milled on the outer ring. Then, the disc surface is grooved (grooving is done on both surfaces). The groove width is 115mm and the groove depth is 2.5mm to obtain the base disc.

[0082] (4) After laying 500 layers of T700-6K carbon fiber unidirectional fabric in the same direction, immerse it in phenolic resin for 60 minutes, remove it, apply 20 kg of pressure, and cure it at 200℃ for 3 hours; the density of the laminate is 1.4 g / cm³. 3 A second carbon fiber preform was obtained by spacing the carbon fiber preform with a spacing of 4μm.

[0083] (5) The cured carbon fiber unidirectional fabric laminate obtained in step (4) is cut along the fiber axis using a cutting machine. The cutting length is 3mm. Then the cut laminate is laid flat, that is, placed vertically along the fiber axis. Then it is cut into corresponding circular sheet according to the size of the matrix disk. Then resin is applied to the bottom of the matrix disk groove. The circular sheet is embedded in the matrix disk groove and cured at 200℃ for 3h (first intermediate).

[0084] (6) The disk is placed in a chemical vapor deposition furnace. During the heating process, the adhesive is removed first, and then trichloromethylsilane and hydrogen are continuously introduced for the second chemical vapor deposition treatment. The flow rate of trichloromethylsilane is 600 mL / min, and the flow rate ratio of trichloromethylsilane to hydrogen is 1:1.3. The furnace pressure is controlled at 800 Pa. Chemical vapor deposition is carried out at 1000℃ for 6 h to obtain a friction layer blank disk containing SiC whiskers (second intermediate). Based on the total volume of the material deposited in the trench, the volume of silicon carbide whiskers in the trench is determined. The fraction is 10% by volume, based on the total volume of material deposited in the trench. The volume percentage of SiC whiskers with growth angles of 30-90° is 2% by volume, with a diameter of 200-250nm and a length of 6-8μm; the volume percentage of SiC whiskers with growth angles of 15°-30° is 3% by volume, with a diameter of 300-400nm and a length of 10-16μm; and the volume percentage of SiC whiskers with growth angles of 0°-15° is 5% by volume, with a diameter of 300-400nm and a length of 20-40μm.

[0085] (7) Place the friction layer blank in a graphite crucible, select 150 mesh silicon powder, the weight ratio of silicon powder to blank is 3:1, spread the silicon powder evenly on the top and bottom of the blank, put it into a silicon infiltration furnace for silicon infiltration treatment, the reaction temperature is 1600℃, the reaction time is 4h, the reaction pressure is 1kPa, and carbon ceramic composite material is prepared.

[0086] Electron microscopy revealed the following composition and volume fraction of the friction layer: based on the total volume of the friction layer, silicon carbide accounted for 85% by volume, SiC whiskers for 10% by volume, carbon for 3% by volume, and silicon for 2% by volume. The carbon ceramic disk composition and content were as follows: based on the total volume of the carbon ceramic disk, silicon carbide accounted for 62% by volume, carbon for 35% by volume, and silicon for 3% by volume. Furthermore, the growth angle and volume percentage of SiC whiskers in the friction layer of the carbon-ceramic composite material product prepared in this disclosure are approximately the same as those of SiC whiskers obtained in the trench during the SiC vapor deposition process. Specifically, in the friction layer of the carbon-ceramic composite material obtained in this embodiment, based on the total volume of the friction layer, the volume percentage of SiC whiskers with a growth angle of 0°-15° was 5% by volume, the volume percentage of SiC whiskers with a growth angle of 15°-30° was 3% by volume, and the volume percentage of SiC whiskers with a growth angle of 30°-90° was 2% by volume. In the carbon-ceramic composite material obtained in this embodiment, the thickness of the friction layer is 2.5 mm, and the ring width of the friction layer is 115 mm.

[0087] Example 2 This embodiment refers to the preparation method in Example 1, but differs from Example 1 in that: In step (4), 900 layers of T700-6K carbon fiber unidirectional cloth are laid in the same direction; in the friction layer blank disk (second intermediate) containing SiC whiskers obtained in step (6), based on the total volume of the friction layer (or based on the total volume of the material deposited in the groove), the volume fraction of silicon carbide whiskers in the friction layer (or the deposit in the groove) is 5% by volume. The volume fraction and whisker size of SiC whiskers in different growth angle ranges are listed in Table 1-1 and Table 1-2.

[0088] In step (7), the friction layer blank is placed in a graphite crucible, and 150-mesh silicon powder is selected. The weight ratio of silicon powder to blank is 5:1. The rest of the process is the same as in Example 1.

[0089] Example 3 This embodiment refers to the preparation method in Example 1, but differs from Example 1 in that: In step (4), 350 layers of T700-6K carbon fiber unidirectional cloth are laid in the same direction; in the friction layer blank disk (second intermediate) containing SiC whiskers obtained in step (6), based on the total volume of the friction layer (or based on the total volume of the material deposited in the groove), the volume fraction of silicon carbide whiskers in the friction layer (or the deposit in the groove) is 13% by volume. The volume fraction and whisker size of SiC whiskers in different growth angle ranges are listed in Table 1-1 and Table 1-2.

[0090] In step (7), the friction layer blank is placed in a graphite crucible, and 150-mesh silicon powder is selected. The weight ratio of silicon powder to blank is 2.5:1. The rest of the process is the same as in Example 1.

[0091] Example 4 This embodiment refers to the preparation method in Example 1, but differs from Example 1 in that: In step (7), the friction layer blank is placed in a graphite crucible, and 150-mesh silicon powder is selected. The weight ratio of silicon powder to blank is 1:1. The rest of the process is the same as in Example 1.

[0092] Example 5 (1) T700-6K carbon fiber unidirectional fabric is alternately laid with the mesh in the directions of 0° / 45° / 90° / 135° (based on the mesh), and then a blank is obtained by step-by-step needle punching. The preform is then cut with a die cutter. The overall density of the preform is 0.4 g / cm³. 3 .

[0093] (2) The preform was placed in a carbon-carbon deposition furnace for chemical vapor deposition. Methane gas was introduced at a flow rate of 50 L / min, the deposition temperature was 1300℃, the deposition pressure was 5 kPa, and the deposition time was 400 h to densify the substrate. After 400 h of deposition, a carbon-carbon disk was obtained with an overall density of 1.25 g / cm³. 3 .

[0094] (3) The deposited densified body is machined. According to the hole size requirements of the brake disc, bolt holes and positioning holes are machined on the surface, and cooling channels are milled on the outer ring. Then, grooves are made on the disc surface with a groove width of 115mm and a groove depth of 2.5mm to obtain the base disc.

[0095] (4) After laying 500 layers of T700-6K carbon fiber unidirectional fabric in the same direction, immerse it in phenolic resin for 180 min, remove it, apply 10 kg of pressure, and cure it at 150℃ for 2 h; the density of the laminate is 1.1 g / cm³. 3 The spacing is 9μm.

[0096] (5) Cut the cured carbon fiber unidirectional fabric laminate obtained in step (4) along the fiber axis using a cutting machine. The cutting length is 3mm. Then lay the cut laminate flat, that is, place it vertically along the fiber axis. Cut it into corresponding circular sheet according to the size of the matrix disk. Then apply resin to the bottom of the matrix disk groove and embed the circular sheet into the matrix disk groove and cure it at 200℃ for 3h.

[0097] (6) Place the disk in a chemical vapor deposition furnace. During the heating process, first remove the adhesive, then continuously introduce trichloromethylsilane and hydrogen. The flow rate of trichloromethylsilane is 250 mL / min, and the flow rate ratio of trichloromethylsilane to hydrogen is 1:2. Control the gas pressure in the furnace to 400 Pa. Perform chemical vapor deposition at 800℃ for 2 hours to obtain a friction layer blank disk containing SiC whiskers. Based on the total volume of the friction layer (or based on the total volume of the material deposited in the groove), the silicon carbide whiskers occupy the friction layer (or the groove) of the friction layer (or the groove). The volume fraction of SiC whiskers (with growth angles of 30-90°) is 8%, of which 2% are SiC whiskers with a diameter of 200-250 nm and a length of 6-8 μm, 2% are SiC whiskers with a growth angle of 15-30° with a diameter of 300-400 nm and a length of 10-16 μm, and 4% are SiC whiskers with a growth angle of 0-15° with a diameter of 300-400 nm and a length of 20-40 μm.

[0098] (7) Place the friction layer blank in a graphite crucible, select 150 mesh silicon powder, the weight ratio of silicon powder to blank is 3:1, spread the silicon powder evenly on the top and bottom of the blank, and put it into a silicon diffusion furnace for silicon diffusion treatment. The reaction temperature is 1900℃, the reaction time is 6h, and the reaction pressure is 2kPa.

[0099] Example 6 This embodiment prepares carbon-ceramic composite materials according to the process conditions in Example 1, but differs from Example 1 in that the preparation is carried out according to the following process conditions: (1) T700-6K carbon fiber unidirectional fabric is alternately laid with the mesh in the directions of 0° / 45° / 90° / 135° (based on the mesh), and then a blank is obtained by step-by-step needle punching. The preform is then cut with a die cutter. The overall density of the preform is 0.4 g / cm³. 3 .

[0100] (2) The preform was placed in a carbon-carbon deposition furnace for chemical vapor deposition. Methane gas was introduced at a flow rate of 9 L / min, the deposition temperature was 1000℃, the deposition pressure was 6 kPa, and the deposition time was 400 h to densify the substrate. After 400 h of deposition, a carbon-carbon disk was obtained with an overall density of 1.2 g / cm³. 3 .

[0101] (3) The deposited densified body is machined. According to the hole size requirements of the brake disc, bolt holes and positioning holes are machined on the surface, and cooling channels are milled on the outer ring. Then, grooves are made on the disc surface with a groove width of 115mm and a groove depth of 2.5mm to obtain the base disc.

[0102] (4) After laying 500 layers of T700-6K carbon fiber unidirectional fabric in the same direction, immerse it in phenolic resin for 120 min, remove it, apply 5 kg of pressure, and cure it at 120℃ for 2 h; the density of the laminate is 1.0 g / cm³. 3 The spacing is 12μm.

[0103] (5) Cut the cured carbon fiber unidirectional fabric laminate obtained in step (4) along the fiber axis using a cutting machine. The cutting length is 3mm. Then lay the cut laminate flat, that is, place it vertically along the fiber axis. Cut it into corresponding circular sheet according to the size of the matrix disk. Then apply resin to the bottom of the matrix disk groove and embed the circular sheet into the matrix disk groove and cure it at 200℃ for 3h.

[0104] (6) Place the disk in a chemical vapor deposition furnace. During the heating process, first remove the adhesive, then continuously introduce trichloromethylsilane and hydrogen. The flow rate of trichloromethylsilane is 200 mL / min, and the flow ratio of trichloromethylsilane to hydrogen is 1:2. Control the gas pressure in the furnace to 400 Pa. Perform chemical vapor deposition at 800℃ for 2 hours to obtain a friction layer blank disk containing SiC whiskers. Based on the total volume of the friction layer (or based on the total volume of the material deposited in the groove), the silicon carbide whiskers occupy the friction layer (or the groove) of the friction layer (or the groove). The volume fraction of SiC whiskers (in the middle sediment) is 6% by volume, of which the volume fraction of SiC whiskers with growth angles of 30-90° is 1% by volume, with a diameter of 200-250nm and a length of 6-8μm; the volume fraction of SiC whiskers with growth angles of 15-30° is 3% by volume, with a diameter of 300-400nm and a length of 10-16μm; and the volume fraction of SiC whiskers with growth angles of 0-15° is 2% by volume, with a diameter of 300-400nm and a length of 20-40μm.

[0105] (7) Place the friction layer blank in a graphite crucible, select 150 mesh silicon powder, the weight ratio of silicon powder to blank is 3:1, spread the silicon powder evenly on the top and bottom of the blank, and put it into a silicon diffusion furnace for silicon diffusion treatment. The reaction temperature is 1600℃, the reaction time is 4h, and the reaction pressure is 1kPa.

[0106] Comparative Example 1 This comparative example prepares a carbon-ceramic composite material according to the process conditions in Example 1. The difference from Example 1 is that no carbon fiber cloth laminate is set, and no SiC whisker deposition is performed. Only the densified preform obtained in step (2) is subjected to silicon infiltration treatment in step (7): 150 mesh silicon powder is selected, the weight ratio of silicon powder to preform disk is 3:1, and the silicon infiltration process conditions are the same as in Example 1. Compared with Example 1, the carbon-ceramic material obtained in this comparative example does not include a friction layer or SiC whiskers, and is only a conventional carbon-ceramic composite material.

[0107] Comparative Example 2 This comparative example prepares carbon-ceramic composite material according to the process conditions in Example 1. The difference from Example 1 is that: after setting the carbon fiber unidirectional fabric laminate in the groove in step (5), SiC whisker deposition in step (6) is not performed. Only the first intermediate obtained in step (5) is subjected to silicon infiltration treatment in step (7). The conditions for silicon infiltration treatment are the same as in Example 1. The product after silicon infiltration includes a carbon-ceramic matrix and a friction layer in the groove. However, the friction layer is only obtained by silicon infiltration of carbon fiber monofilaments and does not include SiC whiskers.

[0108] Comparative Example 3 This comparative example prepares carbon-ceramic composite material according to the process conditions in Example 1. The difference from Example 1 is that steps (4)-(5) are not performed. That is, the matrix disk obtained in step (3) does not have a carbon fiber unidirectional fabric laminate in the groove. SiC whisker deposition in step (6) is performed only in the groove to introduce SiC whiskers into the groove. The silicon infiltration treatment in step (7) is the same as in Example 1. The resulting carbon-ceramic material does not include the friction layer and includes SiC whiskers in the groove.

[0109] The number of unidirectional carbon fiber layers, the volume fraction of SiC whiskers in the deposits obtained after SiC vapor deposition, and the proportion of silicon powder in the silicon infiltration treatment in the above examples and comparative examples are listed in Table 1-1 below.

[0110] Table 1-1

[0111] In Table 1-1, the volume fraction of SiC whiskers is based on the total volume of the material deposited in the trench. A represents the volume percentage of SiC whiskers with a growth angle of 30-90°, B represents the volume percentage of SiC whiskers with a growth angle of 15-30°, and C represents the volume percentage of SiC whiskers with a growth angle of 0-15°.

[0112] The sizes of SiC whiskers with different growth angles in the deposits obtained from the above embodiments are listed in Table 1-2 below.

[0113] Table 1-2

[0114] The volume composition of the composite materials and the volume composition of the friction layer obtained in the above embodiments and comparative examples are listed in Table 2 below.

[0115] Table 2

[0116] In this disclosure, the growth angles and volume percentages of SiC whiskers with growth angles of 0°-15°, 15°-30°, and 30°-90° in the friction layer of the prepared carbon-ceramic composite material are roughly the same as the data on the growth angles and volume percentages of SiC whiskers in the deposits obtained in the trench during the SiC vapor deposition process listed in Tables 1-1 and 1-2 above, so they will not be repeated here.

[0117] Test Example 1 This test example illustrates the bonding force between the friction layer and the matrix in a composite material.

[0118] Based on the AK-Master bench performance testing standard, the brake disc was heated to 700°C by friction, then rapidly cooled to room temperature by compressed air. This performance test was repeated until the friction layer on the surface of the carbon-ceramic brake disc showed signs of peeling, at which point the test was stopped. The number of cycles that could be repeated under the high-temperature rapid cooling condition was used to evaluate the bonding strength between the Si / SiC composite ceramic layer and the carbon-ceramic substrate on the surface of the carbon-ceramic brake disc. The test results are listed in Table 3 below.

[0119] Table 3

[0120] Based on the above embodiments and comparative examples, and in conjunction with the data in Tables 1-1-1-2 and 2-3, it can be seen that: Comparing Examples 1-6 with Comparative Example 2, Comparative Example 2 lacked SiC whiskers; the friction layer and matrix were bonded together solely by resin carbon in the carbon fiber unidirectional fabric laminate through molten silicon infiltration. The bonding force between the friction layer and matrix was weak, resulting in only 75 test cycles. In contrast, the carbon-ceramic disks prepared according to the method provided in Examples 1-6 contained SiC whiskers in the friction layer, leading to a higher number of test cycles for the carbon-ceramic disks in Examples 1-6. This indicates that the bonding force between the friction layer and matrix in the carbon-ceramic disks obtained in Examples 1-6 was significantly better than that in Comparative Example 2. The carbon-ceramic composite materials in Comparative Examples 1 and 3 did not include a friction layer, therefore the bonding force between the friction layer and matrix could not be tested.

[0121] Comparing Examples 1 and 2-3, in Example 1, a carbon-ceramic composite material was prepared according to the preferred number of fiber cloth layers, the preferred volume fraction of silicon carbide whiskers in the friction layer, and the preferred proportion of silicon powder. Based on the data in Table 1-1, it can be seen that the volume fractions of SiC whiskers at 0-15°, 15-30°, and 30-90° in the carbon-ceramic composite material prepared in Example 1 are within the optimized range provided in this application. In contrast, the volume fractions of SiC whiskers in the carbon-ceramic composite materials prepared in Examples 2-3 are not within the optimized range for different growth angles. Compared to the carbon-ceramic discs prepared in Examples 2-4, the carbon-ceramic disc in Example 1 has a higher number of test cycles, indicating that the friction layer of the carbon-ceramic disc in Example 1 has a higher bonding force with the matrix.

[0122] Comparing Example 5 with Example 6, Example 5 was prepared according to the optimized process conditions provided in this disclosure. The volume fractions of SiC whiskers at 0-15°, 15-30°, and 30-90° in the carbon-ceramic composite material obtained in Example 5 are within the optimized content range provided in this application. However, the volume fractions of SiC whiskers at different growth angles in the carbon-ceramic composite material obtained in Example 6 are not within the optimized range. The carbon-ceramic composite material obtained in Example 5 has a higher number of test cycles, that is, the bonding force between the friction layer of the carbon-ceramic disk and the matrix is ​​higher. Further comparing Example 1 with Example 5, Example 1 was prepared according to more preferred process conditions. The volume fractions of SiC whiskers at 0-15°, 15-30°, and 30-90° in the carbon-ceramic composite material obtained in Example 1 are within the further preferred content range provided in this application. The carbon-ceramic composite material obtained in Example 1 has a higher number of test cycles, that is, the bonding force between the friction layer of the carbon-ceramic disk and the matrix is ​​higher.

[0123] Test Example 2 This test example illustrates the antioxidant properties of composite materials in air.

[0124] A static air oxidation test was conducted on the carbon ceramic disc (placed in air at 700℃ for 12 hours). The weight change of the material before and after the test was measured, and the weight loss rate of the carbon ceramic disc was tested. The test results are listed in Table 4 below.

[0125] Table 4

[0126] The data in Table 4 above shows that: The carbon-ceramic composite materials obtained in Comparative Examples 1 and 3, due to the lack of a friction layer for protection, allow oxygen from the air to enter the interior of the carbon-ceramic disk matrix, leading to the oxidation of carbon fibers or matrix carbon and resulting in a high weight loss rate.

[0127] Comparing Examples 1-3 with Example 4, Example 4 had a high weight loss rate because the silicon infiltration reaction was insufficient and some carbon fibers in the friction layer did not react completely, resulting in oxidation in air at 700°C. In Examples 1-3, the amount of silicon powder added was greater, the silicon infiltration was sufficient, the composite material was not easily oxidized, and the weight loss rate was lower.

[0128] Comparing Example 5 with Example 6, Example 5 was prepared according to the optimized process conditions provided in this disclosure, and the carbon-ceramic composite material obtained in Example 5 had a lower weight loss rate and better oxidation resistance. Comparing Example 1 with Example 5, Example 1 was prepared according to more preferred process conditions, and the carbon-ceramic composite material obtained in Example 1 had a lower weight loss rate and better oxidation resistance.

[0129] Test Example 3 This test example illustrates the thermal conductivity of composite materials.

[0130] The thermal conductivity of the carbon ceramic brake disc in the thickness direction was tested using a thermal constant measuring instrument according to standard GJB1201.1 at a temperature of 800℃. The test results are listed in Table 5 below.

[0131] Table 5

[0132] Based on the data in Table 5 above, and combined with the data in Tables 1-1-1-2 and 2, it can be seen that: Comparing Examples 1-6 with Comparative Examples 1 and 3, the carbon-ceramic composite materials obtained in Comparative Examples 1 and 3 do not have a friction layer or whiskers, and their thermal conductivity is low and their thermal conductivity is poor. The carbon-ceramic composite materials in Examples 1-6 introduce a friction layer, and the thermal conductivity of the carbon-ceramic composite materials in Examples 1-6 is significantly better than that of the carbon-ceramic disks in Comparative Examples 1 and 3. Furthermore, SiC whiskers are also introduced into the friction layer of the carbon-ceramic composite materials in Examples 1-6. The SiC whiskers can form vertical heat conduction pathways, and the thermal conductivity of the carbon-ceramic composite materials in Examples 1-6 is also significantly higher than that of traditional carbon-ceramic disks.

[0133] Comparing Examples 1 and 4 with Examples 2-3, the volume fractions of SiC whiskers at 0-15°, 15-30°, and 30-90° in the carbon-ceramic composites obtained in Examples 1 and 4 are within the optimized content range provided in this application. However, the volume fractions of SiC whiskers in the carbon-ceramic composites prepared in Examples 2-3 are not within the optimized range for different growth angles. Compared with the carbon-ceramic composites prepared in Examples 2-3, the carbon-ceramic composites in Examples 1 and 4 have higher thermal conductivity and better thermal conductivity.

[0134] Comparing Example 5 with Example 6, Example 5 prepared a carbon-ceramic composite material according to the optimized process conditions provided in this disclosure. The volume fractions of SiC whiskers at 0-15°, 15-30°, and 30-90° in the carbon-ceramic composite material obtained in Example 5 were within the optimized content range provided in this application, while the volume fractions of SiC whiskers at different growth angles in the carbon-ceramic composite material obtained in Example 6 were not within the optimized range. The carbon-ceramic composite material obtained in Example 5 had a higher thermal conductivity and better thermal conductivity. Further comparing Example 1 with Example 5, Example 1 prepared a carbon-ceramic composite material according to more preferred process conditions. The volume fractions of SiC whiskers at 0-15°, 15-30°, and 30-90° in the carbon-ceramic composite material obtained in Example 1 were within the further preferred content range provided in this application. The carbon-ceramic composite material obtained in Example 1 had better thermal conductivity.

[0135] The preferred embodiments of this disclosure have been described in detail above. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0136] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0137] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A brake disc, characterized in that Comprising: a carbon ceramic base body having two oppositely arranged main surfaces; at least part of the main surfaces of the carbon ceramic base body is provided with a circular annular groove; the width of the circular annular groove is 110-120mm; a friction layer embedded in the circular annular groove of the carbon ceramic base body, the friction layer is annular, and the ring width of the friction layer matches the width of the circular annular groove.

2. The brake disc of claim 1, wherein the ring width of the friction layer is 110-120mm.

3. The brake disc of claim 1, wherein, The width of the circular annular groove is 112-118mm, and the ring width of the friction layer is 112-118mm.

4. The brake disc of claim 1, wherein the depth of the circular annular groove is 1-4mm; or, the depth of the circular annular groove is 2-3mm.

5. The brake disc of claim 1, wherein, The surface of the friction layer is in the same plane as the main surface of the part of the carbon ceramic base body not provided with the circular annular groove.

6. The brake disc of claim 5, wherein, The carbon ceramic base body is disc-shaped, and the friction layer is coaxial with the carbon ceramic base body.

7. The brake disc of claim 1, wherein, The friction layer is a circular annular sheet.

8. The brake disc of claim 1, wherein, The two main surfaces of the carbon ceramic base body are respectively embedded with the friction layer.

9. The brake disc of claim 1, wherein, The brake disc further comprises a connecting layer, and the friction layer and the carbon ceramic base body are connected through the connecting layer; wherein the material of the connecting layer contains resin carbon.

10. The brake disc of claim 1, wherein, The friction layer comprises a silicon carbide matrix, carbon fiber filaments and silicon; Based on the total volume of the friction layer, at least one of the following conditions is met: The volume fraction of silicon carbide in the friction layer is 74-92%, the volume fraction of carbon is 2-5%, and the volume fraction of silicon is 1-6%; The volume fraction of silicon carbide in the friction layer is 81-88%, the volume fraction of carbon is 2-4%, and the volume fraction of silicon is 1-3%; The volume fraction of silicon carbide in the friction layer is 85%, the volume fraction of carbon is 3%, and the volume fraction of silicon is 2%.

11. The brake disc of claim 1, wherein, The carbon ceramic base body comprises silicon carbide, carbon and silicon; The brake disc comprises a carbon ceramic composite material, which comprises the carbon ceramic base body and the friction layer; Based on the total volume of the carbon ceramic composite material, at least one of the following conditions is met: The volume fraction of silicon carbide in the carbon ceramic composite material is 54-76%, the volume fraction of carbon is 22-40%, and the volume fraction of silicon is 2-6%; The volume fraction of silicon carbide in the carbon ceramic composite material is 60-68%, the volume fraction of carbon is 30-36%, and the volume fraction of silicon is 2-4%; The volume fraction of silicon carbide in the carbon ceramic composite material is 62%, the volume fraction of carbon is 35%, and the volume fraction of silicon is 3%.

12. The brake disc of claim 1, wherein, The brake disc comprises a carbon ceramic composite material, which comprises the carbon ceramic base body and the friction layer; The carbon ceramic composite material has a thermal conductivity of 100-150 Wm -1 k -1 ; and / or, the carbon ceramic composite material has a weight loss rate of 1%-7% in a static air oxidation test at 700℃ in air for 12 hours.

13. The brake disc of claim 1, wherein, The carbon ceramic base body has bolt holes and positioning holes; the outer surface of the carbon ceramic base body has a cooling channel.

14. A vehicle characterized by comprising: Comprising the brake disc of any one of claims 1-13.

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