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 a volume percentage of the SiC whisker with a growth angle of 0-15° is 3-10% by volume, a volume percentage of the SiC whisker with a growth angle of 15-30° is 1-3% by volume, and a volume percentage of the SiC whisker with a growth angle of 30-90° is 1-2% by volume, based on a total volume of the friction layer.

[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 is in the same plane as a surface of the carbon-toughened matrix; 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, a volume fraction of silicon carbide in the friction layer is 74-92% by volume, a volume fraction of the SiC whisker is 5-15% by volume, a volume fraction of carbon is 2-5% by volume, and a volume fraction of silicon is 1-6% by volume, based on a total volume of the friction layer.

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

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

[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 filament arrangement direction, and the length direction of the carbon fiber filaments 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.

[0021] 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.

[0022] 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 substances deposited 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.

[0023] Optionally, in step S4, the conditions of the siliconizing treatment include that 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.

[0024] 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.

[0025] 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.

[0026] The fifth aspect of the present disclosure provides a vehicle comprising the brake disc according to the fourth aspect of the present disclosure.

[0027] 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 carbon-ceramic composite material in 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.

[0028] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF DRAWINGS

[0029] The accompanying drawings are included to provide a further understanding of the present disclosure and constitute a part of the specification, and together with the following detailed description, serve to explain the present disclosure but do not constitute a limitation thereof. In the drawings:

[0030] 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);

[0031] Figure 2 A flowchart schematic diagram of the method for preparing the carbon-ceramic composite material provided by the present disclosure.

[0032] Reference signs:

[0033] 1. SiC whisker;

[0034] 2. Carbon fiber monofilament;

[0035] 3. The laminated body (second carbon fiber preform);

[0036] 4. The grooved base body. DETAILED DESCRIPTION

[0037] The specific embodiments of the present disclosure are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present disclosure, and are not used to limit the present disclosure.

[0038] The first aspect of the present disclosure provides a carbon-ceramic composite material, comprising a carbon-ceramic base body, at least part of the surface of the carbon-ceramic base body 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.

[0039] 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 base body 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 base 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.

[0040] 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°.

[0041] 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 electron microscope photograph method.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] In one embodiment, the volume fraction of silicon carbide in the carbon ceramic composite material is 54-76% by volume, the volume fraction of carbon is 22-40% by volume, and the volume fraction of silicon is 2-6% by volume, 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% by volume, the volume fraction of carbon is 30-36% by volume, and the volume fraction of silicon is 2-4% by volume, based on the total volume of the carbon ceramic composite material; further preferably, the volume fraction of silicon carbide is 62% by volume, the volume fraction of carbon is 35% by volume, and the volume fraction of elemental silicon is 3% by volume, based on the total volume of the carbon ceramic composite material; the carbon ceramic composite material with the preferred volume composition of this embodiment can have more excellent thermal conductivity.

[0050] In this disclosure, the volume fractions of the components in the carbon ceramic composite material and the friction layer are obtained by the electron microscope photograph method.

[0051] In one specific embodiment, the carbon ceramic composite material provided by this 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 by this disclosure is significantly higher than that of the conventional carbon ceramic disc.

[0052] The second aspect of this disclosure provides a method for preparing a carbon ceramic composite material, comprising the following steps:

[0053] 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.

[0054] 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.

[0055] S3, performing second chemical vapor deposition treatment on the first intermediate body under SiC deposition conditions to obtain a second intermediate body.

[0056] S4, performing silicon infiltration treatment on the second intermediate body.

[0057] The present disclosure provides a method for preparing a carbon ceramic composite material, which comprises the following steps: a first carbon fiber preform is obtained by chemical vapor deposition, and then a densified preform is obtained; a surface of the densified preform is slotted, and a second carbon fiber preform comprising a plurality of layers of carbon fiber unidirectional cloth is placed vertically in the slot along 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 to form a continuous heat conduction channel in the thickness direction; finally, silicon infiltration treatment is performed to form silicon carbide with carbon in the densified preform and the second carbon fiber preform, and the silicon infiltration treatment can also combine the parts together to improve the bonding force (such as the bonding force between the friction layer and the carbon ceramic substrate) of the overall composite material.

[0058] In the present disclosure, the first carbon fiber preform can be prepared by a conventional method.

[0059] In a specific embodiment, the first carbon fiber preform used in step S1 can be prepared by a method comprising the following steps:

[0060] The carbon fiber unidirectional cloth is alternately layered with the net tire, a green body is obtained by stepwise needling, 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, the layering can be performed according to the angles of 0° / 45° / 90° / 135°. The first carbon fiber preform prepared by the present embodiment has more excellent performance after the carbon-based composite material is prepared.

[0061] In a 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 the present embodiment matches the shape of the densified preform, and can form a friction layer with excellent heat conduction performance in the subsequent process.

[0062] 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.

[0063] 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.

[0064] In one embodiment, the second carbon fiber preform used in step S2 can be prepared by a method comprising the following steps:

[0065] 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.

[0066] 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 spacing between the filaments.

[0067] 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.

[0068] The first resin is selected from one or more of phenolic resin, epoxy resin and furan resin; the impregnation time is 60-300 min; the pressure curing conditions include: pressure of 10-30 kg, curing temperature of 150-250℃, and 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℃, and the curing time is 2.5-3 h.

[0069] The spacing between two adjacent unidirectional carbon fiber layers in the obtained laminate is 1-10 μm, preferably 2-6 μm, and more preferably 4 μm; the density of the obtained laminate is 1.0-1.7 g / cm³. 3 The preferred concentration is 1.2-1.6 g / cm³. 3 Further preferred value is 1.4 g / cm³. 3 The laminate obtained by the preferred resin impregnation and curing conditions in this embodiment has the effect of high bonding strength and resistance to deformation.

[0070] In one specific embodiment, step S2 further includes: cutting the second carbon fiber preform into a shape matching the groove shape; coating the bottom of the groove with a second resin; vertically placing the cut second carbon fiber preform in the groove; and then curing at 150-250°C for 2-4 hours; preferably, curing at 160-230°C for 2.5-3 hours; the second resin is selected from one or more of phenolic resin, furan resin, and epoxy resin; wherein the fiber length in the second carbon fiber preform is 1-4 mm. This disclosure cuts the second carbon fiber preform into a shape corresponding to the circular groove on the substrate, and ensures that the length of the carbon fiber monofilament in the cut second carbon fiber preform is the same as the depth of the groove, so as to ensure that when the second carbon fiber preform is placed vertically in the groove, the bottom of the carbon fiber monofilament in the second carbon fiber preform contacts the bottom of the groove, and the upper surface of the laminate is on the same plane as the top of the groove.

[0071] In one specific embodiment, the product structure obtained after the SiC whisker deposition process is as follows: Figure 1 As shown, the groove on the surface of the grooved substrate 4 includes a laminate 3 (second carbon fiber preform) of unidirectional fiber cloth placed vertically along the length direction of the carbon fiber monofilament. In the groove, the gaps between the carbon fiber monofilaments 2 of the laminate contain SiC whiskers that extend along the depth direction of the groove in the length direction; and the SiC whiskers grow from the bottom surface of the groove upward.

[0072] In one embodiment, in step S3, the SiC deposition conditions include:

[0073] 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.

[0074] 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 fractions of the SiC whiskers in each growth angle range are within the range of this embodiment, especially within the preferred range, the heat conduction direction of the friction layer obtained by the present disclosure is more concentrated, and the thermal conductivity in the thickness direction is higher. 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 approximately 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.

[0075] In one specific embodiment, the diameter of the single SiC whisker is 100-600 nm, and the length is 5-50 μm.

[0076] 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.

[0077] In one embodiment, step S4 comprises:

[0078] The upper surface and the lower surface of the second intermediate body are provided with silicon powder, and the silicon powder is put into a silicon infiltration furnace for silicon infiltration treatment. The present disclosure forms silicon carbide by melting and infiltrating silicon to the carbon in the densification preform and the second carbon fiber preform, so as 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.

[0079] 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 further preferably 1600°C, the silicon infiltration reaction time is 1-6 h, preferably 2-5 h, and further preferably 4 h, and the silicon infiltration reaction pressure is 0.5-3 kPa, preferably 0.8-1.5 kPa, and further preferably 1 kPa. According to the preferred conditions in the embodiment, a carbon ceramic composite material with better performance can be obtained.

[0080] In one specific embodiment, as shown in Figure 2 The method for preparing the carbon ceramic composite material comprises the following steps:

[0081] (1) Carbon fiber unidirectional cloth is alternately laid in the directions of 0° / 45° / 90° / 135° with a net tire, a green body is obtained by using a stepwise needling, and a first carbon fiber preform is obtained by cutting with a mold knife.

[0082] (2) Put the preform into a carbon-carbon deposition furnace for chemical vapor deposition (first chemical vapor deposition treatment), introduce process gas, and densify the substrate to obtain a carbon-carbon disc body.

[0083] (3) After machining according to the brake disc drawing size in step (2), groove the disc surface (the groove is annular) to obtain a substrate disc.

[0084] (4) After layer-by-layer stacking of the carbon fiber unidirectional cloth in the same direction, immerse it in resin, take it out, and then perform pressure curing.

[0085] (5) Use a cutting machine to cut the cured carbon fiber unidirectional cloth stack obtained in step (4) along the fiber axis, then place the cut stack (i.e., the second carbon fiber preform) vertically along the fiber axis, cut it into a corresponding annular sheet according to the size of the substrate disc, and then coat the annular sheet with resin and embed it into the groove of the substrate disc for curing.

[0086] (6) Then put it into a vapor deposition furnace, remove the glue during the warming-up process, and then continuously introduce deposition gas and dilution gas to perform second chemical vapor deposition treatment to obtain a friction layer blank disc containing SiC whiskers.

[0087] (7) Then place the friction layer blank disc in a graphite crucible, lay silicon powder on the top and bottom of the blank, and put it into a siliconizing furnace for siliconizing treatment to finally obtain a carbon ceramic disc.

[0088] The third aspect of the present disclosure provides a carbon ceramic composite material according to the second aspect of the present disclosure.

[0089] 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.

[0090] The fifth aspect of the present disclosure provides a vehicle comprising the brake disc according to the fourth aspect of the present disclosure.

[0091] The present disclosure is further described in detail through the following examples. The raw materials used in the examples can be obtained through commercial channels.

[0092] Example 1

[0093] (1) The T700-6K carbon fiber unidirectional cloth was alternately layered with the tire in the direction of 0° / 45° / 90° / 135° (based on the tire), and then a preform (first carbon fiber preform) was obtained by using a stepwise needling method, and then a mold knife was used to cut the preform. The overall density of the preform was 0.4 g / cm 3 .

[0094] (2) Put the preform into a carbon-carbon deposition furnace for chemical vapor deposition (first chemical vapor deposition treatment), input methane gas with a flow rate of 35 L / min, deposit at a temperature of 1100 ℃ and a pressure of 3 kPa for 400 h to densify the substrate, and obtain a carbon-carbon disc body (densified preform) after 400 h of deposition, with an overall density of 1.4 g / cm 3 and a thickness of 32 mm.

[0095] (3) Mechanically process the densified body after deposition, machine bolt holes and positioning holes on the surface according to the aperture size requirements of the brake disc, mill cooling channels on the outer ring, and then groove the disc surface (groove both surfaces), with a groove width of 115 mm and a groove depth of 2.5 mm, to obtain a substrate disc.

[0096] (4) Stack 500 layers of T700-6K carbon fiber unidirectional cloth in the same direction, then immerse in phenolic resin for 60 min, take out and pressurize at 20 kg, and cure at 200 ℃ for 3 h; the density of the stack is 1.4 g / cm 3 , the pitch is 4 μm, and a second carbon fiber preform is obtained.

[0097] (5) Cut the cured carbon fiber unidirectional cloth stack obtained in step (4) along the fiber axis using a cutting machine, with a cutting length of 3 mm, then lay the cut stack flat, i.e. vertically along the fiber axis, cut into a corresponding annular sheet according to the size of the substrate disc, then brush resin on the bottom of the substrate disc groove, and embed the annular sheet into the substrate disc groove and cure at 200 ℃ for 3 h (first intermediate body).

[0098] (6) Put the disc body into a vapor deposition furnace, remove the glue during the warming-up process, then continuously input trichloromethylsilane and hydrogen for second chemical vapor deposition treatment, with a trichloromethylsilane flow rate of 600 mL / min, a hydrogen flow rate of 1:1.3, and a furnace pressure of 800 Pa, and perform chemical vapor deposition at a temperature of 1000 ℃ for 6 h to obtain a SiC whisker-containing friction layer blank disc (second intermediate body); based on the total volume of the deposited substances in the groove, the volume fraction of the silicon carbide whiskers in the deposited substances in the groove is 10 vol.%, and among them, based on the total volume of the deposited substances in the groove, the volume fraction of the SiC whiskers with a growth angle of 30-90° is 2 vol.%, with a diameter of 200-250 nm and a length of 6-8 μm; the volume fraction of the SiC whiskers with a growth angle of 15°-30° is 3 vol.%, with a diameter of 300-400 nm and a length of 10-16 μm, and the volume fraction of the SiC whiskers with a growth angle of 0°-15° is 5 vol.%, with a diameter of 300-400 nm and a length of 20-40 μm.

[0099] (7) the friction layer blank disc is placed in a graphite crucible, 150-mesh silicon powder is selected, the weight ratio of the silicon powder to the blank disc is 3:1, the silicon powder is laid on the upper and lower surfaces of the blank, and the blank is placed in a siliconizing furnace for siliconizing treatment, the reaction temperature is 1600 DEG C, the reaction time is 4h, and the reaction pressure is 1kPa, so as to prepare the carbon ceramic composite material.

[0100] The composition and volume fraction of the obtained friction layer are as follows: based on the total volume of the friction layer, 85% of the volume is silicon carbide, 10% of the volume is SiC whisker, 3% of the volume is carbon, and 2% of the volume is silicon. The composition and content of the carbon ceramic disc are as follows: based on the total volume of the carbon ceramic disc, 62% of the volume is silicon carbide, 35% of the volume is carbon, and 3% of the volume is silicon. In addition, the growth angle and volume ratio of SiC whisker in the friction layer of the carbon ceramic composite material product prepared in the present disclosure are substantially the same as the data of the growth angle and volume ratio of SiC whisker in the deposit obtained in the grooving during the SiC vapor deposition process in the preparation process. Specifically, in the friction layer of the carbon ceramic composite material obtained in the present embodiment, based on the total volume of the friction layer, the volume ratio of SiC whisker with a growth angle of 0°-15° is 5%, the volume ratio of SiC whisker with a growth angle of 15°-30° is 3%, and the volume ratio of SiC whisker with a growth angle of 30°-90° is 2%. In the carbon ceramic composite material obtained in the present embodiment, the thickness of the friction layer is 2.5mm, and the ring width of the friction layer is 115mm.

[0101] Example 2

[0102] The present embodiment refers to the preparation method in Example 1, and the difference from Example 1 is that:

[0103] In step (4), 900 layers of T700-6K carbon fiber unidirectional cloth are laid in the same direction; and in the SiC whisker-containing friction layer blank disc (the second intermediate body) obtained in step (6), based on the total volume of the friction layer (or the total volume of the deposit in the grooving), the volume fraction of silicon carbide whisker in the friction layer (or the deposit in the grooving) is 5%. The volume fraction and whisker size of SiC whisker in different growth angle ranges are listed in Table 1-1 and Table 1-2.

[0104] In step (7), the friction layer blank disc is placed in a graphite crucible, 150-mesh silicon powder is selected, the weight ratio of the silicon powder to the blank disc is 5:1, and the remaining process is the same as that in Example 1.

[0105] Example 3

[0106] The present embodiment refers to the preparation method in Example 1, and the difference from Example 1 is that:

[0107] In step (4), T700-6K carbon fiber unidirectional cloth was laid in the same direction for 350 layers; and in the SiC whisker-containing friction layer blank disc (second intermediate body) obtained in step (6), the volume fraction of SiC whiskers in the friction layer (or the deposit in the slot) was 13% based on the total volume of the friction layer (or the total volume of the deposit in the slot), and the volume fractions and sizes of SiC whiskers in different growth angle ranges are listed in Table 1-1 and Table 1-2.

[0108] In step (7), the friction layer blank disc was placed in a graphite crucible, 150-mesh silicon powder was selected, and the weight ratio of the silicon powder to the blank disc was 2.5:1, and the remaining process was the same as that in Example 1.

[0109] Example 4

[0110] This example refers to the preparation method in Example 1, and the difference from Example 1 is that:

[0111] In step (7), the friction layer blank disc was placed in a graphite crucible, 150-mesh silicon powder was selected, and the weight ratio of the silicon powder to the blank disc was 2.5:1, and the remaining process was the same as that in Example 1.

[0112] Example 5

[0113] (1) T700-6K carbon fiber unidirectional cloth was laid in the direction of 0° / 45° / 90° / 135° (based on the tire) alternately with the tire, and then a blank was obtained by using a stepwise needling method, and a preform was obtained by cutting with a mold knife. The overall density of the preform was 0.4 g / cm 3 .

[0114] (2) The preform was placed in a carbon-carbon deposition furnace for chemical vapor deposition, and methane gas was introduced at a flow rate of 50 L / min, the deposition temperature was 1300°C, the deposition pressure was 5 kPa, and the deposition time was 400 h. The substrate was densified, and a carbon-carbon disc body was obtained after 400 h of deposition. The overall density of the carbon-carbon disc body was 1.25 g / cm 3 .

[0115] (3) The densified body after deposition was machined, bolt holes and positioning holes were machined on the surface according to the hole size requirements of the brake disc, and cooling channels were milled on the outer ring. Then the disc surface was slotted, the slot width was 115 mm, and the slot depth was 2.5 mm, to obtain a substrate disc.

[0116] (4) T700-6K carbon fiber unidirectional cloth was laid in the same direction for 500 layers, then immersed in phenolic resin for 180 min, taken out and pressed at 10 kg, and cured at 150°C for 2 h; the density of the laminated body was 1.1 g / cm 3 , and the spacing was 9 μm.

[0117] (5) The cured carbon fiber unidirectional cloth stack obtained in step (4) is cut along the fiber axis using a cutting machine, the cutting length is 3 mm, then the cut stack is laid flat, i.e. placed vertically along the fiber axis, and then cut into a corresponding annular sheet according to the size of the matrix disc, then the resin is brushed on the bottom of the matrix disc groove, and the annular sheet is embedded into the matrix disc groove and cured at 200°C for 3h.

[0118] (6) The disc body is placed in a gas deposition furnace, and the glue is removed during the warming-up process, then trichloromethylsilane and hydrogen are continuously introduced, the flow rate of trichloromethylsilane is 250 mL / min, the flow rate ratio of trichloromethylsilane to hydrogen is 1:2, and the furnace pressure is controlled at 400 Pa, chemical vapor deposition is carried out at 800°C for 2h to obtain a SiC whisker-containing friction layer blank disc; based on the total volume of the friction layer (or based on the total volume of the deposited material in the groove), the volume fraction of silicon carbide whiskers in the friction layer (or the deposited material in the groove) is 8 vol.%, among which the volume fraction of SiC whiskers with a growth angle of 30-90° is 2 vol.%, the diameter is 200-250 nm, the length is 6-8 μm, the volume fraction of SiC whiskers with a growth angle of 15-30° is 2 vol.%, the diameter is 300-400 nm, the length is 10-16 μm, and the volume fraction of SiC whiskers with a growth angle of 0-15° is 4 vol.%, the diameter is 300-400 nm, and the length is 20-40 μm.

[0119] (7) The friction layer blank disc is placed in a graphite crucible, 150-mesh silicon powder is selected, the weight ratio of silicon powder to blank disc is 3:1, the silicon powder is laid flat on the upper and lower surfaces of the blank, and the siliconizing furnace is used for siliconizing treatment, the reaction temperature is 1900°C, the reaction time is 6h, and the reaction pressure is 2kPa.

[0120] Example 6

[0121] This example refers to the process conditions in Example 1 to prepare carbon ceramic composite material, which is different from Example 1 in that it is prepared according to the following process conditions:

[0122] (1) The T700-6K carbon fiber unidirectional cloth is alternately laid with the tire in the direction of 0° / 45° / 90° / 135° (based on the tire), and then a blank is obtained by using a stepwise needling method, and a preform is obtained by cutting with a mold knife. The overall density of the preform is 0.4 g / cm 3 .

[0123] (2) The preform is placed in a carbon-carbon deposition furnace for chemical vapor deposition, and methane gas is introduced at a flow rate of 9 L / min, the deposition temperature is 1000°C, the deposition pressure is 6kPa, and the deposition time is 400h, and the matrix is densified, and a carbon-carbon disc body is obtained after 400h of deposition, and the overall density of the carbon-carbon disc body is 1.2 g / cm 3.

[0124] (3) Machining the densified body after deposition, machining bolt holes and positioning holes on the surface according to the aperture size requirements of the brake disc, and milling cooling channels on the outer ring, then slotting the disc surface, the slot width is 115 mm and the slot depth is 2.5 mm, to obtain the base disc.

[0125] (4) After 500 layers of T700-6K carbon fiber unidirectional cloth are laid in the same direction, the unidirectional cloth is immersed in phenolic resin for 120 min, and then taken out and pressed at 5 kg, and cured at 120°C for 2 h; the density of the laminated body is 1.0 g / cm 3 , and the spacing is 12 μm.

[0126] (5) The cured carbon fiber unidirectional cloth laminated body obtained in step (4) is cut along the fiber axis using a cutting machine, and the cutting length is 3 mm, then the cut laminated body is laid flat, that is, placed vertically along the fiber axis, and then cut into a corresponding annular sheet according to the size of the base disc, then the annular sheet is embedded into the groove of the base disc, and cured at 200°C for 3 h.

[0127] (6) The disc body is placed in a gas deposition furnace, and the glue is removed during the heating process, then trichloromethylsilane and hydrogen are continuously introduced, the flow rate of trichloromethylsilane is 200 mL / min, the flow rate ratio of trichloromethylsilane to hydrogen is 1:2, and the gas pressure in the furnace is controlled at 400 Pa, and chemical vapor deposition is carried out at 800°C for 2 h to obtain a friction layer blank disc containing SiC whiskers; based on the total volume of the friction layer (or based on the total volume of the deposited material in the slot), the volume fraction of silicon carbide whiskers in the friction layer (or the deposited material in the slot) is 6%, among which the volume fraction of SiC whiskers with a growth angle of 30-90° is 1%, the diameter is 200-250 nm, the length is 6-8 μm, the volume fraction of SiC whiskers with a growth angle of 15-30° is 3%, the diameter is 300-400 nm, the length is 10-16 μm, and the volume fraction of SiC whiskers with a growth angle of 0-15° is 2%, the diameter is 300-400 nm, and the length is 20-40 μm.

[0128] (7) The friction layer blank disc is placed in a graphite crucible, 150-mesh silicon powder is selected, and the weight ratio of silicon powder to blank disc is 3:1, the silicon powder is laid on the upper and lower surfaces of the blank, and then placed in a silicon infiltration furnace for silicon infiltration treatment, the reaction temperature is 1600°C, the reaction time is 4 h, and the reaction pressure is 1 kPa.

[0129] Comparative Example 1

[0130] The carbon ceramic composite material was prepared according to the process conditions in Example 1, except that the carbon fiber cloth laminate was not arranged in the grooves, and the SiC whisker deposition in step (6) was not performed, and only the densified preform obtained in step (2) was subjected to the silicon infiltration treatment in step (7). The silicon powder with a mesh size of 150 was selected, and the weight ratio of the silicon powder to the blank disc was 3:1. The silicon infiltration process conditions were the same as those in Example 1. The carbon ceramic material obtained in this comparative example did not include the friction layer or the SiC whisker, and was only a conventional carbon ceramic composite material.

[0131] Comparative Example 2

[0132] The carbon ceramic composite material was prepared according to the process conditions in Example 1, except that the carbon fiber cloth laminate was not arranged in the grooves, and the SiC whisker deposition in step (6) was not performed, and only the densified preform obtained in step (2) was subjected to the silicon infiltration treatment in step (7). The silicon powder with a mesh size of 150 was selected, and the weight ratio of the silicon powder to the blank disc was 3:1. The silicon infiltration process conditions were the same as those in Example 1. The carbon ceramic material obtained in this comparative example did not include the friction layer or the SiC whisker, and was only a conventional carbon ceramic composite material.

[0133] Comparative Example 3

[0134] The carbon ceramic composite material was prepared according to the process conditions in Example 1, except that steps (4)-(5) were not performed, i.e., the carbon fiber cloth laminate was not arranged in the grooves of the substrate disc obtained in step (3), and only the SiC whisker deposition in step (6) was performed in the grooves to introduce the SiC whisker into the grooves. The silicon infiltration treatment in step (7) was the same as that in Example 1. The obtained carbon ceramic material did not include the friction layer, and the grooves included the SiC whisker.

[0135] The number of layers of the carbon fiber unidirectional cloth, the volume fraction of the SiC whisker in the deposit obtained after the SiC gas phase deposition, and the proportion of the silicon powder in the silicon infiltration treatment in the above examples and comparative examples are listed in Table 1-1 below.

[0136] Table 1-1

[0137]

[0138] In Table 1-1, the volume fraction of the SiC whisker is based on the total volume of the deposit in the grooves, wherein A represents the volume proportion of the SiC whisker with a growth angle of 30-90°, B represents the volume proportion of the SiC whisker with a growth angle of 15-30°, and C represents the volume proportion of the SiC whisker with a growth angle of 0-15°.

[0139] The sizes of the SiC whisker with different growth angles in the deposit in the grooves obtained in the above examples are listed in Table 1-2 below.

[0140] Table 1-2

[0141]

[0142]

[0143] The volume composition of the composite materials prepared in the above examples and comparative examples and the volume composition of the friction layer are listed in Table 2 below.

[0144] Table 2

[0145]

[0146] In the present disclosure, the growth angles 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 product and the volume ratio thereof are roughly the same as the data of the growth angles of SiC whiskers and the volume ratio thereof in the deposits obtained in the grooves during the SiC vapor deposition process in the preparation process listed in Table 1-1 and Table 1-2, and thus will not be described again.

[0147] Test Example 1

[0148] The present test example is used to illustrate the bonding force between the friction layer and the matrix in the composite material.

[0149] On the basis of the AK-Master bench performance test standard, after the brake disc friction is heated to 700°C, it is rapidly cooled to room temperature by blowing compressed air, and the performance test is repeatedly performed until the friction layer on the surface of the carbon-ceramic brake disc shows peeling problem, i.e. the test is stopped. The number of cycles that can be repeatedly completed under the condition of rapid cooling at high temperature is evaluated as the evaluation of the bonding force between the Si / SiC composite ceramic layer on the surface of the carbon-ceramic brake disc and the carbon-ceramic matrix. The test results are listed in Table 3 below.

[0150] Table 3

[0151]

[0152]

[0153] According to the above examples and comparative examples, and in combination with the data in Table 1-1-Table 1-2, Table 2-Table 3, it can be seen that:

[0154] Comparing Examples 1-6 with Comparative Example 2, in which no SiC whiskers are present and the friction layer and the substrate are only bonded together by the resin carbon in the unidirectional carbon fiber cloth stack through melting and silicon infiltration, the bonding force between the friction layer and the substrate is small, and the test cycle number is only 75; while the carbon ceramic discs prepared according to the method provided in the present disclosure in Examples 1-6 have SiC whiskers in the friction layer, and the test cycle number of the carbon ceramic discs of Examples 1-6 is higher, indicating that the bonding force between the friction layer and the substrate of the carbon ceramic discs of Examples 1-6 is significantly better than that of Comparative Example 2. Comparative Examples 1 and 3 do not include a friction layer, so the bonding force between the friction layer and the substrate cannot be tested.

[0155] Comparing Example 1 with Examples 2-3, respectively, the carbon ceramic composite material is prepared according to the preferred number of fiber cloth stacks, the friction layer with the preferred volume fraction of SiC whiskers, and the preferred proportion of silicon powder in Example 1, and in combination with the data in Table 1-1, it can be seen that the volume fractions of SiC whiskers in the ranges of 0-15°, 15-30°, and 30-90° in the carbon ceramic composite material prepared in Example 1 are within the optimized content range provided in the present disclosure, while the volume fractions of SiC whiskers in different growth angle ranges in the carbon ceramic composite materials prepared in Examples 2-3 are not within the optimized range, and the carbon ceramic disc in Example 1 has a higher test cycle number compared to the carbon ceramic disc prepared in Examples 2-4, indicating that the bonding force between the friction layer and the substrate of the carbon ceramic disc in Example 1 is higher.

[0156] Comparing Example 5 with Example 6, Example 5 is prepared according to the optimized process conditions provided in the present disclosure, the volume fractions of SiC whiskers in the ranges of 0-15°, 15-30°, and 30-90° in the carbon ceramic composite material prepared in Example 5 are within the optimized content range provided in the present disclosure, while the volume fractions of SiC whiskers in different growth angle ranges in the carbon ceramic composite material prepared in Example 6 are not within the optimized range, and the carbon ceramic composite material obtained in Example 5 has a higher test cycle number, i.e., the bonding force between the friction layer and the substrate of the carbon ceramic disc is higher; further comparing Example 1 with Example 5, Example 1 is prepared according to more preferred process conditions, the volume fractions of SiC whiskers in the ranges of 0-15°, 15-30°, and 30-90° in the carbon ceramic composite material prepared in Example 1 are within the further preferred content range provided in the present disclosure, and the carbon ceramic composite material obtained in Example 1 has a higher test cycle number, i.e., the bonding force between the friction layer and the substrate of the carbon ceramic disc is higher.

[0157] Test Example 2

[0158] This test example is used to illustrate the oxidation resistance of the composite material in air.

[0159] The carbon ceramic disc was subjected to static air oxidation test (700℃ in air for 12 hours), and the weight change of the material before and after the test was measured to test the weight loss rate of the carbon ceramic disc. The test results are shown in Table 4 below.

[0160] Table 4

[0161] Example Loss on ignition (%) Example 1 1.0 Example 2 1.5 Example 3 3.0 Example 4 6.0 Example 5 5.0 Example 6 7.0 Comparative Example 1 10.0 Comparative Example 2 3.0 Comparative Example 3 8.0

[0162] From the data in Table 4 above, it can be seen that:

[0163] The carbon ceramic composite material obtained in Comparative Example 1 and Comparative Example 3 has a higher weight loss rate because the oxygen in the air enters the interior of the carbon ceramic disc matrix without the protection of the friction layer, causing the carbon fibers or matrix carbon to be oxidized.

[0164] Comparing Example 1-3 with Example 4, Example 4 has a high weight loss rate because the silicon infiltration reaction is not sufficient, and part of the carbon fibers in the friction layer are not completely reacted, causing oxidation at 700℃ in air. In Example 1-3, the amount of silicon powder added is larger, and the silicon infiltration is sufficient, so the composite material is not easily oxidized, and the weight loss rate is lower.

[0165] Comparing Example 5 with Example 6, Example 5 is prepared according to the optimized process conditions provided by the present disclosure, and the carbon ceramic composite material obtained in Example 5 has a lower weight loss rate and better oxidation resistance. Comparing Example 1 with Example 5, Example 1 is prepared according to more preferred process conditions, and the carbon ceramic composite material obtained in Example 1 has a lower weight loss rate and better oxidation resistance.

[0166] Test Example 3

[0167] This test example is used to illustrate the thermal conductivity of the composite material.

[0168] A thermal constant tester was used to test the thermal conductivity of the carbon ceramic brake disc in the thickness direction of the carbon ceramic disc according to standard GJB1201.1, and the test temperature was 800℃. The test results are shown in Table 5 below.

[0169] Table 5

[0170] Example Thermal conductivity / Wm -1 k -1 ]]> Example 1 115 Example 2 99 Example 3 100 Example 4 112 Example 5 101 Example 6 85 Comparative Example 1 68 Comparative Example 2 113 Comparative Example 3 73 Traditional carbon crucible 80

[0171] From the data in Table 5 above, and in combination with the data in Tables 1-1-1-2 and 2, it can be seen that:

[0172] Comparing the examples 1-6 with the comparative examples 1 and 3, the carbon ceramic composite materials obtained from the comparative examples 1 and 3 do not have a friction layer or whiskers, and have a lower thermal conductivity and a poorer thermal conductivity performance; the carbon ceramic composite materials in the examples 1-6 introduce a friction layer, and the carbon ceramic composite materials in the examples 1-6 have a thermal conductivity performance obviously superior to the carbon ceramic discs of the comparative examples 1 and 3, and the SiC whiskers in the friction layer of the carbon ceramic composite materials in the examples 1-6 can form vertical heat conduction channels, and the carbon ceramic composite materials in the examples 1-6 also have a thermal conductivity performance obviously superior to the traditional carbon ceramic discs.

[0173] Comparing the examples 1 and 4 with the examples 2-3, the volume fractions of the SiC whiskers in the ranges of 0-15°, 15-30° and 30-90° in the carbon ceramic composite materials obtained from the examples 1 and 4 are within the optimized content range provided in the present disclosure, while the volume fractions of the SiC whiskers in the different growth angle ranges in the carbon ceramic composite materials obtained from the examples 2-3 are not within the optimized range, and compared with the carbon ceramic composite materials obtained from the examples 2-3, the carbon ceramic composite materials in the examples 1 and 4 have a higher thermal conductivity and a better thermal conductivity performance.

[0174] Comparing the example 5 with the example 6, the example 5 prepares the carbon ceramic composite material according to the optimized process conditions provided in the present disclosure, the volume fractions of the SiC whiskers in the ranges of 0-15°, 15-30° and 30-90° in the carbon ceramic composite material obtained from the example 5 are within the optimized content range provided in the present disclosure, while the volume fractions of the SiC whiskers in the different growth angle ranges in the carbon ceramic composite material obtained from the example 6 are not within the optimized range, and the carbon ceramic composite material obtained from the example 5 has a higher thermal conductivity and a better thermal conductivity performance; further comparing the example 1 with the example 5, the example 1 prepares the carbon ceramic composite material according to the more preferred process conditions, the volume fractions of the SiC whiskers in the ranges of 0-15°, 15-30° and 30-90° in the carbon ceramic composite material obtained from the example 1 are within the further preferred content range provided in the present disclosure, and the carbon ceramic composite material obtained from the example 1 has a better thermal conductivity performance.

[0175] The above describes the preferred embodiments of the present disclosure, but the present disclosure is not limited to the specific details in the above-described embodiments, and various simple modifications can be made to the technical solutions of the present disclosure within the technical concept of the present disclosure, and these simple modifications all belong to the protection scope of the present disclosure.

[0176] In addition, it should be noted that each specific technical feature described in the above-described specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0177] Furthermore, the various embodiments of the present disclosure can be arbitrarily combined with each other unless they contradict each other, and it should be understood that the same should be construed as being included in the disclosure of the present disclosure.

Claims

1. A brake disc, characterized in that The brake disc comprises: a carbon ceramic base body having two oppositely arranged main surfaces; at least one part of the main surfaces of the carbon ceramic base body is provided with a friction layer embedded in the carbon ceramic base body, the embedded depth of the friction layer is 1-4 mm, and the thickness of the friction layer is 1-4 mm.

2. The brake disc of claim 1, wherein, The thickness of the friction layer is 2-3 mm.

3. The brake disc of claim 1, wherein, The carbon ceramic base body is provided with a groove, and the friction layer is located in the groove.

4. A brake disc according to claim 3, wherein, The groove is a circular annular groove.

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

6. The brake disc of claim 3, 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 where the groove is not arranged.

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

8. The brake disc of claim 7, wherein, The carbon ceramic base body is disc-shaped, and the friction layer is coaxial with the carbon ceramic base body.

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

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

11. 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.

12. 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 vol%, the volume fraction of carbon is 2-5 vol%, and the volume fraction of silicon is 1-6 vol%; The volume fraction of silicon carbide in the friction layer is 81-88 vol%, the volume fraction of carbon is 2-4 vol%, and the volume fraction of silicon is 1-3 vol%; The volume fraction of silicon carbide in the friction layer is 85 vol%, the volume fraction of carbon is 3 vol%, and the volume fraction of silicon is 2 vol%.

13. 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 vol%, the volume fraction of carbon is 22-40 vol%, and the volume fraction of silicon is 2-6 vol%; The volume fraction of silicon carbide in the carbon ceramic composite material is 60-68 vol%, the volume fraction of carbon is 30-36 vol%, and the volume fraction of silicon is 2-4 vol%; The volume fraction of silicon carbide in the carbon ceramic composite material is 62 vol%, the volume fraction of carbon is 35 vol%, and the volume fraction of silicon is 3 vol%.

14. 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°C in air for 12 hours.

15. The brake disc of claim 1, wherein, The carbon ceramic base body is provided with bolt holes and positioning holes; and the outer surface of the carbon ceramic base body is provided with cooling channels.

16. A vehicle characterized by comprising: The brake disc comprises the brake disc according to any one of claims 1-15.

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