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

Abstract

The present application relates to a carbon-ceramic composite material and a preparation method thereof, a carbon-ceramic brake disc and a means of transportation. The preparation method of the carbon-ceramic composite material comprises the following steps: providing raw materials: chopped carbon fiber, ground carbon fiber, carbon powder and organic resin; the length of the chopped carbon fiber is 8 mm to 15 mm, the length of the ground carbon fiber is 200 μm to 500 μm, the aspect ratio of the ground carbon fiber is 30 to 70:1, the mass of the ground carbon fiber accounts for 3% to 8% of the total mass of the raw materials, and the mass of the chopped carbon fiber accounts for 40% to 60% of the total mass of the raw materials; mixing the raw materials and performing molding treatment to prepare a carbon fiber composite material; performing carbonization treatment and siliconization treatment on the carbon fiber composite material in sequence to prepare a carbon-ceramic composite material. The carbon-ceramic composite material prepared by the preparation method has good bending strength, tensile strength and impact toughness.

Description

Technical Field

[0001] The present application relates to the field of materials, and in particular to a carbon-ceramic composite material and a preparation method thereof, a carbon-ceramic brake disc and a vehicle. Background Art

[0002] Carbon ceramic brake discs are made of carbon fiber reinforced silicon carbide-based composite materials. Compared with the most commonly used powder metallurgy brake discs, they have obvious performance advantages: (1) Low density, which can effectively reduce the weight of the braking system. The weight of carbon ceramic brake discs is about 50% lower than that of powder metallurgy brake discs, which can reduce the weight of the automobile braking system by 10~20Kg; (2) Short braking distance. The friction coefficient of carbon ceramic brake discs is between 0.38 and 0.45, which is much higher than the friction coefficient of metal brake pads, greatly improving the braking efficiency. Equipped with carbon ceramic brake discs, the braking distance of a vehicle at a speed of 100 kilometers per hour can be reduced to within 30 meters, improving the vehicle's controllability; (3) High safety: Powder metallurgy brake discs will deform or even melt due to excessive temperature after continuous high-speed braking, causing safety accidents. Carbon ceramic brake discs are resistant to high temperatures and can ensure normal use under high temperature conditions. Currently, high-speed railways and civil aviation passenger aircraft basically all use carbon ceramic brake systems; (4) Long service life: Carbon ceramic brake discs have a low wear rate, and cast iron brake pads can be used for 80,000~100,000 Km, and the service life of carbon ceramic brake discs can exceed 300,000 Km.

[0003] Carbon ceramic brake discs are mainly divided into two types: long fiber discs and short fiber discs. Compared with long fiber discs, short fiber discs have the advantages of short preparation cycle and low cost. However, traditional short fiber discs have poor impact toughness.

[0004] Therefore, it is necessary to improve the traditional technology. Summary of the invention

[0005] Based on this, the present application provides a carbon-ceramic composite material with good impact toughness and a preparation method thereof, a carbon-ceramic brake disc and a vehicle.

[0006] The technical solution of this application to solve the above technical problems is as follows.

[0007] The first aspect of the present application provides a method for preparing a carbon-ceramic composite material, comprising the following steps:

[0008] Providing raw materials: short-cut carbon fiber, ground carbon fiber, carbon powder and organic resin; the length of the short-cut carbon fiber is 8 mm to 15 mm, the length of the ground carbon fiber is 200 μm to 500 μm, the aspect ratio of the ground carbon fiber is 30 to 70:1, the mass of the ground carbon fiber accounts for 3% to 8% of the total mass of the raw materials, and the mass of the short-cut carbon fiber accounts for 40% to 60% of the total mass of the raw materials;

[0009] The raw materials are mixed and molded to prepare a carbon fiber composite material;

[0010] The carbon fiber composite material is subjected to carbonization treatment and siliconization treatment in sequence to prepare a carbon-ceramic composite material.

[0011] In some of the embodiments, in the method for preparing the carbon-ceramic composite material, the mass ratio of the chopped carbon fiber, the resin, the carbon powder and the ground carbon fiber is 40-60:20-30:10-30:3-8.

[0012] In some embodiments, in the method for preparing the carbon-ceramic composite material, the organic resin includes phenolic resin.

[0013] In some of the embodiments, in the method for preparing the carbon-ceramic composite material, a sizing agent is provided on the surface of the chopped carbon fibers, and the sizing agent includes at least one of polyurethane and epoxy resin.

[0014] In some embodiments, in the method for preparing the carbon-ceramic composite material, the raw material further includes an additive, and the additive satisfies at least one of the following characteristics:

[0015] (1) The additive includes at least one of a metal oxide powder and a pore-forming agent;

[0016] (2) The mass ratio of the additive to the chopped carbon fiber is 3-5:40-60.

[0017] In some embodiments, in the method for preparing the carbon-ceramic composite material, the temperature of the molding process is 150° C. to 200° C.; and / or

[0018] Forming process using a vulcanizing press; and / or

[0019] The pressure of the molding process is 80 to 120 tons; and / or

[0020] The holding time of the molding process is 20 min to 40 min.

[0021] In some of the embodiments, in the method for preparing the carbon-ceramic composite material, the temperature of the carbonization treatment is 900° C. to 1200° C., and the time of the carbonization treatment is 50 h to 70 h.

[0022] In some of the embodiments, in the method for preparing the carbon-ceramic composite material, the temperature of the siliconizing treatment is 1500° C. to 1700° C., and the time is 3 h to 5 h.

[0023] A second aspect of the present application provides a carbon-ceramic composite material, which is prepared using the above-mentioned method for preparing the carbon-ceramic composite material.

[0024] In some embodiments, the carbon-ceramic composite material includes a carbon-ceramic brake rotor.

[0025] A third aspect of the present application provides a carbon-ceramic brake disc, comprising the above-mentioned carbon-ceramic composite material.

[0026] A third aspect of the present application provides a vehicle comprising the above-mentioned carbon-ceramic brake disc.

[0027] Compared with the prior art, the carbon fiber composite material of the present application has the following beneficial effects:

[0028] The preparation method of the carbon-ceramic composite material of the present application comprises the following steps: mixing powdered carbon fibers of a specific length and a specific aspect ratio with short-cut carbon fibers of a specific length, carbon powder and an organic resin for molding, and controlling the ratio of the powdered carbon fibers to the short-cut carbon fibers, so that the powdered carbon fibers of a specific length and a specific aspect ratio are evenly distributed in the embryo, thereby effectively improving the bonding strength between the powdered carbon fibers and other components; then carbonizing the carbon fiber composite material obtained by the molding process, carbonizing the organic resin into carbon, and obtaining a short-fiber carbon fiber reinforced carbon matrix composite material; then siliconizing the carbon matrix composite material after the carbonization process, so that the carbon and carbon powder produced after the carbonization of the organic resin react with molten silicon to generate a silicon carbide matrix, and the powdered carbon fibers react with molten silicon to generate silicon carbide whiskers, and the silicon carbide whiskers have good bonding performance with the silicon carbide matrix, thereby effectively improving the bending strength, tensile strength and impact toughness of the carbon-ceramic brake disc. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 This is a metallographic image of the finished carbon ceramic disc prepared in Example 1. DETAILED DESCRIPTION

[0031] References to embodiments of the present application will now be provided in detail, one or more examples of which are described below. Each example is provided as an explanation rather than a limitation of the present application. In fact, it will be apparent to those skilled in the art that various modifications and variations may be made to the present application without departing from the scope or spirit of the present application. For example, a feature described or described as part of one embodiment may be used in another embodiment to produce a further embodiment.

[0032] Therefore, it is intended that the present application covers such modifications and variations that fall within the scope of the appended claims and their equivalents. Other objects, features and aspects of the present application are disclosed in or are apparent from the following detailed description. It will be appreciated by those of ordinary skill in the art that this discussion is merely a description of exemplary embodiments and is not intended to limit the broader aspects of the present application.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0034] The term "comprises", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of more restrictions, the elements defined by the sentence "comprising one..." do not exclude the presence of other identical elements in the process, method, article or equipment including the elements. The indefinite articles "a kind of" and "one" before the elements or components of the present application are not restrictive to the quantity requirements (i.e., the number of occurrences) of the elements or components. Therefore, "one" or "a kind of" should be interpreted as including one or at least one, and the elements or components in the singular form also include the plural form, unless the number obviously refers only to the singular form. The meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0035] The weight of the relevant components mentioned in the specification of the examples of this application can not only refer to the specific content of each component, but also represent the proportional relationship between the weights of the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the specification of the examples of this application, it is within the scope disclosed in the specification of the examples of this application. Specifically, the weight described in the specification of the examples of this application can be mass units known in the chemical industry such as μg, mg, g, and kg.

[0036] Except as shown in the operating examples or otherwise indicated, all numbers used in the specification and claims to indicate the amount of ingredients, physicochemical properties, etc. are understood to be adjusted by the term "about" in all cases. For example, therefore, unless otherwise indicated, the numerical parameters listed in the above specification and the attached claims are approximate values, and those skilled in the art can use the teachings disclosed herein to seek to obtain the desired properties and appropriately change these approximate values. The use of numerical ranges expressed as endpoints includes all numbers within the range and any range within the range, for example, 1 to 5 includes 1, 1.1, 1.3, 1.5, 2, 2.75, 3, 3.80, 4 and 5, etc.

[0037] An embodiment of the present application provides a method for preparing a carbon-ceramic composite material, comprising the following steps:

[0038] Step S10: providing raw materials: chopped carbon fiber, powdered carbon fiber, carbon powder and organic resin; the length of the chopped carbon fiber is 8 mm to 15 mm, the length of the powdered carbon fiber is 200 μm to 500 μm, the aspect ratio of the powdered carbon fiber is 30 to 70:1, the mass of the powdered carbon fiber accounts for 3% to 8% of the total mass of the raw materials, and the mass of the chopped carbon fiber accounts for 40% to 60% of the total mass of the raw materials.

[0039] It can be understood that the length of the chopped carbon fiber includes but is not limited to 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm; the length of the powdered carbon fiber includes but is not limited to 200 μm~500 μm; the aspect ratio of the powdered carbon fiber includes but is not limited to 30:1, 35:1, 40:1, 45:1, 50:1, 55:1, 60:1, 65:1, 70:1; the mass of the powdered carbon fiber accounts for the percentage of the total mass of the raw material, including but not limited to 3%, 4%, 5%, 6%, 7%, 8%; the mass of the chopped carbon fiber accounts for the percentage of the total mass of the raw material, including but not limited to 40%, 42%, 45%, 48%, 50%, 52%, 55%, 58%, 60%; in some examples, it can be within the range formed by any two of these point values ​​as end values, the same below.

[0040] In some of the examples, in step S10, the length of the chopped carbon fibers is 8 mm to 12 mm.

[0041] In some of the examples, in step S10, the length of the ground carbon fibers is 200 μm to 400 μm.

[0042] In some of the examples, in step S10, the aspect ratio of the ground carbon fiber is 50-70:1.

[0043] In some of the examples, in step S10, the mass of the ground carbon fiber accounts for 5% to 6% of the total mass of the raw material.

[0044] In some of the examples, in step S10, the mass of the chopped carbon fibers accounts for 40% to 50% of the total mass of the raw material.

[0045] Furthermore, the mass of the chopped carbon fiber accounts for 40% to 45% of the total mass of the raw material.

[0046] In some of the examples, in step S10, the mass ratio of the chopped carbon fiber, the organic resin, the carbon powder, and the ground carbon fiber is 40-60:20-30:10-30:3-8.

[0047] It can be understood that the mass ratio of chopped carbon fiber to organic resin is 40~60:20~30 (i.e., the mass ratio of chopped carbon fiber to organic resin is 1.33~3:1), the mass ratio of chopped carbon fiber to carbon powder is 40~60:10~30 (i.e., the mass ratio of chopped carbon fiber to carbon powder is 1.33~6:1), and the mass ratio of chopped carbon fiber to ground carbon fiber is 40~60:5~10 (i.e., the mass ratio of chopped carbon fiber to ground carbon fiber is 4~12:1); it can be further understood that the mass ratio of chopped carbon fiber to organic resin is 40~60:20~30 (i.e., the mass ratio of chopped carbon fiber to organic resin is 1.33~3:1), the mass ratio of chopped carbon fiber to carbon powder is 40~60:10~30 (i.e., the mass ratio of chopped carbon fiber to carbon powder is 1.33~6:1), and the mass ratio of chopped carbon fiber to ground carbon fiber is 40~60:5~10 (i.e., the mass ratio of chopped carbon fiber to ground carbon fiber is 4~12:1). The mass ratio of organic resin includes but is not limited to 1.33:1, 1.5:1, 2:1, 2.5:1, 3:1; the mass ratio of chopped carbon fiber to carbon powder includes but is not limited to 1.33:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, 5:1, 5.5:1, 6:1; the mass ratio of chopped carbon fiber to ground carbon fiber includes but is not limited to 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1.

[0048] In some of the examples, in step S10, the mass ratio of the chopped carbon fiber, the organic resin, the carbon powder, and the ground carbon fiber is 40-50:20-30:20-30:4-6.

[0049] In some of the examples, in step S10, the mass ratio of the chopped carbon fiber, the organic resin, the carbon powder, and the ground carbon fiber is 40-45:20-25:22-28:4-6.

[0050] In some examples, in step S10 , the organic resin includes phenolic resin.

[0051] In some of the examples, in step S10, the chopped carbon fibers are provided with a sizing agent, and the sizing agent includes at least one of polyurethane and epoxy resin.

[0052] In some examples, in step S10, the preparation of chopped carbon fibers includes the following steps:

[0053] The carbon fiber is first compressed and bundled, and then chopped after the surface is sizing and solidified.

[0054] Optionally, the sizing includes at least one of a polyurethane solution and an epoxy resin solution.

[0055] Furthermore, the mass concentrations of the polyurethane solution and the epoxy resin solution are independently 2% to 5%.

[0056] It can be understood that the mass concentrations of the polyurethane solution and the epoxy resin solution independently include but are not limited to 2%, 3%, 4%, and 5%.

[0057] Optionally, the carbon fiber includes but is not limited to T700 carbon fiber; further, the carbon fiber includes 24k or 12k.

[0058] In some of these examples, the milled carbon fiber is a debonded carbon fiber.

[0059] To remove the glue, the carbon fiber can be carbonized at 600℃. Removing the glue can reduce the agglomeration of the ground carbon fiber and make it more evenly mixed in the material.

[0060] In some of the examples, in step S10, the raw material further includes an additive.

[0061] In some examples, the additive includes at least one of a metal oxide powder and a pore former.

[0062] Furthermore, the metal oxide powder includes but is not limited to at least one of aluminum oxide, yttrium oxide and zirconium oxide.

[0063] Adding specific types of metal oxide powders to the raw materials can effectively improve the ceramic structure and enhance the anti-oxidation performance.

[0064] Furthermore, the pore-forming agent includes but is not limited to at least one of ethylene glycol, PVB and walnut powder plant fiber.

[0065] Pore ​​formers are added to the raw materials to increase the porosity after carbonization and facilitate ceramicization.

[0066] In some of these examples, the mass ratio of additive to chopped carbon fiber is 3~5:40~60.

[0067] It can be understood that the mass ratio of the additive to the chopped carbon fiber is 1:8~20; it can be further understood that the mass ratio of the additive to the chopped carbon fiber includes but is not limited to 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19, 1:20.

[0068] In some examples, step S10 includes steps S11-S12:

[0069] Step S11: performing a first mixing of the ground carbon fiber, carbon powder and organic resin to prepare a mixed powder.

[0070] In some of the examples, in step S11, the temperature of the first mixing is 25°C to 60°C, the rotation speed is 50 r / min to 300 r / min, and the time is 15 min to 60 min.

[0071] It will be understood that the temperature of the first mixing includes but is not limited to 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 60°C, the rotation speed includes but is not limited to 50 r / min, 100 r / min, 150 r / min, 200 r / min, 300 r / min, and the time includes but is not limited to 15 min, 20 min, 25 min, 30 min, 45 min, 50 min, 60 min.

[0072] Step S12: performing a second mixing of the mixed powder prepared in step S11 and the chopped carbon fibers.

[0073] In some of the examples, in step S12, the temperature of the second mixing is 25°C to 60°C, the rotation speed is 80 r / min to 200 r / min, and the time is 15 min to 30 min.

[0074] It is understood that the temperature of the second mixing includes but is not limited to 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 60°C, the rotation speed includes but is not limited to 80 r / min, 100 r / min, 150 r / min, 200 r / min; the time includes but is not limited to 15 min, 20 min, 25 min, 30 min.

[0075] Step S20: Mix the raw materials and perform molding treatment to prepare a carbon fiber composite material.

[0076] In some of the examples, in step S20, the temperature of the molding process is 150°C to 200°C.

[0077] In some of the examples, in step S20, a flat plate vulcanizing machine is used for the molding process.

[0078] In some of the examples, in step S20, the pressure of the molding process is 80-120 tons.

[0079] In some of the examples, in step S20, the holding time of the molding process is 20 min to 40 min.

[0080] It will be understood that the temperature of the molding process includes but is not limited to 150°C, 160°C, 170°C, 180°C, 190°C, and 200°C; the pressure of the molding process includes but is not limited to 80 tons, 90 tons, 100 tons, 110 tons, and 120 tons; and the holding time of the molding process includes but is not limited to 20 min, 22 min, 25 min, 28 min, 30 min, 32 min, 35 min, 38 min, and 40 min.

[0081] It can be understood that step S20, in the molding process, includes first preparing a blank and then processing the blank into a desired shape. For example, when the prepared carbon-ceramic composite material is a carbon-ceramic brake disc, it is processed into the basic shape of a carbon-ceramic brake disc, including removing burrs, processing heat dissipation holes on the disc surface, processing side ventilation holes, etc.

[0082] In some of these examples, the density of carbon fiber composites is 1.3 g / cm 3 ~1.5 g / cm 3 .

[0083] Step S30: subjecting the carbon fiber composite material to carbonization treatment and siliconization treatment in sequence to prepare a carbon-ceramic composite material.

[0084] The preparation method of the carbon-ceramic composite material of the present application comprises the following steps: mixing ground carbon fiber with chopped carbon fiber, carbon powder and organic resin for molding, and controlling the length and aspect ratio of the ground carbon fiber, the length of the chopped carbon fiber, and the ratio of the ground carbon fiber to the chopped carbon fiber, so that the ground carbon fiber is evenly distributed in the embryo, which can effectively improve the bonding strength between the ground carbon fiber and other components; carbonizing the carbon fiber composite material obtained by the molding process in step S20, carbonizing the organic resin into carbon, and obtaining a short-fiber carbon fiber reinforced carbon matrix composite material; then siliconizing the carbon matrix composite material after the carbonization process, and the carbon and carbon powder produced after the carbonization of the organic resin react with molten silicon to generate a silicon carbide matrix, and the ground carbon fiber reacts with molten silicon to generate silicon carbide whiskers, and the silicon carbide whiskers have good bonding performance with the silicon carbide matrix, which can effectively improve the bending strength, tensile strength and impact toughness of the carbon-ceramic brake disc.

[0085] In some of the examples, in step S30, the temperature of the carbonization treatment is 900° C. to 1200° C., and the time of the carbonization treatment is 60 h to 100 h.

[0086] It can be understood that the temperature of the carbonization treatment includes but is not limited to 900°C, 1000°C, 1100°C, and 1200°C, and the time of the carbonization treatment includes but is not limited to 60 h, 70 h, 80 h, 90 h, and 100 h.

[0087] In some of the examples, in step S30, the temperature of the siliconizing treatment is 1500° C. to 1700° C., and the time is 3 h to 5 h.

[0088] It can be understood that the temperature of the siliconizing treatment includes but is not limited to 1500℃, 1520℃, 1550℃, 1580℃, 1600℃, 1620℃, 1650℃, 1680℃, 1700℃, and the time includes but is not limited to 3 h, 3.5 h, 4 h, 4.5 h, 5 h.

[0089] In some of the examples, in step S30, in the siliconizing step, the mass ratio of silicon to the carbonized body after the carbonization treatment is 1.2-1.8:1.

[0090] It can be understood that the mass ratio of the amount of silicon to the carbonized body after carbonization treatment includes but is not limited to 1.2:1, 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, and 1.8:1.

[0091] In some of the examples, in step S30, in the siliconizing treatment step, silicon is placed on the upper surface and the lower surface of the carbide blank, and the mass ratio of the silicon on the upper surface to the silicon on the lower surface is 1:2-4.

[0092] In some examples, in step S30, the siliconizing treatment includes the following steps:

[0093] The carbide body is placed in a siliconizing tool, the surface of the tool is coated with boron nitride powder, a piece of graphite paper is added between the tool and the carbide body, silicon is added to the upper and lower surfaces of the carbide body, and the body is placed in a siliconizing furnace for siliconizing treatment.

[0094] It can be understood that coating the surface of the tooling with boron nitride powder is beneficial to protecting the tooling and reducing the corrosion of silicon to the tooling.

[0095] In some of the examples, after step S30 is completed, a step of providing a protective coating on the surface of the workpiece after the siliconizing treatment is also included.

[0096] It is understood that the protective coating includes but is not limited to anti-oxidation coating, anti-corrosion coating, etc.

[0097] In some of these examples, providing a protective coating on a siliconized workpiece surface includes the following steps:

[0098] The workpiece after siliconizing treatment is immersed in a protective solution and then sintered to form a protective coating on the surface of the workpiece.

[0099] In some examples, the protective solution includes, but is not limited to, at least one of aluminum dihydrogen phosphate, aluminum chromium phosphate, boric acid, zirconium, nickel, strontium, copper, and the like.

[0100] Applying an anti-oxidation coating on the surface of the workpiece after siliconizing treatment can prevent oxygen from reacting with carbon, silicon and fiber, thereby increasing the life of the brake disc at a low cost.

[0101] In some of these examples, the sintering temperature is 200°C to 300°C.

[0102] Some of the examples further include a step of finishing the workpiece after siliconizing treatment or after providing a protective coating.

[0103] Among them, finishing includes polishing the disc surface, through-hole drilling, etc.

[0104] An embodiment of the present application provides a carbon-ceramic composite material, which is prepared by the above-mentioned preparation method of the carbon-ceramic composite material.

[0105] The carbon-ceramic composite material prepared by the above-mentioned preparation method of the carbon-ceramic composite material has high bending strength, tensile strength and impact toughness. It can be understood that the carbon-ceramic composite material includes but is not limited to brake discs.

[0106] In some of these examples, the carbon-ceramic composite includes silicon carbide whiskers.

[0107] An embodiment of the present application provides a carbon-ceramic brake disc, including the above-mentioned carbon-ceramic composite material.

[0108] It is understandable that the carbon-ceramic composite material preparation method can be directly used to prepare a carbon-ceramic brake disc. That is, one embodiment of the present application provides a carbon-ceramic brake disc, which is prepared by the above-mentioned carbon-ceramic composite material preparation method.

[0109] The carbon-ceramic brake disc prepared by the preparation method of the carbon-ceramic composite material has high bending strength, tensile strength and impact toughness, as well as good thermal conductivity, excellent thermal shock resistance and stable friction performance.

[0110] An embodiment of the present application also provides a vehicle, comprising the above-mentioned carbon-ceramic brake disc.

[0111] It will be appreciated that vehicles include but are not limited to cars.

[0112] The present application is further described in detail below in conjunction with specific implementation methods, but the implementation methods of the present application are not limited thereto.

[0113] Example 1

[0114] S1. Raw material mixing: the raw materials include chopped carbon fiber (12K T700 grade sizing carbon fiber, the sizing agent is PU solution with a solid content of 2% to 4%), solid phenolic resin, carbon powder, metal oxide (aluminum oxide and yttrium oxide with a mass ratio of 1:1) and ground carbon fiber in a mass ratio of 40:25:25:5:5; wherein the length of the chopped carbon fiber is 10 mm, the length of the ground carbon fiber is 200 μm, the aspect ratio of the ground carbon fiber is 70:1, and the mass of the ground carbon fiber accounts for 5% of the total mass of the raw materials;

[0115] The solid phenolic resin, carbon powder, metal oxide and ground carbon fiber were fully mixed at 30°C and 100 r / min for 30 min to obtain a mixed powder; the mixed powder was then fully mixed with chopped carbon fiber at 30°C and 100 r / min for 30 min to obtain a mixed material;

[0116] S2, compression molding: put the mixed material prepared in step S1 into the mold to make it evenly distributed in the mold, cover the mold cover plate, place it in a flat vulcanizer with a pressing pressure of 200 tons for compression molding, the pressure is 120 tons, the mold temperature is 180°C, and the pressure is maintained for 30 minutes for curing; after the curing is completed, take out the mold, put it in cold water for cooling, open the mold, and take it out to obtain a carbon fiber reinforced resin-based composite body with a density of 1.5 g / cm 3 ;

[0117] S3, embryo body processing: machining the embryo body prepared in step S2 to obtain a carbon ceramic brake disc rough embryo, including removing burrs, processing heat dissipation holes on the disc surface, and processing side ventilation holes;

[0118] S4, carbonization: carbonizing the carbon ceramic brake disc blank prepared in step S3 in a carbonization furnace at a carbonization temperature of 1000° C. for 60 h to obtain a carbonized blank;

[0119] S5, ceramicization: placing the carbide embryo prepared in step S4 in a siliconizing tool, brushing boron nitride powder on the surface of the tool, adding a piece of graphite paper between the tool and the carbide embryo, adding silicon particles on the upper and lower surfaces of the carbide embryo, the mass ratio of silicon particles to the carbide embryo is 1.5:1, and the mass ratio of silicon particles on the upper surface and the lower surface of the carbide embryo is 1:3, placing the tool and the embryo in a special siliconizing furnace, siliconizing at 1600°C~1700°C for 3 h~5 h, to obtain a ceramic embryo;

[0120] S6, finishing: polishing the disc surface of the ceramic embryo prepared in step S5, processing through holes and assembly holes, completing subsequent assembly and testing processes, and preparing a finished carbon ceramic disc.

[0121] The metallographic image of the finished carbon ceramic disc prepared in Example 1 is as follows: Figure 1As shown, chopped carbon fibers 100 and milled carbon fibers 200 of different lengths can be seen.

[0122] Example 2

[0123] It is basically the same as Example 1, except that the length of the ground carbon fiber is 500 μm.

[0124] Example 3

[0125] It is basically the same as Example 1, except that the powdered carbon fiber is a first powdered carbon fiber and a second powdered carbon fiber with a mass ratio of 1:1, the length of the first powdered carbon fiber is 200 μm, and the length of the second powdered carbon fiber is 500 μm.

[0126] Example 4

[0127] It is basically the same as Example 1, except that the mass ratio of chopped carbon fiber, solid phenolic resin, carbon powder, metal oxide and powdered carbon fiber in the raw material is 50:25:15:5:5, the mass of the powdered carbon fiber accounts for 5% of the total mass of the raw material, and the mass of the chopped carbon fiber accounts for 50% of the total mass of the raw material.

[0128] Comparative Example 1

[0129] The method is basically the same as Example 1, except that the mass ratio of chopped carbon fiber, solid phenolic resin, carbon powder, additive and powdered carbon fiber in the raw material is 45:25:25:5:0, that is, no powdered fiber is added.

[0130] Comparative Example 2

[0131] The method is basically the same as Example 1, except that the mass ratio of chopped carbon fiber, solid phenolic resin, carbon powder, metal oxide and powdered carbon fiber in the raw material is 35:25:25:5:10, and the mass of the powdered carbon fiber accounts for 10% of the total mass of the raw material.

[0132] Comparative Example 3

[0133] It is basically the same as Example 1, except that the mass ratio of chopped carbon fiber, solid phenolic resin, carbon powder, metal oxide and powdered carbon fiber in the raw material is 30:25:35:5:5, the mass of the powdered carbon fiber accounts for 5% of the total mass of the raw material, and the mass of the chopped carbon fiber accounts for 30% of the total mass of the raw material.

[0134] Comparative Example 4

[0135] It is basically the same as Example 1, except that the length of the ground carbon fiber is 800 μm.

[0136] The finished carbon ceramic discs prepared in each embodiment and comparative example were sampled and tested for bending strength, impact toughness and tensile strength according to T / CAAMTB 09-2019 Passenger Car Brake Disc Product Standard and Test Method. The average test results are shown in Table 1.

[0137]

[0138] As can be seen from Table 1, compared with Comparative Example 1, the bending strength, tensile strength and impact toughness of the carbon ceramic disc prepared in Example 1 are significantly improved, and it is shown that longer milled fibers can better improve the tensile strength, while shorter milled fibers can improve the bending strength and impact toughness of the material. By combining milled carbon fibers of different lengths, the comprehensive performance of the material can be further improved. In Comparative Examples 2 and 3, the proportion of milled carbon fibers or chopped carbon fibers is inappropriate, and their impact toughness is significantly reduced; the milled carbon fibers of Comparative Example 4 are longer in length and have lower overall performance.

[0139] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0140] The above-described embodiments only express several implementation methods of the present application, which is convenient for understanding the technical solution of the present application in detail, but it cannot be understood as limiting the scope of protection of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the scope of protection of the present application. It should be understood that the technical solutions obtained by those skilled in the art through logical analysis, reasoning or limited experiments on the basis of the technical solutions provided in the present application are all within the scope of protection of the claims attached to the present application. Therefore, the scope of protection of the patent of this application shall be based on the content of the attached claims, and the description can be used to interpret the content of the claims.

Claims

1. A method for preparing a carbon-ceramic composite material, characterized in that: The following steps are involved: Providing raw materials: chopped carbon fiber, ground carbon fiber, carbon powder and organic resin; wherein the length of the chopped carbon fiber is 8 mm to 15 mm, the length of the ground carbon fiber is 200 μm to 500 μm, the aspect ratio of the ground carbon fiber is 30 to 70:1, the mass of the ground carbon fiber accounts for 3% to 8% of the total mass of the raw materials, and the mass of the chopped carbon fiber accounts for 40% to 60% of the total mass of the raw materials; the mass ratio of the chopped carbon fiber, the organic resin, the carbon powder and the ground carbon fiber is 40 to 60:20 to 30:10 to 30:3 to 8; The raw materials are mixed and molded to prepare a carbon fiber composite material; The carbon fiber composite material is subjected to carbonization treatment and siliconization treatment in sequence to prepare a carbon-ceramic composite material.

2. The method for preparing the carbon-ceramic composite material according to claim 1, characterized in that: The mass ratio of the chopped carbon fiber, the organic resin, the carbon powder and the ground carbon fiber is 40-50:20-30:15-25:3-8.

3. The method for preparing the carbon-ceramic composite material according to claim 1, characterized in that: The organic resin includes a phenolic resin.

4. The method for preparing the carbon-ceramic composite material according to claim 1, characterized in that: A sizing agent is provided on the surface of the chopped carbon fiber, and the sizing agent includes at least one of polyurethane and epoxy resin.

5. The method for preparing the carbon-ceramic composite material according to claim 1, characterized in that: The raw material further includes an additive, and the additive satisfies at least one of the following characteristics: (1) The additive includes at least one of a metal oxide powder and a pore-forming agent; (2) The mass ratio of the additive to the chopped carbon fiber is 3-5:40-60.

6. The method for preparing the carbon-ceramic composite material according to any one of claims 1 to 5, characterized in that: The temperature of the molding process is 150°C to 200°C; and / or Forming process using a vulcanizing press; and / or The pressure of the molding process is 80 to 120 tons; and / or The holding time of the molding process is 20 min to 40 min.

7. The method for preparing the carbon-ceramic composite material according to any one of claims 1 to 5, characterized in that: The temperature of the carbonization treatment is 900° C. to 1200° C., and the time of the carbonization treatment is 50 h to 70 h.

8. The method for preparing the carbon-ceramic composite material according to any one of claims 1 to 5, characterized in that: The temperature of the siliconizing treatment is 1500° C. to 1700° C., and the time is 3 h to 5 h.

9. A carbon-ceramic composite material, characterized in that: The carbon-ceramic composite material is prepared by the preparation method of any one of claims 1 to 8.

10. A carbon ceramic brake disc, characterized in that: Comprising the carbon-ceramic composite material as described in claim 9.

11. A means of transport, characterized in that: Comprising the carbon-ceramic brake disc as claimed in claim 10.

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