Preparation method of low-cost high-strength carbon ceramic brake disc

Abstract

The invention discloses a preparation method of a low-cost high-strength carbon-ceramic brake disc, and relates to the technical field of automobile braking. The preparation method comprises the following steps: (1) uniformly mixing chopped carbon fibers, carbon powder, silicon carbide powder and resin powder to form powder, wherein the ratio of the chopped carbon fibers to the carbon powder to the silicon carbide powder to the resin powder is (20-70): (10-30): (10-30): (20-40); (2) the powder is evenly spread in a mold, the spreading thickness is 3-9 mm, a layer of carbon fiber cloth with the gram weight being 200-500 g / m < 2 > is spread on the powder, the powder with the thickness being 3-9 mm is spread again after spreading is completed, cold press forming is conducted through the mold at the low temperature of 40-70 DEG C and the pressure of 2-10 MPa, and an annular rough blank is formed; the problems that an existing carbon-ceramic brake disc is high in cost and insufficient in strength are solved, and the prepared brake disc is high in strength, resistant to abrasion and high temperature, low in cost and good in application prospect.

Description

Technical Field

[0001] The invention relates to the technical field of automobile braking, and in particular to a method for preparing a low-cost and high-strength carbon-ceramic brake disc. Background Art

[0002] At present, the production processes of carbon ceramic brake discs are divided into short fiber carbon ceramic brake discs and long fiber carbon ceramic brake discs.

[0003] The strength of short-fiber carbon ceramic brake discs is lower than that of long-fiber carbon ceramic brake discs, and its strength is only about 50% of that of long-fiber carbon ceramic brake discs. When braking, the friction surface between the brake pad and the carbon ceramic brake disc is subjected to a large shear force. Therefore, after long-term use, the surface of the short-fiber carbon ceramic disc is prone to cracks, and the disc body may collapse or even crack. Summary of the invention

[0004] In response to the above technical problems, the present application solves the problem of poor bearing strength of short-cut fibers by molding a preformed blank by combining long-fiber carbon cloth with short-fiber fibers, and then hot-pressing the blanks by stacking them to form a short-fiber carbon-ceramic brake disc with evenly distributed carbon fiber cloth in the thickness direction, thereby improving the overall strength of the brake disc and solving the problem of poor bearing strength of short-cut fibers.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted in this application is: a method for preparing a low-cost and high-strength carbon-ceramic brake disc, comprising the following steps:

[0006] Step (1), uniformly mixing chopped carbon fiber, carbon powder, silicon carbide powder and resin powder to form a powder, wherein the ratio of chopped carbon fiber, carbon powder, silicon carbide powder and resin powder is (20-70): (10-30): (10-30): (20-40);

[0007] Step (2), evenly spread the above powder in the mold, with a thickness of 3 to 9 mm, and lay a layer of 200 to 500 g / m on the top of the powder. 2 The carbon fiber cloth is laid, and after the laying is completed, powder with a thickness of 3 to 9 mm is spread again. It is cold-pressed into a ring-shaped rough blank through a mold at a low temperature of 40 to 70°C and a pressure of 2 to 10 MPa.

[0008] In order to better realize the present invention, further, the ring-shaped rough blank formed by cold pressing in step (1) is placed in a brake disc mold and stacked up. According to the thickness of the brake disc, the number of stacked layers is 10 to 20 layers, and the number of carbon cloth layers per centimeter thickness is 3 to 6 layers.

[0009] In order to better realize the present invention, further, the stacked annular rough blanks are subjected to hot pressing secondary molding through a mold, the hot pressing temperature is 140-220° C., and the hot pressing pressure is 8MPa-30MPa to form a completely formed brake disc ring.

[0010] In order to better realize the present invention, the brake disc after hot pressing secondary molding is further subjected to carbonization treatment, the carbonization treatment temperature is 800° C. to 1000° C., and the treatment time is 2 to 6 hours.

[0011] In order to better realize the present invention, the product after carbonization treatment is further subjected to machining treatment and then siliconization, the siliconization temperature is 1500°C to 1700°C, the siliconization time is 1 to 4 hours, and the density of the product after siliconization is 2.0 to 2.4 g / cm 3 .

[0012] In order to better realize the present invention, further, when the chopped carbon fiber, carbon powder, silicon carbide powder and resin powder are mixed, a high-speed stirring device is used for stirring, the stirring time is 30 minutes, and the stirring speed is 1500 rpm to ensure uniform mixing.

[0013] In order to better realize the present invention, further, the mold needs to be preheated before cold pressing, and the preheating temperature is 50° C. to ensure uniform mold temperature during the cold pressing process.

[0014] In order to better realize the present invention, further, during the hot pressing secondary molding process, the hot pressing time is 1 to 3 hours, and during the hot pressing process, the pressure and temperature are kept within a stable fluctuation range of ±5°C and ±2MPa.

[0015] In order to better realize the present invention, further, during the siliconizing process, vacuum siliconizing equipment is used, and the vacuum degree is maintained at 5×10-2~5×10-3Pa to improve the siliconizing effect.

[0016] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0017] 1. The present invention combines chopped carbon fiber with carbon fiber woven cloth by prefabricating a brake disc annular body, and then hot-presses and solidifies the body to significantly improve the strength of the brake disc itself;

[0018] 2. The present invention prefabricates the brake disc ring blank and processes the molding process in sections, thereby improving the efficiency of work and process connection between each process, improving production efficiency, and shortening the production cycle;

[0019] 3. The present invention can effectively regulate the distribution ratio of long fibers and short fibers between the layers of the brake disc by prefabricating the circular ring embryo, and carry out targeted design of the structure and function of the brake disc;

[0020] 4. The present invention adopts a two-step molding method, which uses cold pressing for rapid molding and then hot pressing and curing, which can effectively reduce the complexity of mold design and save mold costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative labor.

[0022] Figure 1 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0024] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0025] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0026] In the description of this application, it should be noted that if the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the product of the application is usually placed when in use. It is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on this application. In addition, if the terms "first", "second", etc. appear in the description of this application, they are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0027] In addition, if the terms "horizontal" or "vertical" appear in the description of this application, it does not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0028] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0029] Embodiment 1:

[0030] like Figure 1 As shown, a method for preparing a low-cost and high-strength carbon ceramic brake disc comprises the following steps:

[0031] Step (1), uniformly mixing chopped carbon fiber, carbon powder, silicon carbide powder and resin powder to form a powder, wherein the ratio of chopped carbon fiber, carbon powder, silicon carbide powder and resin powder is (20-70): (10-30): (10-30): (20-40);

[0032] Step (2), evenly spread the above powder in the mold, with a thickness of 3 to 9 mm, and lay a layer of 200 to 500 g / m on the top of the powder. 2 The carbon fiber cloth is laid, and after the laying is completed, powder with a thickness of 3 to 9 mm is spread again. It is cold-pressed into a ring-shaped rough blank through a mold at a low temperature of 40 to 70°C and a pressure of 2 to 10 MPa.

[0033] like Figure 1 As shown, in this embodiment, the ring-shaped rough blank formed by cold pressing in step (1) is placed in a brake disc mold and stacked up. Depending on the thickness of the brake disc, the number of stacked layers is 10 to 20 layers, and the number of carbon cloth layers per centimeter thickness is 3 to 6 layers.

[0034] like Figure 1 As shown, in this embodiment, the stacked annular rough blanks are subjected to hot pressing secondary molding through a mold, the hot pressing temperature is 140-220° C., and the hot pressing pressure is 8 MPa-30 MPa to form a completely formed brake disc ring.

[0035] like Figure 1 As shown, in this embodiment, the brake disc after hot pressing secondary molding is carbonized, the carbonization temperature is 800° C. to 1000° C., and the treatment time is 2 to 6 hours.

[0036] like Figure 1As shown, in this embodiment, the product after carbonization is machined and then siliconized. The siliconization temperature is 1500℃~1700℃, the siliconization time is 1~4h, and the density of the product after siliconization is 2.0~2.4g / cm 3 .

[0037] like Figure 1 As shown, in this embodiment, the chopped carbon fiber, carbon powder, silicon carbide powder, and resin powder are mixed using a high-speed stirring device. The stirring time is 30 minutes and the stirring speed is 1500 rpm to ensure uniform mixing.

[0038] like Figure 1 As shown, in this embodiment, the mold needs to be preheated before cold pressing, and the preheating temperature is 50° C. to ensure uniform mold temperature during the cold pressing process.

[0039] like Figure 1 As shown, in this embodiment, during the hot pressing secondary molding process, the hot pressing time is 1 to 3 hours, and during the hot pressing process, the pressure and temperature are kept within a stable fluctuation range of ±5°C and ±2MPa.

[0040] like Figure 1 As shown, in this embodiment, during the siliconizing process, vacuum siliconizing equipment is used, and the vacuum degree is maintained at 5×10-2~5×10-3Pa to improve the siliconizing effect.

[0041] Working principle:

[0042] The chopped carbon fiber, carbon powder, silicon carbide powder and resin powder are uniformly mixed to form a powder, wherein the ratio of chopped carbon fiber, carbon powder, silicon carbide powder and resin powder is (20-70): (10-30): (10-30): (20-40). The chopped carbon fiber has high strength and high modulus characteristics, which can provide a good mechanical performance foundation for the final product; the carbon powder mainly plays the role of filling and adjusting the material structure; the silicon carbide powder has high hardness, high temperature resistance, wear resistance and other characteristics, which can improve the wear resistance and high temperature performance of the brake disc; the resin powder is used as a binder to firmly combine other materials together through curing reaction in the subsequent molding process. High-speed stirring equipment is used for stirring, the stirring time is 30 minutes, and the stirring speed is 1500 rpm. The purpose is to fully and evenly disperse the raw materials of various particle sizes and densities through high-speed stirring to ensure that the performance of the subsequent molded products is uniform and stable.

[0043] The strength of the brake disc can be significantly improved by combining chopped carbon fiber with carbon fiber woven cloth in a prefabricated brake disc ring blank and then hot pressing and curing it. Specifically, in the subsequent molding process, this combination method can better exert the mechanical properties of the material. The high strength of the chopped carbon fiber and the structural advantages of the carbon fiber woven cloth cooperate with each other to enhance the overall strength of the brake disc.

[0044] Spread the above powder evenly in the mold with a thickness of 3 to 9 mm. Spread a layer of 200 to 500 g / m on top of the powder. 2 After the carbon fiber cloth is laid, powder with a thickness of 3 to 9 mm is spread again, and the rough blank is formed by cold pressing at a low temperature of 40 to 70 ° C and a pressure of 2 to 10 MPa through a mold. The mold needs to be preheated before cold pressing. The preheating temperature is 50 ° C. This is to ensure that the temperature of each part of the mold is uniform, and to avoid uneven curing of the powder during the cold pressing process due to temperature differences, which affects the quality of the rough blank. Under low temperature and a certain pressure, the resin powder begins to solidify initially, bonding the powder and the carbon fiber cloth together to form a rough blank with a certain shape and strength. The carbon fiber cloth further enhances the structural strength and toughness of the rough blank.

[0045] The prefabricated brake disc ring blank undergoes a segmented molding process, first cold pressing to form a rough ring blank, and then hot pressing for secondary molding. This processing method improves the efficiency of work and process connection between each process, improves production efficiency, and shortens the production cycle. Cold pressing rapid molding prepares for hot pressing and curing, making the entire production process smoother and more efficient.

[0046] By prefabricating the ring embryo, in the early stage of mixing powder and laying carbon fiber cloth, the distribution ratio of long fibers (carbon fiber woven cloth can be regarded as long fiber form) and short fibers (chopped carbon fiber) between the layers of the brake disc can be effectively regulated, and the structure and function of the brake disc can be designed in a targeted manner. For example, according to different usage requirements and working conditions, the ratio of long fibers to short fibers can be adjusted to optimize the strength, toughness and other properties of the brake disc.

[0047] The cold-pressed rough dough of the ring shape in step (1) is placed in the brake disc mold and stacked. According to the thickness of the brake disc, the number of stacked layers is 10 to 20 layers, and the number of carbon cloth layers per centimeter thickness is 3 to 6 layers. The purpose of stacking is to prepare a brake disc that meets the thickness requirements by increasing the number of layers within the limited mold space. At the same time, the reasonably distributed number of carbon cloth layers further ensures the uniformity of the mechanical properties of the final product in the thickness direction.

[0048] The two-step molding method is adopted, that is, cold pressing molding first and then hot pressing molding. Through cold pressing rapid molding and hot pressing and curing, the complexity of mold design can be effectively reduced and mold costs can be saved. The cold pressing process is relatively simple and the requirements for the mold are relatively low. The hot pressing process is carried out on the basis of cold pressing molding, and does not require an overly complex mold structure to achieve product molding, thereby reducing the design and production costs of the mold.

[0049] The stacked annular rough blanks are subjected to secondary hot pressing molding through a mold. The hot pressing temperature is 140-220°C and the hot pressing pressure is 8MPa-30MPa to form a fully formed brake disc ring. During the hot pressing process, as the temperature rises, the resin powder undergoes further cross-linking and curing reactions to enhance the bonding between the materials. At the same time, under the action of higher pressure, the pores inside the material are further compressed, and the distance between molecules is reduced, making the material denser, thereby improving the strength and hardness of the brake disc, and finally forming a stable brake disc ring shape. The hot pressing time is 2 hours, and the pressure and temperature are kept stable in the fluctuation range of ±5°C and ±2MPa during the hot pressing process. Stable temperature and pressure are the key to ensuring that the resin curing reaction is sufficient and uniform. The small fluctuation range can avoid inconsistent product performance due to excessive changes in temperature and pressure.

[0050] The brake disc after hot pressing secondary molding is carbonized at a temperature of 800℃~1000℃ for 2~6h. During this high-temperature carbonization process, organic matter (mainly resin) gradually decomposes and volatilizes, and the remaining carbon elements are further combined with the original carbon powder, chopped carbon fibers, etc. to form a more stable carbon matrix structure. This process not only removes impurities, but also strengthens the chemical bonding between carbon materials, improving the high temperature resistance and chemical stability of the brake disc.

[0051] The carbonized product is machined and then siliconized. The siliconization temperature is 1500℃~1700℃, the siliconization time is 1~4h, and the density of the product after siliconization is 2.0~2.4g / cm 3 . During the siliconization process, vacuum siliconization equipment is used, and the vacuum degree is maintained at 5×10-3Pa. At high temperatures, silicon atoms are highly active and can more easily diffuse into the pores and lattices of the carbon matrix in a vacuum environment. Silicon and carbon react chemically to form silicon carbide (SiC), which is evenly distributed in the carbon matrix, further enhancing the hardness, wear resistance and high-temperature performance of the brake disc. At the same time, siliconization fills the pores in the carbon matrix, increasing the product density to an appropriate range and improving the overall performance.

[0052] Embodiment 2:

[0053] Step (1), chopped carbon fiber, carbon powder, silicon carbide powder, and resin powder are uniformly mixed to form a powder, wherein the ratio of chopped carbon fiber, carbon powder, silicon carbide powder, and resin powder is 30:20:25:25. A high-speed stirring device is used for stirring, the stirring time is 30 minutes, and the stirring speed is 1500 revolutions per minute.

[0054] Step (2), spread the above powder evenly in the mold, with a spreading thickness of 5mm, and lay a layer of 300g / m2 on the top of the powder. 2After the carbon fiber cloth is laid, a 5mm thick powder is spread again, and the mold is cold-pressed at a low temperature of 50°C and a pressure of 5MPa to form a ring-shaped rough blank. The mold is preheated before cold pressing, and the preheating temperature is 50°C.

[0055] The cold-pressed rough doughnut is placed in a brake disc mold and stacked up. The number of stacked layers is 12, and the number of carbon cloth layers per centimeter thickness is 4.

[0056] The stacked circular rough blanks are subjected to secondary hot pressing molding through a mold. The hot pressing temperature is 160°C, the hot pressing pressure is 15MPa, and the hot pressing time is 2 hours. During the hot pressing process, the pressure and temperature are kept stable within the fluctuation range of ±5°C and ±2MPa to form a fully formed brake disc ring.

[0057] The brake disc after hot pressing secondary molding is carbonized at a temperature of 900°C and a treatment time of 4 hours.

[0058] The carbonized product was machined and then siliconized. The siliconization temperature was 1600℃ and the siliconization time was 2h. The density of the product after siliconization was 2.2g / cm 3 During the siliconizing process, vacuum siliconizing equipment was used and the vacuum degree was maintained at 5×10 -2 Pa.

[0059] Embodiment three:

[0060] Step (1), chopped carbon fiber, carbon powder, silicon carbide powder, and resin powder are uniformly mixed to form a powder, wherein the ratio of chopped carbon fiber, carbon powder, silicon carbide powder, and resin powder is 40:15:20:25. The stirring method is the same as that of Example 1.

[0061] Step (2), spread the above powder evenly in the mold, with a thickness of 7mm, and lay a layer of 400g / m2 on the top of the powder. 2 After the carbon fiber cloth is laid, the powder with a thickness of 7mm is spread again, and the rough blank is formed by cold pressing at a low temperature of 60℃ and a pressure of 8MPa through a mold. The mold preheating temperature is 50℃.

[0062] The cold-pressed ring-shaped rough blank is placed in the brake disc mold and stacked up. The number of stacked layers is 15, and the number of carbon cloth layers per centimeter thickness is 5.

[0063] The stacked annular rough blanks are subjected to hot pressing secondary molding through a mold. The hot pressing temperature is 180° C., the hot pressing pressure is 20 MPa, and the hot pressing time is 2.5 hours. The stable fluctuation range of pressure and temperature during the hot pressing process is the same as in Example 1, forming a completely formed brake disc ring.

[0064] The brake disc after hot pressing secondary molding is carbonized at a temperature of 950°C and a treatment time of 5 hours.

[0065] The carbonized product was machined and then siliconized. The siliconization temperature was 1650℃ and the siliconization time was 3h. The density of the product after siliconization was 2.3g / cm 3 Siliconization is carried out using vacuum siliconization equipment, and the vacuum degree is maintained at 5×10 -3 Pa.

[0066] Embodiment 4:

[0067] Step (1), chopped carbon fiber, carbon powder, silicon carbide powder, and resin powder are uniformly mixed to form a powder, wherein the ratio of chopped carbon fiber, carbon powder, silicon carbide powder, and resin powder is 50:10:20:20. The stirring parameters remain unchanged.

[0068] Step (2), spread the above powder evenly in the mold, with a thickness of 4mm, and lay a layer of 250g / m2 on the top of the powder. 2 After the carbon fiber cloth is laid, 4mm thick powder is spread again, and the mold is cold pressed at a low temperature of 45℃ and a pressure of 6MPa to form a ring-shaped rough blank. The mold is preheated to 50℃.

[0069] The cold-pressed ring-shaped rough blank is placed in the brake disc mold and stacked up. The number of stacked layers is 18, and the number of carbon cloth layers per centimeter thickness is 3.

[0070] The stacked circular rough blanks are subjected to secondary hot pressing molding through a mold. The hot pressing temperature is 150°C, the hot pressing pressure is 12MPa, and the hot pressing time is 1.5 hours. During hot pressing, the pressure and temperature fluctuation ranges are well controlled to form a fully formed brake disc ring.

[0071] The brake disc after hot pressing secondary molding is carbonized at a temperature of 850°C and a treatment time of 3 hours.

[0072] The carbonized product was machined and then siliconized. The siliconization temperature was 1550℃ and the siliconization time was 1.5h. The density of the product after siliconization was 2.1g / cm 3 The vacuum degree was maintained at 5×10 -2 Pa.

[0073] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing a low-cost and high-strength carbon ceramic brake disc, characterized in that: The following steps are involved: Step (1), uniformly mixing chopped carbon fiber, carbon powder, silicon carbide powder and resin powder to form a powder, wherein the ratio of chopped carbon fiber, carbon powder, silicon carbide powder and resin powder is (20-70): (10-30): (10-30): (20-40); Step (2), evenly spread the above powder in the mold, with a thickness of 3 to 9 mm, and lay a layer of 200 to 500 g / m on the top of the powder. 2 The carbon fiber cloth is laid, and after the laying is completed, powder with a thickness of 3 to 9 mm is spread again. It is cold-pressed into a ring-shaped rough blank through a mold at a low temperature of 40 to 70°C and a pressure of 2 to 10 MPa.

2. The method for preparing a low-cost and high-strength carbon ceramic brake disc according to claim 1, characterized in that: The ring-shaped rough blank formed by cold pressing in step (1) is placed in a brake disc mold and stacked up. According to the thickness of the brake disc, the number of stacked layers is 10 to 20 layers, and the number of carbon cloth layers per centimeter thickness is 3 to 6 layers.

3. The method for preparing a low-cost and high-strength carbon ceramic brake disc according to claim 2, characterized in that: The stacked circular rough blanks are subjected to secondary hot pressing molding through a mold, the hot pressing temperature is 140-220°C, and the hot pressing pressure is 8MPa-30MPa, to form a completely formed brake disc ring.

4. The method for preparing a low-cost and high-strength carbon ceramic brake disc according to claim 3, characterized in that: The brake disc after hot pressing secondary molding is carbonized at a temperature of 800°C to 1000°C for a time of 2 to 6 hours.

5. The method for preparing a low-cost and high-strength carbon ceramic brake disc according to claim 4, characterized in that: The carbonized product is machined and then siliconized. The siliconization temperature is 1500℃~1700℃, the siliconization time is 1~4h, and the density of the product after siliconization is 2.0~2.4g / cm 3 .

6. The method for preparing a low-cost and high-strength carbon ceramic brake disc according to claim 1, characterized in that: When the chopped carbon fiber, carbon powder, silicon carbide powder and resin powder are mixed, a high-speed stirring device is used for stirring. The stirring time is 30 minutes and the stirring speed is 1500 revolutions per minute to ensure uniform mixing.

7. The method for preparing a low-cost and high-strength carbon ceramic brake disc according to claim 1, characterized in that: The mold needs to be preheated before cold pressing, and the preheating temperature is 50° C. to ensure uniform mold temperature during the cold pressing process.

8. The method for preparing a low-cost and high-strength carbon ceramic brake disc according to claim 3, characterized in that: During the hot pressing secondary molding process, the hot pressing time is 1 to 3 hours, and the pressure and temperature are kept within a stable fluctuation range of ±5°C and ±2MPa during the hot pressing process.

9. The method for preparing a low-cost and high-strength carbon ceramic brake disc according to claim 5, characterized in that: During the siliconizing process, vacuum siliconizing equipment is used and the vacuum degree is maintained at 5×10-2~5×10-3Pa.

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