A low-cost carbon-ceramic brake material and preparation method thereof

Abstract

The invention discloses a low-cost carbon-ceramic brake material and a preparation method thereof. Carbon fibers are sheared to obtain chopped fibers. The chopped fibers, calcined petroleum coke, phenolic resin, hexamethylenetetramine, nano zirconium silicate powder, and vermiculite powder are mixed to obtain a mixture. The mixture is pressed and formed to obtain a blank. The blank is carbonized to obtain a carbonized blank. The carbonized blank is subjected to siliconization to obtain a carbon-ceramic blank. The carbon-ceramic blank is further subjected to silicon impurity removal treatment. Finally, the carbon-ceramic brake material is obtained by polishing. The preparation method of the invention adopts a resin molding method to prepare a carbon / carbon blank. Not only is the preparation cycle short, but the cost is also low. The carbon-ceramic brake material prepared by the invention has a stable friction coefficient, a wear rate of less than 0.65 μm / surface·time, and a stable braking process with low vibration and no whistling.

Description

Technical Field

[0001] The invention relates to a low-cost carbon-ceramic brake material and a preparation method thereof, belonging to the technical field of brake disc preparation. Background Art

[0002] Carbon ceramic brake material is a high-performance friction material developed on the basis of C / C material. Compared with C / C friction material, its wet friction performance attenuation is small and its static friction coefficient is large. C / C friction material can obtain stable braking ability at high temperature, but cannot obtain stable braking ability at low temperature. C / SiC friction material not only has stable braking ability at high temperature, but also has very stable braking ability at low temperature.

[0003] There are many methods for preparing carbon / silicon carbide ceramic brake materials, including precursor impregnation pyrolysis, plasma spraying, vapor deposition, reactive infiltration, etc. The carbon ceramic brake materials prepared by these methods can basically solve the braking problems of most aircraft, high-speed trains and automobiles. However, due to the high manufacturing cost of carbon ceramic brake materials, they are still not widely used. Summary of the invention

[0004] In view of the high manufacturing cost of existing carbon ceramic brake materials, the first object of the present invention is to provide a low-cost preparation method of carbon ceramic brake materials. The preparation method provided by the present invention not only has low preparation cost and short cycle, but also the prepared carbon ceramic brake material has excellent friction and wear properties.

[0005] The second object of the present invention is to provide a low-cost carbon-ceramic brake material prepared by the above preparation method.

[0006] In order to solve the above problem, the present invention adopts the following technical solution:

[0007] The invention discloses a method for preparing a low-cost carbon-ceramic brake material. The method comprises the following steps: shearing carbon fibers to obtain chopped fibers, mixing the chopped fibers, calcined petroleum coke, phenolic resin, hexamethylenetetramine, nano zirconium silicate powder and vermiculite powder to obtain a mixture, pressing the mixture to form a green body, carbonizing the green body to obtain a carbonized green body, reacting siliconizing the carbonized green body to obtain a carbon-ceramic green body, removing silicon from the carbon-ceramic green body, and finally polishing the green body to obtain the carbon-ceramic brake material.

[0008] The preparation method of the present invention first adopts resin molding to prepare a carbon / carbon blank. The preparation of the molded blank is a key technology to solve the problem of low-cost carbon-ceramic brake materials. In the present invention, short-cut fibers, calcined petroleum coke, phenolic resin, hexamethylenetetramine, nano zirconium silicate powder, and vermiculite powder are used as raw materials for the carbon / carbon blank. Since long fibers are not easy to disperse as reinforcements, the fiber distribution of the molded blank is uneven, and it is difficult to mold or the strength after molding is low. Therefore, the present invention adopts short-cut fibers as reinforcements to increase the mechanical properties of the blank. At the same time, calcined petroleum coke is used as one of the carbon matrices. The calcined petroleum coke also has excellent thermal conductivity, which can effectively reduce the temperature of the friction surface and reduce wear. In addition, the deformation of the blank can be ensured to be small during the molding and heat treatment process, and a large number of microcracks will not appear to cause a decrease in mechanical properties. More importantly, the calcined petroleum coke has high chemical reactivity. In the melt infiltration reaction, it will react with silicon first, which can not only protect the carbon fiber, reduce the corrosion of silicon on the carbon fiber, and retain the strength of the carbon fiber to the maximum extent, but also form continuous silicon carbide. At the same time, phenolic resin is added as a binder and also as a carbon source for silicon-carbon reaction, further improving the overall forming stability of the blank. Hexamethylenetetramine is used as a curing agent for the phenolic resin to make the matrix uniformly cured to prevent local cracks. A small amount of vermiculite powder is added, and the vermiculite powder can expand when the temperature rises to form a uniformly distributed channel, which can ensure the uniform infiltration of silicon liquid during the reaction melt infiltration process. Under the synergistic effect of phenolic resin, calcined petroleum coke and vermiculite powder, a uniform and three-dimensional continuous silicon carbide matrix is ​​finally formed. In addition, a small amount of nano zirconium silicate is added to adjust the hydrophilicity of the blank to reduce the wet attenuation of the final carbon ceramic product. The carbon / carbon blank prepared by molding the above formula is subjected to a siliconizing process to obtain a carbon ceramic blank, which is then subjected to a heat treatment desiliconization process to eliminate stress in the matrix and increase the toughness of the material. In addition, the silicon liquid will react and deposit on the surface during the precipitation process to form a uniform and dense silicon carbide layer with better oxidation resistance. Through the synergistic effect of the above preparation process, the carbon ceramic brake material prepared by the present invention has a stable friction coefficient and a wear rate of less than 0.65 μm / surface·time, and the braking process is stable with little vibration and no whistling.

[0009] In a preferred embodiment, the carbon fiber is polypropylene-based carbon fiber (PANCF), model T300.

[0010] In a preferred embodiment, the carbon fiber is first heat treated at a temperature of 1500-1700°C, preferably 1600°C. The present invention controls the heat treatment temperature of the carbon fiber to maximize the retention of fiber strength, which not only increases the strength of the blank, provides better support for the matrix, but also effectively reduces wear. During the heat treatment process, it is necessary to avoid excessive temperatures to prevent defects on the carbon fiber surface, reduce the strength of the carbon fiber, and increase material fatigue wear.

[0011] In a preferred solution, the length of the chopped fibers is 15 to 25 mm. The inventors have found that when the length of the chopped fibers is controlled within the above range, the strength and wear resistance of the final carbon-ceramic brake material are optimal.

[0012] In a preferred embodiment, the mixture is composed of the following components by mass fraction: 40 to 45 parts of chopped fibers, 38 to 42 parts of calcined petroleum coke, 13 to 17 parts of phenolic resin, 8 to 15 parts of hexamethylenetetramine, 3 to 6 parts of nano zirconium silicate powder, and 5 to 10 parts of vermiculite powder.

[0013] The inventors found that by controlling the components in the mixture within the above range, the performance of the carbon ceramic brake material obtained is optimal. If there are too many chopped fibers, the dispersion becomes poor, and the agglomerated carbon fibers cause the blank to be easily delaminated and cracked after forming, and the strength is reduced; if there are too few chopped fibers, the mechanical properties of the blank are reduced and the toughness is reduced. If there are too many calcined petroleum cokes, the brittleness of the material increases and it is easy to crack; if there are too few calcined petroleum cokes, the thermal conductivity of the material is reduced.

[0014] Wear increases. Too much phenolic resin will result in poor mechanical properties after the green body is formed and it is easy to crack. Too little phenolic resin will make it difficult to solidify and the green body will have poor mechanical properties. Too much hexamethylenetetramine will cause the green body to solidify quickly and local defects such as pores will appear. Too little hexamethylenetetramine will result in poor solidification effect. Too much nano zirconium silicate powder will increase wear. Too little nano zirconium silicate powder will not improve the hydrophilicity of the material. Too much vermiculite powder will result in large voids and reduced mechanical properties of the material. Too little vermiculite powder will not form a good channel and it will easily delaminate and crack after siliconization, and it will be impossible to obtain overall continuous silicon carbide.

[0015] Preferably, the pressing method is hot pressing, and the hot pressing process is to heat up to 75-85°C for the first time within 7.5-8.5 hours, then heat up to 145-155°C for the second time within 13.5-14.5 hours, and finally heat up to 199-209°C for the third time within 19.5-20.5 hours. The pressure of the pressing is controlled to be 18-22t throughout the whole process.

[0016] The pressing molding of the present invention ensures that the blank still retains the maximum mechanical properties after carbonization through effective control of the heating program and slow heating. In the present invention, a slow heating rate is adopted to prevent a large number of bubbles from appearing during the hot pressing process when the phenolic resin is cured, causing cracks in the blank. At the same time, three-stage insulation is adopted. During the first heating and insulation process, the phenolic resin is liquefied to ensure full infiltration and complete liquefaction. During the second heating and insulation process, the phenolic resin begins to solidify and releases a large amount of gas. During the third heating and insulation process, the phenolic resin is completely solidified.

[0017] In a preferred embodiment, the carbonization process is to uniformly heat the temperature to 950-1050° C., preferably 982° C., within 47-49 hours, and keep the temperature for 2-5 hours, preferably 3 hours.

[0018] In the actual operation process, the obtained green body is placed in a carbonization furnace for carbonization treatment, and after vacuuming and replacing nitrogen twice, nitrogen is filled to a slight positive pressure, and then the temperature is slowly raised to 950-1050°C for carbonization. The inventors found that during the carbonization process, the heating rate must be effectively controlled so that the small molecules of the phenolic resin carbonization are slow and appropriate, and the vermiculite powder can be controllably expanded to form an ideal channel while avoiding cracking. In addition, the carbonization temperature is controlled within the above range, and the final composite material has the best performance. If the temperature is too high, the mechanical properties of the green body will be reduced, resulting in increased fatigue wear of the material.

[0019] In a preferred embodiment, the density of the carbonized body is 1.50 to 1.60 g / cm 3 .

[0020] In a preferred embodiment, the purity of silicon used in the reactive infiltration silicon is ≥99.0% and the particle size is ≤400 mesh.

[0021] In a preferred embodiment, the reactive silicon infiltration is carried out in a nitrogen atmosphere, the temperature of the reactive silicon infiltration is 1700-1900°C, preferably 1750°C, the time of the reactive silicon infiltration is 2-5h, preferably 3h, and the pressure is 6-8kPa.

[0022] The present invention adopts micro-negative pressure reaction infiltration during reaction infiltration of silicon, and nitrogen is directly introduced into the reaction chamber while vacuuming, which can not only ensure uniform distribution of nitrogen in the reaction chamber, but also increase the vapor saturation pressure of silicon, so that the silicon-carbon reaction is sufficient. At the same time, nitrogen is utilized so that nitrogen atoms can enter the silicon carbide unit cell and inhibit the rapid growth of silicon carbide grains. In this way, uniform reaction infiltration can be ensured and the silicon carbide grains can be refined.

[0023] The inventors found that by controlling the temperature of the reaction infiltration within the above range, the carbon ceramic brake material obtained has the best comprehensive performance. If the reaction infiltration temperature is too high, the silicon carbide grain size increases, the friction coefficient increases, and the friction vibration increases. If the reaction infiltration temperature is too low, the viscosity of the silicon liquid decreases, the penetration depth is insufficient, and the silicon carbide distribution is prone to uneven distribution. In addition, the silicon carbide grain size decreases, the friction coefficient decreases, and the deceleration rate decreases.

[0024] In a preferred embodiment, the silicon de-impurity treatment is carried out under vacuum, the temperature of the silicon de-impurity treatment is 1600-1700°C, preferably 1650°C, the time of the silicon de-impurity treatment is 2-5h, preferably 2h, and the time for silicon de-impurity treatment is 7-9h from room temperature to 1600-1700°C.

[0025] Through the above process, excess silicon can be removed, and the silicon liquid will react and deposit on the surface during the precipitation process to form a uniform and dense silicon carbide layer.

[0026] In a preferred solution, the polishing process is to polish the friction surface with a grinding wheel of 100 to 300 mesh, preferably 200 mesh. The inventors found that the friction surface roughness is high after processing with a grinding wheel below 100 mesh, and vibration and whistling will be generated during the friction process. Grinding wheels above 300 mesh are not easy to process, and the consumption of grinding wheels increases, which increases the cost.

[0027] The present invention also provides a low-cost carbon-ceramic brake material prepared by the above preparation method.

[0028] In a preferred embodiment, the density of the carbon ceramic brake material is 1.95-2.00 g / cm 3 .

[0029] Principles and advantages

[0030] The preparation method of the present invention adopts a resin molding method to prepare the carbon / carbon blank, which has a short preparation cycle and low cost.

[0031] The present invention firstly heat-treats the chopped fibers, and by controlling the heat-treatment temperature of the carbon fibers, the fiber strength is retained to the maximum, which not only increases the strength of the blank, but also provides better support for the matrix and effectively reduces wear. In the formula of the carbon / carbon blank, on the one hand, by adding calcined petroleum coke, it has high chemical reactivity and high thermal conductivity, which not only forms continuous silicon carbide but also effectively reduces the temperature of the friction surface and reduces wear. The addition of vermiculite powder passes through a uniform silicon infiltration channel, and finally forms a uniform and three-dimensional continuous silicon carbide matrix under the synergistic effect of phenolic resin. At the same time, the addition of nano zirconium silicate has good hydrophobicity, which can effectively reduce the water absorption rate of the matrix and wear debris, and reduce the attenuation of wet brake performance. In the reaction infiltration of silicon, a micro-negative pressure reaction infiltration is used, and nitrogen is directly introduced into the reaction chamber while vacuuming, which can not only ensure the uniform distribution of nitrogen in the reaction chamber, but also increase the vapor saturation pressure of silicon, so that the silicon-carbon reaction is sufficient. At the same time, nitrogen atoms can enter the silicon carbide unit cell to inhibit the rapid growth of silicon carbide grains, so that the reaction infiltration can be uniform and the silicon carbide grains can be refined. Finally, the present invention performs heat treatment after the reaction infiltration to remove the residual elemental silicon, and a layer of silicon carbide is evenly distributed on the surface of the carbon ceramic disk, which has better anti-oxidation performance.

[0032] The advantages of the present invention are as follows:

[0033] 1. The present invention adopts a molded green body to prepare the carbon ceramic brake material, which greatly reduces the production cost and preparation cycle.

[0034] 2. The molded green body prepared by the present invention has high strength, good wear resistance, strong interface bonding with carbon fiber and silicon carbide, enhanced support for silicon carbide, and reduced wear of silicon carbide particles.

[0035] 3. The content of elemental silicon formed in the reaction infiltration process is generally (5-15)%. Elemental silicon can increase the attenuation rate of high-energy braking, and the microsilicon powder formed in the wear debris has strong water absorption, which will increase the attenuation rate of wet braking performance. The molded matrix prepared by the present invention has uniform void distribution and no macropores. There is no elemental silicon in the matrix after reaction infiltration, and the nano zirconium silicate added to the matrix has good hydrophobicity, which greatly reduces the water absorption of the wear debris and reduces the attenuation of wet braking performance.

[0036] 4. The present invention performs reactive infiltration in a nitrogen atmosphere, and nitrogen atoms can enter the silicon carbide crystal cells to inhibit the rapid growth of silicon carbide grains, thereby ensuring uniform reactive infiltration and preventing the silicon carbide grains from growing too large.

[0037] 5. The present invention performs heat treatment after reactive infiltration to remove residual silicon, and a layer of silicon carbide is evenly distributed on the surface of the carbon ceramic disk, which has better anti-oxidation performance.

[0038] The carbon ceramic brake material prepared by the invention has a stable friction coefficient, a wear rate of less than 0.65 μm / surface / time, a stable braking process, small vibration and no whistling. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 : Metallographic diagram of the carbon ceramic brake material obtained in Example 1. DETAILED DESCRIPTION

[0040] Example 1

[0041] Step 1: Preparation of carbon fiber preform

[0042] The polyacrylonitrile T300 carbon fiber was heat treated at 1600°C and cut into short fibers with a length of 20 mm. 40 parts of calcined petroleum coke, 15 parts of phenolic resin, 15 parts of curing agent hexamethylenetetramine, 5 parts of nano zirconium silicate, 8 parts of vermiculite powder and 40 parts of short-cut fibers were mixed evenly in a mixer.

[0043] The mixed raw materials are placed in the mold for hot pressing and shaping. The process parameters are as follows:

[0044] Table 1 Hot pressing process parameters

[0045] Temperature ℃ Time Pressure RT~(80±5) 8±0.5 20±2 (80±5)～(150±5) 14±0.5 20±2 (150±5)～(204±5) 20±0.5 20±2

[0046] Step 2: Carbonization of the green body

[0047] The green body obtained in step 1 is placed in a carbonization furnace for carbonization treatment, and the nitrogen is replaced twice by vacuum and then filled to a slightly positive pressure. The temperature is slowly raised to 982°C, the heating time is 48 hours, and the heat preservation time is 3 hours. The green body after carbonization is machined according to the product size.

[0048] Step 3: Reaction Infiltration

[0049] The green body obtained in step 2 is placed in a reaction infiltration furnace for silicon infiltration. The reaction infiltration temperature is 1750°C, the time is 3 hours, the atmosphere is nitrogen, and while vacuuming, nitrogen is directly introduced into the reaction chamber, using slightly negative pressure reaction infiltration.

[0050] Step 4: Heat treatment

[0051] The green body obtained in step 3 is placed in a heat treatment furnace for heat treatment. The temperature is slowly raised to 1650°C under vacuum for 8 hours and the heat preservation time is 2 hours.

[0052] Step 5: Polishing

[0053] The carbon ceramic body obtained in step 4 is polished on the friction surface with a 200-mesh grinding wheel.

[0054] Figure 1 As shown, it is a metallographic image of the carbon ceramic brake material prepared in Example 1, wherein the metallographic image is silicon carbide. It can be seen that the silicon carbide matrix in the present invention is continuously distributed.

[0055] According to the performance test, the density of the carbon ceramic brake material prepared in Example 1 is 2.0 g / cm 3 , silicon carbide content 40%, compression strength 150MPa. The friction coefficient of carbon ceramic brake disc is 0.55, the wear rate is 0.63μm / surface·time, the peak-to-valley ratio of the friction curve is 1.48, and the wet brake performance attenuation rate is 3.0%.

[0056] Example 2

[0057] Step 1: Preparation of carbon fiber preform

[0058] The polyacrylonitrile T300 carbon fiber was heat treated at 1600°C and cut into short fibers with a length of 20 mm. 40 parts of calcined petroleum coke, 15 parts of phenolic resin, 15 parts of curing agent hexamethylenetetramine, 5 parts of nano zirconium silicate, 8 parts of vermiculite powder and 45 parts of short-cut fibers were mixed evenly in a mixer.

[0059] The mixed raw materials are placed in the mold for hot pressing and shaping. The process parameters are as follows:

[0060] Table 2 Hot pressing process parameters

[0061] Temperature ℃ Time Pressure RT~(80±5) 8±0.5 20±2 (80±5)～(150±5) 14±0.5 20±2 (150±5)～(204±5) 20±0.5 20±2

[0062] Step 2: Carbonization of the green body

[0063] The green body obtained in step 1 is placed in a carbonization furnace for carbonization treatment, and the nitrogen is replaced twice by vacuum and then filled to a slightly positive pressure. The temperature is slowly raised to 982°C, the heating time is 48 hours, and the heat preservation time is 3 hours. The green body after carbonization is machined according to the product size.

[0064] Step 3: Reaction Infiltration

[0065] The green body obtained in step 2 is placed in a reaction infiltration furnace for silicon infiltration. The reaction infiltration temperature is 1750°C and the time is 3 hours. The atmosphere is nitrogen. While evacuating the vacuum chamber, nitrogen is directly introduced into the reaction chamber. A slightly negative pressure reaction infiltration is used.

[0066] Step 4: Heat treatment

[0067] The green body obtained in step 3 is placed in a heat treatment furnace for heat treatment. The temperature is slowly raised to 1650°C under vacuum for 8 hours and the heat preservation time is 2 hours.

[0068] Step 5: Polishing

[0069] The carbon ceramic body obtained in step 4 is polished on the friction surface with a 200-mesh grinding wheel.

[0070] The density of the prepared carbon ceramic brake material is 1.98g / cm 3 , silicon carbide content 38%, compression strength 145MPa. The friction coefficient of carbon ceramic brake disc is 0.50, the wear rate is 0.65μm / surface·time, the peak-to-valley ratio of the friction curve is 1.45, and the wet brake performance attenuation rate is 3.1%.

[0071] Comparative Example 1

[0072] The other conditions were the same as those in Example 1, except that the carbon fiber content was 50 parts. Fiber agglomeration occurred in the mixed powder during the dispersion process, and defects occurred locally in the molded green body, which did not meet the green body molding requirements.

[0073] Comparative Example 2

[0074] The other conditions were the same as those in Example 1, except that the fiber content was 35 parts. The green body after compression molding met the process requirements, but was prone to edge collapse or large pieces falling off during machining, which did not meet the green body molding requirements.

[0075] Comparative Example 3

[0076] The other conditions were the same as those in Example 1, except that the phenolic resin content was 20 parts. A large number of hollows and collapses appeared in the green body after compression molding, and a large number of microcracks appeared in the green body after carbonization, which did not meet the green body molding requirements.

[0077] Comparative Example 4

[0078] The other conditions were the same as those in Example 1, except that the phenolic resin content was 10 parts. The green body was prone to falling off and breaking during machining, and did not meet the green body forming requirements.

[0079] Comparative Example 5

[0080] The other conditions were the same as those in Example 1, except that the curing agent content was 20 parts. There were a lot of hollowing phenomena in the green body after molding, and a lot of microcracks appeared in the green body after carbonization, which did not meet the green body molding requirements.

[0081] Comparative Example 6

[0082] The other conditions were the same as those in Example 1, except that the curing agent content was 5 parts. The green body cracked after carbonization, which did not meet the green body forming requirements.

[0083] Comparative Example 7

[0084] The other conditions were the same as those in Example 1, except that the content of calcined petroleum coke was 30 parts. The density of the prepared carbon ceramic brake material was 1.95 g / cm 3 , silicon carbide content 35%, compression strength 140MPa. The friction coefficient of carbon ceramic brake disc is 0.56, the wear rate is 1.58μm / surface·time, the peak-to-valley ratio of the friction curve is 1.7, and the wet brake performance attenuation rate is 3.0%.

[0085] Comparative Example 8

[0086] The other conditions were the same as those in Example 1, except that the content of calcined petroleum coke was 45 parts. There were a large number of microcracks in the green body after carbonization, and the green body was prone to falling off and breaking during machining, which did not meet the green body forming requirements.

[0087] Comparative Example 9

[0088] The other conditions are the same as those in Example 1, except that the content of nano-zirconium silicate is 2 parts. The density of the prepared carbon ceramic brake material is 1.99 g / cm 3 , silicon carbide content 39%, compression strength 155MPa. The friction coefficient of carbon ceramic brake disc is 0.54, the wear rate is 0.64μm / surface·time, the peak-to-valley ratio of the friction curve is 1.5, and the wet braking performance attenuation rate is 10%.

[0089] Comparative Example 10

[0090] The other conditions are the same as those in Example 1, except that the content of nano-zirconium silicate is 10 parts. The density of the prepared carbon ceramic brake material is 2.0 g / cm 3 , silicon carbide content 39%, compression strength 155MPa. The friction coefficient of carbon ceramic brake disc is 0.58, wear rate 1.73μm / surface·time, peak-to-valley ratio of friction curve 1.8, and wet brake performance attenuation rate 3%.

[0091] Comparative Example 11

[0092] The other conditions were the same as those in Example 1, except that the content of vermiculite powder was 3 parts. The green body showed delamination and cracking after reaction infiltration, which did not meet the product requirements.

[0093] Comparative Example 12

[0094] The other conditions were the same as those in Example 1, except that the content of vermiculite powder was 10 parts. The green body cracked after carbonization, which did not meet the green body forming requirements.

[0095] Comparative Example 13

[0096] Other conditions are the same as those in Example 1, except for the molding process. When the heating time is different during the hot pressing process, as shown in Table 3, the heating in the first stage is too fast, resulting in cracking of the molded green body, which does not meet the green body molding requirements.

[0097] Table 3 Hot pressing process parameters

[0098] Temperature ℃ Time Pressure RT~(80±5) 5±0.5 20±2 (80±5)～(150±5) 14±0.5 20±2 (150±5)～(204±5) 20±0.5 20±2

[0099] Comparative Example 14

[0100] The other conditions were the same as those in Example 1, except for the carbonization process. The heating time during the carbonization process was 40 hours, and as a result, the carbonized green body cracked, which did not meet the green body forming requirements.

Claims

1. A method for preparing a low-cost carbon ceramic brake material, characterized in that: The carbon fibers are sheared to obtain chopped fibers, the chopped fibers, calcined petroleum coke, phenolic resin, hexamethylenetetramine, nano zirconium silicate powder, and vermiculite powder are mixed to obtain a mixture, the mixture is pressed to form a green body, the green body is carbonized to obtain a carbonized green body, the carbonized green body is siliconized to obtain a carbon ceramic green body, the carbon ceramic green body is further siliconized, and finally polished to obtain a carbon ceramic brake material; The mixture is composed of the following components by mass: 40-45 parts of chopped fibers, 38-42 parts of calcined petroleum coke, 13-17 parts of phenolic resin, 8-15 parts of hexamethylenetetramine, 3-6 parts of nano zirconium silicate powder, and 5-10 parts of vermiculite powder; The pressing method is hot pressing, and the hot pressing process is to heat the material to 75-85°C for the first time within 7.5-8.5 hours, then heat it to 145-155°C for the second time within 13.5-14.5 hours, and finally heat it to 199-209°C for the third time within 19.5-20.5 hours, and the pressure of the pressing is controlled to be 18-22t throughout the whole process; The carbonization process is to uniformly heat the temperature to 950-1050° C. within 47-49 hours and keep the temperature for 2-5 hours.

2. The method for preparing a low-cost carbon ceramic brake material according to claim 1, characterized in that: The carbon fiber is polypropylene-based carbon fiber, model T300; the carbon fiber is firstly heat-treated, and the temperature of the heat treatment is 1500-1700°C.

3. A method for preparing a low-cost carbon-ceramic brake material according to any one of claims 1-2, characterized in that: The density of the carbonized body is 1.50-1.60 g / cm 3 .

4. A method for preparing a low-cost carbon-ceramic brake material according to any one of claims 1-2, characterized in that: The purity of silicon used in the reactive siliconizing is ≥99.0% and the particle size is ≤400 mesh; The reactive siliconizing is carried out in a nitrogen atmosphere, the temperature of the reactive siliconizing is 1700-1900° C., the time of the reactive siliconizing is 2-5 hours, and the pressure is 6-8 kPa.

5. A method for preparing a low-cost carbon-ceramic brake material according to any one of claims 1-2, characterized in that: The silicon impurity removal treatment is carried out under vacuum, the temperature of the silicon impurity removal treatment is 1600-1700° C., the time of the silicon impurity removal treatment is 2-5 hours, and during silicon impurity removal, the time from room temperature to 1600-1700° C. is 7-9 hours.

6. A method for preparing a low-cost carbon-ceramic brake material according to any one of claims 1-2, characterized in that: The polishing process is to polish the friction surface using a 100-300 mesh grinding wheel.

7. A low-cost carbon-ceramic brake material prepared by the preparation method according to any one of claims 1 to 6.

8. The low-cost carbon-ceramic brake material according to claim 7, characterized in that: The density of the carbon ceramic brake material is 1.95-2.00 g / cm 3 .

Images