A brake disc containing fibrous free silicon and a method for producing the same

Abstract

The application provides a brake disc containing fibrous free silicon, which comprises a plurality of carbon fiber unidirectional cloth layers and a plurality of carbon fiber web tire layers. The carbon fiber unidirectional cloth layers and the carbon fiber web tire layers are arranged alternately, the carbon fiber unidirectional cloth layer contains carbon, silicon carbide and free silicon, part of the free silicon is arranged in a fibrous form to obtain fibrous free silicon, the length of the fibrous free silicon is 8-13 mm, the cross-sectional area of the fibrous free silicon is 0.0018-0.2 mm 2 , and the length direction of the fibrous free silicon is parallel to the direction of the carbon fiber of the carbon fiber unidirectional cloth. The proper nylon wire is added in the long carbon fiber, the diffusion ability of the deposition gas to the inside of the needled carbon fiber blank is increased by using the characteristic of the nylon wire that can form a through hole, and the difference between the inside and outside of the CVI fiber blank obtained after deposition is obviously reduced, so that the stability of the material preparation process is greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of brake disc manufacturing, and particularly relates to a brake disc containing fibrous free silicon and a preparation method thereof. BACKGROUND

[0002] The brake disc is an important part installed on vehicles such as automobiles and motorcycles, and is used for braking the vehicle. It is usually located between the wheels and cooperates with the brake caliper, brake pad and the like in the brake system. The brake disc mainly plays a role in reducing speed or emergency stopping during the operation of the automobile, and is particularly important in the case of an emergency situation, which is related to the safety of human life. The speed of modern transportation devices is getting higher and higher, and the requirements for the brake disc as a safety device are also getting higher and higher. The carbon fiber reinforced carbon brake disc has become the only choice for high-speed transportation devices. For example, airplanes, high-speed trains, sports cars, heavy-duty transport vehicles and high-end cars all use carbon fiber reinforced carbon brake discs. At present, the brake disc is prepared by the method of stacking unidirectional cloth and net tire and needling. When the blank prepared by the method of stacking and needling is subjected to CVI, since the gap between the fibers is small, the deposition gas is not easy to diffuse to the inside, and the problem of large deposition density on the outside and small deposition density on the inside is prone to occur. When the subsequent silicon infiltration is performed, the problem of uneven density of the silicon infiltration sample may occur, and even the liquid silicon cannot completely penetrate the blank.

[0003] In view of the problem of density difference between the inside and the outside of the material after deposition, a brake disc containing fibrous free silicon is provided, nylon fibers are added to the unidirectional carbon fiber cloth, and the nylon fibers form through holes, which greatly increase the diffusion capacity of the deposition gas to the inside of the needled body. SUMMARY

[0004] The present application aims to provide a brake disc containing fibrous free silicon to solve the problem of excessive density difference between the inside and the outside of the brake disc after CVI treatment.

[0005] To achieve this purpose, the present application provides a brake disc containing fibrous free silicon, which comprises a plurality of layers of unidirectional carbon fiber cloth layers and a plurality of layers of carbon fiber net tire layers, and the unidirectional carbon fiber cloth layers and the carbon fiber net tire layers are arranged alternately. The unidirectional carbon fiber cloth layer contains carbon, silicon carbide and free silicon, part of the free silicon is arranged in a fibrous form to obtain fibrous free silicon, the length of the fibrous free silicon is 8-13mm, the cross-sectional area of the fibrous free silicon is 0.0018-0.2mm 2 , and the length direction of the fibrous free silicon is parallel to the direction of the carbon fibers in the unidirectional carbon fiber cloth.

[0006] Preferably, the fiber bundle k value of the unidirectional carbon fiber cloth is 3-12k, a plurality of fiber bundles form a fiber bundle unit, the fibrous free silicon is located in the middle of the adjacent fiber bundle units, and the number of fiber bundles contained in the fiber bundle unit is 1-20.

[0007] Preferably, the carbon fiber unidirectional cloth has a carbon content of 45-65 vol%, a silicon carbide content of 30-50 vol%, and a free silicon content of 5-15 vol%; the carbon fiber web tire layer has a carbon content of 30-50 vol%, a silicon carbide content of 40-60 vol%, and a free silicon content of 5-12 vol%.

[0008] Preferably, the fibrous free silicon accounts for 40-80% of the free silicon content.

[0009] Preferably, there are large-particle-size silicon carbide particles near the area where the fibrous free silicon is located, and the particle size of the silicon carbide particles is 15-50 microns.

[0010] The application also provides a preparation method of a brake disc containing fibrous free silicon, for preparing the above brake disc containing fibrous free silicon, and the preparation method is as follows:

[0011] S1: The continuous carbon fiber bundle and nylon fiber are arranged into carbon fiber unidirectional cloth according to a predetermined arrangement interval, and one nylon line is arranged every 1-20 fiber bundles, and the diameter of the nylon line is 50-300 microns;

[0012] S2: The carbon fiber unidirectional cloth and the carbon fiber web tire are arranged in an overlapping manner, and needle punching is performed every time the overlapping is performed, to obtain a needle-punched carbon fiber blank;

[0013] S3: The needle-punched carbon fiber blank is placed into a chemical vapor infiltration furnace for chemical vapor deposition, to obtain a CVI fiber blank, the deposition time is 150-300 h, the deposition temperature is 950-1100°C, the gas used for deposition is methane, the dilution gas is nitrogen, the flow rate of methane is 80-200 L / h, and the flow rate of nitrogen is 5-30 L / h;

[0014] S4: The CVI fiber blank is surface polished, and then the polished CVI fiber blank is placed into a boron nitride crucible, and then the boron nitride crucible is placed into a high-temperature vacuum furnace for silicon infiltration treatment to obtain a siliconized blank;

[0015] S5: The siliconized blank is surface polished and outer contour size processed to obtain the brake disc containing fibrous free silicon.

[0016] Preferably, the density of the CVI fiber blank in step S3 is 1.25-1.45 g / cm 3 .

[0017] Preferably, in step S4, the boron nitride crucible is pre-filled with pure silicon powder with a mass of 1.1 times the mass of the CVI fiber blank.

[0018] Preferably, the temperature of the silicon infiltration treatment in step S4 is 1600-1700 DEG C, the holding time is 2-4h, and the furnace pressure is less than 1000Pa.

[0019] Beneficial effects: the brake disc containing fibrous free silicon provided by the application has fibrous free silicon on the surface and inside, which indicates that the density uniformity of the brake disc inside and outside is improved during CVI deposition, the filling property of liquid silicon on the sample is good after silicon infiltration, and there is no unreacted area that is not infiltrated by silicon, so the brake disc has good stability. The application also provides a preparation method of the brake disc containing fibrous free silicon, by adding appropriate nylon threads in the long carbon fibers, the characteristics of the nylon threads can form through holes to increase the diffusion ability of the deposition gas to the inside of the needle-punched carbon fiber blank during gas phase deposition, and the density difference between the inside and outside of the CVI fiber blank obtained after deposition is obviously reduced, which not only improves the stability of the material preparation process. The process also greatly reduces the CVI deposition time, so that the deposition blank can reach a larger density in a shorter time, shortening the manufacturing cycle of the material. At the same time, the CVI fiber blank with uniform density is beneficial to the filling effect of liquid silicon on the blank during subsequent silicon infiltration treatment, and the liquid silicon can be well infiltrated in the CVI fiber blank, and the density of the blank is uniform after gas phase deposition, which can better protect the carbon fibers during silicon infiltration, avoiding corrosion of the carbon fibers and reducing the strength of the brake disc. DETAILED DESCRIPTION

[0020] The examples described below are only a part of the examples of the present application, rather than all the examples. Based on the examples in the present application, all other examples obtained by those skilled in the art without creative labor belong to the scope of protection of the present application.

[0021] The application provides a brake disc containing fibrous free silicon, which comprises a plurality of layers of carbon fiber unidirectional cloth layers and a plurality of layers of carbon fiber tire layers, and the carbon fiber unidirectional cloth layers and the carbon fiber tire layers are arranged alternately. The carbon fiber unidirectional cloth layer contains carbon, silicon carbide and free silicon, part of the free silicon is arranged in a fibrous form to obtain fibrous free silicon, the length of the fibrous free silicon is 8-13mm, the cross-sectional area is 0.0018-0.2mm 2 , and the length direction of the fibrous free silicon is parallel to the direction of the carbon fibers of the carbon fiber unidirectional cloth.

[0022] The fiber bundle k value of the carbon fiber unidirectional cloth is 3-12k, a plurality of fiber bundles form a fiber bundle unit, the fibrous free silicon is located in the middle of adjacent fiber bundle units, and the number of fiber bundles contained in the fiber bundle unit is 1-20. That is, a fiber bundle is formed by a plurality of fiber filaments (3-12), and 1-20 fiber bundles form the fiber bundle unit.

[0023] The carbon content of the carbon fiber unidirectional cloth is 45-65 vol%, the silicon carbide content is 30-50 vol%, and the free silicon content is 5-15 vol%; the carbon content of the carbon fiber web tire layer is 30-50 vol%, the silicon carbide content is 40-60 vol%, and the free silicon content is 5-12 vol%.

[0024] The fibrous free silicon accounts for 40-80% of the free silicon content.

[0025] Large-size silicon carbide particles exist near the area where the fibrous free silicon is located, and the particle size of the silicon carbide particles is 15-50 microns.

[0026] The application also provides a preparation method of the brake disc containing fibrous free silicon, which is used for preparing the brake disc containing fibrous free silicon, and the preparation method is as follows:

[0027] S1: The continuous carbon fiber bundle and nylon fiber are arranged into carbon fiber unidirectional cloth according to a predetermined arrangement interval, one nylon line is arranged every 1-20 fiber bundles, and the diameter of the nylon line is 50-300 microns;

[0028] S2: The carbon fiber unidirectional cloth and the carbon fiber web tire are arranged in an overlapping manner, and needle punching is performed every time the overlapping is performed, so as to obtain a needle-punched carbon fiber blank;

[0029] S3: The needle-punched carbon fiber blank is placed into a chemical vapor infiltration furnace for chemical vapor deposition, so as to obtain a CVI fiber blank, the deposition time is 150-300 h, the deposition temperature is 950-1100°C, the gas used for deposition is methane, the dilution gas is nitrogen, the flow rate of methane is 80-200 L / h, and the flow rate of nitrogen is 5-30 L / h; no deposition gas is passed during the temperature rising stage of the chemical vapor deposition, and the deposition gas is passed again 5-10 minutes before reaching the predetermined temperature, and the nylon line is decomposed during the temperature rising process (the process of not passing the deposition gas), so that through holes are formed, which are prepared for subsequent deposition treatment;

[0030] S4: The CVI fiber blank is polished, and then the polished CVI fiber blank is placed into a boron nitride crucible, and then the boron nitride crucible is placed into a high-temperature vacuum furnace for siliconizing treatment, so as to obtain a siliconized blank;

[0031] S5: The siliconized blank is polished and processed in size to obtain the brake disc containing fibrous free silicon.

[0032] The density of the CVI fiber blank in step S3 is 1.25-1.45 g / cm 3 .

[0033] In step S4, the pure silicon powder with a mass of 1.1 times the mass of the CVI fiber blank is previously placed into the boron nitride crucible.

[0034] The temperature of the silicon infiltration treatment in step S4 is 1600-1700℃, the holding time is 2-4h, and the furnace pressure is less than 1000Pa.

[0035] Embodiment 1

[0036] The embodiment provides a brake disc containing fibrous free silicon, and the preparation steps are as follows:

[0037] S1: continuous carbon fiber bundles and nylon fibers are arranged into carbon fiber unidirectional cloth according to a predetermined arrangement interval, one nylon line is arranged every 10 fiber bundles, and the diameter of the nylon line is 150 microns;

[0038] S2: the carbon fiber unidirectional cloth and the carbon fiber web are arranged in an overlapping manner, and needle punching is performed every time the overlapping is performed, so that a needle-punched carbon fiber blank is obtained;

[0039] S3: the needle-punched carbon fiber blank is placed into a chemical vapor infiltration furnace for chemical vapor deposition, so that a CVI fiber blank is obtained, the deposition time is 200h, the deposition temperature is 1000℃, the gas used for deposition is methane, the dilution gas is nitrogen, the flow rate of the methane is 150L / h, the flow rate of the nitrogen is 20L / h, and the density of the CVI fiber blank is 1.35g / cm 3 ;

[0040] S4: the CVI fiber blank is polished, the polished CVI fiber blank is placed into a boron nitride crucible, the boron nitride crucible is previously filled with pure silicon powder with a mass of 1.1 times that of the CVI fiber blank, then the boron nitride crucible is placed into a high-temperature vacuum furnace for silicon infiltration treatment, so that a siliconized blank is obtained, the temperature of the silicon infiltration treatment is 1650℃, the holding time is 3h, and the furnace pressure is less than 1000Pa;

[0041] S5: the siliconized blank is polished and processed in size to obtain the brake disc containing fibrous free silicon.

[0042] Embodiment 2

[0043] The embodiment provides a brake disc containing fibrous free silicon, and the preparation steps are as follows:

[0044] S1: continuous carbon fiber bundles and nylon fibers are arranged into carbon fiber unidirectional cloth according to a predetermined arrangement interval, one nylon line is arranged every 10 fiber bundles, and the diameter of the nylon line is 300 microns;

[0045] S2: the carbon fiber unidirectional cloth and the carbon fiber web are arranged in an overlapping manner, and needle punching is performed every time the overlapping is performed, so that a needle-punched carbon fiber blank is obtained;

[0046] S3: Put the needle-punched carbon fiber blank into a chemical vapor infiltration furnace for chemical vapor deposition to obtain a CVI fiber blank, the deposition time is 180h, the deposition temperature is 1000℃, the deposition uses methane as the gas, nitrogen as the dilution gas, the methane flow rate is 150L / h, the nitrogen flow rate is 20L / h, and the density of the CVI fiber blank is 1.35g / cm 3 ;

[0047] S4: Put the CVI fiber blank for surface grinding, after grinding, put the CVI fiber blank into a boron nitride crucible, pre-put pure silicon powder with 1.1 times the mass of the CVI fiber blank in the boron nitride crucible, then put the boron nitride crucible into a high-temperature vacuum furnace for siliconizing treatment to obtain a siliconized blank, the siliconizing treatment temperature is 1650℃, the holding time is 3h, and the furnace pressure is less than 1000Pa;

[0048] S5: Put the siliconized blank for surface grinding and outer contour size processing to obtain the free silicon-containing fiber brake disc.

[0049] Example 3

[0050] The embodiment provides a free silicon-containing fiber brake disc, and the preparation steps are as follows:

[0051] S1: Arrange continuous carbon fiber bundles and nylon fibers into carbon fiber unidirectional cloth according to a predetermined arrangement interval, set one nylon line every 5 fiber bundles, and the diameter of the nylon line is 150 microns;

[0052] S2: Overlap the carbon fiber unidirectional cloth and the carbon fiber web tire, and perform needle punching treatment every time, to obtain a needle-punched carbon fiber blank;

[0053] S3: Put the needle-punched carbon fiber blank into a chemical vapor infiltration furnace for chemical vapor deposition to obtain a CVI fiber blank, the deposition time is 200h, the deposition temperature is 1000℃, the deposition uses methane as the gas, nitrogen as the dilution gas, the methane flow rate is 150L / h, the nitrogen flow rate is 20L / h, and the density of the CVI fiber blank is 1.39g / cm 3 ;

[0054] S4: Put the CVI fiber blank for surface grinding, after grinding, put the CVI fiber blank into a boron nitride crucible, pre-put pure silicon powder with 1.1 times the mass of the CVI fiber blank in the boron nitride crucible, then put the boron nitride crucible into a high-temperature vacuum furnace for siliconizing treatment to obtain a siliconized blank, the siliconizing treatment temperature is 1650℃, the holding time is 3h, and the furnace pressure is less than 1000Pa;

[0055] S5: Put the siliconized blank for surface grinding and outer contour size processing to obtain the free silicon-containing fiber brake disc.

[0056] Example 4

[0057] The embodiment provides a brake disc containing fibrous free silicon, and the preparation steps are as follows:

[0058] S1: a continuous carbon fiber bundle and a nylon fiber are arranged into a carbon fiber unidirectional cloth according to a predetermined arrangement interval, one nylon line is arranged every 10 fiber bundles, and the diameter of the nylon line is 150 microns;

[0059] S2: the carbon fiber unidirectional cloth and a carbon fiber web are arranged in an overlapping manner, and needle punching is performed every time the carbon fiber web is overlapped to obtain a needle-punched carbon fiber blank;

[0060] S3: the needle-punched carbon fiber blank is placed into a chemical vapor infiltration furnace to perform chemical vapor deposition to obtain a CVI fiber blank, the deposition time is 150 h, the deposition temperature is 1000 DEG C, the gas used for deposition is methane, the dilution gas is nitrogen, the flow rate of the methane is 150 L / h, the flow rate of the nitrogen is 20 L / h, and the density of the CVI fiber blank is 1.29 g / cm 3 ;

[0061] S4: the CVI fiber blank is polished, the polished CVI fiber blank is placed into a boron nitride crucible, pure silicon powder with a mass of 1.1 times that of the CVI fiber blank is previously placed into the boron nitride crucible, then the boron nitride crucible is placed into a high-temperature vacuum furnace to perform silicon infiltration treatment to obtain a siliconized blank, the temperature of the silicon infiltration treatment is 1650 DEG C, the holding time is 3 h, and the furnace pressure is less than 1000 Pa;

[0062] S5: the siliconized blank is polished and processed in size to obtain the brake disc containing fibrous free silicon.

[0063] Comparative Example 1

[0064] The comparative example provides a brake disc, and the preparation steps are as follows:

[0065] S1: the carbon fiber unidirectional cloth and a carbon fiber web are arranged in an overlapping manner, and needle punching is performed every time the carbon fiber web is overlapped to obtain a needle-punched carbon fiber blank;

[0066] S2: the needle-punched carbon fiber blank is placed into a chemical vapor infiltration furnace to perform chemical vapor deposition to obtain a CVI fiber blank, the deposition time is 200 h, the deposition temperature is 1000 DEG C, the gas used for deposition is methane, the dilution gas is nitrogen, the flow rate of the methane is 150 L / h, the flow rate of the nitrogen is 20 L / h, and the density of the CVI fiber blank is 1.20 g / cm 3 ;

[0067] S3: polishing the surface of the CVI fiber blank, and then putting the polished CVI fiber blank into a boron nitride crucible, and putting pure silicon powder with a mass of 1.1 times that of the CVI fiber blank into the boron nitride crucible in advance, and then putting the boron nitride crucible into a high-temperature vacuum furnace to perform siliconizing treatment to obtain a siliconized blank, the temperature of the siliconizing treatment being 1650°C, the holding time being 3h, and the furnace pressure being less than 1000Pa;

[0068] S4: polishing the surface of the siliconized blank and processing the outer contour size to obtain the free-silicon-containing fiber brake disc.

[0069] Comparative Example 2

[0070] The comparative example provides a free-silicon-containing fiber brake disc, and the preparation steps are as follows:

[0071] S1: preparing carbon fiber unidirectional cloth by arranging continuous carbon fiber bundles and nylon fibers according to a predetermined arrangement interval, and arranging one nylon line every 10 fiber bundles, the diameter of the nylon line being 400 microns;

[0072] S2: arranging the carbon fiber unidirectional cloth and the carbon fiber web in an overlapping manner, and performing needle punching treatment every time the arrangement is performed once to obtain a needle-punched carbon fiber blank;

[0073] S3: putting the needle-punched carbon fiber blank into a chemical vapor infiltration furnace to perform chemical vapor deposition to obtain a CVI fiber blank, the deposition time being 200h, the deposition temperature being 1000°C, the gas used for deposition being methane, the dilution gas being nitrogen, the flow rate of the methane being 150L / h, the flow rate of the nitrogen being 20L / h, and the density of the CVI fiber blank being 1.36g / cm 3 ;

[0074] S4: polishing the surface of the CVI fiber blank, and then putting the polished CVI fiber blank into a boron nitride crucible, and putting pure silicon powder with a mass of 1.1 times that of the CVI fiber blank into the boron nitride crucible in advance, and then putting the boron nitride crucible into a high-temperature vacuum furnace to perform siliconizing treatment to obtain a siliconized blank, the temperature of the siliconizing treatment being 1650°C, the holding time being 3h, and the furnace pressure being less than 1000Pa;

[0075] S5: polishing the surface of the siliconized blank and processing the outer contour size to obtain the free-silicon-containing fiber brake disc.

[0076] The brake discs prepared in the above Examples 1-4 and Comparative Examples 1-2 are tested. The testing method is as follows:

[0077] The density is tested according to GB / T 25995-2010 "Fine Ceramic Density and Apparent Porosity Test Method".

[0078] The bending strength is tested by GBT_65669-2006 Fine Ceramic Bending Strength Test Method.

[0079] The test data is shown in Table 1 below.

[0080] Table 1: Brake disc test data of examples 1-4 and comparative examples 1-2

[0081]

[0082] From the above test data, it can be seen that in example 1, nylon threads are arranged in the fibers, which increases the ability of the deposition gas to diffuse inside the green body, and the density difference between the inner and outer rings of the sample after silicon infiltration is small, and the strength is high; in example 2, the nylon threads are replaced by 300 microns, and the time required to reach the same deposition density is reduced, the sample density changes little after silicon infiltration, and the strength also remains at a high level; in example 3, the fiber bundle between the nylon fibers is reduced to 5, and the sample density (i.e. CVI fiber green body) is increased from 1.35 g / cm 3 to 1.39 g / cm 3 , due to the increase in the density of the CVI green body, the degree of corrosion of silicon on carbon fibers during silicon infiltration is reduced, the carbon content in the sample is increased, and the strength of the material is improved; in example 4, the CVI deposition time is reduced to 150 h, and the sample density after deposition is 1.29 g / cm 3 , the porosity of the sample is increased, and more silicon and deposited carbon and part of the carbon fibers react during silicon infiltration, but the strength of the sample still reaches 98 MPa, indicating that the method can be used to prepare a carbon ceramic brake disc that meets the performance requirements in a shorter CVI time; in comparative example 1, no nylon threads are arranged, the sample density after CVI is low (the deposition gas is difficult to diffuse inside the green body), the density difference between the inner and outer rings of the sample after silicon infiltration is large, and due to the insufficient content of deposited carbon, the corrosion of silicon on the fibers is large, and the strength of the sample is greatly reduced; in comparative example 2, 400 micron nylon threads are used, and after 200 h of deposition, the sample density is not much different from that of example 1, but the sample density after silicon infiltration is insufficient, which is because the holes formed by 400 microns are too large, and the capillary force of liquid silicon is insufficient, and there are some fiber-like holes in the core of the sample that are not filled with silicon, resulting in low sample density and low strength; unlike other schemes, the density of the outer ring of the sample after silicon infiltration is greater than that of the inner part, which is because the silicon and the surface of the CVI sample have good wettability, and for the surface layer, the silicon is easy to infiltrate, and does not need to penetrate a long distance by capillary force, so the density of the area where the outer ring and the silicon easily contact is high, but there are still some fiber-like holes that are not filled with silicon.

[0083] The above only describes several preferred embodiments of the present application, and of course cannot limit the scope of the present application, and any equivalent changes made within the scope of the patent application of the present application are still within the scope of the present application.

Claims

1. A brake disc comprising fibrous free silicon, said brake disc comprising a plurality of layers of carbon fiber unidirectional cloth and a plurality of layers of carbon fiber webbing, characterized in that, The carbon fiber unidirectional cloth layer and the carbon fiber net tire layer are arranged alternately, the carbon fiber unidirectional cloth layer contains carbon, silicon carbide and free silicon, part of the free silicon is arranged in a fibrous form to obtain fibrous free silicon, the length of the fibrous free silicon is 8-13mm, and the cross-sectional area is 0.0018-0.2mm 2 The length direction of the fibrous free silicon is parallel to the direction of the carbon fiber of the carbon fiber unidirectional cloth.

2. The free silica-containing fibrous brake rotor of Claim 1 wherein, The carbon fiber unidirectional cloth has a fiber bundle k value of 3-12k, a plurality of fiber bundles form a fiber bundle unit, the fibrous free silicon is located in the middle of adjacent fiber bundle units, and the number of fiber bundles contained in the fiber bundle unit is 1-20.

3. The free silica-containing fibrous brake rotor of Claim 1 wherein, The carbon fiber unidirectional cloth has a carbon content of 45-65vol%, a silicon carbide content of 30-50vol%, and a free silicon content of 5-15vol%; the carbon fiber net tire layer has a carbon content of 30-50vol%, a silicon carbide content of 40-60vol%, and a free silicon content of 5-12vol%.

4. The free silica-containing fibrous brake rotor of Claim 1 wherein, The fibrous free silicon accounts for 40-80% of the free silicon content.

5. The free silica-containing fibrous brake rotor of claim 4 wherein, The fibrous free silicon is located in a region near which there are large-particle-size silicon carbide particles, and the particle size of the silicon carbide particles is 15-50 microns.

6. A method for producing a brake disc containing fibrous free silicon, for producing a brake disc containing fibrous free silicon according to any one of claims 1 to 5, characterized in that The preparation method is as follows: S1: continuously arranging carbon fiber bundles and nylon fibers into a carbon fiber unidirectional cloth according to a predetermined arrangement interval, setting one nylon line every 1-20 fiber bundles, and the diameter of the nylon line is 50-300 microns; S2: overlapping the carbon fiber unidirectional cloth and the carbon fiber net tire, and performing needle punching treatment every time the overlapping is performed once to obtain a needle-punched carbon fiber blank; S3: placing the needle-punched carbon fiber blank into a chemical vapor infiltration furnace to perform chemical vapor deposition to obtain a CVI fiber blank, the deposition time is 150-300h, the deposition temperature is 950-1100℃, the gas used for deposition is methane, the dilution gas is nitrogen, the methane flow rate is 80-200L / h, and the nitrogen flow rate is 5-30L / h; S4: performing surface polishing on the CVI fiber blank, placing the polished CVI fiber blank into a boron nitride crucible, and then placing the boron nitride crucible into a high-temperature vacuum furnace to perform silicon infiltration treatment to obtain a siliconized blank; S5: performing surface polishing and outer contour size processing on the siliconized blank to obtain the brake disc containing fibrous free silicon.

7. The method of manufacturing a brake disc containing fibrous free silicon according to claim 6, wherein The density of the CVI fibre green body in step S3 is 1.25-1.45 g / cm 3 .

8. The method of claim 6, wherein the fiberized free silicon-containing brake disc is prepared by the steps of: providing a brake disc having a surface; and applying a coating of a fiberized free silicon-containing material to the surface of the brake disc. In step S4, the boron nitride crucible is pre-filled with pure silicon powder with a mass of 1.1 times that of the CVI fiber blank.

9. The method of claim 6, wherein the fiberized free silicon-containing brake disc is prepared by the steps of: providing a brake disc having a surface; and applying a laser beam to the surface of the brake disc to form a plurality of fiberized free silicon-containing brake disc particles on the surface of the brake disc. In step S4, the temperature for silicon infiltration treatment is 1600-1700℃, the holding time is 2-4h, and the furnace pressure is less than 1000Pa.

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