Carbon ceramic brake disc and method for manufacturing the same

Abstract

The application provides a carbon ceramic brake disc and a preparation method thereof; the preparation method comprises the following steps: a) dispersing carbon fiber filaments to prepare a three-dimensional needled brake disc preform; spraying a curing liquid on the three-dimensional needled brake disc preform to perform curing, and then performing carbonization treatment to obtain a carbon / carbon composite material; b) placing the carbon / carbon composite material obtained in the step a) into a deposition furnace containing a liquid precursor to perform chemical liquid gas deposition to obtain a silicon-aluminum modified carbon ceramic composite material; and finally performing mechanical processing to obtain the carbon ceramic brake disc. Compared with the prior art, the preparation method provided by the application adopts specific raw materials and specific process steps, realizes good overall interaction, and has good mechanical properties (bending strength and elastic modulus), high thermal conductivity and small brake disc wear rate of the prepared carbon ceramic brake disc.

Description

Technical Field

[0001] This invention relates to the field of brake material technology, and more specifically, to a carbon ceramic brake disc and its preparation method. Background Technology

[0002] SiC composite materials first appeared in the 1980s as thermal structural materials, such as in spacecraft engines and spacecraft thermal shields, and are a new type of structural and functional material that can well meet the requirements of operation at 1650℃. In the early 1990s, Walter Krenkel and others at the German Aerospace Center (DLR) began to study C / C-SiC composite materials prepared using the RMI method, conducting in-depth research on the process, performance, and structural design of C / SiC brake discs prepared by the RMI method. Between 1994 and 1997, full-size C / C-SiC brake disc models for high-speed trains and buses were produced. By 2001, C / C-SiC brake discs were successfully applied to the braking system of a Porsche 911 GT2 for the first time. In 2008, C / C-SiC began mass production and gradually replaced cast iron and cast steel brake discs used in heavy-duty vehicles. In addition, C / C-SiC composite materials have also begun to be used in elevators and cranes.

[0003] Chinese Patent Application No. 201510991783.9 discloses a method for preparing carbon-ceramic brake materials, including the following steps: 1) preparation of a first carbon fiber preform; 2) preparation of a phenolic resin solution; 3) preparation of a slurry of phenolic resin and ceramic powder; 4) preparation of a second carbon fiber preform; 5) drying of the second carbon fiber preform; 6) hot-pressing curing of the dried preform; 7) pyrolysis of the carbon / phenolic-ceramic composite material; 8) high-temperature treatment of the first porous carbon / carbon-ceramic powder composite material. This invention also provides a method for preparing a carbon-ceramic brake disc, which, in addition to the above eight steps, includes the following steps: 9) pre-processing; 10) silicon infiltration treatment of the first brake disc; 11) final processing. This invention significantly reduces the manufacturing cycle and cost of carbon-ceramic brake materials, and the process is simple, repeatable, and suitable for industrial mass production.

[0004] Chinese Patent Application No. 201810988553.0 discloses a method for preparing carbon-ceramic brake discs. The method for preparing carbon-ceramic brake discs provided by this invention combines vapor deposition, precursor impregnation and fused silica infiltration. By limiting the types and amounts of solvents and gases in each step and adjusting the parameters in the reaction, the advantages and disadvantages of each method are complemented, resulting in carbon-ceramic brake discs with excellent mechanical properties, high fracture toughness, good thermal conductivity, small coefficient of thermal expansion and excellent thermal shock resistance.

[0005] Chinese Patent Application No. 202010190744.X discloses a method for preparing a carbon-ceramic brake disc, comprising the following steps: 1) preparing a carbon fiber preform; 2) CVI densification: the carbon fiber preform prepared above is loaded into a CVI furnace, and natural gas is used as the carbon source gas for CVI densification. After pre-deposition, accelerated deposition, and gap-adjusting deposition, a C / C brake disc is obtained; 3) graphitization treatment: the C / C brake disc is placed in a high-temperature heat treatment furnace to obtain the desired carbon-ceramic brake disc. This invention can accurately and effectively control the density and porosity of the carbon-ceramic preform. The density of the carbon-ceramic preform prepared using this invention can be accurately controlled at (1.45±0.05) g / cm³. 3 The porosity was (25±5)%.

[0006] The presence of ceramic phases SiC and Si in the carbon-ceramic brake discs prepared by the aforementioned patents and other existing technologies can significantly improve the friction coefficient of the carbon-ceramic brake material. However, during the braking process, the presence of the Si phase in the material will cause high-frequency vibration, resulting in a high wear rate of the brake material. In addition, the preparation process of carbon-ceramic brake discs is relatively complex, especially the slurry impregnation stage, which requires multiple impregnations and has a long production cycle, thus resulting in high production costs. Summary of the Invention

[0007] In view of this, the purpose of this invention is to provide a carbon ceramic brake disc and its preparation method. The preparation method provided by this invention can solve the problems of high wear rate of brake materials, complex preparation process, especially the slurry impregnation stage, which requires multiple impregnations, resulting in a long production cycle and high production cost.

[0008] This invention provides a method for preparing a carbon-ceramic brake disc, comprising the following steps:

[0009] a) After dispersing carbon fiber filaments, a three-dimensional needle-punched brake disc preform is prepared; a curing liquid is sprayed onto the three-dimensional needle-punched brake disc preform for curing, and then carbonized to obtain a carbon / carbon composite material.

[0010] b) The carbon / carbon composite material obtained in step a) is placed into a deposition furnace containing liquid precursor and subjected to chemical liquid vapor deposition to obtain silicon-aluminum modified carbon-ceramic composite material; finally, it is machined to obtain carbon-ceramic brake disc.

[0011] Preferably, the carbon fiber filament in step a) has a length of 50 mm to 100 mm and a diameter of 5 μm to 10 μm.

[0012] Preferably, the carbon fiber dispersion process in step a) specifically involves:

[0013] Carbon fiber filaments with a mass ratio of 1:(4~6) and Tween 80 are stirred at 30℃~50℃ for 1h~3h, filtered and dried to obtain uniformly dispersed carbon fiber filaments.

[0014] Preferably, the curing liquid in step a) is composed of phenolic resin, carbon nanotubes, silicon carbide powder and silicon-aluminum alloy in a mass ratio of 100:(8-12):(4-6):(4-6).

[0015] Preferably, the amount of curing liquid sprayed in step a) is 40% to 60% of the mass of the three-dimensional needle-punched brake disc preform.

[0016] Preferably, the curing temperature in step a) is 160℃~180℃, and the time is 1h~3h;

[0017] The carbonization process is carried out at a temperature of 750℃ to 850℃ for a duration of 20h to 24h.

[0018] Preferably, the liquid precursor in step b) is composed of a solvent, polycarbosilane, polydimethylsiloxane, and polymethylsilane; the mass ratio of the solvent, polycarbosilane, polydimethylsiloxane, polymethylsilane, and carbon / carbon composite material is (15-25):(15-25):(15-25):(14-16):100.

[0019] Preferably, the solvent in step b) is selected from one or more of xylene, n-hexane, and cyclohexane.

[0020] Preferably, the chemical liquid vapor deposition in step b) is carried out under an argon atmosphere at a pressure of 0.05 MPa to 0.15 MPa, a temperature of 1000°C to 1200°C, and a time of 4 to 8 hours.

[0021] The present invention also provides a carbon ceramic brake disc, which is prepared by the preparation method described in the above technical solution.

[0022] This invention provides a carbon-ceramic brake disc and its preparation method. The preparation method includes the following steps: a) dispersing carbon fiber filaments to form a three-dimensional needle-punched brake disc preform; spraying a curing liquid onto the three-dimensional needle-punched brake disc preform for curing, followed by carbonization treatment to obtain a carbon / carbon composite material; b) placing the carbon / carbon composite material obtained in step a) into a deposition furnace containing a liquid precursor for chemical liquid vapor deposition to obtain a silicon-aluminum modified carbon-ceramic composite material; and finally machining to obtain a carbon-ceramic brake disc. Compared with the prior art, the preparation method provided by this invention uses specific raw materials and specific process steps to achieve better overall interaction, resulting in a carbon-ceramic brake disc with better mechanical properties (flexural strength and elastic modulus), high thermal conductivity, and low brake disc wear rate.

[0023] Meanwhile, the preparation method is relatively simple, has a short production cycle, and low production cost, and has broad application prospects. Detailed Implementation

[0024] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0025] This invention provides a method for preparing a carbon-ceramic brake disc, comprising the following steps:

[0026] a) After dispersing carbon fiber filaments, a three-dimensional needle-punched brake disc preform is prepared; a curing liquid is sprayed onto the three-dimensional needle-punched brake disc preform for curing, and then carbonized to obtain a carbon / carbon composite material.

[0027] b) The carbon / carbon composite material obtained in step a) is placed into a deposition furnace containing liquid precursor and subjected to chemical liquid vapor deposition to obtain silicon-aluminum modified carbon-ceramic composite material; finally, it is machined to obtain carbon-ceramic brake disc.

[0028] This invention provides a method for preparing carbon-ceramic brake discs, which is a composite process of ceramic uniformly composited with carbon fiber. It can solve the problems of high wear rate of brake materials, complex preparation process, especially the slurry impregnation stage, which requires multiple impregnations, resulting in long production cycle and high production cost.

[0029] The present invention first disperses carbon fiber filaments to form a three-dimensional needle-punched brake disc preform; then sprays curing liquid onto the three-dimensional needle-punched brake disc preform for curing, and then performs carbonization treatment to obtain a carbon / carbon composite material.

[0030] In this invention, the length of the carbon fiber filament is preferably 50mm to 100mm, and the diameter is preferably 5μm to 10μm. This invention does not impose any special restrictions on the source of the carbon fiber filament; commercially available products well-known to those skilled in the art can be used.

[0031] In this invention, the process of dispersing the carbon fiber filaments is preferably as follows:

[0032] Carbon fiber filaments with a mass ratio of 1:(4~6) and Tween 80 are stirred at 30℃~50℃ for 1h~3h, filtered and dried to obtain uniformly dispersed carbon fiber filaments.

[0033] The present invention does not impose any special restrictions on the process of preparing the three-dimensional needle-punctured brake disc preform; any preform preparation method known to those skilled in the art can be used.

[0034] In this invention, the curing liquid is preferably composed of phenolic resin, carbon nanotubes, silicon carbide powder, and silicon-aluminum alloy in a mass ratio of 100:(8-12):(4-6):(4-6). This invention does not impose any special restrictions on the source of the phenolic resin, carbon nanotubes, silicon carbide powder, and silicon-aluminum alloy; commercially available products well-known to those skilled in the art can be used.

[0035] In this invention, the silicon-aluminum alloy in the curing liquid improves the mechanical properties of aluminum, enhances its wear resistance and strength, and also improves its stability; the overall formula can improve the thermal conductivity and density of the product.

[0036] In this invention, the amount of curing liquid sprayed is preferably 40% to 60% of the mass of the three-dimensional needle-punched brake disc preform.

[0037] In this invention, the curing temperature is preferably 160℃~180℃, and the curing time is preferably 1h~3h.

[0038] In this invention, the carbonization treatment temperature is preferably 750℃~850℃, and the time is preferably 20h~24h.

[0039] After obtaining the carbon / carbon composite material, the present invention places the carbon / carbon composite material into a deposition furnace containing a liquid precursor for chemical liquid vapor deposition to obtain a silicon-aluminum modified carbon-ceramic composite material; finally, after machining, a carbon-ceramic brake disc is obtained.

[0040] In this invention, the liquid precursor is preferably composed of a solvent, polycarbosilane, polydimethylsiloxane, and polymethylsilane. The polycarbosilane, polydimethylsiloxane, and polymethylsilane in the liquid precursor not only improve the mechanical properties of the brake disc, namely flexural strength and elastic modulus, but the organosilicon components also improve thermal conductivity.

[0041] In this invention, the preferred mass ratio of the solvent, polycarbosilane, polydimethylsiloxane, polymethylsilane to the carbon / carbon composite material is (15-25):(15-25):(15-25):(14-16):100.

[0042] In this invention, the solvent is preferably selected from one or more of xylene, n-hexane and cyclohexane, and more preferably xylene.

[0043] In this invention, the number-average molecular weight of the polycarbosilane is preferably 500-2000; the number-average molecular weight of the polydimethylsiloxane is preferably 500-10000; and the number-average molecular weight of the polymethylsilane is preferably 500-10000.

[0044] The present invention does not impose any special restrictions on the source of the solvent, polycarbosilane, polydimethylsiloxane and polymethylsilane, and commercially available products well known to those skilled in the art can be used.

[0045] In this invention, the chemical liquid vapor deposition (CLVD) is preferably carried out under an argon atmosphere, with a pressure of 0.05 MPa to 0.15 MPa, a temperature of 1000°C to 1200°C, and a time of 4 to 8 hours.

[0046] The present invention does not impose any special restrictions on the machining process, and any machining and / or grinding techniques known to those skilled in the art can be used, with the aim of obtaining carbon ceramic brake discs of the corresponding specifications and models.

[0047] The preparation method provided by this invention uses specific raw materials and specific process steps to achieve good overall interaction. The resulting carbon-ceramic brake disc has good mechanical properties (bending strength and elastic modulus), high thermal conductivity, and low wear rate. At the same time, the preparation method is relatively simple, has a short production cycle, and low production cost, and has broad application prospects.

[0048] This invention also provides a carbon-ceramic brake disc, prepared using the method described above. Experimental results show that the carbon-ceramic brake disc provided by this invention has a bending strength of 201 MPa, an elastic modulus of 145 GPa, and a coefficient of thermal expansion of 3.0 × 10⁻⁶. -6 / K, thermal conductivity 54W / (m·K), wear rate (0.20~0.31)×10 -7 cm 3 / Nm, fracture toughness is 9.9MPa·m 1 / 2 .

[0049] This invention provides a carbon-ceramic brake disc and its preparation method. The preparation method includes the following steps: a) dispersing carbon fiber filaments to form a three-dimensional needle-punched brake disc preform; spraying a curing liquid onto the three-dimensional needle-punched brake disc preform for curing, followed by carbonization treatment to obtain a carbon / carbon composite material; b) placing the carbon / carbon composite material obtained in step a) into a deposition furnace containing a liquid precursor for chemical liquid vapor deposition to obtain a silicon-aluminum modified carbon-ceramic composite material; and finally machining to obtain a carbon-ceramic brake disc. Compared with the prior art, the preparation method provided by this invention uses specific raw materials and specific process steps to achieve better overall interaction, resulting in a carbon-ceramic brake disc with better mechanical properties (flexural strength and elastic modulus), high thermal conductivity, and low brake disc wear rate.

[0050] Meanwhile, the preparation method is relatively simple, has a short production cycle, and low production cost, and has broad application prospects.

[0051] To further illustrate the present invention, the following embodiments provide a detailed description. All raw materials used in the following embodiments of the present invention are commercially available; among them, the phenolic resin was purchased from Weilin Co., Ltd., and its model is WL-T880SP.

[0052] Example

[0053] Step 1: Carbon fiber filament dispersion: Weigh 20g of carbon fiber filament (70mm in length and 7μm in diameter) and 100g of Tween 80, mix, stir at 40℃ for 2h, filter, and dry to obtain uniformly dispersed carbon fiber filament.

[0054] Step 2: Preform preparation: The three-dimensional needle-punched brake disc preform is prepared using the carbon fiber filaments obtained after the treatment in Step 1.

[0055] Step 3: Curing: Phenolic resin is mixed with carbon nanotubes (particle size 6-13 μm), silicon carbide powder (particle size 6-20 μm), and silicon-aluminum alloy (Si mass ≥12%, aluminum mass <80%) to prepare a mixed solution. The solution is then sprayed onto the preform, with the spraying amount controlled at 50% of the preform mass. Curing is carried out at 170℃ for 2 hours.

[0056] Raw material ratio: 10wt% carbon nanotubes, 5wt% silicon carbide powder, 5wt% silicon-aluminum alloy (percentages are calculated based on the mass of phenolic resin in step 3).

[0057] Step 4: The preform cured in Step 3 is carbonized in a carbonization furnace at 800℃ for 22 hours to obtain a density of 1.5 g / cm³. 3 Carbon / carbon composite materials;

[0058] Step 5: Chemical Liquid Vapor Deposition (CLVD) Processing: The carbon / carbon composite material from Step 4 is placed in a deposition furnace containing a liquid precursor (xylene as solvent, mixed with polycarbosilane, polydimethylsilane, and polymethylsilane). Under an argon atmosphere, the system pressure is 0.1 MPa, the temperature is 1100℃, and the mixture is heated for 6 hours to obtain a silicon-aluminum modified carbon-ceramic composite material with a density of 1.9 g / cm³. 3 .

[0059] The raw material components include: 20 wt% solvent, 20 wt% polycarbosilane, 20 wt% polydimethylsiloxane, and 15 wt% polymethylsilane (the percentages are calculated based on the mass of the carbon / carbon composite material in step 4); wherein the number average molecular weight of polycarbosilane is 1000, the number average molecular weight of polydimethylsiloxane is 500, and the number average molecular weight of polymethylsilane is 1000.

[0060] Step 6: After processing and polishing, the silicon-aluminum modified carbon-ceramic composite material obtained in Step 5 is used to prepare carbon-ceramic brake discs of corresponding specifications and models.

[0061] Quality inspection and finishing: The prepared carbon ceramic brake discs are subjected to quality inspection, including testing of indicators such as bending strength, elastic modulus, coefficient of thermal expansion, and thermal conductivity, and necessary finishing operations are performed.

[0062] According to GB / T6569-2006 standard, the mechanical properties of carbon-ceramic composite materials were tested, and the flexural strength was found to be 201 MPa. According to GB / T22315-2008 standard, the mechanical properties of carbon-ceramic composite materials were tested, and the elastic modulus was found to be 145 GPa. According to GB / T16535-2008 standard, the thermal properties of carbon-ceramic composite materials were tested, and the coefficient of thermal expansion was found to be 3.0 × 10⁻⁶. -6 / K. According to ASTM E1461-13 standard, the thermal properties of the carbon-ceramic composite material were tested, and the thermal conductivity was 54 W / (m·K). Wear rate tests were conducted according to GB / T11834-2000, and the wear rate was (0.20~0.31)×10⁻⁶. -7 cm 3 / Nm. The fracture toughness of the carbon-ceramic composite material was tested according to ASTM E399 74 standard, and the result was 9.9 MPa·m. 1 / 2 .

[0063] In summary, the carbon-ceramic brake discs prepared by the method provided by this invention have good mechanical properties (bending strength and elastic modulus), high thermal conductivity, and low wear rate. At the same time, the preparation method is relatively simple, has a short production cycle, and low production cost, and has broad application prospects.

[0064] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a carbon-ceramic brake disc, comprising the following steps: a) Disperse carbon fiber filaments to form a three-dimensional needle-punched brake disc preform; The curing liquid is sprayed onto the above three-dimensional needle-punched brake disc preform and cured at 160℃~180℃ for 1h~3h, and then carbonized at 750℃~850℃ for 20h~24h to obtain carbon / carbon composite material. The carbon fiber filaments have a length of 50mm to 100mm and a diameter of 5μm to 10μm. The process of dispersing the carbon fiber filaments is specifically as follows: Carbon fiber filaments with a mass ratio of 1:(4~6) and Tween 80 are stirred at 30℃~50℃ for 1h~3h, filtered and dried to obtain uniformly dispersed carbon fiber filaments. The curing liquid is composed of phenolic resin, carbon nanotubes, silicon carbide powder, and silicon-aluminum alloy in a mass ratio of 100:(8~12):(4~6):(4~6); in the silicon-aluminum alloy, the mass content of Si is ≥12%, and the mass content of aluminum is <80%. The amount of curing liquid sprayed is 40% to 60% of the mass of the three-dimensional needle-punched brake disc preform; b) The carbon / carbon composite material obtained in step a) is placed into a deposition furnace containing liquid precursor and subjected to chemical liquid vapor deposition to obtain silicon-aluminum modified carbon-ceramic composite material; finally, it is machined to obtain carbon-ceramic brake disc. The liquid precursor is composed of a solvent, polycarbosilane, polydimethylsiloxane, and polymethylsilane; the mass ratio of the solvent, polycarbosilane, polydimethylsiloxane, polymethylsilane, and carbon / carbon composite material is (15~25):(15~25):(15~25):(14~16):

100. The chemical liquid vapor deposition was carried out under an argon atmosphere at a pressure of 0.05 MPa to 0.15 MPa, a temperature of 1000℃ to 1200℃, and a time of 4 to 8 hours.

2. The preparation method according to claim 1, characterized in that, The solvent mentioned in step b) is selected from one or more of xylene, n-hexane and cyclohexane.

3. A carbon-ceramic brake disc, characterized in that, It is prepared by the preparation method described in any one of claims 1 to 2.