Carbon ceramic / carbon carbon multidimensional composite aircraft brake disc and preparation method thereof
By incorporating graphite separators and silicon powder cold-pressed blocks into carbon-ceramic/carbon-carbon multidimensional composite aircraft brake discs, the problems of low production efficiency and unstable quality of existing carbon-ceramic aircraft brake discs have been solved, achieving high-efficiency production and excellent friction performance, and reducing brake vibration and squealing.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HUNAN BOYUN NEW MATERIALS
- Filing Date
- 2023-07-21
- Publication Date
- 2026-06-30
Smart Images
Figure CN117128264B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of carbon-carbon composite material technology preparation, specifically relating to a carbon-ceramic / carbon-carbon multidimensional composite aircraft brake disc and its preparation method. Background Technology
[0002] Carbon-ceramic aircraft brake discs are multi-component composite brake discs formed by introducing a silicon carbide ceramic matrix onto a carbon-carbon aircraft brake disc base. There are three main manufacturing processes for carbon-ceramic aircraft brake discs: reactive infiltration, chemical vapor deposition, and impregnation. Currently, reactive infiltration is the simplest and most efficient method for obtaining carbon-ceramic materials. Reactive infiltration typically involves directly spreading silicon powder onto the surface of the carbon-carbon brake disc blank. At high temperatures, the silicon powder melts and infiltrates into the pores within the carbon material. The silicon atoms react with carbon atoms at high temperatures to form silicon carbide grains, thereby altering the frictional properties of the brake disc, enhancing the smoothness of the braking curve, increasing the coefficient of friction, and improving wet braking performance.
[0003] Carbon-carbon composite brake discs and carbon-ceramic composite brake discs each have their own advantages and disadvantages in use. For example, carbon-carbon brake discs have lower density, higher specific strength / specific modulus, high temperature resistance (3000℃), and excellent friction and wear performance, while carbon-ceramic brake discs have advantages such as a higher coefficient of friction, better environmental adaptability, smoother braking curve, and lower manufacturing cost. However, existing carbon-ceramic brake discs are mainly produced by reaction melting infiltration, which has the following main problems: 1) Each carbon-ceramic disc requires a separate reaction melting infiltration graphite fixture, occupying furnace space and resulting in a lower furnace loading capacity, which is not conducive to large-scale production; 2) Spreading silicon powder evenly on the surface of the carbon disc in the graphite fixture is cumbersome and difficult to ensure the uniformity of silicon powder spreading, affecting the quality stability of the carbon-ceramic disc; 3) During high-temperature friction, the friction film formed by silicon carbide wear debris in the manufactured carbon-ceramic brake disc has poor lubricity, which easily leads to brake disc vibration, high wear, and brake vibration squealing.
[0004] Effectively combining the advantages of carbon-carbon and carbon-ceramic materials, while mitigating their respective disadvantages, is a key direction for the development of aircraft brake discs. The presence of both materials in an aircraft brake disc allows for the leveraging of their strengths and compensating for their weaknesses, thereby improving brake disc performance and providing support for optimizing aircraft brake disc structural design. Summary of the Invention
[0005] To address the shortcomings of existing technologies, the first objective of this invention is to provide a carbon-ceramic / carbon-carbon multidimensional composite aircraft brake disc. The aircraft brake disc of this invention is composed of alternating sections of carbon-ceramic composite material and carbon-carbon composite material, combining the advantages of both materials and exhibiting an excellent brake disc friction curve. In particular, it reduces the "tailing" phenomenon of the brake curve of carbon-ceramic material and the "peaking" phenomenon of the brake curve of carbon-carbon composite material.
[0006] The second objective of this invention is to provide a method for preparing carbon-ceramic / carbon-carbon multidimensional composite aircraft brake discs. The preparation method of this invention does not require a melting and infiltration mold, and the brake discs can be directly stacked and loaded into the furnace. The loading capacity of the same volume furnace type can be increased by 4 to 8 times, which greatly improves the scale of industrial production and reduces production costs.
[0007] To achieve the above objectives, the present invention adopts the following technical solution:
[0008] The present invention provides a carbon-ceramic / carbon-carbon multidimensional composite aircraft brake disc, wherein the carbon-ceramic / carbon-carbon multidimensional composite aircraft brake disc is composed of N carbon-ceramic composite material regions and N carbon-carbon composite material regions alternating, wherein the N carbon-ceramic composite material regions account for 70%-90% of the area of the carbon-ceramic / carbon-carbon multidimensional composite aircraft brake disc.
[0009] The carbon-ceramic / carbon-carbon multidimensional composite aircraft brake disc provided by this invention is composed of alternating carbon-ceramic composite material and carbon-carbon composite material, combining the advantages of both materials and having an excellent brake disc friction curve, especially reducing the "tailing" phenomenon of the brake curve of carbon-ceramic material and the "peaking" phenomenon of the brake curve of carbon-carbon composite material.
[0010] The inventors discovered that when the area ratio of carbon-ceramic composite material in the carbon-ceramic / carbon-carbon multidimensional composite aircraft brake disc is 70%–90%, the final carbon-ceramic / carbon-carbon multidimensional composite aircraft brake disc exhibits the best performance. The brake disc maintains good dry and wet friction coefficients, with less wear, a smooth braking curve, and virtually no vibration or squealing. When the ratio is greater than 90%, the performance gradually approaches that of a pure carbon-ceramic brake disc, with good dry and wet friction coefficients, but increased wear, a tailing-out braking curve, and vibration and squealing during braking. When the ratio is less than 50%, the dry friction coefficient begins to decrease slightly, the wet friction coefficient decreases significantly, the dry and wet wear increases significantly, the braking curve remains smooth, and there is no vibration or squealing during braking.
[0011] In a preferred embodiment, N is 3 to 6, preferably 4 to 6.
[0012] In this invention, controlling N to be 3 to 6 results in the best performance of the carbon-ceramic / carbon-carbon multidimensional composite aircraft brake disc. If N is too large, the carbon-carbon composite area will become smaller due to the siphon effect during the melting and infiltration process. If N is too small, the friction chip removal effect will be unsatisfactory or the wear of the carbon-carbon composite area will increase.
[0013] This invention also provides a method for preparing a carbon-ceramic / carbon-carbon multidimensional composite aircraft brake disc. According to the design of the carbon-ceramic / carbon-carbon multidimensional composite aircraft brake disc, the carbon disc blank is divided into N alternating carbon-ceramic composite material regions and N carbon-carbon composite material regions. 2N graphite separators are placed on the upper and lower surfaces of the carbon disc blank, respectively located within the N carbon-carbon composite material regions. Then, 2N silicon powder cold-pressed blocks are placed on the upper and lower surfaces of the carbon disc blank, respectively located within the N carbon-ceramic composite material regions, to obtain a carbon disc blank with graphite separators and silicon powder cold-pressed blocks. The mixture undergoes reaction melting and infiltration to obtain a carbon-ceramic / carbon-carbon preform. The carbon-ceramic / carbon-carbon preform is then subjected to resin carbon densification to obtain the carbon-ceramic / carbon-carbon multidimensional composite aircraft brake disc.
[0014] The preparation method of the present invention uses a graphite separator to isolate silicon powder by cold pressing, which allows silicon to be controllably melt-infiltrated into N carbon-ceramic composite material regions to form a SiC matrix in the N carbon-ceramic composite material regions, while the N carbon-carbon composite material regions still only have a carbon matrix. After the melt-infiltration is completed, resin carbon densification is performed to make the N carbon-carbon composite material regions obtain a dense carbon matrix, thereby obtaining a carbon-ceramic / carbon-carbon multidimensional composite aircraft brake disc.
[0015] In this invention, silicon powder is cold-pressed for melting and infiltration, which not only eliminates the need for tooling but also ensures the uniformity of silicon powder spread on the surface of the carbon disk, ensuring consistent silicon infiltration at every point in the microstructure and improving the uniformity of the carbon ceramic matrix.
[0016] In a preferred embodiment, the density of the carbon disc blank is 1.2–1.5 g / cm³. 3 .
[0017] The carbon disk blank used in this invention is obtained by chemical vapor deposition of carbon from a carbon fiber preform, or by carbon densification by chemical vapor deposition of a pyrolytic carbon interface layer from a carbon fiber preform followed by resin impregnation and carbonization.
[0018] In a preferred embodiment, the graphite separator is selected from graphite blocks or graphite paper.
[0019] In a preferred embodiment, furfuryl ketone resin is coated on the bonding surfaces of 2N graphite separators, which are then placed on the upper and lower surfaces of the carbon disk blank and located in N carbon-carbon composite material zones, and then cured at 170–190°C.
[0020] In this invention, the bonding surface of the graphite separator refers to the contact surface between the graphite separator and the carbon disk blank. In actual operation, the bonding surface is coated with furfuryl ketone resin, placed on the surface of the carbon disk blank, fixed with C-clamps under pressure, dried and cured in an oven, and then removed after cooling.
[0021] Using the above method, 2N graphite separators can be precisely fixed to the carbon-carbon composite material area of the carbon disk blank, effectively preventing melting and seepage in the carbon-carbon composite material area. At the same time, after melting and seepage are completed, the graphite separators can be easily removed, avoiding damage to the fibers.
[0022] In a preferred embodiment, the silicon powder cold-pressed block is obtained by mixing silicon powder and paraffin powder to obtain a mixture, and then cold-pressing it into shape.
[0023] In a further preferred embodiment, the mixture contains, by mass ratio, silicon powder:paraffin powder = 92-97:8-3. In this invention, paraffin powder and silicon powder are mixed to allow the silicon powder to be molded. Paraffin powder has a low melting and boiling point, allowing for low molding temperatures and easy operation. It also readily volatilizes during heating, not affecting the reaction and melting process. Using other binders can easily lead to residual carbon, affecting the reaction and melting process. However, the content of paraffin powder needs to be effectively controlled. If the paraffin powder content is too high, it is prone to overflow during molding; if the paraffin powder content is too low, the pressed blank is prone to loosening and damage.
[0024] In a further preferred embodiment, the mixing is carried out in a three-dimensional mixer, and the mixing time is 1 to 2 hours.
[0025] In a further preferred embodiment, the temperature of the pressure plate during cold pressing is 70–90°C, the holding time is 20–40 seconds, and the holding pressure is 170–230 kg / cm². 2 .
[0026] In actual operation, the mixture of silicon powder and paraffin powder is weighed, placed into a metal mold, cold-pressed by a hydraulic press, and after the pressure is maintained, the mold is cooled for 5 minutes, demolded, and the silicon powder cold-pressed block is taken out.
[0027] In the preferred embodiment, carbon disc blanks with graphite separators and cold-pressed silicon powder blocks are stacked in a reaction melting furnace for reaction melting. During the actual charging process, the furnace temperature does not exceed the constant temperature zone of the equipment.
[0028] In a preferred embodiment, the reaction melting temperature is 1400℃~1900℃. In actual operation, after the reaction melting is complete and the equipment has cooled, the melted carbon-ceramic / carbon-carbon brake disc is removed, excess material is cleaned with a scraper, and the graphite spacer is removed.
[0029] In a preferred embodiment, the process of resin carbon densification of the carbon ceramic / carbon carbon preform involves impregnating the carbon ceramic / carbon carbon preform with furfuryl ketone resin under a pressure of 0.3 MPa to 5.0 MPa, and then carbonizing it at 700°C to 1000°C after impregnation.
[0030] In a further preferred embodiment, the impregnation pressure is 0.5 MPa to 1.0 MPa.
[0031] By impregnating the carbon-ceramic / carbon-carbon preform with furfuryl ketone resin under high pressure and then carbonizing it, the resin is converted into resin carbon to increase the regional density of the carbon-carbon composite material. After the resin carbon densification is completed, the carbon-ceramic / carbon-carbon brake disc is machined to the specified size.
[0032] Beneficial effects
[0033] This invention provides a carbon-ceramic / carbon-carbon multidimensional composite aircraft brake disc, which is composed of alternating carbon-ceramic composite material and carbon-carbon composite material, combining the advantages of both materials. In the carbon-carbon composite material area of the aircraft brake disc, chip removal grooves can be formed during friction, which is conducive to the discharge of wear debris, reduces brake disc vibration and squealing, and enhances the overall thermal conductivity of the material. The carbon-ceramic / carbon-carbon multidimensional composite aircraft brake disc provided by this invention has an excellent brake disc friction curve, especially reducing the "tailing" phenomenon of the brake curve of carbon-ceramic material and the "peaking" phenomenon of the brake curve of carbon-carbon composite material.
[0034] Regarding the preparation method, existing technology involves placing a carbon disk in a graphite vessel, covering the upper and lower surfaces of the disk with silicon powder, and then allowing the silicon powder to penetrate into the pores of the carbon material after high-temperature infiltration. While this invention also employs high-temperature melt infiltration of silicon, it first cold-presses the silicon powder into shape, then places the cold-pressed block on the surface of the carbon disk, and uses graphite blocks (paper) for surface isolation and sealing, forming a carbon-ceramic / carbon-carbon multidimensional composite material. The advantages of this method are as follows:
[0035] 1. Hot pressing of silicon powder into blocks ensures the uniformity of silicon powder spread on the surface of the carbon disk, guaranteeing consistent silicon infiltration throughout the microstructure.
[0036] 2. Silicon powder blocks can be assembled into different shapes at the carbon disc, separated by graphite spacers, leaving chip removal grooves between the blocks. This facilitates the discharge of silicon carbide particles and improves thermal conductivity and friction performance. Furthermore, the brake disc contains both carbon-carbon and carbon-ceramic composite materials, allowing for full utilization of their respective friction material performance advantages.
[0037] 3. It can simplify furnace loading. There is no need to set up melting and infiltrating graphite fixtures for each carbon disc billet. They can be directly stacked and loaded into the furnace, which greatly reduces the difficulty of furnace loading, increases the amount of material loaded per furnace, and improves furnace loading efficiency. Attached Figure Description
[0038] Figure 1 A schematic diagram showing the loading of graphite separators and silicon powder cold-pressed blocks on the surface of a carbon disk blank. Detailed Implementation
[0039] Example 1
[0040] The carbon-ceramic / carbon-carbon multidimensional composite aircraft brake disc provided in this embodiment is composed of N alternating carbon-ceramic composite material regions and N carbon-carbon composite material regions, where N is 6, and the total area ratio of the N carbon-ceramic composite material regions to the N carbon-carbon composite material regions is 7:3.
[0041] The preparation process is as follows:
[0042] 1) Mixing: Silicon powder : paraffin powder (weight ratio) = 95 : 5, mix in a three-dimensional mixer for 1 hour; 2) Cold pressing: Weigh the mixture of silicon powder and paraffin powder, place it in a metal mold, and cold press it with a hydraulic press. The platen temperature is 80℃, the holding time is 30s, and the holding pressure is 200Kg / cm. 2 3) Demolding: After the mold cools for 5 minutes, demold and remove the silicon powder cold-pressed block; 4) Bonding of carbon disk graphite blocks (or graphite paper): Coat the bonding surface of the graphite blocks (or graphite paper) with furfuryl ketone resin, place them on the surface of the carbon disk blank, fix them with C-clamps, place them in an oven to dry and cure at 180℃, and remove them after cooling; 5) Placement of silicon powder cold-pressed blocks: Place the silicon powder cold-pressed blocks between the graphite spacers of the carbon disk blank; Carbon ceramic melting zone: Carbon carbon unmelted zone (area ratio) = 7:3; 6) Stacking and loading: Stack the carbon disk blanks with graphite blocks and silicon powder blocks in the reaction melting furnace, without... 7) High-temperature reaction melting and infiltration: Silicon powder reaction melting and infiltration is carried out at 1500℃; 8) Unloading: After the equipment cools down, the carbon ceramic / carbon carbon brake disc that has been melted and infiltrated is taken out, excess material is cleaned with a scraper, and the graphite spacer is taken out; 9) Impregnation: The blank is impregnated with furfuryl ketone resin at 0.8MPa to increase the density of the carbon carbon composite material area; 10) Carbonization: The blank is carbonized at 950℃ to convert the resin into resin carbon; 11) Finishing: The carbon ceramic / carbon carbon brake disc is machined to the specified size to obtain the carbon ceramic / carbon carbon multidimensional composite aircraft brake disc.
[0043] The data from platform tests of the carbon-ceramic / carbon-carbon multidimensional composite aircraft brake disc provided in this embodiment are as follows: dry friction coefficient is 0.405, wet friction coefficient is 0.355, dry wear is 0.0046 mm / surface·cycle, wet wear is 0.0051 mm / surface·cycle, the braking curve is smooth, and there is no vibration or squealing during braking.
[0044] Example 2
[0045] The carbon-ceramic / carbon-carbon multidimensional composite aircraft brake disc provided in this embodiment is composed of N carbon-ceramic composite material regions and N carbon-carbon composite material regions alternating, where N is 4, and the total area ratio of the N carbon-ceramic composite material regions to the N carbon-carbon composite material regions is 8.5:1.
[0046] The preparation process is as follows:
[0047] 1) Mixing: Silicon powder : paraffin powder (weight ratio) = 95 : 5, mix in a three-dimensional mixer for 1 hour; 2) Cold pressing: Weigh the mixture of silicon powder and paraffin powder, place it in a metal mold, and cold press it with a hydraulic press. The platen temperature is 80℃, the holding time is 30s, and the holding pressure is 200Kg / cm. 2 3) Demolding: After the mold cools for 5 minutes, demold and remove the silicon powder cold-pressed block; 4) Bonding of carbon disk graphite blocks (or graphite paper): Coat the bonding surface of the graphite blocks (or graphite paper) with furfuryl ketone resin, place them on the surface of the carbon disk blank, fix them with C-clamps, place them in an oven to dry and cure at 180℃, and remove them after cooling; 5) Placement of silicon powder cold-pressed blocks: Place the silicon powder cold-pressed blocks between the graphite spacers of the carbon disk blank; Carbon ceramic melting zone: Carbon carbon unmelted zone (area ratio) = 8.5:1; 6) Stacking and loading into the furnace: Stack the carbon disk blanks with graphite blocks and silicon powder blocks in the reaction melting furnace. 7) High-temperature reaction melting and infiltration: Silicon powder reaction melting and infiltration is carried out at 1500℃; 8) Unloading: After the equipment cools down, the carbon ceramic / carbon carbon brake disc that has been melted and infiltrated is taken out, excess material is cleaned with a scraper, and the graphite spacer is taken out; 9) Impregnation: The blank is impregnated with furfuryl ketone resin at 0.8MPa to increase the density of the carbon carbon composite material area; 10) Carbonization: The blank is carbonized at 950℃ to convert the resin into resin carbon; 11) Finishing: The carbon ceramic / carbon carbon brake disc is machined to the specified size to obtain the carbon ceramic / carbon carbon multidimensional composite aircraft brake disc.
[0048] The data from platform tests of the carbon-ceramic / carbon-carbon multidimensional composite aircraft brake disc provided in this embodiment are as follows: dry friction coefficient is 0.467, wet friction coefficient is 0.372, dry wear is 0.0056 mm / surface·cycle, wet wear is 0.0071 mm / surface·cycle, the braking curve has a slight tail, there is slight vibration at the start of braking, and there is no whistling.
[0049] Comparative Example 1
[0050] The other conditions were the same as in Example 1, except that the ratio of carbon-ceramic melt-infiltrated area to carbon-carbon unmelted infiltrated area (area ratio) was 10:0. The aircraft brake disc prepared under these conditions had the following data tested on the platform: dry friction coefficient was 0.512, wet friction coefficient was 0.478, dry wear was 0.0066 mm / surface·cycle, wet wear was 0.0085 mm / surface·cycle, the braking curve showed obvious tailing, and vibration and squealing occurred during the braking process.
[0051] Comparative Example 2
[0052] Other conditions were the same as in Example 1, except that the area ratio of the carbon-ceramic melt-infiltrated zone to the carbon-carbon unmelted-infiltrated zone was 5:5, and N was 6. The aircraft brake disc prepared under these conditions had the following data tested on the platform: dry friction coefficient of 0.368, wet friction coefficient of 0.207, dry wear of 0.0104 mm / surface·cycle, and wet wear of 0.0123 mm / surface·cycle. The braking curve was stable, and there was no vibration or squealing during braking. However, the brake disc wore out significantly, and the dry and wet friction coefficients were not ideal.
Claims
1. A method for preparing a carbon-ceramic / carbon-carbon multidimensional composite aircraft brake disc, characterized in that: The carbon-ceramic / carbon-carbon multidimensional composite aircraft brake disc is composed of N carbon-ceramic composite material regions and N carbon-carbon composite material regions, wherein the N carbon-ceramic composite material regions account for 70% to 90% of the area of the carbon-ceramic / carbon-carbon multidimensional composite aircraft brake disc; According to the design of carbon-ceramic / carbon-carbon multidimensional composite aircraft brake discs, the carbon disc blank is divided into N alternating carbon-ceramic composite material zones and N carbon-carbon composite material zones. Furfuryl ketone resin is coated on the bonding surface of 2N graphite separators and placed on the upper and lower surfaces of the carbon disc blank, respectively, located in the N carbon-carbon composite material zones, and then cured at 170~190℃. Then, 2N silicon powder cold-pressed blocks are placed on the upper and lower surfaces of the carbon disc blank, respectively, located in the N carbon-ceramic composite material zones, to obtain a carbon disc blank with graphite separators and silicon powder cold-pressed blocks. The reaction melt infiltration is carried out to obtain a carbon-ceramic / carbon-carbon preform. The carbon-ceramic / carbon-carbon preform is then resin carbon densified to obtain a carbon-ceramic / carbon-carbon multidimensional composite aircraft brake disc. The process of resin carbon densification of the carbon ceramic / carbon carbon preform is as follows: the carbon ceramic / carbon carbon preform is impregnated with furfuryl ketone resin under a pressure of 0.3MPa~5.0MPa, and after impregnation, it is carbonized at 700℃~1000℃ to obtain the final product.
2. The method for preparing a carbon-ceramic / carbon-carbon multidimensional composite aircraft brake disc according to claim 1, characterized in that: The density of the carbon disc blank is 1.2~1.5 g / cm³. 3 .
3. The method for preparing a carbon-ceramic / carbon-carbon multidimensional composite aircraft brake disc according to claim 1, characterized in that: The value of N is 3 to 6.
4. The method for preparing a carbon-ceramic / carbon-carbon multidimensional composite aircraft brake disc according to claim 1, characterized in that: The graphite separator is selected from graphite blocks or graphite paper.
5. The method for preparing a carbon-ceramic / carbon-carbon multidimensional composite aircraft brake disc according to claim 1, characterized in that: The silicon powder cold-pressed block is obtained by mixing silicon powder and paraffin powder to obtain a mixture, and then cold-pressing it into shape.
6. The method for preparing a carbon-ceramic / carbon-carbon multidimensional composite aircraft brake disc according to claim 5, characterized in that: In the mixture, the mass ratio of silicon powder to paraffin powder is 92~97:8~3. The mixing is carried out in a three-dimensional mixer for 1~2 hours. During the cold pressing process, the temperature of the pressure plate is 70~90℃, the holding time is 20~40s, and the holding pressure is 170~230 Kg / cm³. 2 .
7. The method for preparing a carbon-ceramic / carbon-carbon multidimensional composite aircraft brake disc according to claim 1, characterized in that: Carbon disc blanks with graphite separators and silicon powder cold-pressed blocks are stacked in a reaction melting furnace for reaction melting.
8. The method for preparing a carbon-ceramic / carbon-carbon multidimensional composite aircraft brake disc according to claim 1, characterized in that: The reaction melting temperature is 1400℃~1900℃.