CN115819101A - Method for quickly preparing carbon/carbon composite material brake disc - Google Patents
Method for quickly preparing carbon/carbon composite material brake disc Download PDFInfo
- Publication number
- CN115819101A CN115819101A CN202211486769.XA CN202211486769A CN115819101A CN 115819101 A CN115819101 A CN 115819101A CN 202211486769 A CN202211486769 A CN 202211486769A CN 115819101 A CN115819101 A CN 115819101A
- Authority
- CN
- China
- Prior art keywords
- carbon
- annular
- gas
- chemical vapor
- end plate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Landscapes
- Ceramic Products (AREA)
Abstract
The invention discloses a method for quickly preparing a carbon/carbon composite material brake disc, which comprises the steps of enabling a carbon fiber preform to pass through an internal heat source heater to be stacked, enabling gas to flow from the outer diameter to the inner diameter in a limiting area of M +1 deposition chambers through the design of a tool, and enabling the gas to be discharged out of a furnace through a central pipeline, so that the concentration distribution of the gas in each limiting area can be ensured to be uniform, the densification efficiency is improved, hole sealing is avoided, the consistency of a formed carbon structure is better ensured, meanwhile, a central heating body is adopted, the carbon fiber preform is enabled to form a thermal gradient from inside to outside, the arrangement of a furnace wall air inlet nozzle is matched, the gas is enabled to be thermally decomposed and deposited at the outer diameter position of the carbon fiber preform or the carbon/carbon porous body close to the air inlet nozzle, the fresh gas is diffused to the core part and the inner diameter position of the carbon fiber preform or the carbon/carbon porous body, the thermal decomposition and the deposition are simultaneously carried out, the improvement of the gas utilization rate is facilitated, and the densification is realized.
Description
Technical Field
The invention belongs to the technical field of brake disc manufacturing, and particularly relates to a method for quickly preparing a carbon/carbon composite brake disc.
Background
The carbon/carbon composite material has the characteristics of small density, high specific strength, high temperature resistance, excellent thermal shock resistance, excellent frictional wear resistance and large braking absorption energy, and becomes a good friction material. Particularly, the brake disc is applied to the airplane brake disc, so that the reliability, safety, economy and comfort of the airplane are obviously improved, and the brake disc is widely applied to modern airplanes.
At present, the mainstream method for preparing the carbon/carbon composite material aircraft brake disc at home and abroad is a Chemical Vapor Infiltration (CVI) technology: the carbon fiber preform is placed in a carbon source atmosphere, a carbon source gas is cracked into pyrolytic carbon under a high-temperature condition and filled in pores of the preform, the preform is densified to a required density, and meanwhile, the process condition of CVI is controlled to control the structure of the pyrolytic carbon. CVI techniques can be divided in temperature into Isothermal Chemical Vapor Infiltration (ICVI) and Thermal Gradient Chemical Vapor Infiltration (TGCVI) techniques. The carbon/carbon composite material brake disc prepared by the ICVI technology has the advantages of stable and controllable pyrolytic carbon structure, can finally obtain the brake disc with stable frictional wear performance, but has long densification period (usually requiring densification time of more than 800 hours) and low utilization rate of raw material gas, so that the cost of the carbon disc is high. The carbon/carbon composite material brake disc prepared by the TGCVI technology has the advantages of short densification period, high utilization rate of raw material gas and low cost, but the prepared brake disc has poor controllability of pyrolytic carbon and poor consistency of pyrolytic carbon structures, and usually needs auxiliary impregnation densification to reach the required value of density, so that the final brake disc has large fluctuation range of friction and wear performance, is not beneficial to matching design of an airplane brake control system, and has negative influence on economy and comfort of an airplane.
Therefore, how to solve the technical problem of ensuring that the pyrolytic carbon structure obtained by CVI is controllable and stable while the densification efficiency of the CVI technology is solved is a technical problem to be solved urgently in the carbon/carbon composite material brake disc preparation technology.
Aiming at the technical problems, the method for rapidly preparing the carbon/carbon composite material is researched by the industry, and the carbon/carbon composite material is densified to 1.50-1.70 g/cm by adopting the conventional CVI technology in the patent CN101913896A 3 Then obtaining the density of more than or equal to 1.80g/c under high temperature and high pressurem 3 The method solves the problem that the carbon/carbon composite material with higher density is difficult to densify quickly when being densified again, but short plates may exist in the cost and batch production. Patent CN1350959A adopts a thermal gradient directional flow to prepare a carbon/carbon composite material aircraft brake disc, and prepares a carbon/carbon composite material with higher density in a shorter time, but the charging amount of the brake disc is limited, and the structure and the uniformity of the structure of the obtained pyrolytic carbon of the brake disc are unknown.
Disclosure of Invention
The method aims at solving the problems that the existing CVI preparation technology of the carbon/carbon composite material brake disc is difficult to simultaneously consider the consistency of cost/period and a pyrolytic carbon structure, so that the product cost is high or the product performance fluctuation range is large. The invention aims to provide a method for quickly preparing a carbon/carbon composite material brake disc. The preparation method provided by the invention has the characteristics of short preparation period, low cost and suitability for mass production, and the prepared carbon/carbon composite material brake disc has the advantages of pyrolytic carbon structure control and good consistency of pyrolytic carbon structure.
In order to achieve the purpose, the invention adopts the following technical scheme:
the invention relates to a preparation method of a carbon/carbon composite material brake disc, which is characterized in that the center of an annular lower end plate, a plurality of annular carbon fiber preforms or carbon/carbon porous bodies and an annular upper end plate penetrates through a heating body and is loaded in a chemical vapor furnace from bottom to top to form a stock column, and an annular partition plate or an annular gas limiting plate is arranged between any two adjacent carbon fiber preforms or carbon/carbon porous bodies in the stock column; the space between any two annular gas limiting plates is 250-500 mm, the charge column is divided into M +1 deposition chambers by the annular lower end plate, the annular upper end plate and M groups of annular gas limiting plates, M +1 groups of gas inlet rings are distributed in the axial direction of the chemical vapor furnace, any group of gas inlet rings are positioned on the side surfaces of the M +1 deposition chambers, a plurality of gas inlet nozzles are uniformly distributed on any group of gas inlet rings, carbon source gas and carrier gas are introduced into the furnace through the gas inlet nozzles, and chemical vapor deposition densification is carried out on the carbon fiber preform or the carbon/carbon porous body, so that the carbon/carbon composite material brake disc is obtained; in the chemical vapor deposition process, the flow of the introduced carbon source gas and the carrier gas is reduced progressively, the temperature of the inner side of the material column close to the heating element is controlled to be reduced progressively, and the temperature of the outer side of the material column far away from the heating element is controlled to be increased progressively;
the inner diameter of the annular gas limiting plate is consistent with that of the carbon fiber preform or the carbon/carbon porous body, the outer diameter of the annular gas limiting plate is consistent with that of the chemical vapor furnace, a plurality of protruding keys are uniformly arranged on the two end faces of the annular gas limiting plate in the circumferential direction, one end of each protruding key is flush with the inner side face of the annular gas limiting plate, the other end of each protruding key radially extends to be flush with the outer side face of the carbon fiber preform or the carbon/carbon porous body, the height of each protruding key is 1-3 mm, the number of the protruding keys is 3-8, and the thickness of the annular gas limiting plate is 3-7 mm.
In the present invention, the thickness of the annular gas restriction plate means a thickness not including the projecting key.
The inner diameter of the preparation method adopts a resistance heating mode, the carbon fiber preforms penetrate through an inner heat source heater to be stacked, the design of the annular gas limiting plate can effectively enable gas to flow from the outer diameter to the inner diameter in the limiting areas of M +1 deposition chambers and then to be discharged outside the furnace through a central pipeline, the concentration distribution of the gas in each limiting area can be ensured to be uniform, the densification efficiency is improved, hole sealing is avoided, the consistency of the formed carbon structure can be better ensured, meanwhile, a central heating body is adopted, the carbon fiber preforms form the thermal gradient from inside to outside, the degree of thermal decomposition and deposition of the gas at the outer diameter (low temperature) of the carbon fiber preforms or carbon/carbon porous bodies close to the gas inlet nozzles is low, the fresh gas diffuses to the core parts and the inner diameter parts of the carbon fiber preforms or carbon/carbon porous bodies and is simultaneously thermally decomposed and deposited, the gas utilization rate is improved, and the rapid densification is realized. In the chemical deposition process, the porosity is reduced along with the increase of the density of the carbon/carbon porous body, the flow of the introduced carbon source gas and the carrier gas is controlled to be reduced gradually, and the increase of hole sealing caused by gas flow can be effectively avoided so as to be not beneficial to the densification in the subsequent stage. With the increase of the density of the carbon/carbon porous body, the difference of the radial (inner diameter position and outer diameter position) heat conductivity of the carbon/carbon porous body is smaller, the temperature of the inner side of the material column close to the heating body is controlled to decrease progressively, the temperature of the outer side of the material column far away from the heating body is controlled to increase progressively, and the density uniformity of the final carbon/carbon porous body is facilitated: the temperature of the outer diameter part at the early stage is low, the deposition speed is low, the density is low (the porosity is high), the temperature of the inner diameter part is high, the density is high (the porosity is low), the outer diameter part with the high porosity is favorably and quickly compacted through the increase of the outer diameter temperature at the later stage, the penetration and deposition of gas to the core part are favorably realized through the reduction of the temperature of the inner diameter part at the later stage, the density at the inner diameter part is increased, the density difference does not exist between the inner diameter part and the outer diameter part, meanwhile, the carbon structure is controllable and consistent, and a rough layer is mainly used.
The carbon/carbon porous body can be in a uniform micro-gas environment through the arrangement of the tool, and finally, the controllable, uniform and stable consistency of the material structure and the density can be realized in the batch production process of the carbon/carbon composite material brake disc by combining the temperature change arrangement of the chemical vapor deposition.
Preferably, the density of the carbon fiber preform is 0.40 to 0.60g/cm 3 。
In a preferred scheme, the carbon fiber preform is subjected to heat treatment at 1600-2000 ℃ for 2-4h.
The carbon fiber preform is subjected to heat treatment, organic matters on the surface of the carbon fiber are volatilized through the heat treatment, the specific surface area is increased, the interface bonding strength of the pyrolytic carbon and the carbon fiber is increased in the later chemical vapor deposition (CVI) densification process, and the strength of the material is increased.
Preferably, the inner diameter of the annular lower end plate is consistent with that of the carbon fiber preform or the carbon/carbon porous body, the outer diameter of the annular lower end plate is consistent with that of the chemical vapor furnace, a plurality of protruding keys are uniformly arranged on the upper end face of the annular lower end plate in the circumferential direction, one end of each protruding key is flush with the inner side face of the annular lower end plate, the other end of each protruding key radially extends to be flush with the outer side face of the carbon fiber preform or the carbon/carbon porous body, the height of each protruding key is 1-3 mm, the number of the protruding keys is 3-8, and the thickness of the annular lower end plate is 3-7 mm.
In the present invention, the thickness of the annular lower end plate does not include the height of the projecting key.
Preferably, the inner diameter and the outer diameter of the annular upper end plate are consistent with those of a carbon fiber preform or a carbon/carbon porous body, the outer diameter is consistent with that of a chemical vapor furnace, a plurality of protruding keys are uniformly arranged on the lower end surface of the annular upper end plate in the circumferential direction, one end of each protruding key is flush with the inner side surface of the annular upper end plate, the other end of each protruding key radially extends to be flush with the outer side surface of the carbon fiber preform or the carbon/carbon porous body, the height of each protruding key is 1-3 mm, the number of the protruding keys is 3-8, and the thickness of the annular upper end plate is 3-7 mm.
It can be seen that the dimensions of the annular upper end plate and the annular lower end plate are the same, and one end of the convex key is flush with the inner side surface of the annular upper end plate or the annular lower end plate, and the other end of the convex key radially extends to be flush with the outer side surface of the carbon fiber preform or the carbon/carbon porous body, namely, the length of the convex key is the same as the span of the carbon fiber preform or the carbon/carbon porous body, only when the carbon fiber preform or the carbon/carbon porous body is installed, the side of the annular upper end plate containing the convex key is installed downwards, and the side of the annular lower end plate containing the convex key is installed upwards.
Preferably, the inner and outer diameter of the annular partition board is consistent with that of the carbon fiber preform or the carbon/carbon porous body, a plurality of protruding keys are uniformly arranged on the two end faces of the annular partition board in the circumferential direction, one end of each protruding key is flush with the outer side face of the annular partition board, the other end of each protruding key radially extends to be flush with the inner side face of the annular partition board, the height of each protruding key is 1-3 mm, the number of the protruding keys is 3-8, and the thickness of the annular partition board is 3-7 mm.
In a preferred scheme, the annular lower end plate, the annular upper end plate, the annular partition plate and the annular gas limiting plate are made of carbon materials, and the preferred density is more than or equal to 1.72g/cm 3 The density of the graphite or carbon/carbon composite material is more preferably more than or equal to 1.74g/cm after CVI chemical vapor surface deposition hole sealing treatment 3 Graphite or carbon/carbon composite material.
According to the invention, the annular lower end plate, the annular upper end plate, the annular partition plate and the annular gas limiting plate are effectively used as tools, so that the densification efficiency is improved, and particularly, the densification efficiency of the carbon fiber preform is obviously improved. The inventor finds that the uniform and consistent surface of the high-density tool adopting hole sealing treatment is beneficial to the preform or the carbon/carbon porous body to be in a uniform micro-gas environment, so that the controllability and the stability of pyrolytic carbon are beneficial.
In a preferable scheme, the inner wall of the chemical vapor phase furnace is provided with a fulcrum, and the annular gas limiting plate is arranged on the fulcrum.
The inventor finds that the annular gas limiting plate is arranged on the fulcrum of the inner wall of the furnace, so that the function of supporting the carbon fiber preform is achieved, and the adverse effects of pressure-bearing deformation, compression and the like of the lower carbon fiber preform due to the charging height are avoided. Further being beneficial to the consistency of the densification efficiency of the furnace batch products and the consistency of the pyrolytic carbon structure.
In the preferred scheme, 6-10 air inlet nozzles are uniformly distributed on any group of air inlet rings.
The inventor finds that the pressure bearing of the carbon fiber preform at the bottom can be avoided by the design of 6-10 air nozzles uniformly distributed in the circumferential direction of the air ring and the combination of the tool through furnace side air inlet, wherein each circumferential direction is an air ring, so that the carbon fiber preform or the carbon/carbon porous body is in a basically consistent stress environment, airflow field environment and temperature field environment, and the limitation of the height of the CVI material column is broken through.
Preferably, the gas rings of any one group are arranged at 40 to 48 percent of the total height of the corresponding deposition chamber, preferably 43 to 46 percent.
The total height in the present invention is a height from the upper end surface of the annular lower end plate or the annular gas confining plate to the lower end surface of the adjacent annular gas confining plate or the annular upper end plate.
The inventor finds that the position design of the gas ring is crucial to the uniformity of densification efficiency and the consistency of pyrolytic carbon, and the low and high positions of the gas ring lead to large fluctuation range of densification efficiency and pyrolytic carbon.
Preferably, the carbon source gas is propylene, and the carrier gas is nitrogen.
Preferably, the chemical vapor deposition is divided into three sections, when the chemical vapor deposition is carried out in the first section, the flow rate of carbon source gas introduced into each kilogram of carbon fiber preform is 0.2-0.3 SL/Min, and the volume ratio of the introduced carbon source gas to the introduced carrier gas is 1:1.5 to 2.0; the temperature of the inner side of the charge column close to the heating element is 1150-1020 ℃, the temperature of the outer side of the charge column far away from the heating element is 880-970 ℃, the pressure in the furnace is controlled to be 1.0-3.0 Kpa, and the deposition time is 80-120 h;
during the second-stage chemical vapor deposition, the flow of carbon source gas introduced into each kilogram of carbon fiber preform is 0.15-0.25 SL/Min, and the volume ratio of the introduced carbon source gas to the introduced carrier gas is 1:1.5 to 2.0; the temperature of the inner side of the material column close to the heating element is 1110-1010 ℃, the temperature of the outer side of the material column far away from the heating element is 920-980 ℃, the pressure in the furnace is controlled to be 1.0-3.0 Kpa, and the deposition time is 80-120 h;
and during the third-stage chemical vapor deposition, the flow of carbon source gas introduced into each kilogram of carbon fiber preform is 0.10-0.20 SL/Min, and the volume ratio of the introduced carbon source gas to the introduced carrier gas is 1:1.5 to 2.0; the temperature of the inner side of the material column close to the heating element is 1100-1000 ℃, the temperature of the outer side of the material column far away from the heating element is 930-990 ℃, the pressure in the furnace is controlled to be 1.0-3.0 Kpa, and the deposition time is 60-100 h.
In the present invention, the temperature measured inside the stock column is the temperature of the inner side surface of the carbon fiber preform or the carbon/carbon porous body, and the temperature measured outside the stock column is the temperature of the outer side surface of the carbon fiber preform or the carbon/carbon porous body.
It can be seen that in the three-stage deposition process, the temperature measured in the stock column is gradually reduced, the temperature outside the stock column is increased, the temperature at the outer diameter position in the early stage is low, the deposition speed is slow, the density is low (the porosity is high), the temperature at the inner diameter position is high, the deposition speed is fast, the density is high (the porosity is low), the outer diameter position with the high porosity is fast and compact by increasing the outer diameter temperature in the later stage, the gas is favorably permeated and deposited towards the core part by reducing the temperature at the inner diameter position in the later stage, the density at the inner diameter position is increased, and finally, the density difference does not exist between the inner diameter position and the outer diameter position.
In the actual operation process, even in the same deposition process, the temperature of the outer side of the material column is continuously increased, so that the temperature of the outer diameter is ensured by reducing the temperature of the inner diameter, for example, 1150-1020 ℃ of the temperature of the inner side of the material column close to the heating element is deposited in the first section, namely, in the first section of chemical vapor deposition process, the high temperature in the range of 1150-1020 ℃ is gradually reduced to the low temperature in the range.
In the actual operation process, before the propylene gas and the nitrogen gas are introduced into the furnace, the propylene gas and the nitrogen gas need to be uniformly mixed through a gas mixing tank, and the uniformly mixed gas is uniformly distributed to each gas ring through a flow meter.
Further preferably, during the first stage of chemical vapor deposition, the temperature of the inner side of the material column close to the heating element is 1110-1050 ℃, and the temperature of the outer side of the material column far away from the heating element is 900-960 ℃;
during the second stage of chemical vapor deposition, the temperature of the inner side of the material column close to the heating body is
1080-1030 ℃, and 940-970 ℃ of the temperature of the outer side of the material column far away from the heating element;
during the third-stage chemical vapor deposition, the temperature of the inner side of the material column close to the heating element is 1060 DEG C
1020 ℃ below zero, and the temperature of the outer side of the material column far away from the heating element is 950-980 ℃.
In practice, machining is required between CVI stages to eliminate closed cells caused by CVI deposition, which is well known in the art, and the inventors have found in practice that because the present invention produces fewer closed cells, the machined size is less than the prior art.
According to the preferable scheme, after chemical vapor deposition densification, the carbon/carbon composite material is subjected to heat treatment and machining, and the carbon/carbon composite material brake disc is obtained, wherein the heat treatment temperature is 1800-2200 ℃, and the time is 2-4 hours.
Principles and advantages
The inner diameter of the preparation method adopts a resistance heating mode, the carbon fiber preform passes through the inner heat source heater to be stacked, the gas can effectively flow from the outer diameter to the inner diameter in the limited areas of the M +1 deposition chambers through the annular lower end plate and the annular upper end plate and is exhausted outside the furnace through the central pipeline, the concentration distribution of the gas in each limited area can be ensured to be uniform, the densification efficiency is improved, the hole sealing is avoided, the consistency of the formed carbon structure can be better ensured, meanwhile, the central heating body is adopted, the carbon fiber preform forms the thermal gradient from inside to outside, the degree of thermal decomposition and deposition of the gas at the outer diameter (low temperature) of the carbon fiber preform or the carbon/carbon porous body close to the gas inlet nozzle is low, the fresh gas diffuses to the core part and the inner diameter part of the carbon fiber preform or the carbon/carbon porous body and is simultaneously thermally decomposed and deposited, the gas utilization rate is improved, and the rapid realization is facilitated. In the chemical deposition process, the porosity is reduced along with the increase of the density of the carbon/carbon porous body, the flow of the introduced carbon source gas and the carrier gas is controlled to be reduced gradually, and the increase of hole sealing caused by gas flow can be effectively avoided so as to be not beneficial to the densification in the subsequent stage. With the increase of the density of the carbon/carbon porous body, the difference of the radial (inner diameter position and outer diameter position) heat conductivity of the carbon/carbon porous body is smaller, the temperature of the inner side of the material column close to the heating body is controlled to decrease progressively, the temperature of the outer side of the material column far away from the heating body is controlled to increase progressively, and the density uniformity of the final carbon/carbon porous body is facilitated: the temperature of the outer diameter part at the early stage is low, the deposition speed is low, the density is low (the porosity is high), the temperature of the inner diameter part is high, the density is high (the porosity is low), the outer diameter part with the high porosity is favorably and quickly compacted through the increase of the outer diameter temperature at the later stage, the penetration and deposition of gas to the core part are favorably realized through the reduction of the temperature of the inner diameter part at the later stage, the density at the inner diameter part is increased, the density difference does not exist at the positions from the inner diameter part to the outer diameter part, meanwhile, the carbon structure can be controlled to be consistent, and a rough layer is mainly used.
Compared with the prior art, the invention has the following advantages:
1. the carbon/carbon composite material brake disc prepared by the method has the advantages of short period and low cost.
2. The pyrolytic carbon structure of the carbon/carbon composite material brake disc prepared by the method has good consistency.
3. The charging height/number of the invention is not limited, and the invention is suitable for mass production.
The carbon/carbon composite material brake disc prepared by the method meets the requirements on various material performance indexes, is used as an airplane brake disc, and has excellent quality consistency.
Drawings
FIG. 1 is a schematic view of a charging furnace designed by the present invention.
In the figure: 1-heating element 2-heat insulation material 3-annular upper end plate 4-carbon fiber prefabricated body or carbon/carbon porous body 5-annular partition plate, 6-annular air limiting plate 7-air nozzle 8-annular lower end plate.
Fig. 2 is a schematic view of the annular upper end plate and the annular lower end plate, wherein the left side of the figure is the front of the annular lower end plate and the back of the annular upper end plate, and the right side of the figure is the front of the annular upper end plate and the back of the annular lower end plate.
FIG. 3 is a schematic view of the front and back sides of the annular partition.
FIG. 4 is a schematic view of the front and back sides of the annular air restriction plate.
Detailed Description
The present invention is further illustrated by the following examples.
Example 1
The carbon fiber preform for the present embodiment has the following dimensions: an outer diameter of 430mm, an inner diameter of 230mm, a thickness of 25mm, a number of 60 disks, and a density of the carbon fiber preform of 0.5g/cm 3 The carbon fiber preform is subjected to heat treatment at 1800 ℃ for 3 hours.
The inner diameter of the chemical deposition furnace is 500mm, and the outer diameter of the heating element is 170mm.
All the tools are subjected to CVI chemical vapor surface deposition hole sealing treatment, and the density of the tools is 1.75g/cm 3 The carbon/carbon composite of (1).
The inner diameter and the outer diameter of the annular upper end plate are consistent with those of a carbon fiber prefabricated body or a carbon/carbon porous body, the outer diameter of the annular upper end plate is consistent with that of a chemical vapor furnace, a plurality of protruding keys are uniformly arranged on the lower end face of the annular upper end plate in the circumferential direction, one ends of the protruding keys are flush with the inner side face of the annular upper end plate, the other ends of the protruding keys radially extend to be flush with the outer side face of the prefabricated body or the carbon/carbon porous body, the height of each protruding key is 2mm, the number of the protruding keys is 6, and the thickness of the annular upper end plate is 5mm;
the inner diameter of the annular lower end plate is consistent with that of the carbon fiber preform or the carbon/carbon porous body, the outer diameter of the annular lower end plate is consistent with that of the chemical vapor furnace, a plurality of protruding keys are uniformly arranged on the upper end face of the annular lower end plate in the circumferential direction, one end of each protruding key is flush with the inner side face of the annular lower end plate, the other end of each protruding key radially extends to be flush with the outer side face of the carbon fiber preform or the carbon/carbon porous body, the height of each protruding key is 2mm, the number of the protruding keys is 6, and the thickness of the annular lower end plate is 5mm.
The inside and outside footpath size of cyclic annular baffle is unanimous with carbon fiber preform or carbon/carbon porous body, and two equal circumference of terminal surface of cyclic annular baffle evenly are provided with polylith protrusion key, and the one end of protrusion key and the lateral surface parallel and level of cyclic annular baffle, the other end radially extends to the medial surface parallel and level with cyclic annular baffle, the height of protrusion key is 2mm, and quantity is 6, the thickness of cyclic annular baffle is 5mm.
The inner diameter of the annular gas limiting plate is consistent with that of a carbon fiber preform or a carbon/carbon porous body, the outer diameter of the annular gas limiting plate is consistent with that of a chemical vapor furnace, a plurality of protruding keys are uniformly arranged on two end faces of the annular gas limiting plate in the circumferential direction, one end of each protruding key is flush with the inner side face of the annular gas limiting plate, the other end of each protruding key radially extends to be flush with the outer side face of the carbon fiber preform or the carbon/carbon porous body, the height of each protruding key is 2mm, the number of the protruding keys is 6, and the thickness of the annular gas limiting plate is 5mm.
The following is the specific furnace charging and chemical vapor deposition process implementation:
firstly, the center of an annular lower end plate penetrates through a heating body to be loaded below a chemical vapor furnace, then carbon fiber preforms are installed in the same mode, a partition plate or a gas limiting plate is installed between the two carbon fiber preforms, wherein the gas limiting plate is installed at a position of about 400mm (12 preforms and the height of a tool for spacing the preforms) and is installed on a fulcrum of the inner wall of the furnace, partition plates are installed at other positions, after all the carbon fiber preforms are loaded, an upper annular end plate is finally loaded to form a material column, 4 gas limiting plates are installed in the material column, the material column is divided into 5 deposition chambers by the annular lower end plate and the annular upper end plate, 5 groups of gas inlet rings are distributed in the axial direction of the chemical vapor furnace, any one group of the gas inlet rings is located on the side face of the corresponding deposition chamber and is located at 45% of the deposition chamber, 8 gas inlet nozzles are uniformly distributed in the circumferential direction of any one group of the gas inlet rings, propylene is used as a carbon source gas, nitrogen is used as a carrier gas, the carbon source gas and the carbon/carbon preforms or carbon/carbon carrier gas are subjected to chemical vapor deposition densification.
The chemical vapor deposition is divided into three sections, during the first section of chemical vapor deposition, the flow of carbon source gas introduced into each kilogram of carbon fiber preforms is 0.25SL/Min, and the volume ratio of the introduced carbon source gas to the introduced carrier gas is 1:1.75; in the whole deposition process, the temperature of the inner side of the material column close to the heating element is 1105-1055 ℃, the temperature of the outer side of the material column far away from the heating element is 910-955 ℃, the pressure in the furnace is controlled to be 2.0Kpa, and the deposition time is 100 hours;
during the second-stage chemical vapor deposition, the flow of carbon source gas introduced into each kilogram of carbon fiber preform is 0.20SL/Min, and the volume ratio of the introduced carbon source gas to the introduced carrier gas is 1:1.75; in the whole deposition process, the temperature of the inner side of the material column close to the heating element is 1070 to 1040 ℃, the temperature of the outer side of the material column far away from the heating element is 945 to 965 ℃, the pressure in the furnace is controlled to be 2.0Kpa, and the deposition time is 100 hours;
and during the third-stage chemical vapor deposition, the flow of carbon source gas introduced into each kilogram of carbon fiber preform is 0.15SL/Min, and the volume ratio of the introduced carbon source gas to the introduced carrier gas is 1:1.75; the temperature of the inner side of the material column close to the heating element in the whole deposition process is 1055-1025 ℃, the temperature of the outer side of the material column far away from the heating element is 955-975 ℃, the pressure in the furnace is controlled to be 2.0Kpa, and the deposition time is 80h.
And (3) after chemical vapor deposition densification, carrying out heat treatment and machining on the carbon/carbon composite material to obtain the carbon/carbon composite material brake disc, wherein the heat treatment temperature is 2000 ℃ and the time is 3 hours.
The average density of the carbon/carbon composite material prepared by the method is 1.821g/cm 3 The density range is 1.817 to 1.829g/cm 3 Sampling products in different deposition chambers and observing the microstructure of the deposited carbon, wherein the structure of the deposited carbon is a rough layer and a smooth layer, the proportion of the rough layer is 92-95%, the proportion of the smooth layer is 5-8%, the visible density distribution is narrow, the density is uniform, the structure distribution of the pyrolytic carbon is narrow, and the consistency is good.
Example 2
The carbon fiber preform for the present embodiment has the following dimensions: an outer diameter of 430mm, an inner diameter of 230mm, a thickness of 25mm, a number of 70 disks, and a density of the carbon fiber preform of 0.55g/cm 3 The carbon fiber preform is subjected to heat treatment at 1950 ℃ for 4 hours.
The inner diameter of the chemical deposition furnace is 500mm, and the outer diameter of the heating element is 170mm.
The used tools are all subjected to CVI chemical vapor surface deposition hole sealing treatment, and the density of the tools is 1.75g/cm 3 The graphite of (4).
The inner diameter and the outer diameter of the annular upper end plate are consistent with those of a carbon fiber preform or a carbon/carbon porous body, the outer diameter of the annular upper end plate is consistent with that of a chemical vapor furnace, a plurality of protruding keys are uniformly arranged on the lower end face of the annular upper end plate in the circumferential direction, one ends of the protruding keys are flush with the inner side face of the annular upper end plate, the other ends of the protruding keys radially extend to be flush with the outer side face of the carbon fiber preform or the carbon/carbon porous body, the height of each protruding key is 3mm, the number of the protruding keys is 8, and the thickness of the annular upper end plate is 7mm;
the inner diameter of the annular lower end plate is consistent with that of the carbon fiber preform or the carbon/carbon porous body, the outer diameter of the annular lower end plate is consistent with that of the chemical vapor furnace, a plurality of protruding keys are uniformly arranged on the upper end face of the annular lower end plate in the circumferential direction, one end of each protruding key is flush with the inner side face of the annular lower end plate, the other end of each protruding key radially extends to be flush with the outer side face of the carbon fiber preform or the carbon/carbon porous body, the height of each protruding key is 3mm, the number of the protruding keys is 8, and the thickness of the annular lower end plate is 7mm.
The inside and outside footpath size of cyclic annular baffle is unanimous with carbon fiber preform or carbon/carbon porous body, and two equal circumference of terminal surface of cyclic annular baffle evenly are provided with polylith protrusion key, and the one end of protrusion key and the lateral surface parallel and level of cyclic annular baffle, the other end radially extends to the medial surface parallel and level with cyclic annular baffle, the height of protrusion key is 3mm, and quantity is 8, the thickness of cyclic annular baffle is 7mm.
The inner diameter of the annular gas limiting plate is consistent with that of a carbon fiber preform or a carbon/carbon porous body, the outer diameter of the annular gas limiting plate is consistent with that of a chemical vapor furnace, a plurality of protruding keys are uniformly arranged on two end faces of the annular gas limiting plate in the circumferential direction, one end of each protruding key is flush with the inner side face of the annular gas limiting plate, the other end of each protruding key radially extends to be flush with the outer side face of the carbon fiber preform or the carbon/carbon porous body, the height of each protruding key is 3mm, the number of the protruding keys is 8, and the thickness of the annular gas limiting plate is 7mm.
The following is the specific furnace charging and chemical vapor deposition process implementation:
firstly, the center of an annular lower end plate penetrates through a heating body to be loaded on the lowest part of a chemical vapor furnace, then carbon fiber preforms are installed according to the same mode, a partition plate or a gas limiting plate is installed between the two carbon fiber preforms, wherein the gas limiting plate is installed at intervals of about 480mm (the height of 14 preforms and tools for spacing the preforms is equal to that of the preforms) (the gas limiting plate is installed on a fulcrum of the inner wall of the furnace), partition plates are installed at other positions, after all the carbon fiber preforms are loaded, an upper annular end plate is finally loaded to form a material column, 4 gas limiting plates are installed in the material column, the material column is divided into 5 deposition chambers by the annular lower end plate and the annular upper end plate, 5 groups of gas inlet rings are distributed in the axial direction of the chemical vapor furnace, any group of gas inlet rings are located on the side face of the corresponding deposition chamber and at 48% of the total height of the deposition chambers, 10 gas inlet nozzles are uniformly distributed in the circumferential direction of any group of the gas inlet rings, propylene is used as a carbon source gas, the nitrogen is used as a carrier gas, and the carbon source gas is introduced into the furnace through the carbon fiber preforms or carbon/carbon carrier gas for chemical vapor deposition densification.
The chemical vapor deposition is divided into three sections, when the chemical vapor deposition is carried out at the first section, the flow of carbon source gas introduced into each kilogram of preform is 0.30SL/Min, and the volume ratio of the introduced carbon source gas to the introduced carrier gas is 1:2.0 of the total weight of the mixture; in the whole deposition process, the temperature of the inner side of the material column close to the heating element is 1150-1080 ℃, the temperature of the outer side of the material column far away from the heating element is 920-970 ℃, the pressure in the furnace is controlled to be 3.0Kpa, and the deposition time is 80 hours;
during the second-stage chemical vapor deposition, the flow of carbon source gas introduced into each kilogram of the preform is 0.25SL/Min, and the volume ratio of the introduced carbon source gas to the introduced carrier gas is 1:2.0; in the whole deposition process, the temperature of the inner side of the material column close to the heating element is 1110-1060 ℃, the temperature of the outer side of the material column far away from the heating element is 950-980 ℃, the pressure in the furnace is controlled to be 3.0Kpa, and the deposition time is 100 hours;
and in the third stage of chemical vapor deposition, the flow of the carbon source gas introduced into each kilogram of the preform is 0.20SL/Min, and the volume ratio of the introduced carbon source gas to the introduced carrier gas is 1:2.0; the temperature of the inner side of the material column close to the heating element in the whole deposition process is 1100-1070 ℃, the temperature of the outer side of the material column far away from the heating element is 960-990 ℃, the pressure in the furnace is controlled to be 3.0Kpa, and the deposition time is 90h.
And (3) after chemical vapor deposition densification, performing heat treatment and machining on the carbon/carbon composite material to obtain the carbon/carbon composite material brake disc, wherein the heat treatment temperature is 2200 ℃ and the time is 2 hours.
The average density of the carbon/carbon composite material prepared by the method is 1.805g/cm 3 The density range is 1.786-1.814 g/cm 3 Sampling products in different deposition chambers and observing the microstructure of the deposited carbon, wherein the structure of the deposited carbon is a rough layer and a smooth layer, the proportion of the rough layer is 90-95%, the proportion of the smooth layer is 5-10%, the visible density distribution is narrow, the density is uniform, the structure distribution of the pyrolytic carbon is narrow, and the consistency is good.
Example 3
The carbon fiber preform for the present embodiment has the following dimensions: an outer diameter of 430mm, an inner diameter of 230mm, a thickness of 25mm, a number of 72 disks, and a density of the carbon fiber preform of 0.6g/cm 3 The carbon fiber preform is subjected to heat treatment at 1650 ℃ for 2 hours.
The inner diameter of the chemical deposition furnace is 500mm, and the outer diameter of the heating element is 170mm.
The used tools are all subjected to CVI chemical vapor surface deposition hole sealing treatment and have the density of 1.76g/cm 3 The graphite of (4).
The inner diameter and the outer diameter of the annular upper end plate are consistent with those of a carbon fiber preform or a carbon/carbon porous body, the outer diameter of the annular upper end plate is consistent with that of a chemical vapor furnace, a plurality of protruding keys are uniformly arranged on the lower end surface of the annular upper end plate in the circumferential direction, one ends of the protruding keys are flush with the inner side surface of the annular upper end plate, the other ends of the protruding keys radially extend to be flush with the outer side surface of the carbon fiber preform or the carbon/carbon porous body, the height of each protruding key is 1mm, the number of the protruding keys is 4, and the thickness of the annular upper end plate is 3mm;
the inner diameter of the annular lower end plate is consistent with that of the carbon fiber preform or the carbon/carbon porous body, the outer diameter of the annular lower end plate is consistent with that of the chemical vapor furnace, a plurality of protruding keys are uniformly arranged on the upper end face of the annular lower end plate in the circumferential direction, one ends of the protruding keys are flush with the inner side face of the annular lower end plate, the other ends of the protruding keys radially extend to be flush with the outer side face of the carbon fiber preform or the carbon/carbon porous body, the height of each protruding key is 1mm, the number of the protruding keys is 4, and the thickness of the annular lower end plate is 3mm.
The inside and outside footpath size of cyclic annular baffle is unanimous with carbon fiber preform or carbon/carbon porous body, and two equal circumference of terminal surface of cyclic annular baffle evenly are provided with polylith protrusion key, and the one end of protrusion key and the lateral surface parallel and level of cyclic annular baffle, the other end radially extends to the medial surface parallel and level with cyclic annular baffle, the height of protrusion key is 1mm, and quantity is 4, the thickness of cyclic annular baffle is 3mm.
The inner diameter of the annular gas limiting plate is consistent with that of a carbon fiber preform or a carbon/carbon porous body, the outer diameter of the annular gas limiting plate is consistent with that of a chemical vapor furnace, a plurality of protruding keys are uniformly arranged on two end faces of the annular gas limiting plate in the circumferential direction, one end of each protruding key is flush with the inner side face of the annular gas limiting plate, the other end of each protruding key radially extends to be flush with the outer side face of the carbon fiber preform or the carbon/carbon porous body, the height of each protruding key is 1mm, the number of the protruding keys is 4, and the thickness of the annular gas limiting plate is 3mm.
The following is the specific furnace charging and chemical vapor deposition process implementation:
loading the center of the annular lower end plate through a heating body to the lowest part of a chemical vapor furnace, then installing carbon fiber preforms in the same way, and installing a partition plate or a gas limiting plate between the two carbon fiber preforms, wherein the partition plate or the gas limiting plate is arranged at intervals of about 260mm (9 PieceHeight of the prefabricated body and the tooling for spacing the prefabricated body) is provided with a gas limiting plate (the gas limiting plate is arranged on a pivot of the inner wall of the furnace), partition plates are arranged at other positions, and after all the carbon fiber prefabricated bodies are loaded, the carbon fiber prefabricated bodies are finally loadedThe material column is divided into 8 deposition chambers by the annular upper end plate and the annular lower end plate, 8 groups of air inlet rings are distributed in the axial direction of the chemical vapor furnace, any group of air inlet rings are positioned on the side surface of the corresponding deposition chamber and positioned at 40% of the total height of the deposition chamber, 6 air inlet nozzles are uniformly distributed in the circumferential direction of any group of air inlet rings, propylene is used as a carbon source gas, nitrogen is used as a carrier gas, the carbon source gas and the carrier gas are introduced into the furnace through the air inlet nozzles, and chemical vapor deposition densification is carried out on a carbon fiber preform or a carbon/carbon porous body.
The chemical vapor deposition is divided into three sections, during the first section of chemical vapor deposition, the flow of carbon source gas introduced into each kilogram of prefabricated body is 0.2SL/Min, and the volume ratio of the introduced carbon source gas to the introduced carrier gas is 1:1.5; in the whole deposition process, the temperature of the inner side of the material column close to the heating element is 1090-1020 ℃, the temperature of the outer side of the material column far away from the heating element is 880-940 ℃, the pressure in the furnace is controlled to be 1.0Kpa, and the deposition time is 120h;
during the second-stage chemical vapor deposition, the flow of carbon source gas introduced into each kilogram of the preform is 0.15SL/Min, and the volume ratio of the introduced carbon source gas to the introduced carrier gas is 1:1.5; the temperature of the inner side of the material column close to the heating element in the whole deposition process is 1050-1010 ℃, the temperature of the outer side of the material column far away from the heating element is 920-950 ℃, the pressure in the furnace is controlled to be 1.0Kpa, and the deposition time is 120h;
and during the third-stage chemical vapor deposition, the flow of the carbon source gas introduced into each kilogram of the preform is 0.10SL/Min, and the volume ratio of the introduced carbon source gas to the introduced carrier gas is 1:1.5; the temperature of the inner side of the material column close to the heating element is 1040-1000 ℃ in the whole deposition process, the temperature of the outer side of the material column far away from the heating element is 930-960 ℃, the pressure in the furnace is controlled to be 1.0Kpa, and the deposition time is 100h.
And (3) after chemical vapor deposition densification, performing heat treatment and machining on the carbon/carbon composite material to obtain the carbon/carbon composite material brake disc, wherein the heat treatment temperature is 1800 ℃ and the time is 4 hours.
The average density of the carbon/carbon composite material prepared by the method is 1.816g/cm 3 Density range of 1.797～1.826g/cm 3 Sampling products in different deposition chambers and observing the microstructure of the deposited carbon, wherein the structure of the deposited carbon is a rough layer and a smooth layer, the proportion of the rough layer is 88-94%, the proportion of the smooth layer is 6-12%, the visible density distribution is narrow, the density is uniform, the structure distribution of the pyrolytic carbon is narrow, and the consistency is good.
Example 4
The carbon fiber preform for the present embodiment has the following dimensions: an outer diameter of 430mm, an inner diameter of 230mm, a thickness of 25mm, a number of 60 disks, and a density of the carbon fiber preform of 0.45g/cm 3 The carbon fiber preform is subjected to heat treatment at 1900 ℃ for 3h.
The inner diameter of the chemical deposition furnace is 500mm, and the outer diameter of the heating element is 170mm.
The used tool is subjected to CVI chemical vapor surface deposition hole sealing treatment, and the density of the tool is 1.74g/cm 3 The graphite of (4).
The inner diameter and the outer diameter of the annular upper end plate are consistent with those of a carbon fiber prefabricated body or a carbon/carbon porous body, the outer diameter of the annular upper end plate is consistent with that of a chemical vapor furnace, a plurality of protruding keys are uniformly arranged on the lower end face of the annular upper end plate in the circumferential direction, one ends of the protruding keys are flush with the inner side face of the annular upper end plate, the other ends of the protruding keys radially extend to be flush with the outer side face of the prefabricated body or the carbon/carbon porous body, the height of each protruding key is 2mm, the number of the protruding keys is 5, and the thickness of the annular upper end plate is 4mm;
the inner diameter of the annular lower end plate is consistent with that of a carbon fiber prefabricated body or a carbon/carbon porous body, the outer diameter of the annular lower end plate is consistent with that of the chemical vapor furnace, a plurality of protruding keys are uniformly arranged on the upper end face of the annular lower end plate in the circumferential direction, one end of each protruding key is flush with the inner side face of the annular lower end plate, the other end of each protruding key radially extends to be flush with the outer side face of the prefabricated body or the carbon/carbon porous body, the height of each protruding key is 2mm, the number of the protruding keys is 5, and the thickness of the annular lower end plate is 4mm.
The inside and outside footpath size of cyclic annular baffle is unanimous with carbon fiber preform or carbon/carbon porous body, and two equal circumference of terminal surface of cyclic annular baffle evenly are provided with polylith protrusion key, and the one end of protrusion key and the lateral surface parallel and level of cyclic annular baffle, the other end radially extends to the medial surface parallel and level with cyclic annular baffle, the height of protrusion key is 2mm, and quantity is 5, the thickness of cyclic annular baffle is 4mm.
The inner diameter of the annular gas limiting plate is consistent with that of a carbon fiber prefabricated body or a carbon/carbon porous body, the outer diameter of the annular gas limiting plate is consistent with that of a chemical vapor furnace, a plurality of protruding keys are uniformly arranged on the two end faces of the annular gas limiting plate in the circumferential direction, one end of each protruding key is flush with the inner side face of the annular gas limiting plate, the other end of each protruding key radially extends to be flush with the outer side face of the prefabricated body or the carbon/carbon porous body, the height of each protruding key is 2mm, the number of the protruding keys is 5, and the thickness of the annular gas limiting plate is 4mm.
The following is the specific furnace charging and chemical vapor deposition process implementation:
firstly, the center of an annular lower end plate penetrates through a heating body to be loaded on the lowest part of a chemical vapor furnace, then carbon fiber preforms are installed according to the same mode, a partition plate or a gas limiting plate is installed between the two carbon fiber preforms, wherein the gas limiting plate is installed at intervals of about 365mm (12 preforms and the height of a tool for spacing the preforms) and is installed on a fulcrum of the inner wall of the furnace, partition plates are installed at other positions, after all the carbon fiber preforms are loaded, an upper annular end plate is finally loaded to form a material column, 4 gas limiting plates are installed in the material column, the material column is divided into 5 deposition chambers by the annular lower end plate and the annular upper end plate, 5 groups of gas inlet rings are distributed in the axial direction of the chemical vapor furnace, any group of gas inlet rings are located on the side face of the corresponding deposition chamber and 44% of the total height of the deposition chambers, 9 gas inlet nozzles are uniformly distributed in the circumferential direction of any group of gas inlet rings, propylene is used as a carbon source gas, the nitrogen is used as a carrier gas, and the carbon source gas is introduced into the furnace through the carbon inlet nozzles to carry out chemical vapor deposition densification on the carbon preforms or carbon/carbon preforms.
The chemical vapor deposition is divided into three sections, during the first section of chemical vapor deposition, the flow of carbon source gas introduced into each kilogram of prefabricated body is 0.22SL/Min, and the volume ratio of the introduced carbon source gas to the introduced carrier gas is 1:1.6; in the whole deposition process, the temperature of the inner side of the material column close to the heating element is 1100-1040 ℃, the temperature of the outer side of the material column far away from the heating element is 910-960 ℃, the pressure in the furnace is controlled to be 1.5Kpa, and the deposition time is 120h;
during the second-stage chemical vapor deposition, the flow of carbon source gas introduced into each kilogram of the preform is 0.22SL/Min, and the volume ratio of the introduced carbon source gas to the introduced carrier gas is 1:1.9; in the whole deposition process, the temperature of the inner side of the material column close to the heating element is 1070 to 1030 ℃, the temperature of the outer side of the material column far away from the heating element is 930 to 970 ℃, the pressure in the furnace is controlled to be 2.5Kpa, and the deposition time is 90 hours;
and during the third-stage chemical vapor deposition, the flow of the carbon source gas introduced into each kilogram of the preform is 0.14SL/Min, and the volume ratio of the introduced carbon source gas to the introduced carrier gas is 1:1.7; in the whole deposition process, the temperature of the inner side of the material column close to the heating element is 1060-1035 ℃, the temperature of the outer side of the material column far away from the heating element is 945-980 ℃, the pressure in the furnace is controlled to be 2.1Kpa, and the deposition time is 90 hours.
And (3) after chemical vapor deposition densification, performing heat treatment and machining on the carbon/carbon composite material to obtain the carbon/carbon composite material brake disc, wherein the heat treatment temperature is 2150 ℃, and the time is 3 hours.
The average density of the carbon/carbon composite material prepared by the method is 1.812g/cm 3 The density range is 1.791-1.825 g/cm 3 Sampling products in different deposition chambers and observing the microstructure of the deposited carbon, wherein the structure of the deposited carbon is a rough layer and a smooth layer, the proportion of the rough layer is 89-94%, the proportion of the smooth layer is 6-11%, the visible density distribution is narrow, the density is uniform, the structure distribution of the pyrolytic carbon is narrow, and the consistency is good.
Comparative example 1
The other conditions were the same as in example 1 except that: the annular baffle is used to replace the gas-limiting plate. The average density of the carbon/carbon composite material prepared by the method is 1.782g/cm 3 The density range is 1.751-1.831 g/cm 3 And sampling products of different deposition chambers and observing the microstructure of the deposited carbon, wherein the microstructure of the deposited carbon comprises a rough layer and a smooth layer, the proportion of the rough layer is 50-85%, and the proportion of the smooth layer is 15-50%.
Comparative example 2
Other conditions were the same as in example 1 except thatThe method comprises the following steps: the tool density is 1.50-1.65 g/cm 3 And does not undergo CVI chemical vapor surface hole sealing treatment.
The average density of the carbon/carbon composite material prepared by the method is 1.794g/cm 3 The density ranges from 1.772 to 1.813g/cm 3 Sampling products of different deposition chambers and observing the microstructure of the deposited carbon, wherein the structure of the deposited carbon comprises a rough layer and a smooth layer, the proportion of the rough layer is 70-82%, and the proportion of the smooth layer is 18-30%.
Comparative example 3
The other conditions were the same as in example 1 except that: installing a gas limiting plate every 600mm, wherein the average density of the carbon/carbon composite material prepared by the method is 1.799g/cm 3 The density range is 1.782-1.816 g/cm 3 The products from the different chambers were sampled and observed for microstructure of the deposited carbon, which was structured as a rough layer and a smooth layer, wherein the rough layer was 78-90% and the smooth layer was 10-22%.
Comparative example 4
The other conditions were the same as in example 1 except that: the gas ring height is located at 60% of the total height of the deposition chamber.
The average density of the carbon/carbon composite material prepared by the method is 1.804g/cm 3 The density range is 1.773-1.821 g/cm 3 The products from the different chambers were sampled and observed for microstructure of the deposited carbon, which was structured as a rough layer and a smooth layer, wherein the rough layer was 79-88% and the smooth layer was 12-21%.
Comparative example 5
The other conditions were the same as in example 1 except that: the temperature of the inner side of the material column close to the heating element in the whole deposition process of the first-stage chemical vapor deposition is 1210-1155 ℃, and the temperature of the outer side of the material column far away from the heating element is 975-1050 ℃.
The average density of the carbon/carbon composite material prepared by the method is 1.654g/cm 3 The density range is 1.513-1.731 g/cm 3 . Sampling the products from different chambers and observing the microstructure of the deposited carbon, which is a rough layer and lightThe smooth layer and the transition layer, wherein the proportion of the rough layer is 30-55%, the proportion of the smooth layer is 20-40%, and the proportion of the transition layer is 5-50%.
Comparative example 6
The other conditions were the same as in example 1 except that: during the first stage of chemical vapor deposition, the flow of carbon source gas introduced into each kilogram of preform is 0.35SL/Min, and the volume ratio of the introduced carbon source gas to the introduced carrier gas is 1:1.3;
the average density of the carbon/carbon composite material prepared by the method is 1.705g/cm 3 The density range is 1.684-1.730 g/cm 3 . The products from the different chambers were sampled and observed for microstructure of the deposited carbon, which was structured as a rough layer and a smooth layer, wherein the rough layer was 79-88% and the smooth layer was 12-21%.
Comparative example 7
The other conditions were the same as in example 1 except that: 1) The number of the charging prefabricated bodies is 30, and 2) the charging is carried out by adopting a conventional charging tool (a supporting plate, a gasket and a cover plate) instead of the annular lower end plate, the annular upper end plate, the annular partition plate and the gas limiting plate.
The average density of the carbon/carbon composite material prepared by the method is 1.785g/cm 3 The density range is 1.764-1.807 g/cm 3 . Sampling products of different deposition chambers and observing the microstructure of the deposited carbon, wherein the structure of the deposited carbon comprises a rough layer and a smooth layer, the proportion of the rough layer is 30-85%, the proportion of the smooth layer is 15-70%, and the structure is uneven.
Comparative example 8
The other conditions were the same as in example 1 except that: the annular lower end plate, the annular upper end plate, the annular partition plate and the annular gas limiting plate are not adopted, but conventional furnace charging tools (a support plate, a gasket and a cover plate) are adopted for charging; the thickness of the gasket is 2mm, the thickness of the supporting plate and the thickness of the cover plate are 5mm, and the total height of the material column is about 1630mm.
The average density of the carbon/carbon composite material prepared by the method is 1.767g/cm 3 The density range is 1.725 to 1.817g/cm 3 . And 50% of the product even if continuingThe density of the deposit is increased and cannot be more than or equal to 1.78g/cm 3 And sampling products of different deposition chambers and observing the microstructure of the deposited carbon, wherein the structure of the deposited carbon comprises a rough layer and a smooth layer, the proportion of the rough layer is 20-82%, the proportion of the smooth layer is 18-80%, and the structure is uneven.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and any modifications, alterations, and equivalent structural changes made to the above embodiments according to the technical spirit of the present invention still belong to the protection scope of the technical solution of the present invention.
Claims (10)
1. A preparation method of a carbon/carbon composite material brake disc is characterized by comprising the following steps: the center of the annular lower end plate, a plurality of annular carbon fiber preforms or carbon/carbon porous bodies and the center of the annular upper end plate penetrate through the heating body and are loaded in the chemical vapor furnace from bottom to top to form a material column, and an annular partition plate or an annular gas limiting plate is arranged between any two adjacent carbon fiber preforms or carbon/carbon porous bodies in the material column; the space between any two annular gas limiting plates is 250-500 mm, the charge column is divided into M +1 deposition chambers by the annular lower end plate, the annular upper end plate and M groups of annular gas limiting plates, M +1 groups of gas inlet rings are distributed in the axial direction of the chemical vapor furnace, any group of gas inlet rings are positioned on the side surfaces of the M +1 deposition chambers, a plurality of gas inlet nozzles are uniformly distributed on any group of gas inlet rings, carbon source gas and carrier gas are introduced into the furnace through the gas inlet nozzles, and chemical vapor deposition densification is carried out on the carbon fiber preform or the carbon/carbon porous body, so that the carbon/carbon composite material brake disc is obtained; in the chemical vapor deposition process, the flow of the introduced carbon source gas and the carrier gas is reduced progressively, the temperature of the inner side of the material column close to the heating element is controlled to be reduced progressively, and the temperature of the outer side of the material column far away from the heating element is controlled to be increased progressively;
the inner diameter of the annular gas limiting plate is consistent with that of a carbon fiber prefabricated body or a carbon/carbon porous body, the outer diameter of the annular gas limiting plate is consistent with that of a chemical vapor furnace, a plurality of protruding keys are uniformly arranged on the two end faces of the annular gas limiting plate in the circumferential direction, one end of each protruding key is flush with the inner side face of the annular gas limiting plate, the other end of each protruding key extends to be flush with the outer side face of the prefabricated body or the carbon/carbon porous body in the radial direction, the height of each protruding key is 1-3 mm, the number of the protruding keys is 3-8, and the thickness of the annular gas limiting plate is 3-7 mm.
2. The method for preparing a carbon/carbon composite brake disc according to claim 1, wherein the method comprises the following steps: the density of the carbon fiber preform is 0.40-0.60 g/cm 3 ；
The carbon fiber preform is subjected to heat treatment at 1600-2000 ℃ for 2-4h.
3. The method for preparing a carbon/carbon composite brake disc according to claim 1, wherein the method comprises the following steps: the inner diameter of the annular lower end plate is consistent with that of a carbon fiber prefabricated body or a carbon/carbon porous body, the outer diameter of the annular lower end plate is consistent with that of a chemical vapor furnace, a plurality of protruding keys are uniformly arranged on the upper end surface of the annular lower end plate in the circumferential direction, one end of each protruding key is flush with the inner side surface of the annular lower end plate, the other end of each protruding key radially extends to be flush with the outer side surface of the prefabricated body or the carbon/carbon porous body, the height of each protruding key is 1-3 mm, the number of the protruding keys is 3-8, and the thickness of the annular lower end plate is 3-7 mm;
the inner diameter and the outer diameter of the annular upper end plate are consistent with those of a carbon fiber prefabricated body or a carbon/carbon porous body, the outer diameter of the annular upper end plate is consistent with that of the chemical vapor furnace, a plurality of protruding keys are uniformly arranged on the lower end face of the annular upper end plate in the circumferential direction, one ends of the protruding keys are flush with the inner side face of the annular upper end plate, the other ends of the protruding keys radially extend to be flush with the outer side face of the prefabricated body or the carbon/carbon porous body, the height of each protruding key is 1-3 mm, the number of the protruding keys is 3-8, and the thickness of the annular upper end plate is 3-7 mm.
The inner diameter and the outer diameter of the annular partition board are consistent with those of the carbon fiber prefabricated body or the carbon/carbon porous body, a plurality of protruding keys are uniformly arranged on two end faces of the annular partition board in the circumferential direction, one end of each protruding key is flush with the outer side face of the annular partition board, the other end of each protruding key radially extends to be flush with the inner side face of the annular partition board, the height of each protruding key is 1-3 mm, the number of the protruding keys is 3-8, and the thickness of the annular partition board is 3-7 mm.
4. The method for preparing a carbon/carbon composite brake disc according to claim 1, wherein the method comprises the following steps: the annular lower end plate, the annular upper end plate, the annular partition plate and the annular gas limiting plate are made of carbon materials.
5. The method for preparing a carbon/carbon composite brake disc according to claim 4, wherein the method comprises the following steps: the annular lower end plate, the annular upper end plate, the annular partition plate and the annular gas limiting plate are made of materials with the density of more than or equal to 1.74g/cm after CVI chemical vapor surface deposition and hole sealing treatment 3 Graphite or carbon/carbon composites.
6. The method for preparing a carbon/carbon composite brake disc according to claim 1, wherein the method comprises the following steps: the inner wall of the chemical gas phase furnace is provided with a fulcrum, and the annular gas limiting plate is arranged on the fulcrum;
6-10 air inlet nozzles are uniformly distributed on any group of air inlet rings;
any group of gas rings is arranged at 40-48% of the total height of the corresponding deposition chamber.
7. The method for preparing a carbon/carbon composite brake disc according to claim 1, wherein the method comprises the following steps: the carbon source gas is propylene, and the carrier gas is nitrogen.
8. The method for preparing a carbon/carbon composite brake disc according to claim 1 or 7, wherein the method comprises the following steps: the chemical vapor deposition is divided into three sections, during the first section of chemical vapor deposition, the flow of carbon source gas introduced into each kilogram of carbon fiber preforms is 0.2-0.3 SL/Min, and the volume ratio of the introduced carbon source gas to the introduced carrier gas is 1:1.5 to 2.0; the temperature of the inner side of the charge column close to the heating element is 1150-1020 ℃, the temperature of the outer side of the charge column far away from the heating element is 880-970 ℃, the pressure in the furnace is controlled to be 1.0-3.0 Kpa, and the deposition time is 80-120 h;
during the second-stage chemical vapor deposition, the flow of carbon source gas introduced into each kilogram of carbon fiber preform is 0.15-0.25 SL/Min, and the volume ratio of the introduced carbon source gas to the introduced carrier gas is 1:1.5 to 2.0; the temperature of the inner side of the material column close to the heating element is 1110-1010 ℃, the temperature of the outer side of the material column far away from the heating element is 920-980 ℃, the pressure in the furnace is controlled to be 1.0-3.0 Kpa, and the deposition time is 80-120 h;
and during the third-stage chemical vapor deposition, the flow of carbon source gas introduced into each kilogram of carbon fiber preform is 0.10-0.20 SL/Min, and the volume ratio of the introduced carbon source gas to the introduced carrier gas is 1:1.5 to 2.0; the temperature of the inner side of the material column close to the heating element is 1100-1000 ℃, the temperature of the outer side of the material column far away from the heating element is 930-990 ℃, the pressure in the furnace is controlled to be 1.0-3.0 Kpa, and the deposition time is 60-100 h.
9. The method for preparing a carbon/carbon composite brake disc according to claim 8, wherein the method comprises the following steps: during the first-stage chemical vapor deposition, the temperature of the inner side of the material column close to the heating element is 1110-1050 ℃, and the temperature of the outer side of the material column far away from the heating element is 900-960 ℃;
during the second-stage chemical vapor deposition, the temperature of the inner side of the material column close to the heating element is 1080-1030 ℃, and the temperature of the outer side of the material column far away from the heating element is 940-970 ℃;
and during the third-stage chemical vapor deposition, the temperature of the inner side of the material column close to the heating element is 1060-1020 ℃, and the temperature of the outer side of the material column far away from the heating element is 950-980 ℃.
10. The method for preparing a carbon/carbon composite brake disc according to claim 1, wherein the method comprises the following steps: and after chemical vapor deposition densification, performing heat treatment and machining on the carbon/carbon composite material to obtain the carbon/carbon composite material brake disc, wherein the heat treatment temperature is 1800-2200 ℃ and the time is 2-4 hours.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211486769.XA CN115819101B (en) | 2022-11-25 | 2022-11-25 | Method for rapidly preparing carbon/carbon composite brake disc |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211486769.XA CN115819101B (en) | 2022-11-25 | 2022-11-25 | Method for rapidly preparing carbon/carbon composite brake disc |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115819101A true CN115819101A (en) | 2023-03-21 |
| CN115819101B CN115819101B (en) | 2023-07-21 |
Family
ID=85531391
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211486769.XA Active CN115819101B (en) | 2022-11-25 | 2022-11-25 | Method for rapidly preparing carbon/carbon composite brake disc |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115819101B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116573631A (en) * | 2023-07-12 | 2023-08-11 | 玖贰伍碳源科技（天津）有限公司 | Method for producing high-energy-density hard carbon negative electrode and sodium ion battery |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1766153A (en) * | 2005-11-07 | 2006-05-03 | 西安交通大学 | Method for quick-speed preparing carbon/carbon composite material using heat gradient chemical gas phase infiltration |
| CN101328577A (en) * | 2008-07-17 | 2008-12-24 | 居小平 | Method for preparing airplane carbon brake disc through chemical vapor deposition |
| CN104195526A (en) * | 2014-08-28 | 2014-12-10 | 西安航空制动科技有限公司 | Deposition furnace capable of controlling gas flow direction of carbon source |
| CN109400198A (en) * | 2018-12-13 | 2019-03-01 | 上海康碳复合材料科技有限公司 | A kind of carbon/carbon (pottery) composite material brake disc Preparation equipment and preparation method thereof based on quick sedimentation process |
| CN209602394U (en) * | 2018-12-13 | 2019-11-08 | 上海康碳复合材料科技有限公司 | Carbon/carbon compound material brake disc Preparation equipment based on quick sedimentation process |
| CN216237272U (en) * | 2021-10-09 | 2022-04-08 | 上海骐碳复合材料科技有限公司 | Vertical continuous vapor deposition furnace |
| CN115094514A (en) * | 2022-08-15 | 2022-09-23 | 湖南泰坦未来科技有限公司 | Composite material crucible and preparation method thereof |
| CN115231938A (en) * | 2022-07-22 | 2022-10-25 | 常州翊翔炭材科技有限公司 | Preparation method of carbon/carbon composite material brake disc |
-
2022
- 2022-11-25 CN CN202211486769.XA patent/CN115819101B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1766153A (en) * | 2005-11-07 | 2006-05-03 | 西安交通大学 | Method for quick-speed preparing carbon/carbon composite material using heat gradient chemical gas phase infiltration |
| CN101328577A (en) * | 2008-07-17 | 2008-12-24 | 居小平 | Method for preparing airplane carbon brake disc through chemical vapor deposition |
| CN104195526A (en) * | 2014-08-28 | 2014-12-10 | 西安航空制动科技有限公司 | Deposition furnace capable of controlling gas flow direction of carbon source |
| CN109400198A (en) * | 2018-12-13 | 2019-03-01 | 上海康碳复合材料科技有限公司 | A kind of carbon/carbon (pottery) composite material brake disc Preparation equipment and preparation method thereof based on quick sedimentation process |
| CN209602394U (en) * | 2018-12-13 | 2019-11-08 | 上海康碳复合材料科技有限公司 | Carbon/carbon compound material brake disc Preparation equipment based on quick sedimentation process |
| CN216237272U (en) * | 2021-10-09 | 2022-04-08 | 上海骐碳复合材料科技有限公司 | Vertical continuous vapor deposition furnace |
| CN115231938A (en) * | 2022-07-22 | 2022-10-25 | 常州翊翔炭材科技有限公司 | Preparation method of carbon/carbon composite material brake disc |
| CN115094514A (en) * | 2022-08-15 | 2022-09-23 | 湖南泰坦未来科技有限公司 | Composite material crucible and preparation method thereof |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116573631A (en) * | 2023-07-12 | 2023-08-11 | 玖贰伍碳源科技（天津）有限公司 | Method for producing high-energy-density hard carbon negative electrode and sodium ion battery |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115819101B (en) | 2023-07-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111348931B (en) | Annular carbon/carbon composite material gas phase permeation method | |
| CA2849876C (en) | A device for loading porous substrates of three-dimensional shape in order to be densified by directed flow chemical vapor infiltration | |
| US7332195B2 (en) | Chemical vapor deposition method | |
| US8454867B2 (en) | CVI followed by coal tar pitch densification by VPI | |
| US9828670B2 (en) | Loader device and an installation for densifying stackable frustoconical porous preforms | |
| US10457016B2 (en) | Differential needling of a carbon fiber preform | |
| EP3228728B1 (en) | System and method for enhancing a diffusion limited cvi/cvd process | |
| CN115819101A (en) | Method for quickly preparing carbon/carbon composite material brake disc | |
| EP3231890A1 (en) | Method and apparatus for decreasing the radial temperature gradient in cvi/cvd furnaces | |
| CN100370055C (en) | Method for quick-speed preparing carbon/carbon composite material using heat gradient chemical gas phase infiltration | |
| EP1904665B1 (en) | Improved support structure for radiative heat transfer | |
| CN1328215C (en) | Method for preparing carbon/carbon composite material | |
| CN115231938A (en) | Preparation method of carbon/carbon composite material brake disc | |
| JP2015524514A (en) | Chemical vapor infiltration device with large loading capacity | |
| CN113248272B (en) | Preparation method and application of carbon-ceramic friction material | |
| CN111285703B (en) | Method for manufacturing low-cost double-element carbon matrix airplane carbon brake disc | |
| CN109748595B (en) | Mixed permeating agent, application and reaction infiltration preparation method | |
| CN217997314U (en) | Chemical vapor infiltration device for producing carbon/carbon thermal field material | |
| CN112628326A (en) | Preparation method of aircraft brake disc made of carbon/carbon composite material | |
| CN111362714B (en) | Preparation method of carbon-ceramic brake disc | |
| CN115536419B (en) | Aviation carbon ceramic brake material and preparation method thereof | |
| CN113277870B (en) | Method for quickly densifying thin-wall cylindrical carbon/carbon composite material | |
| CN214937078U (en) | Chemical gas phase permeation device for preparing cylindrical carbon/carbon composite material | |
| US20230242451A1 (en) | Tools and methods for their formation and use | |
| CN117865706A (en) | Continuous ceramic preparation method for C/C-SiC brake disc |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |