Carbon-ceramic brake disc silicon infiltration carbon-ceramic crucible and preparation method thereof

Abstract

The application relates to the technical field of a carbon-toughened brake disc silicon infiltration heat field component. The application discloses a carbon-toughened brake disc silicon infiltration carbon-toughened crucible and a preparation method thereof. The preparation method comprises the following steps: S1, a fiber carbon cloth is alternately stacked with a mesh tire to form a composite cloth, the composite cloth is attached to a mold, needling is carried out, and a crucible preform is prepared; S2, carbon-carbon densification is carried out on the crucible preform by using chemical vapor deposition, and a carbon-carbon crucible preform is prepared; S3, the carbon-carbon crucible preform is subjected to heat treatment, and a carbon-carbon crucible is prepared; S4, the carbon-carbon crucible is subjected to finishing; and S5, silicon material is laid on the bottom of the carbon-carbon crucible after finishing, silicon infiltration is carried out, and the carbon-toughened brake disc silicon infiltration carbon-toughened crucible is prepared. The carbon-toughened brake disc silicon infiltration carbon-toughened crucible is prepared by the above preparation method. The carbon-toughened brake disc silicon infiltration carbon-toughened crucible prepared by the application has the advantages of high wear resistance, high strength, long service life and low cost.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of a carbon-toughened brake disc siliconizing heat field component, in particular to a carbon-toughened brake disc siliconizing carbon-toughened crucible and a preparation method thereof. BACKGROUND

[0002] In the process of carbon-toughened brake disc siliconizing, a crucible tool is used to hold silicon material for siliconizing. In the early stage of the carbon-toughened brake disc siliconizing technology, a common refractory material crucible is generally used. Although these crucibles can withstand high temperatures, they have relatively poor thermal conductivity and corrosion resistance.

[0003] With the progress of technology, a graphite crucible is introduced into the carbon-toughened brake disc siliconizing process. The graphite crucible has high-temperature stability, thermal shock resistance, corrosion resistance and good thermal conductivity, and is suitable for the high-temperature environment of the carbon-toughened brake disc siliconizing process. The excellent performance of the graphite crucible improves the siliconizing efficiency and product quality, and therefore the graphite crucible has been widely applied.

[0004] However, before being used for carbon-toughened brake disc siliconizing, the graphite crucible needs to be coated with a boron nitride anti-sticking coating in advance, and an additional layer of graphite paper also needs to be laid, which not only consumes manpower and time, but also increases the cost of auxiliary materials, and is not conducive to automatic production. The graphite crucible also absorbs silicon material during siliconizing, which may cause cracking and damage when reaching a certain degree, shortening the service life and increasing the loss rate. Moreover, the material of the graphite crucible is relatively fragile and is easily damaged by mechanical impact.

[0005] Therefore, there is an urgent need to develop a carbon-toughened brake disc siliconizing carbon-toughened crucible which has strong wear resistance, high strength, long service life and low cost. SUMMARY

[0006] In order to solve at least one of the above technical problems, a carbon-toughened brake disc siliconizing carbon-toughened crucible which has strong wear resistance, high strength, long service life and low cost is developed, and the application provides a carbon-toughened brake disc siliconizing carbon-toughened crucible and a preparation method thereof.

[0007] In one aspect, the application provides a preparation method of a carbon-toughened brake disc siliconizing carbon-toughened crucible, which comprises the following steps: S1, alternately stacking fiber carbon cloth and net tire to form a composite cloth, attaching the composite cloth to a mold, needling to obtain a crucible preform, and the surface layer of the crucible preform being free of a pure net tire layer; the crucible preform comprises a crucible bottom and a crucible side wall arranged on the crucible bottom, and the thickness ratio of the crucible bottom to the crucible side wall is 1:2-2.5;

[0008] S2, carbon-carbon densification of the crucible preform is performed by chemical vapor deposition, and a carbon-carbon crucible preform is obtained, and the gas used in the chemical vapor deposition is a hydrocarbon gas;

[0009] S3, heat treating the carbon-carbon crucible preform to obtain a carbon-carbon crucible;

[0010] S4, finishing the carbon-carbon crucible according to the size of the brake disc and the requirement of silicon infiltration;

[0011] S5, laying silicon material on the bottom of the finished carbon-carbon crucible, melting and infiltrating silicon, cleaning the residual silicon material on the surface to obtain a carbon-carbon crucible for silicon infiltration of carbon ceramic brake disc.

[0012] By adopting the technical scheme, the carbon-carbon crucible for silicon infiltration of carbon ceramic brake disc prepared by the preparation method has high wear resistance, high mechanical strength, long service life and low production cost.

[0013] In the application, the thicknesses of the crucible bottom and the crucible side are inconsistent, which can meet different stress requirements and process requirements of the crucible in use. The crucible bottom needs to bear the weight of the silicon material and the brake disc, while the crucible side mainly bears the lateral pressure and the influence of temperature change. Since the thickness of the crucible side is larger, heat can be better transferred, and the material in the crucible can be heated more uniformly, thereby improving the processing quality and efficiency, reducing the risk of cracking and prolonging the service life. The thickness of the crucible side is higher than that of the crucible bottom, which can increase the overall stability of the crucible and make it less likely to deform or tilt during high-temperature processing.

[0014] The application adopts chemical vapor deposition process to produce deposited carbon on the surface of carbon fibers. The deposited carbon layer has good density, high purity and uniform deposition, which helps to enhance the deformation resistance and mechanical strength of the crucible. Heat treatment can further remove the residual organic matter in the deposition stage, increase the opening rate and facilitate the subsequent silicon infiltration process. Finishing can ensure the fitting accuracy of the crucible and the brake disc, ensure the stability of product quality and the smooth progress of the silicon infiltration process. Finally, through melting and silicon infiltration, the melted silicon is infiltrated into the bottom and inner wall of the crucible by capillary effect, reacts with the deposited carbon and graphite to generate silicon carbide, improves the performance of the crucible, enhances the wear resistance, strength and high-temperature resistance of the crucible, and finally the prepared carbon ceramic crucible can better resist the erosion of silicon, reduce cracking and loss, and prolong the service life.

[0015] Optionally, in the step S1, the carbon fiber cloth is a plain carbon cloth.

[0016] By adopting the above technical scheme, the application adopts a plain carbon cloth, which has good strength and rigidity, can enhance the mechanical properties of the crucible, and is easy to process and operate.

[0017] Optionally, in the step S1, the angle of needling at the joint of the crucible bottom and the crucible side is kept at 30°-70° with the web tire, and the needling density is 16-35 needles / cm 2 .

[0018] By adopting the technical scheme, the crucible bottom and the crucible side with inconsistent thicknesses are connected by needling at a specific angle and density, the bonding force is enhanced, the overall strength is improved, the thickness transition is realized, the stress concentration at the connection is reduced, and the risk of cracking is reduced.

[0019] Optionally, in the step S2, the hydrocarbon gas is selected from at least one of natural gas, ethane, propane and butane.

[0020] By adopting the technical scheme, the hydrocarbon gas is used as the carbon source.

[0021] Optionally, in the step S2, the hydrocarbon gas is natural gas.

[0022] By adopting the technical scheme, the main component of the natural gas is methane, and compared with other hydrocarbon gases, the natural gas has higher stability and purity in the chemical vapor deposition process, which is helpful to obtain high-quality deposited carbon. In addition, the natural gas is a relatively abundant and inexpensive resource, and the use of the natural gas can reduce the cost and is easy to obtain and use.

[0023] Optionally, the flow rate of the hydrocarbon gas is 150-200 L / min.

[0024] By adopting the technical scheme, the flow rate of the hydrocarbon gas used in the application can obtain higher-quality deposited carbon, improve the wear resistance and strength of the crucible, and prolong the service life of the crucible. If the flow rate of the hydrocarbon gas is too high, the deposition rate may be too fast, which may result in a decrease in the quality of the deposited carbon layer, surface roughness, loose structure and other problems. If the flow rate of the hydrocarbon gas is too low, the deposition rate may be too slow, which may affect the production efficiency and result in uneven thickness of the deposited carbon layer.

[0025] Optionally, in the step S2, the chemical vapor deposition temperature is 1000-1200℃, and the chemical vapor deposition time is 200-300 h.

[0026] By adopting the technical scheme, the chemical vapor deposition temperature and the chemical vapor deposition time used in the application can obtain high-quality chemical vapor deposition results and improve the performance of the crucible. If the deposition temperature is too high, the deposit may grow excessively, which may result in abnormal structure of the deposited carbon layer. If the deposition temperature is too low, the quality of the deposited carbon layer may decrease. If the deposition time is too long, the deposit may accumulate excessively, which may result in excessive thickness of the deposited carbon layer. If the deposition time is too short, the thickness of the deposited carbon layer may be insufficient, which may affect the density of the deposit.

[0027] Optionally, the carbon-carbon density of the carbon-carbon crucible preform is 1.3-1.6 g / cm 3 .

[0028] By adopting the technical scheme, the carbon-carbon density of the carbon-carbon crucible preform can make the deformation resistance of the crucible stronger and the mechanical strength stronger.

[0029] Optionally, in the step S3, the heat treatment temperature is 2100-2300℃, and the heat treatment time is 3-6h.

[0030] By adopting the technical scheme, the carbon-carbon crucible preform is heat treated, and the specific heat treatment temperature and heat treatment time can increase the open porosity and graphitization degree of the carbon-carbon crucible, thereby improving the thermal stability of the crucible. If the temperature is too high or the time is too long, it may cause excessive sintering and affect the performance of the crucible. If the temperature is too low or the time is too short, it may cause insufficient heat treatment and cannot achieve the best performance.

[0031] Optionally, the open porosity of the carbon-carbon crucible is 30-45%.

[0032] By adopting the technical scheme, the open porosity of the carbon-carbon crucible is conducive to the subsequent silicon infiltration process. If the open porosity is too high, the strength of the crucible may be reduced; if the open porosity is too low, it may affect the subsequent silicon infiltration process.

[0033] Optionally, in the step S4, the finishing process comprises the following steps: a small groove is opened along the outer bottom of the carbon-carbon crucible, 2-3 slots are opened at the mouth of the carbon-carbon crucible, and the inner bottom of the carbon-carbon crucible is processed into an R angle type with a certain angle.

[0034] By adopting the technical scheme, a small groove is opened along the outer bottom, which facilitates the placement of the workpiece during the silicon infiltration of the brake disc. 2-3 slots are opened at the mouth of the crucible, which facilitates the taking of the crucible and the volatilization of silicon vapor. The inner bottom of the crucible is processed into an R angle type with a certain angle, which can reduce the sticking of materials between the inner wall and the bottom of the crucible during silicon infiltration.

[0035] Optionally, in the step S5, the silicon material is single crystal silicon or polycrystalline silicon, and the mesh number is 30-200 mesh.

[0036] By adopting the technical scheme, the silicon material of the present application adopts single crystal silicon or polycrystalline silicon, which is pure silicon material with high purity and low impurity content, thereby improving the quality and performance of the crucible. The mesh number of the silicon material used in the present application can achieve more uniform silicon infiltration effect, and appropriate mesh number can provide appropriate reaction surface area to better control the reaction rate.

[0037] Optionally, the weight ratio of the silicon material to the carbon-carbon crucible is 1:1-3.

[0038] By adopting the technical scheme, the present application adopts a suitable weight ratio to ensure that the amount of silicon material is appropriate, which can not only ensure sufficient infiltration but also avoid waste and save costs.

[0039] Optionally, in the step S5, the silicon infiltration temperature is 1500-1700 DEG C, and the silicon infiltration time is 1-4 hours.

[0040] By adopting the above technical solution, the specific silicon infiltration temperature and silicon infiltration time are adopted, so that the performance of the crucible is better. If the temperature is too high, the diffusion rate of silicon in the carbon carbon crucible may be accelerated, resulting in deep or uneven silicon penetration. If the temperature is too low, the silicon diffusion may be insufficient. If the time is too long, the silicon may be excessively penetrated, and the energy consumption and production cost may be increased. If the time is too short, the silicon may be insufficiently penetrated. The above factors may affect the performance of the crucible.

[0041] In a second aspect, the carbon ceramic crucible for silicon infiltration of a carbon ceramic brake disc is prepared by the preparation method of the carbon ceramic crucible for silicon infiltration of a carbon ceramic brake disc.

[0042] By adopting the above technical solution, the carbon ceramic crucible for silicon infiltration of a carbon ceramic brake disc prepared by the application has high wear resistance, high strength, long service life, and low cost.

[0043] In summary, the application has at least one of the following beneficial technical effects:

[0044] 1. The carbon ceramic crucible for silicon infiltration of a carbon ceramic brake disc prepared by the preparation method of the application has high wear resistance, high mechanical strength, long service life, and low production cost.

[0045] 2. The chemical vapor deposition process adopted by the application helps to enhance the mechanical strength of the crucible.

[0046] 3. The melting silicon infiltration adopted by the application improves the performance of the crucible, enhances the wear resistance and strength of the crucible, and finally enables the carbon ceramic crucible to better resist the corrosion of silicon, reduce cracking and loss, and prolong the service life.

[0047] 4. The carbon ceramic crucible for silicon infiltration of a carbon ceramic brake disc prepared by the application has high wear resistance, high strength, long service life, and low cost. DETAILED DESCRIPTION

[0048] The application will be further described in detail below in combination with embodiments.

[0049] The application designs a preparation method of a carbon ceramic crucible for silicon infiltration of a carbon ceramic brake disc, which comprises the following steps:

[0050] S1, alternately stack fiber carbon cloth and net tire to form a composite cloth, attach the composite cloth to a mold, needle punch, and prepare a crucible preform, wherein the surface layer of the crucible preform is free of a pure net tire layer; the crucible preform comprises a crucible bottom and a crucible side wall arranged on the crucible bottom, and the thickness ratio of the crucible bottom to the crucible side wall is 1:2-2.5;

[0051] S2. The crucible preform is carbon-densified by chemical vapor deposition to obtain a carbon-carbon crucible preform. The gas used in the chemical vapor deposition is a hydrocarbon gas.

[0052] S3. Heat-treat the carbon-carbon crucible preform to obtain a carbon-carbon crucible.

[0053] S4. The carbon-carbon crucible is precision machined according to the brake disc size and silicon infiltration requirements;

[0054] S5. Spread the silicon material evenly on the bottom of the finely processed carbon crucible, melt and infiltrate the silicon, clean the residual silicon material on the surface, and obtain the carbon ceramic crucible for silicon infiltrating carbon ceramic brake disc.

[0055] The carbon-ceramic crucible for siliconizing carbon-ceramic brake discs in this application is prepared by the above-described method for preparing carbon-ceramic crucibles for siliconizing carbon-ceramic brake discs.

[0056] Prior to this application, existing siliconizing crucibles for carbon-ceramic brake discs were traditional graphite crucibles. Using graphite crucibles for siliconizing carbon-ceramic brake discs requires auxiliary materials such as graphite paper and boron nitride, increasing costs and labor, and hindering automated production. Furthermore, graphite crucibles absorb silicon material during siliconizing, which can lead to cracking and breakage if a certain level is reached, shortening their lifespan and increasing the loss rate.

[0057] The applicant has designed the technical solution of this application to address the existing problems of graphite crucibles. This application proposes a method for preparing a carbon-ceramic crucible for siliconizing carbon-ceramic brake discs, and also proposes a carbon-ceramic crucible for siliconizing carbon-ceramic brake discs prepared by the above method. The carbon-ceramic crucible for siliconizing carbon-ceramic brake discs proposed in this application has strong wear resistance, high mechanical strength, long service life, and low production cost. Specific Implementation

[0059] Examples 1-4

[0060] Example 1

[0061] This embodiment provides a method for preparing a carbon ceramic crucible for siliconizing a carbon ceramic brake disc, comprising the following steps:

[0062] S1. Plain carbon fiber cloth and a mesh substrate are alternately layered to form a composite fabric. The composite fabric is then attached to a mold and needle-punched to obtain a crucible preform. The surface of the crucible preform has no pure mesh substrate layer. The crucible preform includes a crucible bottom and a crucible side set on the crucible bottom. The thickness ratio of the crucible bottom to the crucible side is 1:2. The needle-punching angle at the junction of the crucible bottom and the crucible side is 70° with the mesh substrate, and the needle-punching density is 35 needles / cm. 2 .

[0063] S2, carbon carbon densification is carried out on the crucible preform by chemical vapor deposition, natural gas is used as the gas, the natural gas flow is 150 L / min, deposition is carried out at 1000 DEG C for 200 h, a carbon carbon crucible preform is prepared, and the carbon carbon density is 1.3 g / cm 3 .

[0064] S3, the carbon carbon crucible preform is heat treated at 2100 DEG C for 6 h, and a carbon carbon crucible is prepared, and the open porosity is 45%.

[0065] S4, the carbon carbon crucible is finished: a small groove is opened along the outer bottom of the carbon carbon crucible, three slots are opened at the mouth of the carbon carbon crucible, and the inner bottom of the carbon carbon crucible is processed into an R angle type with a certain angle.

[0066] S5, silicon material with a mesh number of 100 is laid on the inner bottom of the finished carbon carbon crucible, the silicon material is single crystal silicon, the weight ratio of the silicon material to the carbon carbon crucible is 1:1, silicon infiltration is carried out at 1500 DEG C for 4 h, a carbon ceramic material composed of carbon fibers, silicon carbide and residual silicon material and graphite is formed, the residual silicon material on the surface is cleaned, and a carbon ceramic crucible for silicon infiltration of a carbon ceramic brake disc is prepared.

[0067] Example 2

[0068] The embodiment provides a preparation method of a carbon ceramic crucible for silicon infiltration of a carbon ceramic brake disc, and the method comprises the following steps:

[0069] S1, plain carbon cloth and net tire are alternately stacked to form a composite cloth, the composite cloth is attached to a mold, and needle punching is carried out, so that a crucible preform is prepared, and the surface layer of the crucible preform is free of pure net tire layer; the crucible preform comprises a crucible bottom and a crucible side wall arranged on the crucible bottom, the thickness ratio of the crucible bottom to the crucible side wall is 1:2.4; the needle punching angle at the joint of the crucible bottom and the crucible side wall is 40 DEG with the net tire, and the needle punching density is 20 needles / cm 2 .

[0070] S2, carbon carbon densification is carried out on the crucible preform by chemical vapor deposition, natural gas is used as the gas, the natural gas flow is 150 L / min, deposition is carried out at 1200 DEG C for 300 h, a carbon carbon crucible preform is prepared, and the carbon carbon density is 1.6 g / cm 3 .

[0071] S3, the carbon carbon crucible preform is heat treated at 2300 DEG C for 3 h, and a carbon carbon crucible is prepared, and the open porosity is 30%.

[0072] S4, the carbon carbon crucible is finished: a small groove is opened along the outer bottom of the carbon carbon crucible, three slots are opened at the mouth of the carbon carbon crucible, and the inner bottom of the carbon carbon crucible is processed into an R angle type with a certain angle.

[0073] S5, 100 mesh silicon material is laid on the inner bottom of the carbon carbon crucible after finishing, the silicon material is single crystal silicon, the weight ratio of the silicon material to the carbon carbon crucible is 1:1, silicon infiltration is melted, silicon infiltration is carried out at 1600 DEG C for 3h, the residual silicon material on the surface is cleaned, and the carbon ceramic brake disc silicon infiltration carbon ceramic crucible is prepared.

[0074] Example 3

[0075] The embodiment provides a preparation method of a carbon ceramic brake disc silicon infiltration carbon ceramic crucible, including the following steps:

[0076] S1, the plain carbon cloth is alternately stacked with the net tire to form a composite cloth, the composite cloth is attached to the mold, and the crucible preform is prepared by needling, the surface layer of the crucible preform is free of pure net tire layer; the crucible preform includes a crucible bottom and a crucible side arranged on the crucible bottom, the thickness ratio of the crucible bottom to the crucible side is 1:2.2; the needling angle at the junction of the crucible bottom and the crucible side is 50 DEG with the net tire, and the needling density is 25 needles / cm 2 .

[0077] S2, carbon carbon densification is carried out on the crucible preform by chemical vapor deposition, natural gas is used, the natural gas flow is 150L / min, deposition is carried out at 1100 DEG C for 250h, the carbon carbon crucible preform is prepared, and the carbon carbon density is 1.5g / cm 3 .

[0078] S3, the carbon carbon crucible preform is heat treated at 2250 DEG C for 4h, and the carbon carbon crucible is prepared, and the opening rate is 40%.

[0079] S4, the carbon carbon crucible is finished: a small groove is opened along the outer bottom of the carbon carbon crucible, three slots are opened at the mouth of the carbon carbon crucible, and the inner bottom of the carbon carbon crucible is processed into an R angle type with a certain angle.

[0080] S5, 100 mesh silicon material is laid on the inner bottom of the carbon carbon crucible after finishing, the silicon material is single crystal silicon, the weight ratio of the silicon material to the carbon carbon crucible is 1:1, silicon infiltration is melted, silicon infiltration is carried out at 1600 DEG C for 3h, the residual silicon material on the surface is cleaned, and the carbon ceramic brake disc silicon infiltration carbon ceramic crucible is prepared.

[0081] Example 4

[0082] The embodiment provides a preparation method of a carbon ceramic brake disc silicon infiltration carbon ceramic crucible, including the following steps:

[0083] S1, the plain carbon cloth and the tire alternately stacked to form a composite cloth, the composite cloth attached to the mold, needling, to prepare a crucible preform, the surface layer of the crucible preform is free of pure tire layer; the crucible preform comprises a crucible bottom and a crucible side arranged on the crucible bottom, the thickness ratio of the crucible bottom and the crucible side is 1:2.5; the needle angle at the junction of the crucible bottom and the crucible side is 30° with the tire, and the needle density is 16 needles / cm 2 .

[0084] S2, carbon-carbon densification is carried out on the crucible preform by chemical vapor deposition, the gas used is natural gas, the natural gas flow is 150L / min, and the carbon-carbon density is 1.4g / cm after deposition at 1050℃ for 220h. 3 .

[0085] S3, the carbon-carbon crucible preform is heat treated at 2200℃ for 5h to prepare a carbon-carbon crucible, and the opening rate is 43%.

[0086] S4, finishing the carbon-carbon crucible: a small groove is opened along the outer bottom of the carbon-carbon crucible, three slots are opened at the mouth of the carbon-carbon crucible, and the inner bottom of the carbon-carbon crucible is processed into an R-angle type with a certain angle.

[0087] S5, the silicon material with a mesh number of 100 is laid on the inner bottom of the finished carbon-carbon crucible, the silicon material is single crystal silicon, and the weight ratio of the silicon material to the carbon-carbon crucible is 1:1, silicon infiltration is carried out at 1700℃ for 1h, the residual silicon material on the surface is cleaned, and a carbon-ceramic crucible for carbon-ceramic brake disc silicon infiltration is prepared.

[0088] Comparative Examples 1-4

[0089] Comparative Example 1

[0090] Comparative Example 1 is a traditional graphite crucible.

[0091] Comparative Example 2

[0092] The difference between Comparative Example 2 and Example 3 is that in step S1 of Comparative Example 2, the thickness ratio of the crucible bottom and the crucible side is 1:1.

[0093] Comparative Example 3

[0094] The difference between Comparative Example 3 and Example 3 is that in step S2 of Comparative Example 3, the chemical vapor deposition is changed to liquid immersion, and the specific steps are as follows: the crucible preform is immersed in ethylene glycol, pressurized to 3MPa, and kept for 8h, then the immersed crucible preform is taken out and solidified.

[0095] Comparative Example 4

[0096] The difference between Comparative Example 4 and Example 3 is that, in step S5 of Comparative Example 4, the molten silicon infiltration is changed to gas phase silicon infiltration, the gas phase silicon infiltration temperature is 1500℃, and the time is 25h.

[0097] Experimental detection

[0098] Detection items and detection methods

[0099] Wear resistance: the wear rate of the carbon ceramic crucible was tested by using a M-2000 type wear tester.

[0100] According to GB / T 39826-2021 "Determination of Interfacial Bending Strength of Fine Ceramics-Four Point Bending Method", the bending strength of the carbon ceramic crucible was detected.

[0101] The carbon ceramic brake disc prepared in Examples 1-4 and Comparative Examples 1-4 was subjected to wear rate, bending strength and service life detection by using a carbon ceramic crucible for silicon infiltration, and the detection results are shown in Table 1.

[0102] Table 1

[0103]

[0104] From the detection results in Table 1, it can be seen that the carbon ceramic brake disc prepared in Examples 1-4 has low wear rate, high bending strength and long service life, which indicates that the carbon ceramic brake disc for silicon infiltration has strong wear resistance, high mechanical strength and long service life.

[0105] Comparative Example 1 is a traditional graphite crucible, the wear rate is much higher than that of Example 3, and the bending strength and service life are much lower than those of Example 3, which indicates that the wear resistance, mechanical strength and service life of the traditional graphite crucible are not as good as those of Example 3.

[0106] In step S1 of Comparative Example 2, the thickness ratio of the crucible bottom to the crucible side is 1:1, and the wear resistance, mechanical strength and service life of the carbon ceramic brake disc prepared by using the carbon ceramic crucible for silicon infiltration are not as good as those of Example 3, and the carbon ceramic crucible is severely deformed after use.

[0107] Comparative Example 3 uses liquid phase impregnation, and Comparative Example 4 uses gas phase silicon infiltration, and the wear resistance, mechanical strength and service life of the carbon ceramic brake disc prepared by using the carbon ceramic crucible for silicon infiltration are not as good as those of Example 3.

[0108] Examples 5-16

[0109] Example 5

[0110] The difference between Example 5 and Example 3 is that, in Example 5, the plain carbon cloth is replaced by weftless carbon cloth.

[0111] Example 6

[0112] The difference between Example 6 and Example 3 is that in step S1 of Example 6, the needle angle at the junction of the crucible bottom and the crucible side is kept 90° with the wire tire.

[0113] Example 7

[0114] The difference between Example 7 and Example 3 is that in step S2 of Example 7, natural gas is replaced by propane.

[0115] Example 8

[0116] The difference between Example 8 and Example 3 is that in step S2 of Example 8, the flow rate of natural gas is 180 L / min.

[0117] Example 9

[0118] The difference between Example 9 and Example 3 is that in step S2 of Example 9, the flow rate of natural gas is 200 L / min.

[0119] Example 10

[0120] The difference between Example 10 and Example 3 is that in step S2 of Example 10, the deposition temperature is 1000°C.

[0121] Example 11

[0122] The difference between Example 11 and Example 3 is that in step S2 of Example 11, the deposition time is 200 h.

[0123] Example 12

[0124] The difference between Example 12 and Example 3 is that in step S2 of Example 12, the deposition time is 300 h.

[0125] Example 13

[0126] The difference between Example 13 and Example 3 is that in step S3 of Example 13, the open porosity is 30%.

[0127] Example 14

[0128] The difference between Example 14 and Example 3 is that in step S3 of Example 14, the open porosity is 45%.

[0129] Example 15

[0130] The difference between Example 15 and Example 3 is that in step S5 of Example 15, the mesh size of the silicon material is 30 mesh.

[0131] Example 16

[0132] The difference between Example 16 and Example 3 is that in step S5 of Example 16, the mesh size of the silicon material is 200 mesh.

[0133] The carbon ceramic brake disc prepared in examples 5-16 was used to prepare the silicon infiltration carbon ceramic crucible, and the wear rate, bending strength and service life of the silicon infiltration carbon ceramic crucible were detected, and the detection results are shown in Table 2.

[0134] Table 2

[0135]

[0136]

[0137] From the detection results in Table 2, it can be seen that the wear resistance, mechanical strength and service life of the silicon infiltration carbon ceramic crucible prepared by replacing the plain carbon cloth with the weftless carbon cloth in example 5 are all inferior to those of example 3.

[0138] The needle angle of the joint in example 6 is 90°, and the natural gas is replaced with methane in example 7, and the wear resistance, mechanical strength and service life of the silicon infiltration carbon ceramic crucible prepared in example 7 are all inferior to those of example 3.

[0139] The difference between example 3, example 8 and example 9 is that the flow rate of natural gas is different, and among them, the wear resistance, mechanical strength and service life of the silicon infiltration carbon ceramic crucible prepared in example 8 are the best.

[0140] The deposition temperature in example 10 is too low, the deposition time in example 11 is too short, and the deposition time in example 12 is too long, and the wear resistance, mechanical strength and service life of the silicon infiltration carbon ceramic crucible prepared in examples 10-12 are all inferior to those of example 3.

[0141] The opening rate in example 13 is too small, the opening rate in example 14 is too large, the mesh number of silicon material in example 15 is too small, and the mesh number of silicon material in example 16 is too large, and the wear resistance, mechanical strength and service life of the silicon infiltration carbon ceramic crucible prepared in examples 13-16 are all inferior to those of example 3.

[0142] The above are preferred embodiments of the present application, and do not limit the protection scope of the present application, so: any equivalent changes made on the basis of the structure, shape, principle of the present application should be covered within the protection scope of the present application.

Claims

1. A method for preparing a carbon ceramic crucible for siliconizing a carbon ceramic brake disc, characterized in that, Includes the following steps: S1. Alternately stacking fiber carbon cloth and mesh to form a composite cloth, attaching the composite cloth to a mold, and needle-punching to obtain a crucible preform. The surface of the crucible preform has no pure mesh layer. The crucible preform includes a crucible bottom and a crucible side set on the crucible bottom. The thickness ratio of the crucible bottom to the crucible side is 1:2~2.

5. S2. The crucible preform is carbon-densified by chemical vapor deposition to obtain a carbon-carbon crucible preform. The gas used in the chemical vapor deposition is a hydrocarbon gas. S3. Heat-treat the carbon-carbon crucible preform to obtain a carbon-carbon crucible. S4. The carbon-carbon crucible is precision machined according to the brake disc size and silicon infiltration requirements; S5. Spread the silicon material evenly in the bottom of the finely processed carbon crucible, melt and infiltrate the silicon, clean the residual silicon material on the surface, and obtain the carbon ceramic crucible for silicon infiltrating carbon ceramic brake disc. In step S1, the needle-punching angle at the junction of the crucible bottom and crucible side is maintained at 30°~70° with the mesh, and the needle-punching density is 16~35 needles / cm. 2 ; In step S4, the finishing process includes the following steps: opening a small groove around the bottom of the carbon crucible, opening 2 to 3 grooves at the mouth of the carbon crucible, and machining the bottom of the carbon crucible into an R-angle shape with a certain angle. In step S5, the silicon material is monocrystalline silicon or polycrystalline silicon with a mesh size of 30 to 200 mesh, and the weight ratio of the silicon material to the carbon-carbon crucible is 1:1 to 3. In step S5, the silicon diffusion temperature is 1500~1700℃ and the silicon diffusion time is 1~4h.

2. The method for preparing the carbon ceramic crucible for siliconizing carbon ceramic brake discs according to claim 1, characterized in that, In step S1, the fiber carbon cloth is plain weave carbon cloth.

3. The method for preparing the carbon ceramic crucible for siliconizing carbon ceramic brake discs according to claim 1, characterized in that, In step S2, the hydrocarbon gas is selected from at least one of natural gas, ethane, propane, and butane, and the flow rate of the hydrocarbon gas is 150~200 L / min.

4. The method for preparing the carbon ceramic crucible for siliconizing the carbon ceramic brake disc according to claim 1, characterized in that, In step S2, the chemical vapor deposition temperature is 1000~1200℃, the chemical vapor deposition time is 200~300h, and the carbon density of the carbon-carbon crucible preform is 1.3~1.6g / cm³. 3 .

5. The method for preparing the carbon ceramic crucible for siliconizing carbon ceramic brake discs according to claim 1, characterized in that, In step S3, the heat treatment temperature is 2100~2300℃, the heat treatment time is 3~6h, and the porosity of the carbon crucible is 30~45%.

6. A carbon ceramic crucible for siliconizing a carbon ceramic brake disc, characterized in that, It is prepared by the method for preparing the carbon ceramic crucible for siliconizing the carbon ceramic brake disc according to any one of claims 1 to 5.

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