Carbon / carbon-silicon carbide tooling, its preparation method and application in liquid silicon infiltration of carbon ceramic brake disc

Abstract

The application relates to the technical field of brake materials, and provides a carbon / carbon-silicon carbide tool and a preparation method and application of the carbon / carbon-silicon carbide tool in liquid silicon infiltration of a carbon ceramic brake disc. The carbon / carbon-silicon carbide tool is prepared by the following steps: needling carbon fiber cloth and a carbon fiber tire to obtain a tool preform, brushing a binder, curing, chemical vapor deposition densification, rough machining and liquid silicon infiltration. The carbon / carbon-silicon carbide tool is in the shape of a cylinder with sawteeth at one end. The tool material is carbon / carbon-silicon carbide, has the characteristics of high-temperature resistance, wear resistance, corrosion resistance, high-temperature stability, high thermal conductivity, oxidation resistance and the like, is not prone to cracking, can be repeatedly used, and reduces production cost. In addition, the tool bottom is designed in the shape of sawteeth, so that, during liquid silicon infiltration, a large amount of silicon material can be prevented from being accumulated at the bottom of the brake disc and from sticking to the brake disc due to the contact of the silicon material with the brake disc, thereby solving the problems of residual silicon slag bonding and affecting the appearance of the disc surface.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of brake materials, in particular to a carbon / carbon-silicon carbide tool and a preparation method thereof and application thereof in liquid silicon infiltration of carbon ceramic brake disc. BACKGROUND

[0002] The carbon ceramic brake disc is a new type of brake material, which has the advantages of low density, high temperature resistance, high and stable friction performance, and has a wide application prospect in the field of high energy brakes such as automobiles, high speed trains and airplanes.

[0003] The material of the carbon ceramic brake disc is C / C-SiC, which is a composite material taking carbon fiber as a reinforcing body and taking C and SiC as a matrix. Compared with C / C composite material, the most important difference is that SiC with excellent oxidation resistance and high hardness is used to replace part of the C matrix in the C / C composite material, thereby significantly changing the oxidation resistance on the basis of the mechanical properties of the C / C composite material. Therefore, the C / C-SiC material has a series of excellent properties such as high specific strength, high specific modulus, excellent high temperature mechanical properties, thermal stability, high thermal conductivity and low thermal expansion coefficient, in addition to the high density of the matrix, heat shock resistance, ablation resistance, strong adaptability to harsh environments and low wear performance.

[0004] At present, when preparing the carbon ceramic brake disc, a low-density carbon / carbon blank is usually prepared by using a CVD process, then the carbon / carbon blank is buried in a crucible containing silicon powder, and then placed in a siliconizing treatment furnace to form a SiC ceramic phase in the carbon / carbon blank by using a molten silicon infiltration process (LSI). The LSI process has the advantages of simple process, significantly shortened densification cycle, reduced production cost, and low residual porosity. However, during actual liquid silicon infiltration, residual silicon slag often adheres after reaction, which is difficult to clean and affects the appearance of the disc surface. In addition, the traditional tool used for liquid silicon infiltration is made of graphite material, which is prone to cracking and cannot be used repeatedly, thereby increasing the production cost. SUMMARY

[0005] Therefore, the present application provides a carbon / carbon-silicon carbide tool and a preparation method thereof and application thereof in liquid silicon infiltration of carbon ceramic brake disc. The carbon-silicon carbide tool provided by the present application solves the problem of a large amount of residual silicon slag adhesion, and the tool can be used repeatedly, thereby reducing the production cost.

[0006] In order to achieve the above-mentioned application purposes, the present application provides the following technical solutions:

[0007] A preparation method of a carbon / carbon-silicon carbide tool, comprising the following steps:

[0008] The carbon fiber cloth and the carbon fiber web are needled to obtain a tool preform; the tool preform is in a cylindrical shape;

[0009] solidifying the prepreg to obtain a cured prepreg;

[0010] chemical vapor deposition densification of the cured prepreg to obtain a carbon-carbon prepreg;

[0011] saw-toothed at one end to obtain a carbon-carbon tooling;

[0012] liquid silicon infiltration of the carbon-carbon tooling with excess solid silicon to obtain the carbon / carbon-silicon carbide tooling; the carbon / carbon-silicon carbide tooling is a cylinder with saw-toothed at one end.

[0013] Preferably, the carbon fiber cloth is a unidirectional carbon fiber cloth; the specification of the carbon fiber cloth is 12-24K, and the gram weight is 140-180g / m 2 .

[0014] Preferably, the binder is phenolic resin; the brushing amount of the binder is 10%-20% of the weight of the tooling prepreg.

[0015] Preferably, the density of the carbon-carbon prepreg is 1.4-1.7g / cm 3 .

[0016] Preferably, the mass of the solid silicon is 1.5-2 times of the mass of the carbon-carbon tooling; the highest temperature of the liquid silicon infiltration is 1400-1700℃, and the holding time at the highest temperature is 1-3h.

[0017] Preferably, the heating process from room temperature to the highest temperature of the liquid silicon infiltration is divided into a first heating stage and a second heating stage; the first heating stage is from room temperature to 800℃, the first heating stage is pressurized with nitrogen, and the pressure is 70-85kPa; the second heating stage is from 800℃ to the highest temperature of the liquid silicon infiltration, and the second stage is vacuumed to the limit; the total heating time of the first heating stage and the second heating stage is 25-35h.

[0018] The application further provides the carbon / carbon-silicon carbide tooling prepared by the preparation method.

[0019] Preferably, the outer diameter of the carbon / carbon-silicon carbide tooling is 150-170mm, the inner diameter is 140-150mm, the height is 55-75mm, the tooth pitch is 20-40mm, and the tooth height is 25-45mm.

[0020] The application further provides the application of the carbon / carbon-silicon carbide tooling in liquid silicon infiltration of a carbon ceramic brake disc.

[0021] The application also provides a method for liquid silicon infiltration of carbon ceramic brake disc, comprising the following steps:

[0022] Part of the solid silicon material is laid on the bottom of the carbon / carbon brake disc blank, the sawtooth end of the carbon / carbon-silicon carbide tooling described in the above scheme is placed in the center hole of the carbon / carbon brake disc blank with the sawtooth end facing down, and the remaining solid silicon material is placed in the carbon / carbon-silicon carbide tooling, then the temperature is raised for liquid silicon infiltration to obtain the carbon ceramic brake disc.

[0023] The application provides a preparation method of carbon / carbon-silicon carbide tooling, comprising the following steps: needling carbon fiber cloth and carbon fiber tire to obtain tooling preform; the tooling preform is cylindrical; after coating adhesive on the surface of the tooling preform, curing is performed to obtain a cured preform; the cured preform is subjected to chemical vapor deposition densification to obtain a carbon / carbon preform; one end of the carbon / carbon preform is processed into a sawtooth shape to obtain a carbon / carbon tooling; the carbon / carbon tooling is subjected to liquid silicon infiltration with excess solid silicon material to obtain the carbon / carbon-silicon carbide tooling; the carbon / carbon-silicon carbide tooling is cylindrical with a sawtooth at one end. The tooling prepared by the application is made of carbon / carbon-silicon carbide, has the characteristics of high temperature resistance, wear resistance, corrosion resistance, high temperature stability, high thermal conductivity, oxidation resistance and the like, is not easy to crack, can be repeatedly used, and reduces production cost; and the carbon / carbon-silicon carbide tooling of the application is cylindrical with a sawtooth at the bottom, when liquid silicon infiltration is performed, the sawtooth end of the tooling of the application is placed in the center of the carbon blank with the sawtooth end facing down, part of the solid silicon material is placed in the tooling of the application, and the solid silicon material flows out through the interstitial pores of the sawtooth after being liquefied and infiltrates into the brake disc, thereby avoiding that a large amount of silicon material accumulates at the bottom of the brake disc and causes the silicon material to touch the brake disc and stick, so that the problem of adhesion of a large amount of residual silicon slag and influence on the appearance of the disc surface is solved. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The figure is a preparation process flow chart of the carbon / carbon-silicon carbide tooling of the application;

[0025] Figure 2 The figure is a structure schematic diagram of the carbon / carbon-silicon carbide tooling of the application;

[0026] Figure 3 The figure is an effect diagram of the carbon ceramic brake disc obtained after liquid silicon infiltration in Example 2;

[0027] Figure 4 The figure is an effect diagram of the carbon ceramic brake disc obtained after liquid silicon infiltration in Example 3;

[0028] Figure 5 The figure is an effect diagram of the carbon ceramic brake disc obtained after liquid silicon infiltration in Example 4;

[0029] Figure 6This is an image of a carbon-ceramic brake disc obtained without the use of tooling for liquid-phase silicon infiltration. Detailed Implementation

[0030] This invention provides a method for preparing carbon / carbon-silicon carbide tooling, comprising the following steps:

[0031] Carbon fiber cloth and carbon fiber mesh are needle-punched to obtain a tooling preform; the tooling preform is cylindrical.

[0032] After applying an adhesive to the surface of the tooling preform, it is cured to obtain a cured preform.

[0033] The solidified preform is densified by chemical vapor deposition to obtain a carbon-carbon preform.

[0034] One end of the carbon-carbon preform is processed into a serrated shape to obtain a carbon-carbon tooling.

[0035] The carbon-carbon tooling is subjected to liquid-phase silicon infiltration using an excess of solid silicon material to obtain the carbon / carbon-silicon carbide tooling; the carbon / carbon-silicon carbide tooling is a cylindrical shape with serrations at one end.

[0036] Figure 1 This is a process flow diagram for the fabrication of the carbon / carbon-silicon carbide tooling of the present invention. The following is in conjunction with… Figure 1 Please provide a detailed explanation.

[0037] This invention involves needle-punching carbon fiber cloth and carbon fiber mesh to obtain a tooling preform; the tooling preform is cylindrical. In this invention, the carbon fiber cloth is preferably unidirectional carbon fiber cloth; the preferred specifications of the carbon fiber cloth are 12-24K, and the preferred basis weight is 140-180 g / m², more preferably 160 g / m²; the preferred needle-punching density is 20-30 needles / cm². 2 In a specific embodiment of the present invention, carbon fiber cloth and carbon fiber mesh are preferably laid alternately in a manner of 1 layer of carbon fiber cloth and 1 to 2 layers of mesh, with the included angle between adjacent carbon fiber cloths preferably being 90°, and each layer of mesh is needle-punched once; in the present invention, the density of the tooling prefabricated body is preferably 0.3 to 0.6 g / cm³. 3 The number of layers can be determined based on the final required thickness of the tooling prefabrication; the tooling prefabrication is preferably cylindrical; the size of the cylinder is preferably determined based on the size of the target tooling.

[0038] After obtaining the tooling preform, the present application coats the surface of the tooling preform with a binder and then solidifies the tooling preform to obtain a solidified preform. In the present application, the binder is preferably a phenolic resin, and in a specific embodiment of the present application, the model of the phenolic resin is preferably EXP-0026E; the coating amount of the binder is preferably 10% to 20%, more preferably 13% to 15%, of the weight of the tooling preform; and the solidification temperature is preferably 150 to 230°C, and the time is preferably 4 to 9 hours.

[0039] After obtaining the solidified preform, the present application densifies the solidified preform by chemical vapor deposition to obtain a carbon-carbon preform. In the present application, the carbon source gas used in the chemical vapor deposition densification is preferably natural gas; and the density of the carbon-carbon preform is preferably 1.4 to 1.7 g / cm 3 ; the present application does not have special requirements for the specific operating conditions of the chemical vapor deposition densification, and conditions well known to those skilled in the art can be used as long as they can achieve the density of the carbon-carbon preform as required above.

[0040] After obtaining the carbon-carbon preform, the present application processes one end of the carbon-carbon preform into a sawtooth shape (i.e. Figure 1 the rough machining step in the present application) to obtain a carbon-carbon tooling. In the present application, it is preferred to polish the rough burrs on the surface of the carbon-carbon preform first, and then process one end of the carbon-carbon preform; the present application does not have special requirements for the method of processing, and any method that can form a sawtooth shape is acceptable.

[0041] After obtaining the carbon-carbon tooling, the present application adopts excess solid silicon material to liquid silicon infiltration on the carbon-carbon tooling, and obtains the carbon / carbon-silicon carbide tooling; the carbon / carbon-silicon carbide tooling is in the shape of a cylinder with serrations on one end. In the present application, the mass of the solid silicon material is preferably 1.5-2 times, more preferably 1.6-1.8 times, of the mass of the carbon-carbon tooling; the solid silicon material is preferably silicon powder; the highest temperature of the liquid silicon infiltration is preferably 1400-1700℃, more preferably 1550-1650℃, and the holding time at the highest temperature is preferably 1-3h, more preferably 1.5-2.5h; the heating process from room temperature to the highest temperature of the liquid silicon infiltration is divided into a first heating stage and a second heating stage; the first heating stage is from room temperature to 800℃, and the first heating stage is pressurized with nitrogen gas, preferably at a pressure of 70-85kPa; the second heating stage is from 800℃ to the highest temperature of the liquid silicon infiltration, and the second stage is preferably under an extreme vacuum; the total heating time of the first heating stage and the second heating stage is preferably 25-35h, and the heating process from room temperature to the highest temperature of the liquid silicon infiltration is preferably uniform heating. During the liquid silicon infiltration, the carbon-carbon tooling is preferably placed flat on the solid silicon material, and then heated; the present application adopts excess solid silicon material for liquid silicon infiltration, which can ensure that the tooling does not absorb the required silicon material during subsequent use.

[0042] After the liquid silicon infiltration is completed, the obtained carbon / carbon-silicon carbide tooling is preferably finished; the method of finishing is preferably polishing, which removes the residual silicon slag on the surface of the tooling.

[0043] The present application also provides a carbon / carbon-silicon carbide tooling prepared by the preparation method described in the above scheme. In the present application, the carbon / carbon-silicon carbide tooling is in the shape of a cylinder with serrations on one end, and the serrations are uniformly distributed on the circumference of one end of the cylinder, and the specific structure is shown in Figure 1 In the present application, one end of the tooling is serrated, which allows the solid silicon material to flow into the brake disc after being liquefied through the interstitial pores between the serrations, while reducing the contact area between the tooling and the bottom to avoid sticking and make it difficult to remove the tooling.

[0044] In the present application, the outer diameter of the carbon / carbon-silicon carbide tooling is smaller than the inner diameter of the carbon ceramic brake disc, and during use, the carbon / carbon-silicon carbide tooling is placed at the center of the carbon brake disc blank; in the present application, the outer diameter of the carbon / carbon-silicon carbide tooling is preferably 150-170mm, more preferably 165mm, the inner diameter is preferably 140-150mm, more preferably 145mm, the height is preferably 55-75mm, more preferably 45mm, the pitch is preferably 20-40mm, more preferably 30mm, and the tooth height is preferably 25-45mm, more preferably 30mm; the height of the carbon / carbon-silicon carbide tooling is specifically calculated as the distance from the tip of the serration to the circumference on the other side of the circular ring.

[0045] The application further provides the carbon / carbon-silicon carbide tooling in the above-mentioned scheme for use in liquid silicon infiltration of a carbon ceramic brake disc.

[0046] The application further provides a method for liquid silicon infiltration of a carbon ceramic brake disc, comprising the following steps:

[0047] Part of the solid silicon material is laid on the bottom of the carbon / carbon brake disc blank, the carbon / carbon-silicon carbide tooling in the above-mentioned scheme is placed in the center hole of the carbon / carbon brake disc blank with the serrated end downward, the remaining solid silicon material is placed inside the carbon / carbon-silicon carbide tooling, then liquid silicon infiltration is performed by heating to obtain a carbon ceramic brake disc.

[0048] The carbon / carbon brake disc blank in the application has no special requirements and can be prepared by the method known to those skilled in the art; in the application, the mass of the remaining solid silicon material is preferably 20% to 40% of the total mass of the solid silicon material; the highest temperature of the liquid silicon infiltration is preferably 1600 DEG C; in the specific embodiments of the application, a pad is preferably placed at the bottom of the carbon / carbon brake disc blank during the liquid silicon infiltration; the application has no special requirements for other operation conditions of the liquid silicon infiltration and the operation conditions known to those skilled in the art can be used.

[0049] The technical solutions in the application will be described clearly and completely in the embodiments in the application. Obviously, the described embodiments are only some of the embodiments of the application, but not all the embodiments. Based on the embodiments in the application, all the other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0050] Embodiment 1

[0051] (1) A tooling preform is prepared by needling 24K, 160g / m2 of single-directional carbon fiber cloth and carbon fiber net tire, and the layers are laid in the order of one layer of carbon fiber cloth and one layer of carbon fiber net tire, the included angle of adjacent carbon fiber cloths is 90 DEG, and the carbon fiber net tire is needled once for each layer, and the needling density is 25 needles / cm 2 . The density of the obtained tooling preform is 0.42g / cm 3 .

[0052] (2) The surface of the tooling preform is brushed with a phenolic resin (EXP-0026E) binder, and the brushing amount is 10% of the weight of the tooling preform, then the resin is cured by heating at 200 DEG C for 6h to obtain a cured preform.

[0053] (3) The cured preform is densified to 1.5g / cm 3 by chemical vapor deposition using natural gas as the carbon source gas to obtain a carbon / carbon preform.

[0054] (4) Polishing the surface roughness burr of the carbon-carbon preform, processing the lower part of the tool into a zigzag shape, and obtaining a carbon-carbon tool.

[0055] (5) Adding excess solid silicon material (the weight of the solid silicon material is 2 times the weight of the carbon-carbon tool) to perform liquid silicon infiltration, the highest temperature of the liquid silicon infiltration is 1600°C, the temperature rising time is 35h, the highest temperature holding time is 2h, during the temperature rising process, N2is filled at the stage of room temperature rising to 800°C, the pressure is 80KPa, and the stage of 800°C rising to the highest temperature is extracted to limit vacuum, and the liquid silicon infiltration ensures that the tool does not absorb the required silicon material of the product in subsequent use.

[0056] (6) After the liquid silicon infiltration is completed, the surface residual silicon slag of the tool is polished, and a carbon / carbon-silicon carbide tool is obtained; the structural diagram of the obtained carbon / carbon-silicon carbide tool is as shown in Figure 1 , and the size of the carbon / carbon-silicon carbide tool is as follows: the outer diameter is 165mm, the inner diameter is 145mm, the height is 45mm, the tooth pitch is 30mm, and the tooth height is 30mm.

[0057] The carbon / carbon-silicon carbide tool prepared in Example 1 is applied to Examples 2-4 to perform liquid silicon infiltration of carbon ceramic brake discs.

[0058] Example 2

[0059] A carbon ceramic brake disc product with an inner diameter of 172mm is prepared, and a total silicon material amount of 1832g is required for silicon infiltration and ceramicization, 1222g of which is laid on the bottom of the carbon / carbon blank (the bottom of the carbon / carbon blank is padded with a pad), the zigzag end of the tool is placed downward in the center of the carbon / carbon blank, and the remaining 610g of silicon material is poured into the inside of the tool, and the silicon infiltration and ceramicization is performed by heating to 1600°C, and the effect of the product obtained after the silicon infiltration is as shown in Figure 3 . According to Figure 3 , it can be seen that there is no silicon material bonding on the surface of the brake disc after the silicon infiltration.

[0060] Example 3

[0061] A carbon ceramic brake disc product with an inner diameter of 170mm is prepared, and a total silicon material amount of 1242g is required for silicon infiltration and ceramicization, 828g of which is laid on the bottom of the carbon / carbon blank (the bottom of the carbon / carbon blank is padded with a pad), the zigzag end of the tool is placed downward in the center of the carbon / carbon blank, and the remaining 414g of silicon material is poured into the inside of the tool, and the silicon infiltration and ceramicization is performed by heating to 1600°C, and the effect of the product obtained after the silicon infiltration is as shown in Figure 4 . The block in Figure 4 is a pad. According to Figure 4 , it can be seen that there is no silicon material bonding on the surface of the brake disc after the silicon infiltration.

[0062] Example 4

[0063] A carbon ceramic brake disc product with an inner diameter of 175 mm is prepared, and 2400 g of total silicon material is added for silicon infiltration ceramization, 1600 g of which is laid on the bottom of the carbon / carbon blank (the bottom of the carbon / carbon blank is padded with a pad), the sawtooth end of the tooling is placed downward, and the remaining 800 g of silicon material is poured into the tooling, and the temperature is raised to 1600 ℃ for silicon infiltration ceramization. The effect of the product obtained after silicon infiltration is shown in Figure 5 Figure 5 The block in the figure is a pad). The effect of the product obtained after silicon infiltration without using tooling is shown in Figure 6 Figures 5-6 It can be seen that the product disc surface is not bonded with silicon material when the carbon ceramic brake disc is subjected to liquid phase silicon infiltration using the tooling of the present application, while the surface of the carbon ceramic brake disc without using the tooling is bonded with residual silicon slag, which affects the appearance of the disc surface.

[0064] In addition, through testing, the carbon / carbon-silicon carbide tooling of the present application is not damaged by human factors, and will not be damaged under normal use, and can be reused, thereby reducing the preparation cost of the carbon ceramic brake disc.

[0065] The above only describes the preferred embodiments of the present application, and it should be noted that those skilled in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be considered within the protection scope of the present application.​​

Claims

1. A method of making a carbon / carbon-silicon carbide tooling, characterized by, The method comprises the following steps: The carbon fiber cloth and the carbon fiber tire are needled to obtain a tooling preform; the tooling preform is cylindrical; The tooling preform is coated with a binder and then cured to obtain a cured preform; The cured preform is subjected to chemical vapor deposition densification to obtain a carbon-carbon preform; One end of the carbon-carbon preform is processed into a sawtooth shape to obtain a carbon-carbon tooling; The carbon-carbon tooling is subjected to liquid silicon infiltration using an excess amount of solid silicon material to obtain the carbon / carbon-silicon carbide tooling; The carbon / carbon-silicon carbide tooling is cylindrical and has a sawtooth at one end; The carbon / carbon-silicon carbide tooling is used for liquid silicon infiltration of a carbon ceramic brake disc.

2. The production method according to claim 1, characterized by, The carbon fiber cloth is a unidirectional carbon fiber cloth; the specification of the carbon fiber cloth is 12-24K, and the grammage is 140-180g / m2; the needling density of the needling is 20-30 needles / cm 2 .

3. The preparation method according to claim 1, characterized in that, The binder is phenolic resin; and the binder is applied in an amount of 10-20% of the weight of the tooling preform.

4. The method of claim 1, wherein, The carbon-carbon preform has a density of 1.4 to 1.7 g / cm 3 .

5. The preparation method according to claim 1, characterized in that, The mass of the solid silicon material is 1.5-2 times the mass of the carbon-carbon tooling; the maximum temperature of the liquid silicon infiltration is 1400-1700℃, and the holding time at the maximum temperature is 1-3h.

6. The preparation method according to claim 5, characterized in that, The temperature rising process from room temperature to the maximum temperature of the liquid silicon infiltration is divided into a first temperature rising stage and a second temperature rising stage; the first temperature rising stage is from room temperature to 800℃, the first temperature rising stage is pressurized with nitrogen gas, and the pressure is 70-85kPa; the second temperature rising stage is from 800℃ to the maximum temperature of the liquid silicon infiltration, and the second stage is subjected to an extreme vacuum; and the total temperature rising time of the first temperature rising stage and the second temperature rising stage is 25-35h.

7. The carbon / carbon-silicon carbide tooling prepared by the preparation method of any one of claims 1-6.

8. The carbon / carbon-silicon carbide tooling of claim 7, wherein, The carbon / carbon-silicon carbide tooling has an outer diameter of 150-170mm, an inner diameter of 140-150mm, a height of 55-75mm, a tooth pitch of 20-40mm, and a tooth height of 25-45mm.

9. The use of the carbon / carbon-silicon carbide tooling of claim 7 or 8 in liquid silicon infiltration of a carbon ceramic brake disc.

10. A method for liquid silicon infiltration of a carbon ceramic brake disc, characterized in that, The method comprises the following steps: A portion of the solid silicon material is laid on the bottom of the carbon / carbon brake disc blank, the carbon / carbon-silicon carbide tooling of claim 8 or 9 is placed in the center hole of the carbon / carbon brake disc blank with the sawtooth end facing downward, the remaining portion of the solid silicon material is placed inside the carbon / carbon-silicon carbide tooling, and then the temperature is raised for liquid silicon infiltration to obtain a carbon ceramic brake disc.

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