A carbon ceramic material and its preparation method and application, a carbon ceramic brake disc and its preparation method

Abstract

The present invention belongs to the field of materials technology, and specifically relates to a carbon ceramic material, a preparation method and application thereof, and a carbon ceramic brake disc and a preparation method thereof. The carbon ceramic material provided by the present invention has a density of approximately one-third that of iron. Using it to prepare brake discs can achieve the purpose of lightweighting and increase the endurance of a vehicle. Furthermore, the carbon ceramic material has a high temperature resistance of over 1000°C and exhibits excellent heat resistance. However, the temperature generated by vehicle braking is far below 1000°C. Carbon ceramic materials are very stable below 1000°C, and brake discs prepared using them will not deform due to heat during braking. Furthermore, the carbon ceramic material has high hardness and very strong wear resistance. Carbon ceramic brake discs prepared using this carbon ceramic material have a long service life of over 500,000 kilometers.

Description

Technical Field

[0001] The present invention belongs to the field of material technology, and specifically relates to a carbon ceramic material and a preparation method and application thereof, a carbon ceramic brake disc and a preparation method thereof. Background Art

[0002] During braking, automotive brake discs are subject to tremendous friction and pressure, and are subject to alternating hot and cold conditions, making them susceptible to deformation and cracking. Currently, the brake discs used on the market are primarily cast iron discs, primarily made from gray cast iron. Traditional cast iron discs typically have a lifespan of approximately 100,000 to 150,000 kilometers. With improved vehicle performance and increasing demands for environmental protection and lightweighting, the market is placing increasingly high demands on the quality of automotive brake discs. Traditional cast iron discs are no longer able to meet these demands. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a carbon ceramic material, a preparation method and application thereof, a carbon ceramic brake disc and a preparation method thereof. The carbon ceramic material provided by the present invention has high strength and excellent heat resistance and wear resistance. The carbon ceramic brake disc prepared with it has a long service life and is lightweight, which can improve the endurance of the car.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] The present invention provides a carbon ceramic material, the raw materials used for preparation include mixed materials and silicon powder;

[0006] Calculated by mass percentage, the mixture includes: 30-50% carbon fiber filaments, 10-30% carbon powder, 10-30% phenolic resin and 20-30% silicon carbide powder.

[0007] The present invention also provides a method for preparing the carbon ceramic material described in the above technical solution, comprising the following steps:

[0008] The mixed material is subjected to hot pressing and carbonization treatment in sequence to obtain a carbonized material;

[0009] The carbonized material is placed on a graphite plate paved with silicon powder and subjected to ceramic treatment to obtain a carbon ceramic material.

[0010] Preferably, the carbon fiber filaments have a length of 9-11 mm and a width of 4-6 mm.

[0011] Preferably, the hot pressing temperature is 145-155° C., the pressure is 30 MPa, and the heat preservation and pressure holding time is 3 hours.

[0012] Preferably, the temperature of the carbonization treatment is 800° C. and the holding time is 72 hours.

[0013] Preferably, the ceramic treatment is to raise the temperature to 1690-1710° C. within 30-35 hours.

[0014] The present invention also provides the use of the carbon ceramic material described in the above technical solution or the carbon ceramic material prepared by the preparation method described in the above technical solution in a brake disc.

[0015] The present invention also provides a carbon ceramic brake disc, comprising a first carbon ceramic friction plate, an aluminum alloy, and a second carbon ceramic friction plate which are sequentially combined in a sandwich structure;

[0016] One side of the first carbon ceramic friction plate and the second carbon ceramic friction plate has an inverted trapezoidal structure and the other side has a flat structure;

[0017] The first carbon ceramic friction plate and the second carbon ceramic friction plate have opposite sides with an inverted trapezoidal structure, and the middle space formed therein is filled with aluminum alloy;

[0018] The material of the first carbon ceramic friction plate and the second carbon ceramic friction plate is the carbon ceramic material described in the above technical solution or the carbon ceramic material prepared by the preparation method described in the above technical solution.

[0019] The present invention also provides a method for preparing the carbon ceramic brake disc described in the above technical solution, comprising the following steps:

[0020] After the first machining, the first carbon ceramic friction plate and the second carbon ceramic friction plate are fixed in a fixed mold so that the sides with the inverted trapezoidal structure are opposite to each other to form a pouring space. Semi-solid aluminum alloy is injected into the pouring space, and after die-casting, a second machining is performed to obtain a carbon ceramic brake disc.

[0021] Preferably, the die-casting temperature is 720-740° C., the pressure is 80-100° C., and the heat and pressure holding time is 180-600 s.

[0022] The present invention provides a carbon ceramic material, the raw materials used for its preparation include a mixture and silicon powder. The mixture comprises, by mass percentage, 30-50% carbon fiber filaments, 10-30% carbon powder, 10-30% phenolic resin, and 20-30% silicon carbide powder. The carbon ceramic material provided by the present invention has a density approximately one-third that of iron. Using it to manufacture brake discs can achieve lightweighting and increase a vehicle's range. Furthermore, the carbon ceramic material exhibits excellent heat resistance, with a high temperature resistance exceeding 1000°C. However, the temperatures generated by vehicle braking far exceed 1000°C, and the carbon ceramic material is very stable below 1000°C. Brake discs made from this material will not deform due to heat during braking. Furthermore, the carbon ceramic material has high hardness and strong wear resistance, resulting in a long service life of over 500,000 kilometers. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the structure of a carbon ceramic friction plate prepared in Example 1 of the present invention;

[0024] Figure 2 This is a schematic diagram of the aluminum alloy structure in the carbon ceramic brake disc prepared in Example 1 of the present invention;

[0025] Figure 3 This is a schematic diagram of the combined structure of the aluminum alloy and carbon ceramic friction plate in the carbon ceramic brake disc prepared in Example 1 of the present invention;

[0026] Figure 4 This is a schematic diagram of the sandwich structure consisting of a carbon-ceramic friction plate, an aluminum alloy, and a carbon-ceramic friction plate in the carbon-ceramic brake disc prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0027] The present invention provides a carbon ceramic material, the raw materials used for preparation include mixed materials and silicon powder;

[0028] Calculated by mass percentage, the mixture includes: 30-50% carbon fiber filaments, 10-30% carbon powder, 10-30% phenolic resin and 20-30% silicon carbide powder.

[0029] Unless otherwise specified, the present invention has no special requirements on the sources of the raw materials used, and commercially available products known to those skilled in the art can be used.

[0030] In the present invention, the mass percentage of the carbon fiber filaments is preferably 35-45%, the mass percentage of the carbon powder is preferably 20-25%, the mass percentage of the phenolic resin is preferably 15-25%, and the mass percentage of the silicon carbide powder is preferably 20-25%.

[0031] In the present invention, the carbon fiber filaments are preferably obtained by dipping, drying, and cutting long carbon fiber filaments. In the present invention, the dipping is preferably performed with a phenolic resin solution having a mass concentration of 50%; the dipping time is preferably 60 seconds; the drying temperature is preferably 75°C; the drying time is preferably 15 minutes; and the cutting is preferably performed with aluminum alloy cutting blades.

[0032] In the present invention, the shape of the carbon fiber filaments is preferably rectangular; the length of the carbon fiber filaments is preferably 9-11 mm, more preferably 10 mm, the width is preferably 4-6 mm, more preferably 5 mm, and the thickness is preferably 0.7 mm.

[0033] The present invention also provides a method for preparing the carbon ceramic material described in the above technical solution, comprising the following steps:

[0034] The mixed material is subjected to hot pressing and carbonization treatment in sequence to obtain a carbonized material;

[0035] The carbonized material is placed on a graphite plate paved with silicon powder and subjected to ceramic treatment to obtain a carbon ceramic material.

[0036] The present invention hot-presses the mixed material to obtain the carbon-carbon material.

[0037] In the present invention, the hot pressing temperature is preferably 145-155° C., more preferably 150° C., the pressure is preferably 30 MPa, and the heat preservation and pressure holding time is preferably 3 hours; and the hot pressing equipment is preferably a hot press.

[0038] After obtaining the carbon-carbon material, the present invention performs carbonization treatment on the carbon-carbon material to obtain a carbonized material.

[0039] In the present invention, the temperature of the carbonization treatment is preferably 800° C., and the holding time is preferably 72 h.

[0040] During the carbonization process, high temperature is used to remove the hydrogen and oxygen substances in the carbon-carbon material, making it completely carbonized.

[0041] The carbonized material is obtained. In the present invention, the carbonized material is placed on a graphite plate paved with silicon powder and subjected to ceramic treatment to obtain a carbon ceramic material.

[0042] In the present invention, the thickness of the laid silicon powder is preferably 2-5 mm, more preferably 2.5-4 mm.

[0043] In the present invention, the ceramic treatment is preferably performed by heating the temperature to 1690-1710° C. within 30-35 hours, more preferably by heating the temperature to 1700° C. within 35 hours.

[0044] During the ceramicization process, the carbon on the surface of the carbonized material reacts chemically with the silicon powder to form a new substance - silicon carbide.

[0045] The present invention also provides the use of the carbon ceramic material described in the above technical solution in a brake disc.

[0046] The present invention also provides a carbon ceramic brake disc, comprising a first carbon ceramic friction plate, an aluminum alloy, and a second carbon ceramic friction plate which are sequentially combined in a sandwich structure;

[0047] One side of the first carbon ceramic friction plate and the second carbon ceramic friction plate has an inverted trapezoidal structure and the other side has a flat structure;

[0048] The first carbon ceramic friction plate and the second carbon ceramic friction plate have opposite sides with an inverted trapezoidal structure, and the middle space formed therein is filled with aluminum alloy;

[0049] The material of the first carbon ceramic friction plate and the second carbon ceramic friction plate is the carbon ceramic material described in the above technical solution.

[0050] In the present invention, the method for preparing the first carbon ceramic friction plate and the second carbon ceramic friction plate preferably comprises the following steps:

[0051] placing the mixed material in a hot pressing mold for hot pressing to obtain a carbon-carbon friction plate, wherein one side of the carbon-carbon friction plate has an inverted trapezoidal structure and the other side has a planar structure;

[0052] The mixed material is the mixed material described in the above technical solution;

[0053] The carbon-carbon friction plate is subjected to machining and carbonization treatment in sequence to obtain a carbonized friction plate;

[0054] The carbonized material is placed on a graphite plate paved with silicon powder and subjected to a ceramic treatment to obtain a first carbon ceramic friction plate and a second carbon ceramic friction plate.

[0055] The present invention has no special limitation on the structure of the hot pressing mold, as long as a carbon-carbon friction plate having an inverted trapezoidal structure on one side and a planar structure on the other side can be obtained.

[0056] In the present invention, the machining is preferably grinding; the grinding is preferably performed to a surface runout of <0.1 mm, more preferably ≤0.05 mm; and the equipment used for the grinding is preferably a grinding machine.

[0057] In the preparation method of the first carbon ceramic friction plate and the second carbon ceramic friction plate, the parameters of the hot pressing, carbonization treatment and ceramicization treatment are as described above and will not be repeated here.

[0058] In the present invention, the surface of the first carbon ceramic friction plate and the second carbon ceramic friction plate bonded to the aluminum alloy is preferably a surface that has not been ceramicized.

[0059] The present invention also provides a method for preparing the carbon ceramic brake disc described in the above technical solution, comprising the following steps:

[0060] After the first machining, the first carbon ceramic friction plate and the second carbon ceramic friction plate are fixed in a fixed mold so that the sides with the inverted trapezoidal structure are opposite to each other to form a pouring space. Semi-solid aluminum alloy is injected into the pouring space, and after die-casting, a second machining is performed to obtain a carbon ceramic brake disc.

[0061] The present invention preferably fixes the first carbon ceramic friction plate and the second carbon ceramic friction plate in a fixed mold after first machining, so that the sides with the inverted trapezoidal structure are opposite to form a pouring space, injects semi-solid aluminum alloy into the pouring space, and obtains a carbon ceramic brake disc blank after die casting.

[0062] In the present invention, the first machining is preferably grinding; the grinding is preferably performed to a surface runout of less than 0.1 mm, more preferably ≤ 0.05 mm; and the equipment used for the grinding is preferably a grinder.

[0063] The present invention has no special limitation on the structure of the fixed mold, as long as it can fix the carbon ceramic friction plate.

[0064] In the present invention, the die-casting temperature is preferably 720-740°C, more preferably 720-730°C, the pressure is preferably 80-100T, more preferably 85-95T, and the holding time is preferably 180-600s, more preferably 200-300s.

[0065] The present invention obtains a carbon ceramic brake disc blank having a sandwich structure of a first carbon ceramic friction plate, an aluminum alloy and a second carbon ceramic friction plate by die casting.

[0066] After obtaining the carbon ceramic brake disc blank, the present invention performs a second machining process on the carbon ceramic brake disc blank to obtain a carbon ceramic brake disc.

[0067] In the present invention, the second machining is preferably grinding; the grinding is preferably performed to a surface runout of less than 0.1 mm, more preferably less than or equal to 0.05 mm; and the equipment used for the grinding is preferably a grinder.

[0068] The carbon ceramic material provided by the present invention has a density of approximately 1 / 3 that of iron. Using it to prepare brake discs can achieve the purpose of lightweighting and increase the endurance of the vehicle. Moreover, the carbon ceramic material has a high temperature resistance of above 1000°C and has excellent heat resistance. The temperature generated by automobile braking is far less than 1000°C. The carbon ceramic material is very stable below 1000°C, and the brake disc prepared with it will not deform due to heat during automobile braking. In addition, the carbon ceramic material has high hardness and very strong wear resistance. The carbon ceramic brake disc prepared using this carbon ceramic material has a long service life of more than 500,000 kilometers.

[0069] The technical solutions of the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention, but they should not be understood as limiting the scope of protection of the present invention.

[0070] Example 1

[0071] The long carbon fiber filaments were impregnated with a phenolic resin solution having a mass concentration of 50% for 60 seconds, dried at 75°C for 15 minutes, and cut with aluminum alloy cutting scissors to obtain carbon fiber filaments with a length of 10 mm, a width of 5 mm, and a thickness of 0.7 mm. 40% of the above carbon fiber filaments were mixed with 20% carbon powder, 20% phenolic resin, and 20% silicon carbide powder, based on the mass percentage. The mixture was placed in a hot pressing mold and hot pressed at 150°C and 30 MPa for 3 hours to obtain a carbon-carbon friction plate with an inverted trapezoidal structure on one side and a planar structure on the other side.

[0072] The carbon-carbon friction plate was ground with a grinder until the surface runout was less than 0.1 mm, and then carbonized at 800° C. for 72 h to obtain a carbonized friction plate. The carbonized friction plate with a flat surface was placed on a graphite plate with silicon powder (the thickness of the silicon powder was 3 mm), and the whole was placed in a sealed high-temperature furnace for 35 h, and then heated to 1700° C. for ceramicization to obtain a carbon-ceramic friction plate (such as Figure 1 shown);

[0073] The two carbon ceramic friction plates are ground with a grinder until the surface runout is less than 0.1 mm, and then fixed in a fixed mold and fixed on a die-casting device so that the sides with the inverted trapezoidal structure face each other to form a pouring space. Semi-solid aluminum alloy is poured into the pouring space. After die-casting at 740°C and 90T for 300s, the obtained carbon ceramic brake disc blank is ground with a grinder until the surface runout is less than 0.1 mm to obtain a carbon ceramic brake disc (such as Figures 2-4 shown).

[0074] Examples 2-3

[0075] The differences from Example 1 are shown in Table 1, and the rest of the contents are consistent with Example 1.

[0076] Table 1 Parameter differences between Examples 1 to 3

[0077]

[0078] Comparative Example 1

[0079] A grey cast iron brake disc is used as a comparative example, and the type of grey cast iron is GG-20.

[0080] Comparison of physical and chemical properties tests

[0081] (1) The performance of the carbon ceramic brake discs prepared in Examples 1 to 3 and the gray cast iron brake disc of Comparative Example 1 were tested. The results are shown in Table 2.

[0082] Table 2 Performance test results of the carbon ceramic brake discs prepared in Examples 1 to 3 and the gray cast iron brake disc of Comparative Example 1

[0083]

[0084] As can be seen from Table 2, under the same volume, due to the low density, the weight of each embodiment is only about 1 / 3 of that of the comparative example, which greatly reduces the weight of the product and achieves the purpose of lightweighting; due to the improvement of materials, the tensile strength and bending strength of the product are better than those of comparative example 1; the operating temperature of the products of each embodiment is much higher than that of comparative example 1, which can meet the extreme high temperature operating conditions; and the service life is also greatly increased.

[0085] (2) The carbon ceramic brake discs prepared in Examples 1 to 3 and the gray cast iron brake disc of Comparative Example 1 were subjected to bench test items. The tests were conducted using the J2522 test standard. The results are shown in Table 3.

[0086] Table 3 Bench test results of the carbon ceramic brake discs prepared in Examples 1 to 3 and the gray cast iron brake disc of Comparative Example 1

[0087]

[0088]

[0089] As can be seen from Table 3, the µF1 value of Fade1 in the Example test, 0.32, is significantly higher than the 0.24 of Comparative Example 1, indicating that the carbon-ceramic brake disc prepared by the present invention performs better in high-temperature fade. The µF1 of Fade1 of the carbon-ceramic brake disc prepared by the present invention is more stable than the µF2 of Fade2, meaning that it will perform better in use. The disc wear data shows that the carbon-ceramic brake disc prepared by the present invention has almost zero wear in one cycle test, while the thickness of the gray cast iron brake disc of Comparative Example 1 has wear of 0.23 mm. This shows that the carbon-ceramic brake disc prepared by the present invention has better high-temperature fade performance, usage performance, and wear performance than the gray cast iron brake disc of Comparative Example 1.

[0090] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention rather than all the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the scope of protection of the present invention.

Claims

1. A carbon ceramic brake disc, characterized in that: It includes a first carbon ceramic friction plate, an aluminum alloy, and a second carbon ceramic friction plate which are sequentially combined into a sandwich structure; One side of the first carbon ceramic friction plate and the second carbon ceramic friction plate has an inverted trapezoidal structure and the other side has a flat structure; The first carbon ceramic friction plate and the second carbon ceramic friction plate have opposite sides with an inverted trapezoidal structure, and the middle space formed therein is filled with aluminum alloy; The first carbon ceramic friction plate and the second carbon ceramic friction plate are made of carbon ceramic material, and the raw materials for preparing the carbon ceramic material are composed of a mixture and silicon powder; The mixture is composed of the following raw materials in terms of mass percentage: 30-50% carbon fiber filaments, 10-30% carbon powder, 10-30% phenolic resin and 20-30% silicon carbide powder; The method for preparing the carbon ceramic material comprises the following steps: The mixed material is subjected to hot pressing and carbonization treatment in sequence to obtain a carbonized material; placing the carbonized material on a graphite plate paved with silicon powder and performing a ceramic treatment to obtain a carbon ceramic material; The carbon fiber filaments have a length of 9 to 11 mm and a width of 4 to 6 mm; The hot pressing temperature is 145-155°C, the pressure is 30 MPa, and the heat preservation and pressure holding time is 3 hours; The carbonization temperature is 800°C and the holding time is 72h; The ceramic treatment is to raise the temperature to 1690-1710° C. within 30-35 hours.

2. The method for preparing the carbon ceramic brake disc according to claim 1, characterized in that: The following steps are involved: After the first machining, the first carbon ceramic friction plate and the second carbon ceramic friction plate are fixed in a fixed mold so that the sides with the inverted trapezoidal structure are opposite to each other to form a pouring space. Semi-solid aluminum alloy is injected into the pouring space, and after die-casting, a second machining is performed to obtain a carbon ceramic brake disc.

3. The preparation method according to claim 2, characterized in that The die-casting temperature is 720-740° C., the pressure is 80-100° C., and the heat and pressure holding time is 180-600 seconds.

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