Ceramic slurry for preparing 3D printed composite brake disc and method thereof

Abstract

The application provides a kind of ceramic slurry for preparing 3D printing composite brake disc and a method thereof, the ceramic slurry comprises the following material composition by weight parts: alumina powder: 30-40 parts, silicon carbide powder: 60-70 parts, kaolin: 10-20 parts, binder: 2-6 parts, deionized water: 55-75 parts, the above-mentioned materials are mixed in the weight ratio, stirred uniformly, and the ceramic slurry is prepared. The prepared ceramic slurry is suitable for 3D printing process, and a brake disc with high SiC content, high wear resistance and heat resistance, and light weight can be prepared to meet the requirements of new energy vehicle braking system.

Description

Technical Field

[0001] This invention relates to the field of brake disc material technology, and in particular to a method for preparing a 3D printed composite brake disc. Background Technology

[0002] With the rapid development of the global new energy vehicle industry, my country, as a major producer and seller of new energy vehicles, saw its production and sales volume exceed 13 million units in 2024, with a market penetration rate of over 40%. Range and overall performance have become the core concerns of consumers. As a core component of the vehicle's braking system, the brake disc's performance directly affects the vehicle's driving safety and is one of the keys to improving vehicle performance.

[0003] Aluminum-based composite brake discs have rapidly gained popularity due to their lightweight, high thermal conductivity, and wear and heat resistance. However, existing manufacturing processes for aluminum-based silicon carbide brake discs still face numerous technical bottlenecks, limiting their large-scale application and performance improvement. Currently, the commonly used method is stir casting: its drawback lies in the poor compatibility between silicon carbide (SiC) particles and the aluminum matrix, making it difficult to increase the SiC content, typically only reaching 15%-25%, resulting in casting defects such as porosity, inclusions, and shrinkage cavities, thus failing to guarantee product consistency. Powder metallurgy: this process prepares composite brake discs through powder mixing, pressing, and sintering, but the process is cumbersome and costly. Furthermore, the sintering process requires a sealed, vacuum, or protective atmosphere, making process control difficult, and improper sintering temperature selection can easily lead to material segregation. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a method for preparing a 3D printed composite brake disc.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a ceramic slurry for preparing 3D printed composite brake discs, comprising the following materials by weight: alumina powder: 30-40 parts, silicon carbide powder: 60-70 parts, kaolin: 10-20 parts, binder: 2-6 parts, deionized water: 55-75 parts. The above materials are mixed according to the weight ratio and stirred evenly to obtain the ceramic slurry.

[0006] In the first aspect, the ceramic slurry further includes a rheology modifier, which includes modified cellulose, and the amount of modified cellulose added is 1.5-2 parts.

[0007] In the first aspect, the ceramic slurry further includes a dispersant, which is ammonium polyacrylate, and the amount added is 0.05%-0.07% of the total mass of the alumina powder, silicon carbide powder and kaolin.

[0008] The second aspect of the present invention provides a method for preparing a 3D printed composite brake disc from ceramic slurry, comprising: step (1), 3D printing: using a medium-sized 3D ceramic printer to print the ceramic slurry into a hollow bracket; step (2), sintering: after drying the hollow bracket, placing it in a sintering furnace for sintering, and then naturally cooling it for later use; step (3), casting: placing the hollow bracket in a 500°C holding furnace for 1 hour, then placing the hollow bracket in a mold, injecting molten aluminum into the hollow bracket through a low-pressure high-strength process, and obtaining a brake disc blank after cooling; step (4), machining: removing the riser of the center hole of the brake disc blank, rough machining the ventilation channel, mounting hole and center hole of the brake disc blank, and fine grinding the friction surface of the brake disc blank to obtain the 3D printed composite brake disc.

[0009] In the second aspect, the hollow support in step (1) is a cyclone ventilation duct structure, and the wall thickness of the cyclone ventilation duct is 2.5mm.

[0010] In the second aspect, the sintering temperature in step (2) is 1500-1650℃, and the Mohs hardness of the hollow bracket after sintering reaches 9-9.5.

[0011] In the second aspect, the molten aluminum injected in step (3) is a high-performance heat-resistant aluminum alloy melt.

[0012] In the second aspect, the method further includes step (5), testing: performing dynamic balance testing, physical property testing and bench testing on the finished brake disc blank.

[0013] In the second aspect, the method further includes step (6), coating: applying one or more coating layers to the surface of the brake disc blank to complete the preparation of the 3D printed composite brake disc.

[0014] In the second aspect, the coating in step (6) is selected from one or more of ceramic coatings and graphene-modified coatings.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: This application provides a ceramic slurry for preparing 3D printed composite brake discs, comprising the following components by weight: alumina powder: 30-40 parts, silicon carbide powder: 60-70 parts, kaolin: 10-20 parts, binder: 2-6 parts, and deionized water: 55-75 parts. The ceramic slurry is prepared by mixing and stirring the above components in the specified weight ratio. The ceramic slurry prepared by this invention, using a specific ratio of the above components, retains the high hardness of the composite powder while also possessing molding stability and ease of operation. The silicon carbide content is higher than that of aluminum-based composite materials prepared by traditional stirring casting methods. During braking, it effectively resists frictional wear, reduces the wear rate of the brake disc, extends its service life, and does not produce fine cracks under prolonged high-temperature friction, thus enhancing safety. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Legend: Figure 1 This is a front view diagram of the present invention; Figure 2 This is a left-side view diagram of the mechanism of the present invention; In the diagram: 1. Brake disc body; 2. Mounting hole; 3. Center hole; 4. Ventilation duct. Detailed Implementation

[0018] The present invention will be described in detail below with reference to specific embodiments and examples, thereby making its advantages and various effects more clearly apparent. Those skilled in the art should understand that these specific embodiments and examples are for illustrative purposes only and are not intended to limit the invention.

[0019] This invention provides a ceramic slurry for preparing 3D printed composite brake discs, comprising the following materials by weight: alumina powder: 30-40 parts, silicon carbide powder: 60-70 parts, kaolin: 10-20 parts, binder: 2-6 parts, deionized water: 55-75 parts. The above materials are mixed in the indicated weight proportions and stirred evenly to obtain the ceramic slurry.

[0020] Specifically, this application provides a ceramic slurry for preparing 3D printed composite brake discs, comprising the following components by weight: alumina powder: 30-40 parts, silicon carbide powder: 60-70 parts, kaolin: 10-20 parts, binder: 2-6 parts, and deionized water: 55-75 parts. The ceramic slurry is prepared by mixing and stirring the above components in the specified weight ratio. The ceramic slurry prepared by this invention, using a specific ratio of the above components, retains the high hardness of the composite powder while also possessing molding stability and ease of operation. The silicon carbide content is higher than that of aluminum-based composite materials prepared by traditional stirring casting methods (SiC content is typically around 25%). During braking, it effectively resists frictional wear, reduces the wear rate of the brake disc, extends its service life, and does not produce fine cracks under prolonged high-temperature friction, thus ensuring greater safety.

[0021] In some possible implementations, the ceramic slurry also includes a rheology modifier, which includes modified cellulose, with an addition amount of 1.5-2 parts.

[0022] Specifically, the modified cellulose is preferably hydroxypropyl methylcellulose. Adding 1.5-2 parts of hydroxypropyl methylcellulose allows for full hydration in the aqueous phase, providing sufficient yield stress to resist gravity during printing and ensuring that the printed hollow support does not flow or collapse.

[0023] In some possible implementations, the ceramic slurry also includes a dispersant, which is an ammonium polyacrylate salt, added at an amount of 0.05%-0.07% of the total mass of alumina powder, silicon carbide powder and kaolin.

[0024] Specifically, adding the aforementioned proportion of ammonium polyacrylate allows its molecules to adsorb onto the surface of ceramic powder particles, preventing particle agglomeration and promoting uniform dispersion in the slurry. This improves its flowability and printability, and further ensures the uniformity of the composition and structure of the ceramic skeleton at the microscale after printing, thus guaranteeing the stability of the brake disc's mechanical properties and wear resistance.

[0025] Based on a general inventive concept, the present invention also provides a method for preparing 3D printed composite brake discs using ceramic slurry, including: step (1), 3D printing: using a medium-sized 3D ceramic printer, using Sic direct writing technology, the skeleton structure adopts Sic truss lattice structure to ensure that the slurry is deposited uniformly layer by layer and the interlayer bonding is tight, and the ceramic slurry is printed into a hollow bracket. The hollow bracket is a cyclone ventilation channel 4 structure. The wall thickness of the cyclone ventilation channel 4 is 2.5mm to avoid the wall thickness being too thin, which would cause brittle fracture after sintering, or the wall thickness being too thick, which would increase the overall weight of the brake disc and hinder heat dissipation.

[0026] Step (2), sintering: Place the hollow bracket in a constant temperature oven at 60-80℃ and dry for 3-4 hours. After drying, place it in a sintering furnace for sintering. After natural cooling, it is ready for use. The sintering temperature is 1500-1650℃. After sintering, the Mohs hardness of the hollow bracket reaches 9-9.5.

[0027] Step (3), casting: The hollow bracket is placed in a 500℃ heat preservation furnace for 1 hour. The purpose of heat preservation is to eliminate the temperature difference stress between the ceramic bracket and the high temperature aluminum liquid, and to avoid the ceramic bracket from cracking due to thermal shock when the aluminum liquid is injected. Then the hollow bracket is placed in the mold, and aluminum liquid is injected into the hollow bracket through a low pressure and high strength process. After cooling, the brake disc blank is obtained.

[0028] Step (4), machining: The casting riser at the center hole 3 of the brake disc blank is removed by CNC lathe to ensure the accuracy of the blank's reference dimensions; then the cyclone ventilation channel 4, mounting hole 2 and center hole 3 of the blank are rough machined by milling machine, with a dimensional tolerance of ±0.10mm; finally, the friction surface of the brake disc is finely ground by grinding machine to ensure the flatness and surface roughness of the friction surface, and to meet the contact stability requirements during assembly and braking.

[0029] Step (5), testing: Perform dynamic balancing test (G2.5 grade balancing quality to ensure that the brake disc has no obvious wobble or vibration when the speed is ≥3000r / min), physical property test (to ensure that the hardness of the ceramic / aluminum composite structure is ≥9.0 Mohs hardness, the friction coefficient at room temperature is 0.35-0.45, and the friction coefficient attenuation rate at 400℃ is ≤10%) and bench test (to test the maximum braking temperature of the brake disc is ≤400℃, the thermal deformation of a single braking is ≤0.01mm, and there are no cracks, deformations and obvious wear failures after 50 consecutive braking cycles). Step (6), Coating: Apply one or more of ceramic coatings and graphene modified coatings to the surface of the brake disc blank to complete the preparation of the 3D printed composite brake disc. Specifically, the use of ceramic coatings can further improve the wear resistance of the brake disc friction surface and reduce the wear rate; graphene-modified coatings can improve the thermal conductivity of the brake disc, accelerate the dissipation of heat during braking, and avoid high-temperature thermal fade; and a multi-coating composite structure is adopted to balance wear resistance and heat dissipation performance.

[0030] Example 1 This embodiment provides a ceramic slurry for preparing 3D printed composite brake discs and a preparation method thereof. The ceramic slurry comprises the following components by weight: 35 parts alumina powder, 65 parts silicon carbide powder, 15 parts kaolin, 2 parts binder, 1.5 parts rheology modifier, and 55 parts deionized water. The binder is polyvinyl alcohol, the rheology modifier is hydroxypropyl methylcellulose, and the dispersant is ammonium polyacrylate (added at 0.05% of the total mass of alumina powder, silicon carbide powder, and kaolin).

[0031] The specific steps for fabricating a 3D-printed composite brake disc are as follows: Pulping: Weigh alumina powder, silicon carbide powder, and kaolin according to the weight parts, add them to deionized water, and stir at 500 r / min for 30 min at room temperature; then add ammonium polyacrylate and continue stirring for 20 min; then add polyvinyl alcohol and hydroxypropyl methylcellulose, heat to 40℃, and continue stirring at 800 r / min for 60 min to obtain ceramic slurry; 3D printing: A medium-sized 3D ceramic printer is used, employing SiC direct writing technology. The skeleton structure adopts a SiC truss lattice structure to print ceramic slurry into a hollow support structure of cyclone ventilation duct 4, with a wall thickness of 2.5mm. Drying and sintering: The hollow support was placed in a 60℃ oven and dried for 4 hours until the moisture content was ≤1%; then it was placed in a sintering furnace, heated to 1500℃ and sintered for 2 hours, and then naturally cooled to room temperature. The Mohs hardness of the support after sintering was measured to be 9.0. Insulating casting: The sintered ceramic support is placed in a 500℃ holding furnace for 1 hour, then removed and placed into a mold. High-performance heat-resistant aluminum alloy melt is injected through a low-pressure high-strength process. After cooling to room temperature, a brake disc blank is obtained. Machining: The casting riser at the center hole 3 of the brake disc blank is removed using a CNC lathe to ensure the accuracy of the blank's reference dimensions; then, the cyclone ventilation channel 4, mounting hole 2 and center hole 3 of the blank are roughly machined using a milling machine with a dimensional tolerance of ±0.10mm; finally, the friction surface of the brake disc is finely ground using a grinding machine to ensure the flatness and surface roughness of the friction surface, meeting the contact stability requirements during assembly and braking. Testing and experimentation: Dynamic balancing, physical property testing and bench testing were conducted on the precision-machined brake discs; the highest braking temperature of the brake discs was measured to be 323℃, the thermal deformation during a single braking event was 0.003mm, the thermal deformation during continuous braking was 0.004mm, and no cracks, deformation or other failure phenomena were observed. Coating: A ceramic coating with a thickness of 80μm is sprayed onto the surface of the brake disc to obtain the finished 3D printed composite brake disc.

[0032] Testing revealed that the SiC mass fraction of the composite brake disc ceramic skeleton material prepared in this embodiment was approximately 56.5%, with a density of 2.82 g / cm³, representing a 61% weight reduction compared to a traditional cast iron brake disc of the same size (density 7.20 g / cm³). The coefficient of friction remained stable at 0.37, and the wear rate was 0.25 × 10⁻⁻⁻⁻⁶. 7 cm³ / (N·m).

[0033] Example 2 This embodiment provides a ceramic slurry for preparing 3D printed composite brake discs and a preparation method thereof. The ceramic slurry, by weight, includes the following components: 30 parts alumina powder, 70 parts silicon carbide powder, 12 parts kaolin, 3 parts binder (polyvinyl alcohol), 2 parts rheology modifier (hydroxypropyl methylcellulose), and 60 parts deionized water; the dispersant is ammonium polyacrylate (added at 0.07% of the total mass of alumina powder, silicon carbide powder, and kaolin).

[0034] The specific steps for fabricating a 3D-printed composite brake disc are as follows: Pulping: Weigh alumina powder, silicon carbide powder, and kaolin according to the weight parts, add them to deionized water, and stir at 500 r / min for 30 min at room temperature; then add ammonium polyacrylate and continue stirring for 20 min; then add polyvinyl alcohol and hydroxypropyl methylcellulose, heat to 40℃, and continue stirring at 800 r / min for 60 min to obtain ceramic slurry; 3D printing: A medium-sized 3D ceramic printer is used, employing direct writing technology. The skeleton structure adopts a SiC truss lattice structure to print ceramic slurry into a hollow support structure of cyclone ventilation duct 4, with a wall thickness of 2.5mm. Drying and sintering: The hollow support was placed in a 60℃ oven and dried for 4 hours until the moisture content was ≤1%; then it was placed in a sintering furnace and heated to 1650℃ for 2 hours, and then naturally cooled to room temperature. The Mohs hardness of the support after sintering was measured to be 9.3. Insulating casting: The sintered ceramic support is placed in a 500℃ holding furnace for 1 hour, then removed and placed into a mold. High-performance heat-resistant aluminum alloy melt is injected through a low-pressure high-strength process. After cooling to room temperature, a brake disc blank is obtained. Machining: The casting riser at the center hole 3 of the brake disc blank is removed by a CNC lathe to ensure the accuracy of the blank's reference dimensions; then, the cyclone ventilation channel 4, mounting hole 2 and center hole 3 of the blank are roughly machined by a milling machine with a dimensional tolerance of ±0.10mm; finally, the friction surface of the brake disc is finely ground by a grinding machine. Testing and experimentation: Dynamic balancing, physical property testing and bench testing were conducted on the precision-machined brake discs; the highest braking temperature of the brake discs was measured to be 315℃, the thermal deformation during a single braking event was 0.002mm, the thermal deformation during continuous braking was 0.003mm, and there were no failure phenomena such as cracks or deformation. Coating: A ceramic coating with a thickness of 80μm is sprayed onto the surface of the brake disc to obtain the finished 3D printed composite brake disc.

[0035] Testing revealed that the SiC mass fraction of the composite brake disc ceramic skeleton material prepared in this embodiment was approximately 62%, with a density of 2.80 g / cm³. This represents a 61.5% weight reduction compared to a traditional cast iron brake disc of the same size. The coefficient of friction remained stable at 0.39, and the wear rate was 0.22 × 10⁻⁻⁻⁻⁶. 7 cm³ / (N·m).

[0036] Example 3 This embodiment provides a ceramic slurry for preparing 3D printed composite brake discs and a preparation method thereof. The ceramic slurry, by weight, comprises the following components: 40 parts alumina powder, 60 parts silicon carbide powder, 18 parts kaolin, 2 parts binder (polyvinyl alcohol), 1.5 parts rheology modifier (hydroxypropyl methylcellulose), and 70 parts deionized water; the dispersant is ammonium polyacrylate (added at 0.05% of the total mass of alumina powder, silicon carbide powder, and kaolin).

[0037] The specific steps for fabricating a 3D-printed composite brake disc are as follows: Pulping: Weigh alumina powder, silicon carbide powder, and kaolin according to the weight parts, add them to deionized water, and stir at 500 r / min for 30 min at room temperature; then add ammonium polyacrylate and continue stirring for 20 min; then add polyvinyl alcohol and hydroxypropyl methylcellulose, heat to 40℃, and continue stirring at 800 r / min for 60 min to obtain ceramic slurry; 3D printing: A medium-sized 3D ceramic printer is used, employing direct writing technology. The skeleton structure adopts a SiC truss lattice structure to print ceramic slurry into a hollow support structure of cyclone ventilation duct 4, with a wall thickness of 2.5mm. Drying and sintering: The hollow support was placed in a 60℃ oven and dried for 4 hours until the moisture content was ≤1%; then it was placed in a sintering furnace and heated to 1550℃ for 2 hours, and then naturally cooled to room temperature. The Mohs hardness of the support after sintering was measured to be 9.0. Insulating casting: The sintered ceramic support is placed in a 500℃ holding furnace for 1 hour, then removed and placed into a mold. High-performance heat-resistant aluminum alloy melt is injected through a low-pressure high-strength process. After cooling to room temperature, a brake disc blank is obtained. Machining: The casting riser at the center hole 3 of the brake disc blank is removed by a CNC lathe to ensure the accuracy of the blank's reference dimensions; then, the cyclone ventilation channel 4, mounting hole 2 and center hole 3 of the blank are roughly machined by a milling machine with a dimensional tolerance of ±0.10mm; finally, the friction surface of the brake disc is finely ground by a grinding machine. Testing and experimentation: Dynamic balancing, physical property testing and bench testing were conducted on the precision-machined brake discs; the highest braking temperature of the brake discs was measured to be 335℃, the thermal deformation during a single braking event was 0.003mm, the thermal deformation during continuous braking was 0.004mm, and no cracks, deformation or other failure phenomena were observed. Coating: A graphene-modified ceramic coating with a thickness of 80μm is sprayed onto the surface of the brake disc to obtain the finished 3D printed composite brake disc.

[0038] Testing revealed that the SiC mass fraction of the composite brake disc ceramic skeleton material prepared in this embodiment was approximately 50%, with a density of 2.85 g / cm³. This represents a 60.5% weight reduction compared to a traditional cast iron brake disc of the same size. The coefficient of friction remained stable at 0.36, and the wear rate was 0.28 × 10⁻⁻⁻⁻⁶. 7 cm³ / (N·m).

[0039] Comparative Example 1 This comparative example adopts the technical solution of Example 1. The content of silicon carbide powder in the ceramic slurry formula is set to 50 parts, and the content of alumina powder is adjusted to 50 parts accordingly; the remaining components and preparation steps are the same as in Example 1.

[0040] During the 3D printing process, the slurry flowability and molding stability were not significantly different from those in Example 1, and the printing of the cyclone-type ventilation channel 4 hollow support was successfully completed, with an intact green body structure. However, due to the reduced silicon carbide content in the formulation, the microstructure and mechanical properties of the ceramic skeleton changed after sintering. Testing showed that the Mohs hardness of the sintered support was 8.5, lower than 9.0 in Example 1. This indicates that the hardness and rigidity of the ceramic skeleton itself weakened due to the decreased proportion of the hard phase SiC.

[0041] In the subsequent aluminum alloy melting and casting process, the distribution density of the wear-resistant reinforcing phase (SiC) in the ceramic skeleton decreases, which leads to a decrease in the stability and overall load-bearing capacity of the composite material when subjected to shear force.

[0042] Testing revealed that the composite brake disc prepared in this comparative example contained approximately 43.5% SiC ceramic skeleton material by mass, with a density of 2.95 g / cm³, representing a weight reduction of approximately 59% compared to traditional cast iron brake discs. However, in the same bench test, its performance was inferior to Example 1: the maximum braking temperature increased to 358℃; thermal stability deteriorated, with a single braking thermal deformation of 0.006 mm; and wear resistance decreased, with a wear rate reaching 0.38 × 10⁻⁻⁻⁶. 7 cm³ / (N·m). The results show that when the silicon carbide powder content is reduced to 50 parts, although the basic composite structure can be maintained, the key performance of the product has been significantly reduced, proving the necessity of the preferred formulation range of the present invention for obtaining comprehensive performance.

[0043] Comparative Analysis of Examples and Comparative Cases The test results of Examples 1-3 were compared with those of Comparative Example 1. Examples 1-3 of this invention are characterized by using a ceramic powder formulation with high silicon carbide and low alumina ratio (SiC: 60-70 parts, alumina: 30-40 parts). This formulation uses 3D printing direct-write molding technology to construct a hollow ceramic preform. Subsequently, an aluminum alloy infiltration process is used to form a metal matrix composite material with a ceramic network. While Comparative Example 1 uses the same 3D printing and infiltration process, its formulation reduces the SiC content to 50 parts and increases the alumina ratio, directly leading to a decrease in the bulk density of the hard, wear-resistant phase in the ceramic skeleton.

[0044] Example 1 Example 2 Example 3 Comparative Example 1 Core formula proportions (parts by weight) Alumina 35 + SiC 65 + Kaolin 15 Alumina 30 + SiC 70 + Kaolin 12 Alumina 40 + SiC 60 + Kaolin 18 Alumina 50 + SiC 50 + Kaolin 15 SiC mass fraction in ceramic framework (%) 56.5 62 50 43.5 Sintering temperature (°C) 1500 1650 1550 1500 Mohs hardness of the sintered support 9.0 9.3 9.0 8.5 Density of composite brake discs (g / cm³) 2.82 2.80 2.85 2.95 Weight loss rate (%) 61 61.5 60.5 59 Maximum braking temperature (°C) 323 315 335 358 Thermal deformation during a single braking event (mm) 0.003 0.002 0.003 0.006 coefficient of friction 0.37 0.39 0.36 - <![CDATA[Wear rate (×10⁻ 7 cm³ / (N·m))]]> 0.25 0.22 0.28 0.38 Table 1 In summary, this invention, through the proportioning of ceramic slurry and the synergistic combination of 3D printing structural design and fabrication process, successfully solves the problem of reduced wear resistance caused by insufficient SiC content in existing technologies. The resulting composite brake disc is superior to products with low SiC content in terms of SiC content, wear resistance, and heat dissipation and temperature rise, thus meeting the requirements of braking systems for new energy vehicles.

[0045] Finally, it should be noted that the above embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the scope of the technology disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention. All should be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

[0046] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A ceramic slurry for preparing 3D printed composite brake discs, characterized in that, The ceramic slurry comprises the following materials in parts by weight: alumina powder: 30-40 parts, silicon carbide powder: 60-70 parts, kaolin: 10-20 parts, binder: 2-6 parts, and deionized water: 55-75 parts. The above materials are mixed in the proportions of the above weight parts and stirred evenly to obtain the ceramic slurry.

2. The ceramic slurry for preparing 3D printed composite brake discs according to claim 1, wherein the ceramic slurry further comprises a rheology modifier, wherein the rheology modifier comprises modified cellulose, and the amount of modified cellulose added is 1.5-2 parts.

3. The ceramic slurry for preparing 3D printed composite brake discs according to claim 1, characterized in that, The ceramic slurry also includes a dispersant, which is ammonium polyacrylate, and the amount added is 0.05%-0.07% of the total mass of the alumina powder, silicon carbide powder and kaolin.

4. A method for preparing a 3D-printed composite brake disc using the ceramic slurry according to any one of claims 1-3, characterized in that, include: Step (1), 3D printing: Using a medium-sized 3D ceramic printer, the ceramic slurry is printed into a hollow bracket; Step (2), sintering: After the hollow support is dried, it is placed in a sintering furnace for sintering and then cooled naturally for later use; Step (3), casting: The hollow bracket is placed in a 500℃ heat preservation furnace for 1 hour, and then the hollow bracket is placed in a mold. Molten aluminum is injected into the hollow bracket through a low-pressure high-strength process. After cooling, a brake disc blank is obtained. Step (4), machining: remove the riser of the center hole of the brake disc blank, perform rough machining on the ventilation channel, mounting hole and center hole of the brake disc blank, and perform fine grinding on the friction surface of the brake disc blank to obtain the 3D printed composite brake disc.

5. The method for preparing 3D printed composite brake discs using ceramic slurry according to claim 4, characterized in that, The hollow support in step (1) is a cyclone ventilation duct structure with a wall thickness of 2.5mm.

6. The method for preparing 3D printed composite brake discs using ceramic slurry according to claim 4, characterized in that, In step (2), the sintering temperature is 1500-1650℃, and the Mohs hardness of the hollow bracket after sintering reaches 9-9.

5.

7. The method for preparing 3D printed composite brake discs using ceramic slurry according to claim 4, characterized in that, The molten aluminum injected in step (3) is a high-performance heat-resistant aluminum alloy melt.

8. The method for preparing 3D printed composite brake discs using ceramic slurry according to claim 4, characterized in that, The method also includes step (5), testing: dynamic balance test, physical property test and bench test on the finished brake disc blank.

9. The method for preparing 3D printed composite brake discs using ceramic slurry according to claim 4, characterized in that, The method further includes step (6), coating: applying one or more coating layers to the surface of the brake disc blank to complete the preparation of the 3D printed composite brake disc.

10. The method for preparing 3D printed composite brake discs using ceramic slurry according to claim 9, characterized in that, The coating in step (6) is selected from one or more of ceramic coatings and graphene modified coatings.

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