Al-based silicon carbide composite material component and preparation method thereof

Abstract

The invention discloses a method for 3D printing of an Al-based silicon carbide composite material component, which comprises the following steps: S11, selecting silicon carbide powder with the particle size of 50-200 microns as a base material, and forming a green body with a required structure by adopting an additive manufacturing technology; s12, dipping the green body prepared in the previous step in a silica sol solution or silicone oil for dipping treatment, and curing to form silicon dioxide on the surface of the green body, or oxidizing the green body in an oxygen-containing atmosphere at 800-1000 DEG C for 1-2 hours to form silicon dioxide on the surface of the green body; and S13, the blank with the surface coated with the silicon dioxide is subjected to aluminizing-magnesium alloy treatment, the Al-based silicon carbide composite material component is obtained, and the content of magnesium in the alloy is larger than or equal to 10 wt%. According to the method, the Al-based silicon carbide composite material component is prepared through the additive technology, and the manufacturing problem of thin-wall components with complex structures can be solved.

Description

Technical Field

[0001] This invention relates to the field of advanced manufacturing additive manufacturing technology, specifically to an Al-based silicon carbide composite material component and its preparation method. Background Technology

[0002] Particle-reinforced aluminum matrix composites are among the most studied and widely used composite materials. High volume fraction SiC p / Al composite materials combine the properties of SiC particles and aluminum, possessing excellent physical and mechanical properties. They exhibit specific strength 2-3 times higher than titanium alloys, superior dimensional stability compared to beryllium, a low coefficient of linear expansion comparable to steel, titanium alloys, and even ceramic substrates, thermal conductivity comparable to beryllium and silicon carbide ceramics, yield strength far exceeding that of aluminum alloys, and fracture toughness comparable to cast aluminum alloys. Coupled with low raw material costs, these properties make them one of the most ideal electronic packaging materials. Furthermore, as structural materials, they have significant applications in aerospace, high-speed rail, and defense. For example, due to the requirements of long-distance flight and successful orbital insertion and landing, the materials for Mars rovers must first be "light," with weight control measured in grams (g); secondly, they must be "strong" to meet load-bearing and wear-resistant requirements; and thirdly, they must be "tough" to withstand the complex impacts and collisions faced by the rover on the unknown Martian surface without damage. SiC... p The Al composite material underwent rigorous ground testing, and all data indicate that it meets the application requirements.

[0003] Currently, it is used to prepare high volume fraction SiC p The main methods for preparing Al composite materials include extrusion casting and colloidal forming-melt infiltration. However, these methods have obvious advantages in preparing composite materials with simple structures, but there are certain difficulties in preparing complex structures and thin-walled components. Summary of the Invention

[0004] Traditional methods for preparing large and complex Al-based silicon carbide composite materials present difficulties, requiring further processing into complex shapes after molding, which hinders large-scale industrial application and promotion. This invention provides a 3D printing method for Al-based silicon carbide composite materials, which can directly prepare complex structural and thin-walled complex Al-based silicon carbide composite material components.

[0005] This invention provides a method for 3D printing Al-based silicon carbide composite material components, comprising: S11, selecting silicon carbide powder with a particle size of 50-200μm as the matrix material, and forming a blank with the desired structure using additive manufacturing technology; S12, immersing the blank obtained in the previous step in a silica sol solution or silicone oil for impregnation treatment and then curing it to form silicon dioxide on the surface of the blank, or oxidizing the blank at 800℃-1000℃ for 1-2 hours in an oxygen-containing atmosphere to form silicon dioxide on the surface of the blank; S13, subjecting the blank coated with silicon dioxide to aluminizing-magnesium alloy treatment to obtain the Al-based silicon carbide composite material component, wherein the magnesium content in the alloy is greater than or equal to 10wt%.

[0006] According to one embodiment of the present invention, before step S12, the method further includes: S12a, performing a densification treatment on the blank obtained in step S11, wherein the densification treatment is performed by chemical vapor infiltration or precursor impregnation pyrolysis.

[0007] According to another embodiment of the present invention, the chemical vapor infiltration densification treatment is as follows: the flow rate of the silicon-based gas is 200-300 mL / min, the pressure is controlled at 100 torr-300 torr, the high temperature is 1000-1300℃, and the densification time is 1-10 days; preferably, the silicon-based gas is one or more of trichloromethylsilane, dimethyldichlorosilane, and methyldichlorosilane.

[0008] According to another embodiment of the present invention, the precursor impregnation pyrolysis densification treatment is as follows: the preform obtained in step S11 is impregnated and crosslinked in a precursor polymer solution and then pyrolyzed at high temperature; the impregnation-curing-pyrolysis process is repeated 1-3 times; wherein the impregnation and crosslinking curing time is 2-12 h; the pyrolysis temperature is 900-1200℃ and the time is 1-2 h.

[0009] According to another embodiment of the present invention, in step S12, the conditions for curing the preform after impregnation in silica sol solution or silicone oil are: vacuuming to below 1000 Pa, applying a pressure of 0.2-2 MPa, and curing at 60-220°C.

[0010] This invention also provides a method for 3D printing Al-based silicon carbide composite material components, comprising: S21, selecting silicon carbide powder with a particle size of 50-200 μm, and oxidizing the silicon carbide powder in an oxygen-containing atmosphere at 800℃-1100℃ for 1-2 hours to form silicon dioxide on the surface of the silicon carbide powder; S22, using the silicon carbide powder treated in step S21 as a matrix material, forming a blank with the desired structure using additive manufacturing technology; S23, subjecting the blank obtained in step S22 to aluminizing-magnesium alloying treatment to obtain the Al-based silicon carbide composite material component, wherein the magnesium content in the alloy is greater than or equal to 10 wt%.

[0011] According to one embodiment of the present invention, the silicon carbide powder used in the above method is one or more of silicon carbide micro powder, chopped silicon carbide fiber, silicon carbide whisker and silicon carbide nanowire.

[0012] According to one embodiment of the present invention, the binder used in the additive manufacturing technology is one or more of phenolic resin, furan resin, polyvinyl alcohol, or polyvinyl butyral.

[0013] According to another embodiment of the present invention, the additive manufacturing technology in the above method is stereolithography, powder bed melting, material extrusion, directional energy deposition, adhesive spraying, or thin-film stacking.

[0014] According to another embodiment of the present invention, the aluminizing-magnesium alloy treatment is carried out under vacuum or a protective atmosphere, wherein the protective atmosphere is argon or nitrogen, the vacuum degree is 0 to 100 Pa, the aluminizing temperature is 800°C to 1100°C, and the aluminizing time is 0.5 h to 5 h.

[0015] According to another embodiment of the present invention, the porosity of the blank prepared in step S11 or step S21 is 20-80%.

[0016] The present invention also provides an Al-based silicon carbide composite material component prepared by the above method.

[0017] The method of this invention prepares Al-based silicon carbide composite material components using additive manufacturing technology, which can solve the manufacturing challenges of complex structures and thin-walled components. Furthermore, in this method, the surface of the silicon carbide particles undergoes oxidation treatment, resulting in a silicon dioxide oxide layer. This further improves the wettability with molten metal, and the magnesium metal can also participate in the reaction through the silicon dioxide to form a reactive bond, enhancing the mechanical properties of the composite material. Attached Figure Description

[0018] Figure 1 This is a flowchart illustrating one embodiment of the present invention.

[0019] Figure 2This is a flowchart illustrating another embodiment of the present invention.

[0020] Figure 3 This is a flowchart illustrating another embodiment of the present invention. Detailed Implementation

[0021] The present invention will now be described in detail with reference to specific embodiments.

[0022] like Figure 1 As shown, the method for 3D printing Al-based silicon carbide composite material components of the present invention includes: S11, selecting silicon carbide powder with a particle size of 50-200 μm as the matrix material, and forming a blank with the desired structure using additive manufacturing technology; S12, immersing the blank obtained in the previous step in a silica sol solution or silicone oil for impregnation treatment and then curing to form silica on the surface of the blank, or oxidizing the blank at 800℃-1000℃ in an oxygen-containing atmosphere for 1-2 hours to form silica on the surface of the blank; S13, subjecting the blank coated with silica to aluminizing-magnesium alloy treatment to obtain an Al-based silicon carbide composite material component, wherein the magnesium content in the alloy is greater than or equal to 10 wt%. In the method of the present invention, the surface of the silicon carbide particles is oxidized, and a layer of silica oxide is attached to the surface, which can further improve its wettability with the molten metal. Moreover, metallic magnesium can also participate in the reaction through silica to form a reaction bond, enhancing the mechanical properties of the composite material. The method of this invention employs additive manufacturing technology, which can solve the manufacturing challenges of complex structures and thin-walled components. Preferably, the magnesium content in the aluminum-magnesium alloy is below 15 wt%. This is because if the magnesium content exceeds 15 wt%, most of the Mg will volatilize after melting and will not remain in the component. Of course, aluminum-magnesium alloys with a magnesium content exceeding 15 wt% are also suitable for the method of this invention for 3D printing Al-based silicon carbide composite material components, but magnesium volatilization would result in unnecessary waste.

[0023] like Figure 2As shown, before step S12, the process may further include: S12a, which densifies the green body obtained in step S11 using chemical vapor infiltration (CVI) or precursor impregnation pyrolysis. CVI or precursor impregnation pyrolysis can be performed under conventional reaction conditions. For example, CVI densification may involve using at least one or more silicon-based ceramic media gases (i.e., silicon-based gases), which are then decomposed and polycondensed at high temperatures to transform the silicon-based gases into silicon carbide ceramics and deposited within the pores of the green body. CVI treatment can be performed in a chemical vapor deposition (CVD) apparatus. Specific reaction parameters are: silicon-based gas flow rate of 200-300 mL / min, pressure controlled at 100-300 torr, maximum temperature of 1000-1300℃, and densification time of 1-10 days. The silicon-based gas can be one or more of trichloromethylsilane (CH3SiCl3), dimethyldichlorosilane (CH3)2SiCl2, and methyldichlorosilane CH3SiHCl2.

[0024] The precursor impregnation-pyrolysis densification treatment can be performed as follows: the green body prepared in step S11 is impregnated and cross-linked in a precursor polymer solution, followed by high-temperature pyrolysis to convert the precursor polymer into SiC ceramic; the impregnation-curing-pyrolysis process is repeated to obtain the densified ceramic sample. Specific reaction parameters are as follows: the green body obtained in step S11 is impregnated and cross-linked in a precursor polymer solution, followed by high-temperature pyrolysis; the impregnation-curing-pyrolysis process is repeated 1-3 times; the impregnation and cross-linking curing time is 2-12 hours, preferably 6 hours; after each impregnation, a high-temperature pyrolysis is performed at 900-1200℃ for 1-2 hours. The precursor impregnation resin is a high-residue SiC ceramic precursor, polycarbosilane.

[0025] exist Figure 1 and Figure 2 In the illustrated embodiment, in step S12, forming silica on the surface of the preform can be achieved by immersing the preform in a silica sol solution or silicone oil and then curing it. Specific immersion curing conditions are: vacuuming to below 1000 Pa, applying a pressure of 0.2-2 MPa, and curing at 60-220°C. The silica sol solution has a concentration of 10-25 wt% and a particle size of 2-10 nm. The silicone oil can be any polysiloxane capable of forming silica on its surface, such as, but not limited to, methyl silicone oil, ethyl silicone oil, phenyl silicone oil, etc. Alternatively, it can be formed by oxidizing the preform at 800°C-1000°C in an oxygen-containing atmosphere. The oxygen-containing atmosphere can be air, oxygen, or a mixture of oxygen and an inert gas.

[0026] The method for 3D printing Al-based silicon carbide composite material components of the present invention can also involve first oxidizing the silicon carbide, which serves as the matrix material, to form a silicon dioxide film on its surface, and then forming a preform using additive manufacturing technology. By first oxidizing the silicon carbide powder, an oxide layer has already been formed on the surface of the particles, so subsequent densification treatment (i.e., step S12a) and impregnation and curing to form silicon dioxide (i.e., step S13) are not required.

[0027] The following combination Figure 3 Detailed description of a method for preparing Al-based silicon carbide composite components by first oxidizing silicon carbide powder. Specifically, the method includes: S21, selecting silicon carbide powder with a particle size of 50-200 μm, and oxidizing the silicon carbide powder in an oxygen-containing atmosphere at 800℃-1100℃ for 1-2 hours to form silicon dioxide on the surface of the silicon carbide powder; S22, using the silicon carbide powder treated in step S21 as the matrix material, forming a blank of the desired structure using additive manufacturing technology; S23, subjecting the blank obtained in step S22 to aluminizing-magnesium alloying treatment to obtain an Al-based silicon carbide composite component, wherein the magnesium content in the alloy is greater than or equal to 10 wt%.

[0028] In optional embodiments, the silicon carbide powder used in the above method can be one or more of silicon carbide micro powder, chopped silicon carbide fibers, silicon carbide whiskers, and silicon carbide nanowires.

[0029] In an optional embodiment, the binder used in the additive manufacturing technology is one or more of phenolic resin, furan resin, polyvinyl alcohol, or polyvinyl butyral.

[0030] In optional embodiments, the additive manufacturing technology in the above method is stereolithography, powder bed melting, material extrusion, directional energy deposition, adhesive spraying, or thin-film stacking.

[0031] In an optional embodiment, the aluminizing-magnesium alloy treatment is carried out under a vacuum or protective atmosphere, wherein the protective atmosphere is argon or nitrogen, the vacuum degree is 0 to 100 Pa, the aluminizing temperature is 800°C to 1100°C, and the aluminizing time is 0.5 h to 5 h.

[0032] In an optional embodiment, the porosity of the blank prepared in step S11 or step S21 is 20-80%.

[0033] This invention also protects Al-based silicon carbide composite material components prepared by the above method.

[0034] The following examples further illustrate the present invention in detail. It should also be understood that the following examples are only for further explanation of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above description of the present invention are within the scope of protection of the present invention. The specific process parameters, etc., in the following examples are merely examples within a suitable range; that is, those skilled in the art can make appropriate selections within the appropriate range based on the description herein, and are not intended to be limited to the specific values ​​in the examples below. Unless otherwise specified, the reagents, materials, and instruments used in the following examples and comparative examples are commercially available.

[0035] Example 1

[0036] Using silicon carbide powder with an average particle size of 150 μm as raw material and phenolic resin as binder (10 wt% of the silicon carbide powder mass), complex structural components were fabricated using SLS (Selective Laser Sintering) 3D printing, with porosity controlled at 45%. A silicon carbide preform was immersed in a 10 wt% silica sol solution, vacuumed to below 500 Pa, subjected to a pressure of 2 MPa, and cured at 220℃ for 2 hours to obtain a silicon carbide matrix material with a silica coating. The impregnated silicon carbide preform was then subjected to aluminizing alloy treatment in nitrogen atmosphere, with magnesium content in the alloy at 10 wt%, aluminizing temperature of 900℃, and a time of 2 hours to obtain a 3D-printed Al-based silicon carbide composite material.

[0037] Example 2

[0038] Using silicon carbide powder with an average particle size of 80 μm as raw material, complex structural components were prepared using the BJ (binder jet printing) 3D printing method, with furan resin binder (1 wt% of the silicon carbide powder mass). The silicon carbide preform was immersed in a liquid polycarbosilane solution, vacuumed to 1000 Pa, subjected to a pressure of 1.6 MPa, and cured at 120℃ for 6 hours to obtain a denser silicon carbide preform with a porosity controlled at 20%. The silicon carbide preform was then oxidized in air at 1100℃ for 2 hours to obtain a silicon carbide-based material with a surface oxidation to SiO2. The oxidized silicon carbide preform was then subjected to aluminizing alloying in nitrogen, with magnesium content in the alloy at 10 wt%, aluminizing temperature of 900℃, and a time of 2 hours to obtain a 3D-printed Al-based silicon carbide composite material.

[0039] Example 3

[0040] Using silicon carbide powder with an average particle size of 50 μm as raw material, it is oxidized in air at 1100℃ for 2 hours to obtain a silicon dioxide film layer on the surface of the silicon carbide powder. Polyvinyl alcohol binder (20 wt% of the mass of silicon carbide powder) is used. Then, complex structure components are prepared by extrusion molding (DIW) 3D printing method, and its porosity is controlled to be 80%. The obtained silicon carbide preform is subjected to aluminizing alloy treatment in vacuum, wherein the magnesium content in the alloy is 12 wt%, the vacuum degree is 100 Pa, the aluminizing temperature is 1000℃, and the time is 1 hour, to obtain 3D printed Al-based silicon carbide composite material.

[0041] Example 4

[0042] Using silicon carbide powder with an average particle size of 200 μm as raw material, it is oxidized in air at 1100℃ for 2 hours to obtain a silicon dioxide film layer on the surface of the silicon carbide powder. Furan resin binder (1.5 wt% of the mass of silicon carbide powder) is used. Then, complex structure components are prepared by BJ (binder jet printing) 3D printing method. The porosity of the complex structure components is controlled at 50%. The obtained silicon carbide preform is then subjected to aluminizing alloy treatment in vacuum, in which the magnesium content in the alloy is 12 wt%, the vacuum degree is 100 Pa, the aluminizing temperature is 1000℃, and the time is 1 hour, to obtain 3D printed Al-based silicon carbide composite material.

[0043] The components from Examples 1-4 were tested, and their mechanical and thermal properties were characterized according to GB / T 6569-2006 and GB / T 39862-2021. The test results are shown in Table 1.

[0044] Table 1

[0045] Flexural strength / MPa Elastic modulus / GPa <![CDATA[Thermal conductivity / Wm -1 K -1 > Example 1 375 151 206 Example 2 346 268 167 Example 3 303 146 153 Example 4 352 143 217

[0046] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for 3D printing Al-based silicon carbide composite material components, characterized in that, include: S11, using silicon carbide powder with a particle size of 50-200μm as the matrix material, and employing additive manufacturing technology to form a blank with the required structure; S12, the preform obtained in the previous step is immersed in a silica sol solution or silicone oil for immersion treatment and then cured to form silica on the surface of the preform, or the preform is oxidized in an oxygen-containing atmosphere at 800℃-1000℃ for 1-2 hours to form silica on the surface of the preform. S13, the blank coated with silicon dioxide is subjected to aluminizing-magnesium alloy treatment to obtain the Al-based silicon carbide composite material component, wherein the magnesium content in the alloy is greater than or equal to 10 wt%.

2. The method as described in claim 1, characterized in that, The steps preceding step S12 also include: S12a, the green body obtained in step S11 is subjected to a densification treatment, wherein the densification treatment is performed by chemical vapor infiltration or precursor impregnation pyrolysis.

3. The method as described in claim 2, characterized in that, The chemical vapor infiltration densification process is as follows: the flow rate of the silicon-based gas is 200-300 mL / min, the pressure is controlled at 100 torr-300 torr, the high temperature is 1000-1300℃, and the densification time is 1-10 days; preferably, the silicon-based gas is one or more of trichloromethylsilane, dimethyldichlorosilane, and methyldichlorosilane.

4. The method as described in claim 2, characterized in that, The precursor impregnation pyrolysis densification treatment is as follows: the preform obtained in step S11 is impregnated and cross-linked in a precursor polymer solution and then pyrolyzed at high temperature; the impregnation-curing-pyrolysis process is repeated 1-3 times; wherein the impregnation and cross-linking curing time is 2-12h; the pyrolysis temperature is 900-1200℃ and the time is 1-2h.

5. The method as described in claim 1, characterized in that, In step S12, the conditions for curing the preform after impregnation in silica sol solution or silicone oil are: vacuuming to below 1000 Pa, applying a pressure of 0.2-2 MPa, and curing at 60-220°C.

6. A method for 3D printing Al-based silicon carbide composite material components, characterized in that, include: S21, select silicon carbide powder with a particle size of 50-200μm, and oxidize the silicon carbide powder in an oxygen-containing atmosphere at 800℃-1100℃ for 1-2 hours to form silicon dioxide on the surface of the silicon carbide powder. S22, using silicon carbide powder processed in step S21 as the matrix material, a blank with the required structure is formed by additive manufacturing technology; S23, the billet obtained in step S22 is subjected to aluminizing-magnesium alloying treatment to obtain the Al-based silicon carbide composite material component, wherein the magnesium content in the alloy is greater than or equal to 10 wt%.

7. The method as described in claim 1 or 6, characterized in that, The silicon carbide powder is one or more of silicon carbide micro powder, chopped silicon carbide fibers, silicon carbide whiskers, and silicon carbide nanowires; and / or The binder used in the additive manufacturing technology is one or more of phenolic resin, furan resin, polyvinyl alcohol, or polyvinyl butyral; and / or The additive manufacturing technology includes stereolithography, powder bed melting, material extrusion, directional energy deposition, adhesive spraying, or thin-film stacking.

8. The method as described in claim 1 or 6, characterized in that, The aluminizing-magnesium alloy treatment is carried out under vacuum or a protective atmosphere, wherein the protective atmosphere is argon or nitrogen, the vacuum degree is 0-100 Pa, the aluminizing temperature is 800℃-1100℃, and the aluminizing time is 0.5h-5h.

9. The method according to any one of claims 1-8, characterized in that, The porosity of the blank prepared in step S11 or step S21 is 20-80%.

10. An Al-based silicon carbide composite material component, characterized in that, Prepared by the method according to any one of claims 1-9.

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