A gradient aluminum silicon carbide composite material device and its preparation method and application

Abstract

The present invention discloses a gradient aluminum-silicon carbide composite material device and its preparation method and application, comprising the following steps: S1, respectively configuring several gel slurries with different silicon carbide volume contents; S2, pouring the gel slurry into a mold in the order of high, medium and low silicon carbide volume contents and then vibrating the mold; S3, demoulding, drying and sintering after curing to obtain a silicon carbide preform with a gradient porosity; S4, loading the silicon carbide preform into a mold for aluminum infiltration to obtain a gradient aluminum-silicon carbide composite material blank; S5, after shelling, fine-machining the gradient aluminum-silicon carbide composite material blank to obtain a gradient aluminum-silicon carbide composite material device. The gradient aluminum-based silicon carbide composite material device prepared by the present invention has a gradient change in the volume proportion of silicon carbide, and the material properties also show a gradient change, so that the product can achieve the structural and functional integration requirements.

Description

Technical Field

[0001] The invention relates to the technical field of composite materials, in particular to a gradient aluminum silicon carbide composite material device and a preparation method and application thereof. Background Art

[0002] SiC p The silicon carbide content in / Al composite materials is different, and their material properties are also quite different. P / Al composite materials can obtain special properties that "alloy" materials do not have. Gradient SiC p The gradual change of silicon carbide content in SiC / Al composites does not have the essential defect problem of incompatibility of the interface between dissimilar materials, which is beneficial to the p / Al composite materials realize gradient performance design. Gradient SiC p / Al composite materials can realize the integration of structural functions within a limited design space. The application of gradient materials weakens the assembly interface relationship, alleviates the assembly stress and thermal stress, solves the matching problem of heterogeneous material assembly interface, improves the service capability of components, and improves the compatibility and environmental applicability of devices, which is of great significance to improving the service performance of related devices and equipment.

[0003] Gradient SiC p The preparation methods of SiCp / Al composite materials include powder metallurgy, melt infiltration, centrifugal casting, spray deposition, 3D printing, etc. Powder metallurgy: The advantage is that the composition can be adjusted arbitrarily and the material performance is excellent. The disadvantage is that the layered structure SiCp / Al composite material has a complex process and high mold cost. Melt infiltration method: including pressureless infiltration, gas pressure infiltration, and extrusion infiltration. The advantage is high density, and the disadvantage is high requirements for preforms. Centrifugal casting: The advantage is low equipment requirements, low cost, and suitable for batch production. The disadvantage is that the structure is barrel-shaped, and the gradient is radial, which has limitations. Other methods such as spray deposition and 3D printing have extremely high equipment requirements, very complex processes, and it is difficult to meet the material density requirements.

[0004] The patent with publication number CN1789434A discloses a functional gradient composite material lining for a blast furnace tank and a preparation method thereof. The method first prepares silicon carbide preforms with different porosities by molding, and then places the silicon carbide preforms with different porosities in a pressureless infiltration mold in order of porosity, and then infiltrates aluminum alloy by pressureless infiltration to obtain a composite material lining. The patent adopts a molding method to prepare silicon carbide preforms with a silicon carbide volume ratio of more than 50%, and the gradient change range of the material is limited. Moreover, it is to stack sintered silicon carbide preforms with different porosities and then infiltrate aluminum. The silicon carbide content of each layer increases in a step-by-step manner, and even an aluminum alloy interlayer appears, which will lead to excessive stress concentration and easy cracking.

[0005] The patent with publication number CN108746637A discloses an aluminum silicon / aluminum silicon carbide gradient composite material and a preparation method thereof, wherein the mixed aluminum / silicon powder and aluminum / silicon carbide powder are pre-pressed into aluminum silicon and aluminum silicon carbide blanks respectively, and then laminated for hot pressing sintering or hot isostatic pressing to obtain an aluminum silicon / aluminum silicon carbide gradient composite material. Powder molding is only suitable for forming flat plates with limited thickness, which limits the shape of the product. The laminated blanks are connected by melting / diffusion of the interlayer aluminum alloy, and the silicon and silicon carbide therein do not penetrate each other. The junction is a transitional gradient interface layer, which can produce stress concentration or even cracking.

[0006] Patent publication number CN111995425A discloses a gel injection molding material composition of aluminum silicon carbide composite material and a method for preparing preforms and structural parts. The structural parts prepared by the method have a uniform material and a non-gradient structure.

[0007] The patent with publication number CN202210769261 discloses a method for preparing gradient porous ceramics. The gradient porous ceramics are prepared by using a water-absorbent gypsum mold to solidify a layer of ceramic slurry and then pouring another layer. As the water saturation of the gypsum increases, the thickness of each gradient layer of water absorption and solidification will decrease successively. The overall water absorption of the gypsum is limited, and the thickness of the prepared material is limited, so three-dimensional gradient material devices cannot be prepared. Summary of the invention

[0008] The technical problem to be solved by the present invention is to provide a gradient aluminum silicon carbide composite material device and its preparation method and application, so as to realize the gradient change of the volume proportion of silicon carbide in the aluminum silicon carbide component and the gradual change of material properties, so as to form a lightweight, high-strength and high-stability structural and functional integrated device.

[0009] In order to solve the above technical problems, the technical solution of the present invention is as follows:

[0010] A method for preparing a gradient aluminum silicon carbide composite material device comprises the following steps:

[0011] S1. preparing several gel slurries with different silicon carbide volume contents respectively;

[0012] S2, pouring the gel slurry into the mold in the order of high, medium and low silicon carbide volume contents and vibrating the mold;

[0013] S3, demoulding, drying and sintering after curing to obtain a silicon carbide preform with a gradient porosity;

[0014] S4, placing the silicon carbide preform into a mold for aluminum infiltration to obtain a gradient aluminum silicon carbide composite material blank;

[0015] S5, after shelling, fine-processing the gradient aluminum silicon carbide composite material blank to obtain a gradient aluminum silicon carbide composite material device;

[0016] The several kinds are 3-6 kinds;

[0017] The gel slurry comprises: silicon carbide powder, deionized water, monomers, a crosslinking agent, an initiator and a dispersant.

[0018] Preferably, the volume ratio of the gel slurries with high, medium and low silicon carbide volume contents is (1-5):(1-5):(1-5).

[0019] Preferably, the volume fraction of silicon carbide in the gel slurry with low volume content of silicon carbide is 35% to 44%, the volume fraction of silicon carbide in the gel slurry with medium volume content of silicon carbide is 45% to 54%, and the volume fraction of silicon carbide in the gel slurry with high volume content of silicon carbide is 55% to 70%.

[0020] Among them, since the gaps between silicon carbide particles are too large, the strength of the green body after sintering is too low, and the impact of aluminum liquid during aluminization will cause damage, so the volume content of silicon carbide in the gel slurry should not be less than 35%.

[0021] Preferably, the gel slurry with high silicon carbide volume content includes 3 to 5 kinds of silicon carbide with different particle sizes, including 1 to 2 kinds of coarse particles, 1 to 2 kinds of medium particles, and 0 to 1 kind of fine particles; the particle size range of coarse silicon carbide particles is: 50μm-120μm; the particle size range of medium silicon carbide particles is: 10μm-50μm; the particle size range of fine silicon carbide particles is: 1μm-10μm.

[0022] Preferably, the particle size is selected in such a way that the smaller silicon carbide particle size fills the gap between the larger particles. If the particle size difference is too large, the gap between the larger particles cannot be filled; if the particle size difference is too small, the smaller particles cannot fill the gap between the larger particles. The particle size of the coarse-grained silicon carbide is 2-4 times that of the medium-grained silicon carbide; and the particle size of the medium-grained silicon carbide is 2-4 times that of the fine-grained silicon carbide.

[0023] Preferably, the gel slurry with medium silicon carbide volume content includes 2 to 3 silicon carbides with different particle sizes. In order to prevent silicon carbide with other particle sizes from settling into the gel slurry with high silicon carbide volume content during subsequent vibration, affecting the continuity of silicon carbide particle sedimentation, changing its silicon carbide gradation, and thus affecting the smooth transition of the gradient, the particle size of large particles in the gel slurry with medium silicon carbide volume content is consistent with the particle size of smaller particles in the gel slurry with high silicon carbide volume content; further preferably, the particle size of large particles in the gel slurry with medium silicon carbide volume content is consistent with the particle size of medium particles in the gel slurry with high silicon carbide volume content.

[0024] Preferably, the gel slurry with low silicon carbide volume content includes 1 to 2 silicon carbides with different particle sizes. Similarly, the particle size thereof is consistent with the particle size of the relatively fine silicon carbide included in the gel slurry with medium silicon carbide volume content.

[0025] Preferably, in order to further reduce the volume content of silicon carbide, an ablative pore former may be added to the gel slurry with low silicon carbide volume content.

[0026] Preferably, the main oxidation products of the ablative pore former are water and volatile gases, including graphite and some organic matter.

[0027] Preferably, in order to ensure that each layer of slurry fully fills the mold and the upper surface is leveled after pouring, the injection molding interval of the gel slurries with different silicon carbide volume contents is 1 min to 3 min.

[0028] Preferably, the vibration frequency of the mold is 1 Hz to 20 Hz, the vibration amplitude is 0.5 mm to 2 mm, and the vibration time is 0 to 30 s.

[0029] Preferably, the curing temperature is 50°C to 70°C.

[0030] Preferably, after demoulding, the blank is placed at room temperature for more than 24 hours, dried at 50° C. to 70° C. until the weight loss rate in 24 hours is ≤1%, and then sintered.

[0031] Preferably, the sintering temperature is 900° C. to 1200° C., the heating rate is 1 to 3° C. / min, and the holding time is 1 to 3 hours.

[0032] Preferably, the aluminizing temperature is 650° C. to 850° C., the nitrogen pressure is 6 MPa to 12 MPa, and the vacuum degree is 30 Pa to 80 Pa.

[0033] The present invention also claims protection for the gradient aluminum silicon carbide composite material device prepared by the above preparation method.

[0034] The present invention also claims to protect the application of the gradient aluminum silicon carbide composite material device in the preparation of aerospace lightweight structural parts.

[0035] The working principle of this application is:

[0036] Aiming at the difficulty of preparing gradient SiCp / Al composite materials by melt infiltration method, the present invention has high requirements for preforms. On the basis of the colloidal forming process of ceramic materials, the volume fraction of silicon carbide is regulated by silicon carbide grading and adding an ablative pore-forming agent. After the colloid containing different volume fractions of silicon carbide is poured layer by layer, micro-vibration is applied to make silicon carbide particles at the interface of the colloid settle over a short distance, the layer interface of the whole component is eliminated, the gradient transition is achieved, and the macro-microstructure of the whole component has a smooth gradient transition. A silicon carbide preform with gradient porosity is prepared by sintering and debinding, and the aluminum-silicon carbide composite material aluminizing process is combined to form a device for preparing a gradient functional aluminum-based silicon carbide composite material.

[0037] The technical difficulty of the present invention is: the present invention relates to a preparation technology of a gradient aluminum silicon carbide composite material and device, wherein the silicon carbide volume fraction gradient is 35% to 70%, and the silicon carbide volume fraction varies widely. In order to achieve precise regulation of gradient components and performance and dual regulation of device molding process, the control of silicon carbide particle size ratio, pouring interval of each slurry, vibration parameters and other aspects is very demanding. The silicon carbide particle size ratio and silicon carbide volume fraction in the slurry ratio are quite different, and the process characteristics such as gel slurry fluidity control are quite different. Conventional casting has interlayer interfaces. The present invention adopts corresponding process technology to eliminate this layer interface, and adopts vibration to make the interface silicon carbide settle and combine. In order to eliminate the layer interface after pouring layer by layer, the melt infiltration method is adopted on this basis to achieve one-time aluminum infiltration, so as to achieve good metallurgical bonding of each gradient area when the gradient material device is formed.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] The gradient composition and overall structural forming of the aluminum-silicon carbide composite material are precisely controlled to meet the product index requirements of "gradient volume change of silicon carbide" and "one-time forming of the overall structure". The slurry forming process and the melt infiltration aluminum infiltration process are combined to form a gradient aluminum-silicon carbide composite material device. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 These are photos of the gradient silicon carbide preform and materials in Example 1 of the present invention.

[0041] Figure 2 This is a SEM image of the interface of the gradient aluminum silicon carbide composite material in Example 1 of the present invention.

[0042] Figure 3 These are photos of the gradient silicon carbide preform and the prepared gradient functional device in Example 2 of the present invention. DETAILED DESCRIPTION

[0043] The technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0044] The present invention provides a method for preparing a gradient aluminum silicon carbide composite material and a device, wherein S1: a method for respectively configuring several gel slurries with different silicon carbide volume fractions, specifically, the gel formula refers to the patent application number 202010777650.2, entitled "A gel injection molding material composition of an aluminum silicon carbide composite material and a method for preparing preforms and structural parts" in the invention content of the specification, paragraphs 0010 to 0013. Wherein S3: parameters of the catalytic temperature and time of the curing of the gel slurry, specifically, refer to the patent application number 202010777650.2, entitled "A gel injection molding material composition of an aluminum silicon carbide composite material and a method for preparing preforms and structural parts" in the invention content of the specification, paragraph 0018.

[0045] The technical solution of the present invention is further described below in conjunction with embodiments.

[0046] Embodiment 1:

[0047] 1) Prepare three gel slurries with different silicon carbide volume fractions, including silicon carbide powder, deionized water, acrylamide, methylene bisacrylamide, ammonium persulfate, and dispersant. Mix the components except silicon carbide powder into a gel composition in advance, wherein deionized water, acrylamide, methylene bisacrylamide, dispersant, and ammonium persulfate are 40 parts, 3 parts, 0.3 parts, 0.2 parts, and 0.1 parts, respectively. The silicon carbide particle ratio is as follows:

[0048] a: Silicon carbide particles with particle sizes of 63 μm, 10 μm, and 3.5 μm are mixed in a weight ratio of 5:3:2;

[0049] b: Silicon carbide particles with a particle size of 10 μm and 3.5 μm are mixed in a weight ratio of 4:1;

[0050] c: Silicon carbide particles with a particle size of 3.5 μm are mixed with polyvinyl alcohol in a weight ratio of 4:1.

[0051] The weight ratio of the three types of silicon carbide particles a, b and c is 60:50:50, and they are mixed with the gel composition respectively to form gel slurries with the same volume.

[0052] 2) Use partitions to divide the mold into three compartments: left, middle, and right.

[0053] 3) After adding the initiator, slurries a, b, and c are poured into the three compartments of the mold in sequence. After pouring, the partitions are pulled out, the lid is closed, and the mold is rotated 90 degrees after standing for 1 minute for interface fusion, so that the slurries are a, b, and c from bottom to top.

[0054] 4) The mold was transferred to a vibration platform and vibrated at a frequency of 10 Hz, an amplitude of 0.5 mm, and a vibration time of 10 s.

[0055] 5) Transfer the mold and the material into a 60°C constant temperature oven to initiate curing, and cool and demould after 30 minutes.

[0056] 6) Dry the blank at room temperature for 2 days and then transfer it to a 60°C constant temperature oven for drying.

[0057] 7) Dry until the weight loss is less than 1% every 24 hours and then proceed to sintering.

[0058] 8) The average heating rate is 2°C / min, the sintering temperature is 1000°C, and the furnace is cooled after keeping the temperature for 2 hours to obtain a silicon carbide preform with a gradient porosity of 40% to 50% to 60% (such as Figure 1 a) From Figure 1 Sampling the position marked in a, we get Figure 2 The microstructure of a. Figure 2 SEM analysis in a shows that large and small silicon carbide particles are interspersed with each other, with no obvious interface layer and good bonding.

[0059] 9) After the mold is loaded, vacuum pressure aluminum infiltration is performed to infiltrate the silicon carbide preform with a gradient porosity. The process parameters are: preheating the preform to 700°C, the aluminum infiltration temperature to 800°C, the nitrogen pressure to 8.5MPa, and the vacuum degree to 50Pa to obtain a gradient aluminum silicon carbide composite material blank with a silicon carbide volume fraction of 60% to 50% to 40% (such as Figure 1 b) Combined Figure 2 From the SEM analysis in b, the distribution of silicon carbide particles and aluminum alloy presents an obvious gradient, and the aluminum alloy is continuously distributed throughout the gradient material, achieving good metallurgical bonding.

[0060] Comparative Example 1:

[0061] The particle size ratio of slurry b in Example 1 was replaced with 30 μm and 10 μm silicon carbide particles mixed in a weight ratio of 4:1, and the operation methods of other steps remained unchanged. It was found that after the green body was sintered in step 8, the porosity of the low-porosity silicon carbide layer was reduced to 37% (silicon carbide volume accounted for 63%). The reason was analyzed and found that the 30 μm silicon carbide particles were heavier than the 10 μm and 3.5 μm silicon carbide particles. During the vibration process, a large number of 30 μm silicon carbide particles in slurry b settled into slurry a, forming 63 μm The grading of silicon carbide is 30μm, 10μm and 3.5μm. The change of silicon carbide grading leads to the change of silicon carbide volume proportion. Cracks appear in the silicon carbide transition layer with a porosity of 50% to 60%. The test shows that the content of 3.5μm silicon carbide is relatively small in the 50% layer close to the high porosity end. Compared with 30μm and 10μm silicon carbide particles, 3.5μm silicon carbide particles are too light. No silicon carbide sedimentation occurs between the slurries containing different volume fractions of silicon carbide, so the interface bonding is poor.

[0062] Therefore, the large particle size of the gel slurry with medium silicon carbide volume content is consistent with the medium particle size of the gel slurry with high silicon carbide volume content; the particle size of the gel slurry with low silicon carbide volume content is consistent with the particle size of fine-grained silicon carbide included in the gel slurry with medium silicon carbide volume content, which can ensure good bonding and filtration between the interfaces.

[0063] Embodiment 2:

[0064] 1) Three gel slurries with different silicon carbide volume fractions were prepared respectively, and the preparation method of the gel composition was the same as that of Example 1. The proportion of silicon carbide particles was as follows:

[0065] a: Silicon carbide particles with particle sizes of 120 μm, 63 μm, 20 μm, and 10 μm are mixed in a weight ratio of 3:2:3:2;

[0066] b: Silicon carbide particles with a particle size of 20 μm and 10 μm are mixed in a weight ratio of 3:2;

[0067] c: Silicon carbide particles with a particle size of 10 μm and 3.5 μm are mixed with C black (high purity) in a weight ratio of 2:2:1.

[0068] The weight ratio of the three mixed powders a, b and c is 65:50:45, and they are mixed with the gel composition respectively to form gel slurries with the same volume.

[0069] 2) After adding the initiator, slurries a, b, and c are poured into the mold one after another. The injection molding interval of each ratio of silicon carbide slurry is 2 minutes.

[0070] 3) After all the slurry is poured, transfer it to a vibration platform and vibrate it with a vibration frequency of 10 Hz, a vibration amplitude of 1 mm, and a vibration time of 30 s.

[0071] 4) Transfer the mold and the material into a 60°C constant temperature oven to initiate curing, and cool and demould after 60 minutes.

[0072] 5) Dry the blank at room temperature for 3 days and then transfer it to a 60°C constant temperature oven for drying.

[0073] 6) Dry until the weight loss is less than 1% every 24 hours and then proceed to sintering.

[0074] 7) The average heating rate is 1°C / min, the sintering temperature is 1200°C, and the furnace is cooled after keeping the temperature for 2 hours to obtain a silicon carbide preform with a gradient porosity of 35% to 50% to 65% (such as Figure 3 a) (The actual photography and operation process are reversed).

[0075] 8) After the mold is loaded, vacuum pressure aluminum infiltration is performed to infiltrate the silicon carbide preform with gradient porosity. The process parameters are: preheating the preform to 700°C, aluminum infiltration temperature to 800°C, nitrogen pressure to 8.5MPa, and vacuum degree to 50Pa to obtain a gradient aluminum silicon carbide composite body (such as Figure 3 b).

[0076] 9) After shelling, the desired gradient functional aluminum silicon carbide composite material device is obtained by fine processing, and the silicon carbide volume fraction gradient of the device is 65% to 50% to 35%.

[0077] The overall density of the gradient functional aluminum silicon carbide composite device is less than 3.0g / cm 3 There is no obvious interface layer between the gradients, and the transition of mechanical properties is continuous.

[0078] Comparative Example 2

[0079] The vibration step 3) in Example 2 is cancelled. After demolding and drying, the interface layers of each slurry are clear and straight, and even a transparent glue layer occasionally appears (a small amount of glue is precipitated on the surface during the interlayer pouring and standing process, which may disappear if silicon carbide settles in later). It is easy to crack during the drying and sintering process.

[0080] Comparative Example 3:

[0081] The vibration frequency of step 3) in Example 2 was changed to 50 Hz, the vibration amplitude was 2 mm, and the vibration time was 30 s. The operation methods of other steps remained unchanged. After vibration, the large green particles in the slurry settled to the bottom, the small light green particles were in the middle layer, and the graphite floated on the top layer. After demolding and drying, the large particle size end had very low strength (too many large particles, few small particles, and high sintering energy was required), and the silicon carbide had no sintering strength after the graphite on the upper end was ablated.

[0082] In comparison examples 2 and 3, the vibration frequency of the mold is set to 1 Hz to 20 Hz, the vibration amplitude is 0.5 mm to 2 mm, and the vibration time is 0 to 30 seconds. The vibration parameters are closely related to the particle size distribution of silicon carbide particles added to the system. Under this particle size distribution, too much or too little vibration will have a significant adverse effect on the overall performance of the material.

[0083] The gradient functional aluminum silicon carbide composite material device prepared in Example 1 and Example 2 is a lightweight structural part integrating the structure and function of the optical system. A high volume fraction aluminum silicon carbide composite material is used on the functional end side to match with materials with a small thermal expansion coefficient such as optical devices and ceramics, and the thermal stress is small; a low volume fraction aluminum silicon carbide composite material with good mechanical properties is used on the structural end to match with other metal materials and other materials with a large expansion coefficient, and the assembly thermal stress is small. During use, the device has no obvious mutation point in mechanical properties, is not easy to generate concentrated stress, has higher strength, and is less likely to break.

Claims

1. A method for preparing a gradient aluminum silicon carbide composite material device, characterized in that: The following steps are involved: S1. preparing several gel slurries with different silicon carbide volume contents respectively; S2. Pour the gel slurry into the mold in the order of high, medium and low silicon carbide volume content and vibrate the mold to make the macro and micro structures smoothly transition; S3, demoulding, drying and sintering after curing to obtain a silicon carbide preform with a gradient porosity; S4, placing the silicon carbide preform into a mold for aluminum infiltration to obtain a gradient aluminum silicon carbide composite material blank; S5, after shelling, fine-processing the gradient aluminum silicon carbide composite material blank to obtain a gradient aluminum silicon carbide composite material device; The several kinds are 3-6 kinds; The gel slurry comprises: silicon carbide powder, deionized water, monomer, cross-linking agent, initiator and dispersant; The volume fraction of silicon carbide in the gel slurry with low silicon carbide volume content is 35%~44%, the volume fraction of silicon carbide in the gel slurry with medium silicon carbide volume content is 45%~54%, and the volume fraction of silicon carbide in the gel slurry with high silicon carbide volume content is 55%~70%; The gel slurry with high silicon carbide volume content includes 3 to 5 kinds of silicon carbides with different particle sizes; In the gel slurry with high silicon carbide volume content, there are 1 to 2 kinds of coarse particles, 1 to 2 kinds of medium particles, and 0 to 1 kind of fine particles; the particle size range of the coarse silicon carbide particles is: 50 μm-120 μm; the particle size range of the medium silicon carbide particles is: 10 μm-50 μm; the particle size range of the fine silicon carbide particles is: 1 μm-10 μm; The gel slurry with medium silicon carbide volume content includes 2 to 3 silicon carbides with different particle sizes; the particle size of large particles of the gel slurry with medium silicon carbide volume content is consistent with the particle size of smaller particles of the gel slurry with high silicon carbide volume content; In the gel slurry with low silicon carbide volume content, when silicon carbide of one particle size is included, the particle size of the gel slurry with low silicon carbide volume content is consistent with the particle size of the silicon carbide with a smaller particle size included in the gel slurry with a medium silicon carbide volume content; when silicon carbide of two different particle sizes is included, the larger particle size is consistent with the particle size of the silicon carbide with a finer particle size included in the gel slurry with a medium silicon carbide volume content; The vibration frequency of the mold is 1 Hz to 20 Hz, the vibration amplitude is 0.5 mm to 2 mm, and the vibration time is 10 to 30 s.

2. The method for preparing a gradient aluminum silicon carbide composite material device according to claim 1, characterized in that: A burnable pore former is also added to the gel slurry with low silicon carbide volume content.

3. The method for preparing a gradient aluminum silicon carbide composite material device according to claim 1 or 2, characterized in that: The sintering temperature is 900°C to 1200°C, the heating rate is 1 to 3°C / min, and the holding time is 1 to 3h; the aluminizing temperature is 650°C to 850°C, the nitrogen pressure is 6MPa to 12MPa, and the vacuum degree is 30Pa to 80Pa.

4. A gradient aluminum silicon carbide composite material device prepared by the method for preparing a gradient aluminum silicon carbide composite material device according to any one of claims 1 to 3.

5. Use of the gradient aluminum silicon carbide composite material device according to claim 4 in the preparation of aerospace lightweight structural parts.

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