Preparation method of modulus-adjustable component SiC / Al composite material for additive manufacturing

Abstract

The invention discloses a preparation method of a SiC / Al composite material with an adjustable modulus in additive manufacturing. The preparation method comprises the following steps: 1, designing a SiC skeleton target structure according to a target elastic modulus requirement; 2, partitioning the SiC skeleton target structure according to the middle volume fraction distribution characteristics, carrying out unit cell structure design on each SiC skeleton partition, and determining the volume specific gravity of a SiC entity of each partition unit cell; 3, determining the SiC solid content of SiC particles in the SiC green body manufactured by the additive material; 4, preparing a SiC skeleton target structure; and 5, aluminizing the porous SiC skeleton target structure. According to the SiC / Al composite material formed through the method, the volume fraction of SiC is accurately controlled between 10 vol% and 45 vol%, meanwhile, the elasticity modulus of the prepared SiC / Al composite material is adjustable, SiC / Al composite material products can be manufactured according to different application occasions and requirements, and the method has wide application prospects.

Description

Technical Field

[0001] The invention belongs to the technical field of additive manufacturing, and particularly relates to a preparation method of an additively manufactured adjustable modulus medium-ratio SiC / Al composite material. Background Art

[0002] Aluminum (Al)-based SiC composite materials have performance advantages such as low density, low thermal expansion coefficient, good thermal conductivity, high specific stiffness and high specific modulus, and are widely used in the fields of aerospace, military equipment, automobile manufacturing, electronic packaging, etc. In recent years, with the rapid development of new energy vehicles, new aerospace equipment and other fields in China, for the application requirements of SiC / Al composite materials, they have also started to develop in the direction of more complex shape structures, controllable elastic modulus, and lower economic costs.

[0003] At present, the additive manufacturing of SiC / Al composite materials with complex structures mainly focuses on two aspects: direct selective laser melting forming and indirect forming by combining ceramic additive manufacturing technology and aluminizing technology. However, when directly forming SiC / Al composite materials by selective laser melting technology, the volume fraction of SiC can often only be lower than 10 vol%, and problems such as poor lap joint, poor fusion, and inability to form will occur when the SiC volume fraction is further increased; when indirectly forming SiC / Al composite materials by ceramic additive manufacturing technology and aluminizing technology, limited by the debinding process, the volume fraction of the SiC / Al composite materials formed under this technical condition can only be controlled between 45 vol% and 55 vol%. The above two additive manufacturing methods can only prepare SiC / Al composite materials with low volume fractions (≤10 vol%) and high volume fractions (45 vol% - 55 vol%), and there is a blank in the manufacturing of SiC / Al composite materials with intermediate volume fractions (10 vol% - 45 vol%). In addition, the volume fraction of SiC / Al composite materials is closely related to the elastic modulus of SiC / Al composite materials. Therefore, there is a large interval missing in the corresponding elastic modulus range of Al-based SiC composite materials prepared by metal additive manufacturing technology, which limits the application range of SiC / Al composite materials. Therefore, there is currently a lack of a preparation method for additively manufactured adjustable modulus medium-ratio SiC / Al composite materials. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a preparation method of an additively manufactured adjustable modulus medium-ratio SiC / Al composite material aiming at the deficiencies in the above-mentioned prior art.

[0005] To solve the above technical problem, the technical solution adopted by the present invention is: a preparation method of an additively manufactured adjustable modulus medium-ratio SiC / Al composite material, characterized in that the method comprises the following steps:

[0006] Step 1. Design the target structure of the SiC skeleton: Design and adjust the target structure of the SiC skeleton in the middle-ratio SiC / Al composite material in the finite element software according to the required elastic modulus range of the SiC / Al composite material, and obtain the elastic modulus corresponding to the finally qualified middle-ratio SiC / Al composite material;

[0007] Step 2. Partition the target structure of the SiC skeleton according to the intermediate volume fraction distribution characteristics to obtain multiple SiC skeleton partitions;

[0008] Perform uniform partitioning of each SiC skeleton partition into unit cells. According to the formula Determine the volume ratio R of the SiC entity in the j-th unit cell of the i-th SiC skeleton partition, where i is the number of the SiC skeleton partition, i = 1, 2,..., I, I is the total number of SiC skeleton partitions, j is the number of the unit cell in the SiC skeleton partition, j = 1, 2,..., J, J is the total number of divided unit cells in the SiC skeleton partition, V ij is the volume of each unit cell in the i-th SiC skeleton partition, and V i is the volume of the SiC entity in the j-th unit cell of the i-th SiC skeleton partition; ij

[0009] Step 3. Determine the SiC solid content W of the SiC particles in the additively manufactured SiC green body according to the formula where ω i is the target intermediate volume fraction corresponding to the i-th SiC skeleton partition;

[0010] Step 4. Prepare the target structure of the SiC skeleton, and the process is as follows:

[0011] Step 401. Import the designed target structure of the SiC skeleton into the additive manufacturing equipment system, select a binder according to the SiC particles determined in Step 3, and layer by layer form the SiC skeleton green body of the target structure;

[0012] Step 402. Perform degreasing and sintering treatments on the SiC skeleton green body. The degreasing temperature is 400 °C to 650 °C, the heating rate during the degreasing stage shall not exceed 1.5 °C / min, the sintering temperature is 1200 °C to 1600 °C, the sintering time is 1 h to 3 h, and the degreasing and sintering atmosphere is a single gas or a mixed gas of nitrogen, argon, and air. After degreasing, a porous SiC skeleton target structure is obtained;

[0013] Step 5. Aluminize the porous SiC skeleton target structure: Perform aluminum alloy infiltration treatment on the prepared porous SiC skeleton target structure to finally obtain a middle-ratio SiC / Al composite material product with the designed SiC volume fraction.

[0014] ​The preparation method of the above-mentioned additively manufactured adjustable modulus medium-ratio SiC / Al composite material is characterized in that: in step one, the target structure of the SiC skeleton includes a target structure of a SiC lattice skeleton, a target structure of a SiC lattice skeleton or a target structure of a SiC framework skeleton.

[0015] The preparation method of the above-mentioned additively manufactured adjustable modulus medium-ratio SiC / Al composite material is characterized in that: in step three, the SiC solid content W of the SiC particles in the additively manufactured SiC green body ranges from 45 vol% to 55 vol%.

[0016] The preparation method of the above-mentioned additively manufactured adjustable modulus medium-ratio SiC / Al composite material is characterized in that: in step four, the binder includes a resin binder, and the forming method includes stereolithography 3D printing forming, selective laser sintering forming or fused deposition forming.

[0017] The preparation method of the above-mentioned additively manufactured adjustable modulus medium-ratio SiC / Al composite material is characterized in that: in step 402, the porosity of the rib structure in the unit cell of the porous SiC skeleton target structure obtained after debinding and sintering is 45% to 55%. The pores of the entire porous SiC skeleton target structure are composed of the pores between the macroscopic rib structures and the pores between the microscopic SiC particles. After debinding and sintering, the skeleton is strengthened, and the strengthening method includes oxidation treatment or chemical vapor infiltration.

[0018] The preparation method of the above-mentioned additively manufactured adjustable modulus medium-ratio SiC / Al composite material is characterized in that: in step five, the porous SiC skeleton target structure prepared is subjected to aluminum alloy infiltration treatment by means of vacuum pressure infiltration.

[0019] The present invention has the following advantages compared with the prior art:

[0020] 1. According to the elastic modulus range of the required SiC / Al composite material, the target structure of the SiC skeleton in the medium-ratio SiC / Al composite material is designed and adjusted in the finite element software until the target structure of the SiC skeleton meets the design requirements. The present invention has a wide application range and makes up for the blank in the manufacture of SiC / Al composite materials with intermediate volume fractions.

[0021] 2. The present invention forms the SiC / Al composite material, making the SiC volume fraction accurately controllable between 10 vol% and 45 vol%. At the same time, the elastic modulus of the prepared SiC / Al composite material is adjustable, and SiC / Al composite material products can be manufactured according to different application occasions and requirements, which is reliable and stable and has good use effects.

[0022] 3. The method steps of the present invention are simple, can achieve precise control of the SiC content in each region of the Al-based SiC composite parts, have a high degree of design freedom, and can greatly optimize the part structure, save resources and facilitate popularization and use compared with the additively manufactured adjustable modulus medium-ratio SiC / Al composite materials.

[0023] In summary, the present invention forms a SiC / Al composite material, enabling precise control of the SiC volume fraction within the range of 10 vol% to 45 vol%. At the same time, the elastic modulus of the prepared SiC / Al composite material is adjustable, and SiC / Al composite products can be manufactured according to different application scenarios and requirements, having a broad application prospect and being convenient for popularization and use.

[0024] The technical solution of the present invention will be further described in detail below through the drawings and embodiments. Description of the Drawings

[0025] Figure 1 It is a flowchart of the method of the present invention.

[0026] Figure 2 It is the target structure of the porous SiC skeleton when the SiC entity of the present invention is in a homogeneous state.

[0027] Figure 3 It is the target structure of the porous SiC skeleton when the SiC entity of the present invention is in a non-homogeneous gradient state.

[0028] Figure 4 It is the target structure of the porous SiC skeleton when the SiC entity of the present invention is in an irregular random distribution state. Detailed Embodiments

[0029] As Figure 1 shown, the method for preparing an additively manufactured adjustable modulus medium-ratio SiC / Al composite material of the present invention includes the following steps:

[0030] Step 1. Design the target structure of the SiC skeleton: Design and adjust the target structure of the SiC skeleton in the medium-ratio SiC / Al composite material in the finite element software according to the required elastic modulus range of the SiC / Al composite material, and obtain the elastic modulus corresponding to the finally qualified medium-ratio SiC / Al composite material.

[0031] Step 2. Divide the target structure of the SiC skeleton according to the intermediate volume fraction distribution characteristics to obtain multiple SiC skeleton partitions.

[0032] Uniformly divide each SiC skeleton partition into unit cells, and determine the volume proportion R of the SiC entity in the j-th unit cell of the i-th SiC skeleton partition according to the formula ij, where i is the number of SiC skeleton partitions, i = 1, 2, ..., I, I is the total number of SiC skeleton partitions, j is the number of unit cells in the SiC skeleton partition, j = 1, 2, ..., J, J is the total number of separated unit cells in the SiC skeleton partition, V i is the volume of each unit cell in the i-th SiC skeleton partition, V ij is the volume of the SiC entity of the j-th unit cell in the i-th SiC skeleton partition;

[0033] Step Three. According to the formula determine the SiC solid content W of the SiC particles in the additively manufactured SiC green body, where ω i is the target intermediate volume fraction corresponding to the i-th SiC skeleton partition;

[0034] Step Four. Prepare the SiC skeleton target structure, and the process is as follows:

[0035] Step 401. Import the designed SiC skeleton target structure into the additive manufacturing equipment system. According to the SiC particles determined in Step Three, select a binder and layer by layer form the SiC skeleton green body of the target structure;

[0036] Step 402. Carry out degreasing and sintering treatments on the SiC skeleton green body. The degreasing temperature is 400°C to 650°C, the heating rate in the degreasing stage shall not exceed 1.5°C / min, the sintering temperature is 1200°C to 1600°C, the sintering time is 1h to 3h, and the degreasing and sintering atmosphere is a single gas or a mixed gas of nitrogen, argon, and air. After degreasing, obtain the porous SiC skeleton target structure;

[0037] Step Five. Aluminize the porous SiC skeleton target structure: Carry out aluminum alloy infiltration treatment on the prepared porous SiC skeleton target structure to finally obtain a medium-ratio SiC / Al composite material product with the designed SiC volume fraction.

[0038] In this embodiment, in Step One, the SiC skeleton target structure includes a SiC lattice skeleton target structure, a SiC lattice skeleton target structure, or a SiC frame skeleton target structure.

[0039] In this embodiment, in Step Three, the range of the SiC solid content W of the SiC particles in the additively manufactured SiC green body is 45 vol% to 55 vol%.

[0040] In this embodiment, in Step Four, the binder includes a resin binder, and the forming method includes stereolithography 3D printing forming, selective laser sintering forming, or fused deposition modeling forming.

[0041] In this embodiment, in step 402, the porosity of the rib structure in the unit cell of the target structure of the porous SiC skeleton obtained after debinding and sintering is 45% - 55%. The pores of the entire target structure of the porous SiC skeleton are composed of the pores between the macroscopic rib structures and the pores between the microscopic SiC particles. After debinding and sintering, the skeleton is strengthened, and the strengthening methods include oxidation sintering treatment or chemical vapor infiltration.

[0042] In this embodiment, in step five, the vacuum pressure infiltration method is used to perform aluminum alloy infiltration treatment on the prepared target structure of the porous SiC skeleton.

[0043] Example 1

[0044] As Figure 2 shown, the SiC solid content of the SiC particles in the additively manufactured SiC skeleton green body is 50 vol%, and the volume ratio of each SiC entity in each unit cell of each designed layer is 50%, that is, R 11 = R 12 =... = R 1J = R 21 = R 22 =... = R 2J =... = R I1 = R I2 =... = R IJ = 50%, then the finally obtained SiC / Al composite product under this condition is a macroscopically homogeneous product, and its SiC content is 25 vol%.

[0045] Example 2

[0046] As Figure 3 shown, the SiC solid content of the SiC particles in the additively manufactured SiC skeleton green body is 50 vol%, and the volume fraction of each SiC entity in each unit cell of the designed first layer is 50 vol%, that is, R 11 = R 12 =... = R 1J = 50%, and the volume fraction of each SiC entity in each unit cell of the I-th layer is 30 vol%, that is, R I1 = R I2 =... = R IJ = 30%;

[0047] The volume ratio of each SiC entity in each unit cell of the second layer is The designed volume fraction of each SiC entity in each unit cell of the second layer is The volume ratio of each SiC entity in each unit cell of the third layer is The designed volume fraction of each SiC entity in each unit cell of the third layer is And so on, the finally obtained SiC / Al composite material product under this condition has the SiC volume fraction gradually changing from 25 vol% to 15 vol% from the bottom to the top.

[0048] Example 3

[0049] As Figure 4 shown, the SiC solid content of SiC particles in the additive manufacturing SiC skeleton green body is 50 vol%. The part structure is divided into 14 regions as required. The volume ratio of the SiC entity in the unit cell of the first region is designed as m1%, and the volume ratio of the SiC entity in the unit cell of the first region is designed as m2%. And so on, the volume ratio of the SiC entity in the unit cell of the 14th region is designed as m 14 %, then the finally obtained SiC / Al composite material product under this condition has the SiC volume fraction divided into 14 regions as follows: In this example, the shapes of each region can be designed as any regular or irregular shapes.

[0050] When the present invention is used, the formed SiC / Al composite material has the SiC volume fraction accurately controllable between 10 vol% and 45 vol%. At the same time, the elastic modulus of the prepared SiC / Al composite material is adjustable. The elastic moduli corresponding to the SiC volume fractions of 10% and 45% are about 80 GPa and 150 GPa respectively. SiC / Al composite material products can be manufactured according to different application scenarios and requirements, and have broad application prospects.

[0051] The above are only the preferred embodiments of the present invention, and do not impose any limitations on the present invention. Any simple modifications, changes, and equivalent structural changes made to the above embodiments according to the technical essence of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A method for preparing an additively manufactured SiC / Al composite material with an adjustable modulus and a neutral ratio, characterized in that: The method includes the following steps: Step 1. Design the target structure of the SiC skeleton: Design and adjust the target structure of the SiC skeleton in the medium-ratio SiC / Al composite material in the finite element software according to the required elastic modulus range of the SiC / Al composite material, and obtain the elastic modulus corresponding to the finally qualified medium-ratio SiC / Al composite material; Step 2. Partition the target structure of the SiC skeleton according to the intermediate volume fraction distribution characteristics to obtain multiple SiC skeleton partitions; Uniformly divide each SiC skeleton partition into unit cells, and according to the formula Determine the volume ratio R of the SiC entity in the j-th unit cell of the i-th SiC skeleton partition ij , where i is the number of the SiC skeleton partition, i = 1, 2,..., I, I is the total number of SiC skeleton partitions, j is the number of the unit cell in the SiC skeleton partition, j = 1, 2,..., J, J is the total number of divided unit cells in the SiC skeleton partition, V i is the volume of each unit cell in the i-th SiC skeleton partition, and V ij is the volume of the SiC entity in the j-th unit cell of the i-th SiC skeleton partition; Step 3. According to the formula determine the SiC solid content W of SiC particles in the additive manufacturing SiC green body, where ω i is the target intermediate volume fraction corresponding to the i-th SiC skeleton partition; Step 4. Prepare the target structure of the SiC skeleton, and the process is as follows: Step 401. Import the designed target structure of the SiC skeleton into the additive manufacturing equipment system, select a binder according to the SiC particles determined in Step 3, and layer by layer form the SiC skeleton blank of the target structure; Step 402. Carry out degreasing and sintering treatment on the SiC skeleton blank. The degreasing temperature is 400°C to 650°C, the heating rate in the degreasing stage shall not exceed 1.5°C / min, the sintering temperature is 1200°C to 1600°C, the sintering time is 1h to 3h, and the degreasing and sintering atmosphere is a single gas or a mixed gas of nitrogen, argon, and air. After degreasing, a porous SiC skeleton target structure is obtained; Step 5. Aluminize the porous SiC skeleton target structure: Carry out aluminum alloy infiltration treatment on the prepared porous SiC skeleton target structure to finally obtain a medium-ratio SiC / Al composite material product with the designed SiC volume fraction.

2. The preparation method of the additively manufactured adjustable modulus medium-ratio SiC / Al composite material according to claim 1, characterized in that: In Step 1, the target structure of the SiC skeleton includes a SiC lattice skeleton target structure, a SiC lattice skeleton target structure, or a SiC frame skeleton target structure.

3. The method for preparing an additively manufactured SiC / Al composite material with an adjustable modulus and a neutral ratio according to claim 1, wherein: In Step 3, the range of the SiC solid content W of the SiC particles in the additive manufacturing SiC blank is 45 vol% to 55 vol%.

4. The method for preparing the additively manufactured adjustable modulus medium-ratio SiC / Al composite material according to claim 1, wherein: In Step 4, the binder includes a resin binder, and the forming method includes stereolithography 3D printing forming, selective laser sintering forming, or fused deposition modeling.

5. The method for preparing an additively manufactured adjustable modulus medium ratio SiC / Al composite material according to claim 1, wherein: In Step 402, the porosity of the middle rib structure of the single cell of the porous SiC skeleton target structure obtained after degreasing and sintering is 45% to 55%. The pores of the entire porous SiC skeleton target structure are composed of pores between the macroscopic rib structures and pores between the microscopic SiC particles. After degreasing and sintering, the skeleton is strengthened, and the strengthening treatment method includes oxidation sintering treatment or chemical vapor infiltration.

6. The method for preparing an additively manufactured SiC / Al composite material with an adjustable modulus and a neutral ratio according to claim 1, characterized in that: In Step 5, a vacuum pressure infiltration method is used to carry out aluminum alloy infiltration treatment on the prepared porous SiC skeleton target structure.

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