Efficient pressure preparation equipment and method for aluminum silicon carbide composite material

Abstract

The invention discloses equipment and a method for preparing an aluminum silicon carbide (Al-SiC) composite material through a pressure infiltration process, and belongs to the technical field of metal matrix composite material preparation. The efficient pressure preparation equipment for the aluminum-silicon carbide composite material comprises a furnace body, a lower graphite crucible, an upper graphite crucible, a liftable graphite rod, an inflation connector and an exhaust connector, during specific use, an aluminum ingot and a silicon carbide preform are heated respectively and prevented from making contact with each other, so that the interface reaction strength is relieved, and combination of aluminum and silicon carbide is facilitated; after the target temperature is reached, the graphite rod is lifted to open the leak hole, so that the molten aluminum falls into the lower graphite crucible, and under the action of high-pressure gas, the molten aluminum is infiltrated into the silicon carbide prefabricated body, so that the aluminum-silicon carbide composite material is prepared; the problems of low density, poor process stability, violent interface reaction and low bonding strength in the prior art can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of metal matrix composite material preparation, and in particular to an apparatus and method for preparing aluminum silicon carbide (Al-SiC) composite material by a pressure infiltration process. Background Art

[0002] Aluminum silicon carbide composites are widely used in aerospace, electronic packaging and other fields due to their high specific strength, low thermal expansion coefficient and excellent thermal conductivity. Traditional preparation methods include pressureless infiltration and gas pressure infiltration, but there are the following problems:

[0003] 1. The efficiency of pressureless infiltration is low, and the aluminum liquid cannot completely fill the pores of the silicon carbide preform, resulting in insufficient density. 2. The temperature control accuracy of existing pressure infiltration equipment is poor, and the interface reaction between the aluminum liquid and silicon carbide is violent, resulting in low bonding strength. 3. The process has a low degree of automation, making it difficult to achieve large-scale production.

[0004] In view of this, it is necessary to propose a new technical solution to solve the above technical problems. Summary of the Invention

[0005] The purpose of the present invention is to provide an efficient pressure preparation device and method for aluminum silicon carbide composite materials, so as to solve the problems of low density, poor process stability, violent interface reaction and low bonding strength in the prior art.

[0006] To achieve the above objectives, the present invention adopts the following technical means:

[0007] A high-efficiency pressure preparation device for aluminum silicon carbide composite materials, comprising:

[0008] The furnace body includes a furnace shell and a furnace cover, the furnace cover is sealed and connected to the top of the furnace shell, and a reaction space is formed inside the furnace body;

[0009] a lower graphite crucible, located at the bottom of the reaction space and open upward; an outer wall of the lower graphite crucible is covered with a first electromagnetic heating component, the first electromagnetic heating component being used to heat the silicon carbide preform placed in the lower graphite crucible;

[0010] An upper graphite crucible can be stacked on the opening of the lower graphite crucible to maintain thermal insulation between the two, and a leakage hole is opened on the bottom wall of the upper graphite crucible; the outer wall of the upper graphite crucible is covered with a second electromagnetic heating component, which is used to heat the aluminum ingot placed in the upper graphite crucible;

[0011] A graphite rod is connected to the furnace cover in a liftable manner so that the lower end of the graphite rod can be switched between a position of closing or opening the leakage hole;

[0012] The gas charging interface is connected to the wall of the furnace body and is used to connect to an external gas source to introduce gas into the reaction space;

[0013] The exhaust interface is connected to the wall of the furnace body and is used to connect to a vacuum pumping device for evacuating the gas in the reaction space to create a vacuum.

[0014] As a further improvement, the bottom wall of the upper graphite crucible is V-shaped, and the leakage hole is opened in the center of the bottom wall.

[0015] As a further improvement, the graphite rod is connected to a hydraulic device, and the hydraulic device drives the graphite rod to move up and down.

[0016] A method for preparing an aluminum silicon carbide composite material using the above-mentioned apparatus comprises the following steps:

[0017] Step 1: Place the silicon carbide preform in the lower chamber and the aluminum ingot in the upper chamber, and evacuate to the process requirements;

[0018] Step 2: Heat the silicon carbide preform and the aluminum ingot to the target temperature respectively and keep them warm for 30-60 minutes;

[0019] Step 3: Pull up the graphite plug to allow the molten aluminum to flow down into the mold below and come into contact with the silicon carbide preform;

[0020] Step 4: Introduce inert gas and apply stepped pressure, maintaining the pressure for 30-60 minutes, so that the aluminum liquid combines with the silicon carbide;

[0021] Step 5: After cooling to 300°C, release the pressure and take out the aluminum silicon carbide composite material.

[0022] As a further improvement, the volume fraction of the silicon carbide preform is 40-65%;

[0023] In the aluminum silicon carbide composite material, aluminum alloy accounts for 35-60%.

[0024] As a further improvement, the step of evacuating the reaction space to a vacuum below 5 Pa is carried out to meet the process requirements.

[0025] As a further improvement, the step heats the silicon carbide preform and the aluminum ingot to target temperatures respectively, wherein the target temperature of the silicon carbide preform is 620°C; the target temperature of the aluminum ingot is 720-750°C.

[0026] As a further improvement, the heating rate is 5°C / min-10°C / min; the target temperature is maintained for 30-60 minutes.

[0027] As a further improvement, the inert gas includes nitrogen or argon.

[0028] As a further improvement, the gas pressure is 5-10 MPa.

[0029] Compared with the prior art, the present invention brings the following technical effects:

[0030] The high-efficiency pressure preparation equipment of the aluminum silicon carbide composite material of the present invention comprises a furnace body, a lower graphite crucible, an upper graphite crucible, a liftable graphite rod, an air charging interface and an exhaust interface. When in use, the aluminum ingot and the silicon carbide preform are respectively placed in the lower graphite crucible and the upper graphite crucible, the graphite rod blocks the leakage hole, and then the aluminum ingot and the silicon carbide preform are heated separately. During this process, the two are independent of each other and do not come into contact. When the target temperature is reached, the graphite rod is raised to open the leakage hole, so that the aluminum liquid falls into the lower graphite crucible. At this time, high-pressure gas is introduced. Under the action of high pressure, the aluminum liquid is immersed in the lower graphite crucible. The aluminum liquid penetrates into the interior of the silicon carbide preform, thereby producing an aluminum-silicon carbide composite material; since the heating processes are independent of each other, the two are only brought into contact after reaching the target temperature, which can reduce the interfacial reaction, making the aluminum and silicon carbide bond more firmly, thereby improving the material performance; the introduction of high-pressure gas forces the aluminum liquid to fully penetrate the pores of the silicon carbide preform, thereby increasing the density of the final material; at the same time, both electromagnetic heating and the setting of the liftable graphite rod improve the controllability of the aluminum-silicon carbide composite material production process, thereby ensuring the stable acquisition of products that meet performance standards. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0032] Figure 1 A schematic structural diagram of a highly efficient pressure preparation device for an aluminum silicon carbide composite material according to a preferred embodiment of the present invention is shown;

[0033] Figure 2 Shows a comparison of the microstructures of aluminum silicon carbide composite materials (left is the interface view of the prior art product, right is the interface view of the product of the present invention);

[0034] Figure 3 A schematic structural diagram of the high-efficiency pressure preparation equipment for the aluminum silicon carbide composite material used in Comparative Example 3 is shown;

[0035] Figure 4 A schematic structural diagram of the high-efficiency pressure preparation equipment for the aluminum silicon carbide composite material used in Comparative Example 4 is shown.

[0036] Description of main component symbols:

[0037] Lower graphite crucible 10; upper graphite crucible 20; leak hole 21; graphite rod 30; furnace shell 41; furnace cover 42; reaction space 43; support cup 50; cup rim 51; insulation layer 60; thermal insulation layer 70. DETAILED DESCRIPTION

[0038] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0039] In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other. The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions.

[0040] See also Figure 1 and Figure 2 This embodiment provides an efficient pressure preparation device for aluminum silicon carbide composite materials, including a furnace body, a lower graphite crucible 10, an upper graphite crucible 20, a liftable graphite rod 30, an inflation interface (not shown) and an exhaust interface (not shown).

[0041] The furnace body is cylindrical and includes a furnace shell 41 and a furnace cover 42. The furnace cover 42 is arc-shaped and sealed to the top of the furnace shell 41. A reaction space 43 is formed inside the furnace body.

[0042] The lower graphite crucible 10 is located at the bottom of the reaction space 43, open upward. The outer wall of the lower graphite crucible 10 is coated with a first electromagnetic heating assembly (not shown), which is used to heat the silicon carbide preform placed in the lower graphite crucible 10. The first electromagnetic heating assembly includes a coil and a corresponding circuit board, which is easy to achieve precise control and facilitates automated control.

[0043] The upper graphite crucible 20 can be stacked on the opening of the lower graphite crucible 10, maintaining thermal insulation between the two. The upper and lower graphite crucibles 20 and 10 have the same diameter. A leak hole 21 is provided in the bottom wall of the upper graphite crucible 20, which serves as an inlet for molten aluminum to flow into the lower graphite crucible 10. The outer wall of the upper graphite crucible 20 is coated with a second electromagnetic heating assembly (not shown), which is used to heat the aluminum ingot placed in the upper graphite crucible 20. This second electromagnetic heating assembly also includes a coil and corresponding circuit board, which offers the advantage of easy and precise control, facilitating automated control.

[0044] The graphite rod 30 is connected to the furnace cover 42 in a liftable manner so that the lower end of the graphite rod 30 can be switched between closing or opening the leakage hole 21. Specifically, the device for driving the graphite rod 30 to rise and fall can be a hydraulic device or a motor (not shown).

[0045] The gas charging port is connected to the wall of the furnace body and is used to connect to an external gas source for introducing gas into the reaction space 43. The external gas source is used to generate nitrogen or argon. As those skilled in the art will appreciate, transporting the external gas source to the reaction space 43 requires auxiliary components such as an air pump and air pipe. Furthermore, to control the pressure of the gas input into the reaction space 43, devices such as a pressure valve and an air flow meter may be provided on the pipe. These are all existing technologies and are easily implemented, so they will not be further described here.

[0046] The exhaust port is connected to the wall of the furnace body for connecting to a vacuum pumping device for evacuating the gas in the reaction space 43 to create a vacuum. Those skilled in the art will appreciate that the vacuum pumping device is a prior art, and that a complete vacuuming function is supplemented by instruments such as a barometer and a gas valve. These are prior art and easily implemented, and will not be further described here.

[0047] In one embodiment, a support cup 50 is further provided within the furnace shell 41. The top of the support cup 50 extends horizontally outward to form a cup rim 51, which is fixedly connected to the inner wall of the furnace shell 41. The lower graphite crucible 10 and the upper graphite crucible 20 are both accommodated within the support cup 50. Specifically, the support cup 50 is made of copper.

[0048] In a preferred embodiment, the height of the lower graphite crucible 10 and the upper graphite crucible 20 stacked together is less than the depth of the support cup 50, and a plurality of insulation layers 60, such as asbestos layers, glass fiber layers, etc., are provided in the remaining support cup 50. In addition to having a heat-insulating effect, the insulation layer 60 is also breathable, allowing gas to freely penetrate between the layers.

[0049] More specifically, a heat insulating layer 70 is provided between the support cup 50 and the furnace shell 41 . The heat insulating layer 70 surrounds the periphery of the support cup 50 to prevent heat from being dissipated to the outside, thereby ensuring heating efficiency.

[0050] As can be seen from the above, the high-efficiency pressure preparation equipment of the aluminum silicon carbide composite material of the present invention includes a furnace body, a lower graphite crucible 10, an upper graphite crucible 20, a liftable graphite rod 30, an inflation interface and an exhaust interface. During specific use, the aluminum ingot and the silicon carbide preform are placed in the lower graphite crucible 10 and the upper graphite crucible 20 respectively, and the graphite rod 30 blocks the leak 21. Then the aluminum ingot and the silicon carbide preform are heated separately. During this process, the two are independent of each other and do not contact each other. When the target temperature is reached, the graphite rod 30 is raised to open the leak 21, allowing the aluminum liquid to fall into the lower graphite crucible 10. At this time, high-pressure gas is introduced. Under the action of high pressure, the aluminum liquid infiltrates into the interior of the silicon carbide preform, thereby obtaining an aluminum silicon carbide composite material; silicon carbide and aluminum liquid are easily chemically reacted under high temperature and high pressure for a long time, generating aluminum carbide (Al4 C3). Aluminum carbide has poor stability and is easy to decompose, affecting the performance of the composite material. In the present application, however, the heating processes are independent of each other, and the two are brought into contact only after reaching the target temperature, thereby reducing the interfacial reaction and making the aluminum and silicon carbide more firmly bonded, thereby achieving the effect of improving the material performance; the introduction of high-pressure gas in this solution forces the aluminum liquid to fully penetrate the pores of the silicon carbide preform, thereby increasing the density of the final material; at the same time, both the electromagnetic heating and the setting of the liftable graphite rod 30 improve the controllability of the aluminum-silicon carbide composite material production process, thereby ensuring the stable acquisition of products that meet the performance standards.

[0051] Example 1

[0052] Place a silicon carbide preform with a volume fraction of 60% in a mold and place it in the lower graphite crucible;

[0053] Place the upper graphite crucible on top of the lower crucible, and place a graphite plug to block the opening of the upper crucible;

[0054] Place the weighed aluminum block into the upper graphite crucible;

[0055] Cover with the insulation layer 60 and fix the top of the graphite plug to the device of the cover;

[0056] Close the furnace cover 42 and start the vacuum pump to evacuate the chamber;

[0057] When the vacuum drops below 5 Pa, heating begins;

[0058] Start heating at 10℃ / min, upper chamber 750℃, lower chamber 620℃, keep warm for 30min;

[0059] Start the device connected to the graphite plug on the furnace cover 42, pull out the graphite plug, and allow the aluminum liquid to enter the lower cavity mold;

[0060] When the aluminum liquid has completely entered the mold, start to fill the furnace with pressurized gas (high-purity nitrogen or argon) until the pressure inside the furnace reaches 6MPa and maintain the pressure for 30 minutes;

[0061] After completion, the product is cooled with the furnace to below 300 degrees, the high-pressure gas in the furnace is released, and the product is taken out.

[0062] Example 2

[0063] 1. Place a 60% volume fraction silicon carbide preform in a mold and place it inside the lower graphite crucible;

[0064] 2. Place the upper graphite crucible on top of the lower crucible, and place a graphite plug to block the opening of the upper graphite crucible;

[0065] 3. Place the weighed aluminum block into the upper graphite crucible;

[0066] 4. Cover the insulation layer 60 and fix the top of the graphite plug to the device of the cover;

[0067] 5. Cover the furnace cover 42 and start the vacuum pump to evacuate the chamber;

[0068] 6. When the vacuum drops below 5 Pa, start heating;

[0069] 7. Start heating at 10℃ / min, upper chamber 750℃, lower chamber 620℃, keep warm for 30 minutes;

[0070] 8. Start the device connected to the graphite plug on the furnace cover 42, pull out the graphite plug, and allow the aluminum liquid to enter the lower cavity mold;

[0071] 9. When the aluminum liquid has completely entered the mold, start to fill the furnace with pressurized gas (high-purity nitrogen or argon) until the pressure inside the furnace reaches 6MPa and maintain the pressure for 60 minutes;

[0072] 10. After completion, the product is cooled down to below 300 degrees in the furnace, the high-pressure gas in the furnace is released, and the product is taken out.

[0073] Example 3

[0074] 1. Place a 60% volume fraction silicon carbide preform in a mold and place it inside the lower graphite crucible;

[0075] 2. Place the upper graphite crucible on top of the lower crucible, and place a graphite plug to block the opening of the upper graphite crucible;

[0076] 3. Place the weighed aluminum block into the upper graphite crucible;

[0077] 4. Cover the insulation layer 60 and fix the top of the graphite plug to the device of the cover;

[0078] 5. Cover the furnace cover 42 and start the vacuum pump to evacuate the chamber;

[0079] 6. When the vacuum drops below 5 Pa, start heating;

[0080] 7. Start heating at 10℃ / min, upper chamber 750℃, lower chamber 620℃, keep warm for 60 minutes;

[0081] 8. Start the device connected to the graphite plug on the furnace cover 42, pull out the graphite plug, and allow the aluminum liquid to enter the lower cavity mold;

[0082] 9. When the aluminum liquid has completely entered the mold, start to fill the furnace with pressurized gas (high-purity nitrogen or argon) until the pressure inside the furnace reaches 6MPa and maintain the pressure for 60 minutes;

[0083] 10. After completion, the product is cooled down to below 300 degrees in the furnace, the high-pressure gas in the furnace is released, and the product is taken out.

[0084] Example 4

[0085] 1. Place a 60% volume fraction silicon carbide preform in a mold and place it inside the lower graphite crucible;

[0086] 2. Place the upper graphite crucible on top of the lower crucible, and place a graphite plug to block the opening of the upper graphite crucible;

[0087] 3. Place the weighed aluminum block into the upper graphite crucible;

[0088] 4. Cover the insulation layer 60 and fix the top of the graphite plug to the device of the cover;

[0089] 5. Cover the furnace cover 42 and start the vacuum pump to evacuate the chamber;

[0090] 6. When the vacuum drops below 5 Pa, start heating;

[0091] 7. Start heating at 10℃ / min, upper chamber 750℃, lower chamber 620℃, keep warm for 30 minutes;

[0092] 8. Start the device connected to the graphite plug on the furnace cover 42, pull out the graphite plug, and allow the aluminum liquid to enter the lower cavity mold;

[0093] 9. When the aluminum liquid has completely entered the mold, start to fill the furnace with pressurized gas (high-purity nitrogen or argon) until the pressure inside the furnace reaches 8MPa and maintain the pressure for 60 minutes;

[0094] 10. After completion, the product is cooled down to below 300 degrees in the furnace, the high-pressure gas in the furnace is released, and the product is taken out.

[0095] Example 5

[0096] 1. Place a 60% volume fraction silicon carbide preform in a mold and place it inside the lower graphite crucible;

[0097] 2. Place the upper graphite crucible on top of the lower crucible, and place a graphite plug to block the opening of the upper graphite crucible;

[0098] 3. Place the weighed aluminum block into the upper graphite crucible;

[0099] 4. Cover the insulation layer 60 and fix the top of the graphite plug to the device of the cover;

[0100] 5. Cover the furnace cover 42 and start the vacuum pump to evacuate the chamber;

[0101] 6. When the vacuum drops below 5 Pa, start heating;

[0102] 7. Start heating at 10℃ / min, upper chamber 720℃, lower chamber 620℃, keep warm for 30 minutes;

[0103] 8. Start the device connected to the graphite plug on the furnace cover 42, pull out the graphite plug, and allow the aluminum liquid to enter the lower cavity mold;

[0104] 9. When the aluminum liquid has completely entered the mold, start to fill the furnace with pressurized gas (high-purity nitrogen or argon) until the pressure inside the furnace reaches 6MPa and maintain the pressure for 30 minutes;

[0105] 10. After completion, the product is cooled down to below 300 degrees in the furnace, the high-pressure gas in the furnace is released, and the product is taken out.

[0106] Example 6

[0107] 1. Place a 50% volume fraction silicon carbide preform in a mold and place it inside the lower graphite crucible;

[0108] 2. Place the upper graphite crucible on top of the lower crucible, and place a graphite plug to block the opening of the upper graphite crucible;

[0109] 3. Place the weighed aluminum block into the upper graphite crucible;

[0110] 4. Cover the insulation layer 60 and fix the top of the graphite plug to the device of the cover;

[0111] 5. Cover the furnace cover 42 and start the vacuum pump to evacuate the chamber;

[0112] 6. When the vacuum drops below 5 Pa, start heating;

[0113] 7. Start heating at 10℃ / min, upper chamber 750℃, lower chamber 620℃, keep warm for 30 minutes;

[0114] 8. Start the device connected to the graphite plug on the furnace cover 42, pull out the graphite plug, and allow the aluminum liquid to enter the lower cavity mold;

[0115] 9. When the aluminum liquid has completely entered the mold, start to fill the furnace with pressurized gas (high-purity nitrogen or argon) until the pressure inside the furnace reaches 6MPa and maintain the pressure for 30 minutes;

[0116] 10. After completion, the product is cooled down to below 300 degrees in the furnace, the high-pressure gas in the furnace is released, and the product is taken out.

[0117] Example 7

[0118] The only difference between this embodiment and embodiment 1 is that, except for placing a silicon carbide preform with a volume fraction of 45% in step (1) in the mold, the rest is the same as embodiment 1.

[0119] Example 8

[0120] The only difference between this embodiment and embodiment 1 is that, except for the step (9) of filling the furnace with pressurized gas to a pressure of 10 MPa, the rest is the same as embodiment 1.

[0121] Example 9

[0122] The only difference between this embodiment and embodiment 3 is that, except for the heating at 5° C. / min in step (7), the rest is the same as embodiment 3.

[0123] Comparative Example 1

[0124] The only difference between this comparative example and Example 5 is that, except for the step (9) of filling the furnace with pressurized gas to a pressure of 2 MPa, the rest is the same as Example 5.

[0125] Comparative Example 2

[0126] The only difference between this comparative example and Example 5 is that, except for the upper chamber temperature of 850° C. in step (7), the rest are the same as Example 5.

[0127] Comparative Example 3

[0128] See also Figure 3 This comparative example is a traditional aluminum silicon carbide manufacturing method. The aluminum liquid and the silicon carbide preform are placed in the same chamber. The specific operations are as follows:

[0129] placing a 60% volume fraction silicon carbide preform in a mold;

[0130] placing an aluminum block on top of the silicon carbide preform;

[0131] Close the furnace door and use a vacuum pump to pump the vacuum inside the furnace to below 5Pa;

[0132] Heat the furnace to 750°C at a rate of 10°C / min and keep it at that temperature for 30 minutes;

[0133] Fill the furnace with pressurized gas to 6MPa and maintain the pressure for 30 minutes;

[0134] After completion, the product is cooled with the furnace to below 300 degrees, the high-pressure gas in the furnace is released, and the product is taken out.

[0135] Comparative Example 4

[0136] See also Figure 4 This comparative example shows another common traditional aluminum silicon carbide manufacturing method. The aluminum liquid and the silicon carbide preform are placed in the same chamber. The specific operation is as follows:

[0137] Place the aluminum block into the lower chamber crucible;

[0138] Place the 60% volume fraction silicon carbide preform into the mold and weld it to the riser pipe, ensuring that all parts of the mold except the riser pipe opening are welded and sealed;

[0139] Place the welded mold in the designated position of the upper cavity and close the furnace door;

[0140] Use a vacuum pump to pump the pressure in the furnace to below 5 Pa;

[0141] Start heating at 10°C / min, upper chamber 620°C, lower chamber 750°C, and keep constant temperature for 30 minutes;

[0142] Raise the lower chamber crucible so that the aluminum liquid floods the rising liquid mouth and the rising liquid mouth reaches near the bottom of the crucible;

[0143] Fill the furnace with pressurized gas until the pressure reaches 6MPa, then hydraulically pour aluminum into the upper cavity mold and maintain the pressure for 30 minutes;

[0144] Lower the lower chamber crucible to separate the remaining aluminum liquid in the crucible from the riser tube;

[0145] After completion, the product is cooled to below 300 degrees with the furnace, and the high-pressure gas in the furnace is released.

[0146] After the product has completely cooled, cut open the mold and take out the product.

[0147] Performance Testing

[0148] The above examples and comparative examples were tested for performance, and the results are shown in Table 1 below:

[0149] Example No. <![CDATA[Density (g / cm 3 )]]> Flexural strength (MPa) Example 1 3.0 298 Example 2 3.0 290 Example 3 3.04 343 Example 4 3.05 350 Example 5 2.98 285 Example 6 2.97 275 Example 7 2.95 260 Example 8 3.05 353 Example 9 3.04 340 Comparative Example 1 3.03 240 Comparative Example 2 2.95 262 Comparative Example 3 2.98 258 Comparative Example 4 3.0 295

[0150] 1) Through the analysis of the data in Table 1, it can be concluded that when using the same raw materials, the performance of the aluminum silicon carbide composite material prepared by the new process is better than that of the aluminum silicon carbide composite material prepared by the traditional method.

[0151] 2) Through Example 1 and Example 8, it can be seen that when other parameters remain unchanged, as the pressurization pressure increases, the density and strength of the silicon carbide composite material increase.

[0152] 3) It can be seen from Examples 1, 6 and 7 that, when other parameters remain unchanged, the performance of the aluminum silicon carbide composite material increases with the increase of the volume fraction of silicon carbide.

[0153] 4) It can be seen from Examples 3 and 9 that, when other parameters remain unchanged, changes in the heating rate of the molten aluminum have little effect on the performance of the aluminum-silicon carbide composite material.

[0154] 5) Examples 1 and 5 show that, within a certain range, increasing the temperature of the molten aluminum can improve its fluidity and increase the density and strength of the aluminum-silicon carbide composite. However, when the temperature reaches a certain level, the interfacial reaction between the silicon carbide and the molten aluminum increases, leading to an increase in the aluminum carbide phase. While this can increase the density of the aluminum-silicon carbide composite, it also reduces bonding strength and flexural strength.

[0155] 6) It can be seen from Example 5 and Comparative Example 1 that when the pressure is less than a certain level, the performance of the aluminum silicon carbide composite material decreases significantly.

[0156] 7) Through Example 1 and Comparative Example 3, it can be seen that the new process method greatly reduces the contact time between the silicon carbide preform and the aluminum liquid, can effectively reduce the interfacial reaction, reduce aluminum carbide (Al4C3), reduce the generation of unstable phases, and improve the performance of the aluminum silicon carbide composite material.

[0157] 8) Through Example 1 and Comparative Example 4, it can be seen that both process methods can reduce the reaction time of aluminum liquid and silicon carbide, but the production process of Comparative Example 4 is complicated, the production mold requirements are high, and the production cost is high.

[0158] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. An efficient pressure preparation device for aluminum silicon carbide composite materials, characterized in that: include: The furnace body includes a furnace shell and a furnace cover, the furnace cover is sealed and connected to the top of the furnace shell, and a reaction space is formed inside the furnace body; a lower graphite crucible, located at the bottom of the reaction space and open upward; an outer wall of the lower graphite crucible is covered with a first electromagnetic heating component, the first electromagnetic heating component being used to heat the silicon carbide preform placed in the lower graphite crucible; An upper graphite crucible can be stacked on the opening of the lower graphite crucible to maintain thermal insulation between the two, and a leakage hole is opened on the bottom wall of the upper graphite crucible; the outer wall of the upper graphite crucible is covered with a second electromagnetic heating component, which is used to heat the aluminum ingot placed in the upper graphite crucible; A graphite rod is connected to the furnace cover in a liftable manner so that the lower end of the graphite rod can be switched between a position of closing or opening the leakage hole; The gas charging interface is connected to the wall of the furnace body and is used to connect to an external gas source to introduce gas into the reaction space; The exhaust interface is connected to the wall of the furnace body and is used to connect to a vacuum pumping device for evacuating the gas in the reaction space to create a vacuum.

2. The preparation device according to claim 1, characterized in that The bottom wall of the upper graphite crucible is V-shaped, and the leakage hole is opened in the center of the bottom wall.

3. The preparation device according to claim 1, characterized in that The graphite rod is connected to a hydraulic device, and the hydraulic device drives the graphite rod to move up and down.

4. A method for preparing an aluminum silicon carbide composite material using the apparatus according to any one of claims 1 to 3, characterized in that: The following steps are involved: Step 1: Place the silicon carbide preform in the lower chamber and the aluminum ingot in the upper chamber, and evacuate to the process requirements; Step 2: Heat the silicon carbide preform and the aluminum ingot to the target temperature respectively and keep them warm for 30-60 minutes; Step 3: Pull up the graphite plug to allow the molten aluminum to flow down into the mold below and come into contact with the silicon carbide preform; Step 4: Introduce inert gas and apply stepped pressure, maintaining the pressure for 30-60 minutes, so that the aluminum liquid combines with the silicon carbide; Step 5: After cooling to 300°C, release the pressure and take out the aluminum silicon carbide composite material.

5. The preparation method according to claim 4, wherein The volume fraction of the silicon carbide preform is 40-65%; In the aluminum silicon carbide composite material, aluminum alloy accounts for 35-60%.

6. The preparation method according to claim 4, wherein The step of evacuating the reaction space to a vacuum below 5 Pa is performed to meet the process requirements.

7. The preparation method according to claim 4, wherein The step heats the silicon carbide preform and the aluminum ingot to target temperatures respectively, wherein the target temperature of the silicon carbide preform is 620°C; the target temperature of the aluminum ingot is 720-750°C.

8. The preparation method according to claim 7, wherein The heating rate is 5℃ / min-10℃ / min; the target temperature is maintained for 30-60 minutes.

9. The preparation method according to claim 4, wherein The inert gas includes nitrogen or argon.

10. The preparation method according to claim 4 or 8, characterized in that: The air pressure is 5-10 MPa.

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