Preparation and simultaneous reaction bonding method of an Al-Si / SiC composite material

Abstract

The present invention relates to a method for preparing and synchronously reaction-bonding an Al-Si / SiC composite material. The method for preparing and synchronously reaction-bonding the Al-Si / SiC composite material includes: spreading Al-Si alloy particles on at least two stacked SiC / C porous preforms, and performing in-situ reaction infiltration sintering to achieve integrated bonding of the SiC-based composite material; wherein, the mass fraction of Al in the Al-Si alloy particles is 2 wt.% to 14 wt.%.

Description

Technical Field

[0001] The present invention belongs to the field of new material preparation and connection, and relates to a preparation and synchronous reaction connection method of Al-Si / SiC composite materials. Background Art

[0002] Integrated circuits made of semiconductor materials (such as silicon, gallium nitride, silicon carbide, etc.) are the core of modern electronic devices widely used today, and the semiconductor industry has an extremely important impact on a country's economic growth and national defense security. Silicon carbide (SiC) materials have excellent physical and chemical properties (such as high strength, high hardness, high temperature resistance, excellent chemical stability, high oxidation resistance and wear resistance, etc.), and can effectively avoid the introduction of impurities during the processing process. They are widely used as ceramic components for semiconductor processing and occupy a large proportion in semiconductor processing components. At present, SiC components for semiconductors are difficult to meet the requirements of processing components. In view of the problems existing in the existing SiC components, in order to break the restrictions of foreign countries on the development of China's semiconductor industry and at the same time make up for the short board of key materials in China's semiconductor industry, it is of great significance to develop a high-density SiC-based ceramic component with good high-temperature mechanical properties, appropriate thermal expansion coefficient, high thermal conductivity and excellent plasma corrosion resistance for the development of China's semiconductor industry.

[0003] However, the high wear resistance and high hardness of SiC-based composite materials applied in the semiconductor field make their processing performance poor, and it is very difficult to process them into complex-shaped components and large-sized components like metals through plastic forming processes such as forging and extrusion. Using connection technology to connect relatively simple composite material components is an effective method for preparing complex SiC-based composite material components and large-sized structural components. Therefore, the connection problem of SiC-based composite materials is a key problem that must be solved for the engineering application of SiC-based composite materials.

[0004] At present, the connection methods of SiC-based ceramic materials have developed rapidly, mainly including direct connection, metal brazing connection, solid-phase diffusion connection, precursor connection, MAX phase connection and other methods. However, when these connection methods are applied to the field of semiconductor material connection, there are mainly problems such as mismatched thermal expansion coefficients resulting in connection stresses, difficult processing, limited connection strength, and inability to perform large-sized processing.

[0005] Therefore, it is very necessary to explore a connection method applicable to SiC ceramics. Brazing, as one of the most widely used methods in ceramic connection, has a good background for engineering application. During the brazing connection process, the welding stress caused by the mismatch of thermal expansion coefficients between the ceramic base material and the metal solder has always been one of the technical problems plaguing the brazing of silicon carbide ceramics. Summary of the Invention

[0006] Aiming at the defects of the existing SiC-based composite material connection methods applicable to the semiconductor field, the present invention first proposes a synchronous reaction connection method that combines the in-situ reaction infiltration method with the brazing connection technology to prepare a dense Al-Si / SiC composite material with a certain connection strength and applicable to the semiconductor material field, using SiC powder, Si particles, Al particles and carbon black as raw materials.

[0007] On the one hand, the present invention provides a preparation and synchronous reaction connection method for Al-Si / SiC composite materials. The Al-Si alloy particles are spread on at least two stacked SiC / C porous preforms, and through in-situ reaction infiltration sintering, the integrated connection of SiC-based composite materials is realized; wherein, the mass fraction of Al in the Al-Si alloy particles is 2wt.% - 14wt.%.

[0008] In the present invention, the Al-Si alloy has good chemical compatibility with the SiC-based base material, and by creatively regulating the content of Al in the Al-Si alloy, its thermal expansion coefficient is further adjusted, so that it is close to the thermal expansion coefficient of the SiC-based base material. While reducing its thermal stress, the preparation and reaction connection of the Al-Si / SiC composite material are realized synchronously.

[0009] In the present invention, the Al-Si alloy particles are placed above the porous preform, and through the synchronous reaction connection method, the in-situ infiltration method and the brazing connection method are combined to prepare a dense Al-Si / SiC composite material with a certain connection strength and applicable to the semiconductor field. The present invention completes the preparation and connection of the Al-Si / SiC composite material synchronously, without the two-step process of sintering preparation followed by brazing connection. The process is convenient and simple, with low cost, high efficiency and good industrial application prospects. This connection method is of great significance in the field of semiconductor material connection, and it has an indelible promoting effect on the progress of semiconductor industrial production technology and the improvement of production efficiency. After retrieval, there are currently no patents or papers reporting this in-situ reaction synthesis technology.

[0010] In the present invention, the preparation and connection of the Al-Si / SiC composite material are completed synchronously, without the two-step process of sintering preparation followed by brazing connection. The process is convenient and simple, with low cost, high efficiency and good industrial application prospects. This connection method is of great significance in the field of semiconductor material connection, and it has an indelible promoting effect on the progress of semiconductor industrial production technology and the improvement of production efficiency.

[0011] Preferably, the particle size of the Al-Si alloy particles is 3 - 5 mm. In the present invention, the relevant properties of the prepared Al-Si / SiC composite material with a certain connection strength can be regulated by controlling the mass fraction of Al in the Al-Si alloy and C:SiC in the starting material composition.

[0012] Preferably, the preparation process of the Al-Si alloy particles includes:

[0013] (1) Mix Al particles and Si particles in proportion and place them in a water-cooled copper crucible. After vacuum arc melting and cooling to room temperature, an ingot is obtained.

[0014] (2) Repeat step (1) 5 - 7 times and turn the obtained ingot 180° each time to obtain an Al-Si alloy ingot.

[0015] (3) Crush the prepared Al-Si alloy ingot to obtain Al-Si alloy particles.

[0016] Preferably, in step (1), the particle size of the Al particles is 1 - 3 mm and the purity is ≥99.9%; the particle size of the Si particles is 3 - 5 mm and the purity is ≥99.9%.

[0017] The parameters of the vacuum arc melting include: the vacuum degree ≤8×10 -3 Pa; the current range is 120 - 260 A; the temperature of the cooling water used for the water-cooled copper crucible is 22 - 24°C, and the pressure of the cooling water used is 0.1 - 0.2 MPa.

[0018] Preferably, the pore diameter of each SiC / C porous preform is 400 nm - 1.5 μm, and the thickness is 5 - 10 mm.

[0019] Preferably, the SiC / C porous preform contains SiC powder and carbon black, and the mass ratio of the SiC powder to the carbon black is 1:(0.1 - 0.66); the preparation process of the SiC / C porous preform includes: ball milling, atomizing granulating and forming the SiC powder, carbon black and binder to obtain the SiC / C porous preform.

[0020] Preferably, the particle size of the SiC powder is 5 - 50 μm and the purity is ≥99.9%; the particle size of the carbon black is 1 - 5 μm and the purity is ≥99.9%.

[0021] Preferably, the binder is at least one of phenolic resin, PVB, and PVA, and preferably phenolic resin; the binder used herein can be added in the form of a phenolic resin alcohol solution with a concentration of 40-60 wt% (for example, 50 wt.%), and it is only necessary to ensure that the mass fraction of the binder (at least one of phenolic resin, PVB, and PVA) is 6-10 wt% of the total mass of SiC powder and carbon black.

[0022] Preferably, the parameters of the ball milling and mixing include: the rotation speed is 300-400 r / min, and the time is 240-300 min; the parameters of the spray granulation include: the peristaltic speed is 30-60 r / min; the temperature is 90-100 °C;

[0023] The forming method is dry pressing, the pressure is 10-15 MPa, and the pressure holding time is 30-60 seconds. Here, the ball milling medium can be anhydrous ethanol.

[0024] Preferably, the connection process of the synchronous reaction connection method includes: the atmosphere is vacuum or inert atmosphere; the temperature is 1500-1600 °C; the heat preservation time is 60-120 min.

[0025] Preferably, the spreading amount of the Al-Si alloy particles is 1.5-2.0 times the theoretically calculated value.

[0026] Preferably, the in-situ reaction infiltration sintering includes: under a vacuum condition of ≤5×10 -3 Pa, heating from room temperature to 1100-1200 °C at a rate of 8-12 °C / min, then heating from 1200-1300 °C at a rate of 3-7 °C / min, and then heating from 1500-1600 °C at a rate of 1-3 °C / min to the welding temperature, holding for 60-120 min and then cooling to room temperature with the furnace.

[0027] On the other hand, the present invention realizes the preparation and synchronous connection of the Al-Si / SiC composite material through the synchronous reaction connection method to obtain the Al-Si / SiC composite material; an interfacial phase layer is formed at the joint of the Al-Si / SiC composite material; the composition of the interfacial phase layer is Si phase; the thickness of the interfacial phase layer does not exceed 30 μm (for example, 1-30 μm), preferably 10-20 μm. Among them, the shear strength of the Al-Si / SiC composite material is 45.13-89.74 MPa, and the conductivity of the Al-Si / SiC composite material is 4.78×10 -4 ~9.16×10 -5 S cm -1 .

[0028] On the other hand, the present invention also provides an application of the synchronous reaction bonding method of Al-Si / SiC composite materials in the field of semiconductor material bonding.

[0029] In the present invention, by adjusting the mass fraction of Al in the Al-Si alloy, the Al content in the Al-Si / SiC composite material is changed, thereby affecting the mechanical properties and electrical conductivity of the prepared composite material. In addition, the present invention also adjusts the C:SiC ratio in the SiC / C porous preform, so that the SiC content in the prepared Al-Si / SiC composite material is changed, thereby affecting its microscopic morphology and further affecting its mechanical properties and electrical conductivity. Through the above two aspects of changes and adjustments, it is possible to better prepare Al-Si / SiC composite materials that meet the requirements and can be applied in the semiconductor field according to actual application needs.

[0030] Beneficial effects:

[0031] In the present invention, the porous preform is infiltrated with Al-Si alloy particles, and the in-situ infiltration method and the brazing connection method are combined to prepare a dense Al-Si / SiC composite material with a certain connection strength. The present invention completes the preparation of the Al-Si / SiC composite material and the integrated connection technology in one step, without the two-step process of sintering preparation and then brazing connection. The process is convenient and simple, with low cost, high efficiency, and has good industrial application prospects. This kind of connection technology is of great significance in the field of semiconductor material bonding, and it has an indelible promoting effect on the progress of semiconductor industrial production technology and the improvement of production efficiency. Description of the drawings

[0032] Figure 1 Microscopic morphology diagram of the Ti-Si alloy prepared in Example 1;

[0033] Figure 2 Synchronous reaction bonding process implementation diagram of the Al-Si / SiC composite material prepared by synchronous reaction bonding of the porous preform with Al-Si alloy particles in Example 1, combining the in-situ infiltration method and the brazing connection method to prepare a dense Al-Si / SiC composite material with a certain connection strength;

[0034] Figure 3 Microscopic morphology diagram of the Al-Si / SiC composite material prepared by the synchronous reaction bonding method in Example 1;

[0035] Figure 4 Al-Si / SiC composite material prepared and bonded by the synchronous reaction bonding method in Example 1;

[0036] Figure 5Schematic diagram showing residual carbon black particles found after sintering the Al-Si / SiC composite material prepared in Comparative Example 1 and the "undercooked" phenomenon. Detailed implementation manners

[0037] To further illustrate the content, features and actual effects of the present invention, the present invention will be described in detail below with reference to the embodiments. It should be noted that the modified methods designed in the present invention are not limited to these specific implementation manners. Without departing from the spirit and connotation of the design of the present invention, equivalent replacements and modifications made by those skilled in the art on the basis of reading the content of the present invention are also within the scope of protection required by the present invention.

[0038] The present invention first proposes to use SiC powder, Si particles, Al particles and carbon black as raw materials, and through a preparation method combining in-situ reaction infiltration method and brazing connection method and a synchronous reaction connection method to form a dense Al-Si / SiC composite material with a certain connection strength and applicable to the semiconductor material field.

[0039] In the present invention, the Al-Si alloy and the SiC-based base material have good chemical compatibility, and by adjusting the thermal expansion coefficient of the Al-Si alloy to be close to that of the SiC-based base material, the stress of the welded joint is reduced.

[0040] The following exemplarily illustrates the preparation and synchronous reaction connection method of the Al-Si / SiC composite material provided by the present invention.

[0041] Specifically, the present invention provides a preparation and synchronous reaction connection method for an Al-Si / SiC composite material, including: placing Al-Si alloy particles above a porous preform stacked by two or more pieces, and through a combination of in-situ infiltration method and brazing connection method, a dense Al-Si / SiC composite material with a certain connection strength and applicable to the semiconductor field is prepared.

[0042] In the present invention, according to the Al-Si binary phase diagram, Al particles and Si particles are weighed by mass percentage and mechanically mixed, placed in a water-cooled copper crucible, and melted 5 to 7 times by a vacuum arc melting device. Each time, the ingot is turned 180°, and under vacuum conditions, it is naturally cooled to room temperature to complete the preparation of the Al-Si alloy. The raw materials used for the Al-Si alloy component include two components, Si particles and Al particles. The particle size of the Si particles is 3 to 5 mm, and the purity is ≥99.9%; the particle size of the Al particles is 1 to 3 mm, and the purity is ≥99.9%. Among them, the vacuum degree of the arc melting furnace is better than 8×10 -3Pa, the current range is 120 - 260 A, the cooling water temperature of the copper crucible is 22 - 24 °C, and the cooling water pressure is 0.1 - 0.2 MPa. In addition, a vibration mill is used to crush the arc-melted Al-Si alloy ingot into Al-Si alloy particles with uniform particle size, and the particle size is 3 - 5 mm.

[0043] In the present invention, using SiC powder and carbon black as raw materials, SiC powder and carbon black are weighed according to the designed mass percentages of each component, and the proportioned powders are mixed evenly and then pressed into a green body. The mixing method is not particularly limited, and ball milling can be used. The ball milling solvent is anhydrous ethanol. The binder can be added to the raw materials in the form of a 50 wt.% phenolic resin alcohol solution. The method used for pressing is dry pressing. The mixed powder is loaded into a mold with a specified size, and a certain pressure (such as 10 - 15 MPa) is applied to form the powder into a green body of a SiC / C porous preform.

[0044] The crushed Al-Si alloy particles are placed on the green body of SiC / C porous preforms which are made of SiC powder and carbon black as raw materials, mixed evenly in a certain proportion, and at least two pieces are stacked.

[0045] The green body is sintered into a dense Al-Si / SiC composite material with a certain connection strength by a synchronous reaction connection method that combines the in-situ infiltration method and the brazing connection method. The evenly crushed Al-Si alloy particles are evenly placed on the green body of at least two stacked SiC / C porous preforms, and the amount of Al-Si alloy particles placed is 1.5 - 2 times the theoretically calculated value to ensure complete infiltration of the green body. If the amount of Al-Si alloy particles placed is not within the above range, incomplete reaction will occur and there will be an undercooked phenomenon inside the prepared green body.

[0046] The green body is placed in a vacuum brazing furnace to complete the vacuum brazing process, realizing the preparation of the Al-Si / SiC composite material and the synchronous reaction connection. The connection process is as follows: under a vacuum condition of ≤5×10 -3 Pa, it is heated to 1100 - 1200 °C at a rate of 8 - 12 °C / min, then heated to 1200 - 1300 °C at a rate of 3 - 7 °C / min, and then heated to the welding temperature of 1500 - 1600 °C at a rate of 1 - 3 °C / min. After holding for 60 - 120 min, it is cooled to room temperature with the furnace.

[0047] In the present invention, during the synchronous reaction joining process, the temperature is raised to the sintering temperature at different heating rates. The purpose is to make the entire synchronous reaction joining process more sufficient. Compared with one-step heating, this method can better control the grain size and phase transformation, reduce the internal stress during sintering, and promote the diffusion of gas. If the heating rate is too low, it will lead to an extended sintering time, an uneven structure of the sintered body, incomplete grain growth, thereby affecting the density and mechanical properties of the material. If the heating rate is too high, it will cause rapid generation of thermal stress inside the sintered body, resulting in uneven thermal expansion of the material and causing cracks or deformation in the sintered body. In addition, too high or too low sintering temperature will cause defects inside the material (such as a large number of pores and inability to be densified), and thus it is impossible to prepare a composite material with excellent performance. If the vacuum degree > 5×10 -3 Pa, it will cause the prepared sample to fail to achieve the synchronous reaction joining process.

[0048] Generally speaking, by selecting an appropriate heating rate, better control of the grain size can be obtained during the sintering process of ceramic materials, the accumulation of internal stress can be reduced, and gas diffusion can be promoted, thereby improving the performance and quality of the sintered body. However, the optimal heating rate depends on the specific material composition and sintering conditions, and experiments and optimizations need to be carried out in practical applications.

[0049] In the present invention, the contents of Al and SiC in the Al / SiC-based composite material can be adjusted by controlling the mass fraction of Al in the Al-Si alloy and the ratio of SiC powder and carbon black in the green body. The Al content range in the green body of the SiC / C porous preform is 2 - 14 wt.%. When the Al content is less than 2 wt.%, it will lead to a relatively low Al content inside the prepared Al-Si / SiC composite material during the synchronous joining process, unable to meet its conductivity requirements. When the Al content is greater than 14 wt.%, it will cause its thermal expansion coefficient to be too large, which does not match the thermal expansion coefficient of the matrix, and there will be thermal stress during the synchronous reaction joining process, and the synchronous reaction joining process cannot be achieved.

[0050] The conductivity of the Al-Si / SiC composite material joined by the synchronous reaction joining method of an Al-Si / SiC composite material provided by the present invention is in the range of 4.78×10 -4 ~8.86×10 -5 S cm -1 range, and the shear strength is in the range of 45.13 - 89.74 MPa.

[0051] The following are further examples to illustrate the present invention in detail. It should also be understood that the following examples are only for further illustrating the present invention and cannot be construed as limiting the protection scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention all fall within the protection scope of the present invention. The specific process parameters and the like in the following examples are also only an example within a suitable range, that is, those skilled in the art can make selections within a suitable range through the description herein, rather than being limited to the specific values in the following examples.

[0052] Example 1

[0053] (1) Preparation of Al-Si alloy powder: According to the Al-Si binary phase diagram, Al particles and Si particles are weighed in a certain mass ratio and mechanically mixed, placed in a water-cooled copper crucible, and melted 5 to 7 times using a vacuum arc melting device. Each time, the ingot is flipped 180°. Under vacuum conditions, it is naturally cooled to room temperature to complete the preparation of the Al-Si metal ingot. Among them, the particle size of the used Si particles is 3 to 5 mm, and the purity is ≥99.9%; the particle size of the Al particles is 1 to 3 mm, and the purity is ≥99.9%. The vacuum degree of the arc melting furnace is 3×10 -3 Pa, the current is 200 A, the cooling water temperature of the copper crucible is 23°C, and the cooling water pressure is 0.2 MPa. In addition, a vibration mill is used to crush the Al-Si alloy into Al-Si alloy particles with uniform particle size, and the particle size is 3 to 5 mm.

[0054] (2) Preparation of SiC / C porous preform: ① Preparation of mixed powder: SiC powder (particle size 5 μm, purity ≥99.9%), carbon black (particle size 1 to 5 μm, purity ≥99.9%), 50 wt.% phenolic resin alcohol solution (the mass fraction of phenolic resin is 8 wt.% of the total mass of SiC powder and carbon black), and ethanol are mixed evenly by a planetary ball mill, and the prepared slurry is atomized into mixed powder with uniform size through atomization granulation; ② Pressing of preform: The mixed powder obtained in ① is filled into a rectangular mold of 36.00×52.00 mm, and a pressure of 10 - 15 MPa is applied to prepare a rectangular tablet sample of 36.00×52.00 mm, and a SiC / C porous preform is prepared. The pore size distribution of the preform is 400 nm to 1.1 μm, and the thickness is 5.0 mm.

[0055] The raw materials and their ratios used in this Example 1 are shown in Table 1:

[0056] Name Particle size Ratio (wt.%) Al 1 - 3 mm 8.00 Si 3 - 5 mm 92.00 SiC 5 μm 83.42 Carbon black 1 - 5 μm 8.58 Phenolic resin - 8.00

[0057] (3)Preparation and synchronous reaction joining method of Al-Si / SiC composites: The uniformly sized Al-Si alloy particles prepared in (1) are evenly laid on the green body of the SiC / C porous preform prepared in (2) which consists of two stacked parts, and the amount of the placed Al-Si alloy particles is 1.5 - 2.0 times of the theoretically required amount of Al-Si alloy particles to ensure that the porous preform can be completely penetrated by the alloy particles. The stacked green body is put into a vacuum brazing furnace for the preparation and synchronous reaction joining method of the composites. The specific process is as follows: Under a vacuum condition of ≤5×10 -3 Pa, it is heated to 1200 °C at a rate of 10 °C / min, then heated to 1300 °C at a rate of 5 °C / min, and then heated to the welding temperature of 1600 °C at a rate of 2 °C / min. After holding for 120 min, it is cooled to room temperature with the furnace.

[0058] Figure 3 This is the micrograph of the Al-Si / SiC composite prepared in Example 1. It can be seen from the figure that no residual carbon black particles are found after sintering. Among them, SiC particles are distributed in the Al-Si matrix, the interface between the particles and the matrix is clean, tightly combined, and there is no agglomeration.

[0059] Figure 4 This is the cross-section of the Al-Si / SiC composite prepared and joined by the synchronous reaction joining method in Example 1. It can be seen from the figure that for the composite joined by this method, the particles are evenly distributed and the Al-Si / SiC has a good contact interface. The composition of the interfacial phase layer is Si; the average thickness of the interfacial phase layer is 20 μm, and the interface is pollution-free and defect-free, and has a high bonding strength. The conductivity of the Al-Si / SiC composite prepared in Example 1 is 4.79×10 -4 Scm -1 , and the shear strength of the composite joined by the synchronous reaction joining method is 89.74 MPa.

[0060] Example 2

[0061] (1)Preparation of Al-Si alloy particles: According to the Al-Si binary phase diagram, Al particles and Si particles are weighed and mechanically mixed in a certain mass ratio, placed in a water-cooled copper crucible, and melted 5 - 7 times by a vacuum arc melting device. Each time, the ingot is turned over 180°. Under vacuum conditions, it is naturally cooled to room temperature to complete the preparation of the Al-Si metal ingot. Among them, the particle size of the used Si particles is 3 - 5 mm, and the purity ≥99.9%; the particle size of the Al particles is 1 - 3 mm, and the purity ≥99.9%. The vacuum degree of the arc melting furnace is 5×10 -3Pa, with a current of 250 A, the cooling water temperature of the copper crucible is 22 °C, and the cooling water pressure is 0.15 MPa. In addition, a vibratory mill is used to crush the Al-Si alloy into Al-Si alloy particles with uniform particle size, and the particle size is 3 - 5 mm.

[0062] (2) Preparation of SiC / C porous preform: ① Preparation of mixed powder: SiC powder (particle size 5 μm, purity ≥ 99.9%), carbon black (particle size 1 - 5 μm, purity ≥ 99.9%) and 50 wt.% phenolic resin alcohol solution are mixed evenly with ethanol as the solvent using a planetary ball mill, and the prepared slurry is atomized into mixed powder with uniform size through atomization granulation; ② Pressing of preform: The mixed powder obtained in ① is loaded into a rectangular mold of 36.00 × 52.00 mm, and a pressure of 10 - 15 MPa is applied to prepare a rectangular tablet sample of 36.00 × 52.00 mm, and a SiC / C porous preform is prepared. The pore size distribution of the preform is 600 nm - 1.0 μm, and the thickness is 5.0 mm.

[0063] The raw materials and their ratios used in Example 2 are shown in Table 2:

[0064] Name Particle size Ratio (wt.%) Al 1 - 3 mm 6.00 Si 3 - 5 mm 94.00 SiC 5 μm 83.42 Carbon black 1 - 5 μm 8.58 Phenolic resin - 8.00

[0065] (3) Preparation of Al-Si / SiC composite material and synchronous reaction joining method: The uniformly sized Al-Si alloy particles prepared in (1) are evenly spread on the preform of two stacked SiC / C porous preforms prepared in (2), and the amount of Al-Si alloy particles placed is 1.5 - 2.0 times the theoretically required amount of Al-Si alloy particles to ensure that the porous preform can be completely penetrated by the alloy particles. The stacked green body is placed in a vacuum brazing furnace for the preparation of the composite material and the synchronous reaction joining method. The specific process is as follows: Under a vacuum condition of ≤ 5 × 10 -3 Pa, it is heated to 1200 °C at a rate of 10 °C / min, then heated to 1300 °C at a rate of 5 °C / min, and then heated to the welding temperature of 1600 °C at a rate of 2 °C / min, and after holding for 120 min, it is cooled to room temperature with the furnace.

[0066] In the Al-Si / SiC composite material prepared in Example 2, the particles are uniformly distributed in the matrix, interspersed, and there is no agglomeration. The conductivity of the prepared Al-Si / SiC composite material is 5.75 × 10 -4 S cm -1 . The Al-Si / SiC composite material joined by this synchronous reaction joining method has a good combination at the joining interface, no pollution, no defects, and has a high bonding strength. The shear strength of the joined Al-Si / SiC composite material is 87.69 MPa.

[0067] Example 3

[0068] (1) Preparation of Al-Si alloy particles: According to the Al-Si binary phase diagram, Al particles and Si particles were weighed in a certain mass ratio and mechanically mixed, placed in a water-cooled copper crucible, and melted 5 to 7 times using a vacuum arc melting device. Each time, the ingot was turned over 180°. Under vacuum conditions, it was naturally cooled to room temperature to complete the preparation of the Al-Si metal ingot. Among them, the particle size of the used Si particles was 3 to 5 mm, and the purity was ≥99.9%; the particle size of the Al particles was 1 to 3 mm, and the purity was ≥99.9%. The vacuum degree of the arc melting furnace was 8×10 -3 Pa, the current was 220 A, the cooling water temperature of the copper crucible was 23 °C, and the cooling water pressure was 0.2 MPa. In addition, a vibration mill was used to crush the Al-Si alloy into Al-Si alloy particles with uniform particle size, and the particle size was 3 to 5 mm.

[0069] (2) Preparation of SiC / C porous preform: ① Preparation of mixed powder: SiC powder (particle size 5 μm, purity ≥99.9%), carbon black (particle size 1 to 5 μm, purity ≥99.9%) and 50 wt.% phenolic resin alcohol solution were mixed evenly with ethanol as the solvent using a planetary ball mill, and the prepared slurry was atomized into mixed powder with uniform size through atomization granulation; ② Pressing of preform: The mixed powder obtained in ① was loaded into a rectangular mold of 36.00×52.00 mm, and a pressure of 10 - 15 MPa was applied to prepare a rectangular tablet sample of 36.00×52.00 mm, and a SiC / C porous preform was prepared. Among them, the pore size distribution of the preform was 400 nm to 1.1 μm, and the thickness was 5.0 mm.

[0070] The raw materials and their ratios used in this Example 3 are shown in Table 3:

[0071] Name Particle size Ratio (wt.%) Al 1 - 3 mm 4.00 Si 3 - 5 mm 96.00 SiC 5 μm 82.50 Carbon black 1 - 5 μm 9.50 Phenolic resin - 8.00

[0072] (3) Preparation of Al-Si / SiC composite material and synchronous reaction joining method: The uniformly sized Al-Si alloy particles prepared in (1) were evenly spread on the preform of two stacked SiC / C porous preforms prepared in (2), and the amount of Al-Si alloy particles placed was 1.5 to 2.0 times the theoretically required amount of Al-Si alloy particles to ensure that the porous preform could be completely penetrated by the alloy particles. The stacked green body was put into a vacuum brazing furnace for the preparation of the composite material and the synchronous reaction joining method. The specific process was: Under a vacuum condition of ≤5×10 -3 Pa, it was heated to 1200 °C at a rate of 10 °C / min, then heated to 1300 °C at a rate of 5 °C / min, and then heated to the welding temperature of 1600 °C at a rate of 2 °C / min. After holding for 120 min, it was cooled to room temperature with the furnace.

[0073] In Example 3, no residual carbon black particles were found in the sintered Al-Si / SiC composite material. The particles were evenly distributed in the matrix, distributed interphase, and there was no agglomeration. The conductivity of the composite material prepared in Example 3 was 8.64×10 - 4 Scm -1 . For the Al-Si / SiC composite material connected by this synchronous reaction connection method, the connection interface has good bonding, no pollution, no defects, and has a high bonding strength. The shear strength of the connected Al-Si / SiC composite material is 76.54 MPa.

[0074] Example 4

[0075] (1) Preparation of Al-Si alloy particles: According to the Al-Si binary phase diagram, weigh Al particles and Si particles according to a certain mass ratio and mechanically mix them. Place them in a water-cooled copper crucible and melt them 5 to 7 times using a vacuum arc melting device. Each time, turn the ingot 180°. Under vacuum conditions, naturally cool to room temperature to complete the preparation of the Al-Si metal ingot. Among them, the particle size of the used Si particles is 3 to 5 mm, and the purity is ≥99.9%; the particle size of the Al particles is 1 to 3 mm, and the purity is ≥99.9%. The vacuum degree of the arc melting furnace is 3×10 -3 Pa, the current is 260 A, the cooling water temperature of the copper crucible is 24 °C, and the cooling water pressure is 0.2 MPa. In addition, use a vibration mill to crush the Al-Si alloy into Al-Si alloy particles with uniform particle size, and the particle size is 3 to 5 mm.

[0076] (2) Preparation of SiC / C porous preform: ① Preparation of mixed powder: Mix SiC powder (particle size 5 μm, purity ≥99.9%), carbon black (particle size 1 to 5 μm, purity ≥99.9%) with 50 wt.% phenolic resin alcohol solution and use ethanol as a solvent and mix them evenly with a planetary ball mill, and atomize the prepared slurry into mixed powder with uniform size through atomization granulation; ② Pressing of preform: Load the mixed powder obtained in ① into a rectangular mold of 36.00×52.00 mm, apply a pressure of 10 - 15 MPa to prepare a rectangular tablet sample of 36.00×52.00 mm, and prepare a SiC / C porous preform. Among them, the pore size distribution of the preform is 800 nm to 1.2 μm, and the thickness is 10.0 mm.

[0077] The raw materials and their ratios used in this Example 4 are shown in Table 4:

[0078] Name Particle size Ratio (wt.%) Al 1 - 3 mm 8.00 Si 3 - 5 mm 92.00 SiC 5 μm 83.42 Carbon black 1 - 5 μm 8.58 Phenolic resin - 8.00

[0079] (3)Preparation and synchronous reaction joining method of Al-Si / SiC composites: The uniformly sized Al-Si alloy particles prepared in (1) are evenly laid on the green body of the SiC / C porous preform prepared in (2) which consists of two stacked pieces, and the amount of Al-Si alloy particles placed is 1.5 - 2.0 times the theoretically required amount of Al-Si alloy particles to ensure that the porous preform can be completely penetrated by the alloy particles. The stacked green body is placed in a vacuum brazing furnace for the preparation of the composite material and the synchronous reaction joining method. The specific process is as follows: Under a vacuum condition of ≤ 5×10 -3 Pa, it is heated to 1200 °C at a rate of 10 °C / min, then heated to 1300 °C at a rate of 5 °C / min, and then heated to the welding temperature of 1600 °C at a rate of 2 °C / min. After holding for 120 min, it is cooled to room temperature with the furnace.

[0080] In Example 4, no residual carbon black particles were found in the sintered Al-Si / SiC composites. The particles were evenly distributed in the matrix, interspersed, and there was no agglomeration. The conductivity of the composite material joined in Example 4 was 1.31×10 - 5 Scm -1 . For the Al-Si / SiC composites joined by this synchronous reaction joining method, the joining interface has good bonding, no pollution, no defects, and has a high bonding strength. The shear strength of the Al-Si / SiC composites joined by the synchronous reaction joining method in Example 4 was 83.76 MPa.

[0081] Example 5

[0082] (1)Preparation of Al-Si alloy particles: According to the Al-Si binary phase diagram, Al particles and Si particles are weighed and mechanically mixed in a certain mass ratio, placed in a water-cooled copper crucible, and melted 5 - 7 times using a vacuum arc melting equipment. Each time, the ingot is flipped 180°. Under vacuum conditions, it is naturally cooled to room temperature to complete the preparation of the Al-Si metal ingot. Among them, the particle size of the used Si particles is 3 - 5 mm, and the purity is ≥ 99.9%; the particle size of the Al particles is 1 - 3 mm, and the purity is ≥ 99.9%. The vacuum degree of the arc melting furnace is 6×10 -3 Pa, the current is 200 A, the cooling water temperature of the copper crucible is 22 °C, and the cooling water pressure is 0.1 MPa. In addition, a vibration mill is used to crush the Al-Si alloy into Al-Si alloy particles with a uniform particle size, and the particle size is 3 - 5 mm.

[0083] (2) Preparation of SiC / C porous preform: ① Preparation of mixed powder: SiC powder (particle size 5 μm, purity ≥ 99.9%) and carbon black (particle size 1 - 5 μm, purity ≥ 99.9%) were mixed with 50 wt.% phenolic resin alcohol solution using ethanol as the solvent in a planetary ball mill and homogenized. The obtained slurry was atomized into uniformly sized mixed powder through atomization granulation; ② Compression of preform: The mixed powder obtained in ① was filled into a rectangular mold of 36.00×52.00 mm, and a pressure of 10 - 15 MPa was applied to prepare a rectangular tablet sample of 36.00×52.00 mm, thus preparing a SiC / C porous preform. The pore size distribution of the preform was 500 nm - 1.1 μm, and the thickness was 5.0 mm.

[0084] The raw materials and their ratios used in Example 5 are shown in Table 5:

[0085] Name Particle size Ratio (wt.%) Al 1 - 3 mm 12.00 Si 3 - 5 mm 88.00 SiC 5 μm 83.42 Carbon black 1 - 5 μm 8.58 Phenolic resin - 8.00

[0086] (3) Preparation of Al - Si / SiC composite and synchronous reaction bonding method: The uniformly sized Al - Si alloy particles prepared in (1) were evenly spread on the preforms of two stacked SiC / C porous preforms prepared in (2), and the amount of Al - Si alloy particles placed was 1.5 - 2.0 times the theoretically required amount of Al - Si alloy particles to ensure that the porous preform could be completely penetrated by the alloy particles. The stacked green bodies were placed in a vacuum brazing furnace for the preparation of the composite and the synchronous reaction bonding method. The specific process was as follows: Under a vacuum condition of ≤ 5×10 -3 Pa, it was heated to 1200℃ at a rate of 10℃ / min, then heated to 1300℃ at a rate of 5℃ / min, and then heated to the welding temperature of 1550℃ at a rate of 2℃ / min. After holding for 120 min, it was cooled to room temperature with the furnace.

[0087] No residual carbon black particles were found in the sintered Al - Si / SiC composite prepared in Example 5. The particles were evenly distributed in the matrix, interspersed, and there was no agglomeration. The conductivity of the composite bonded in Example 5 was 8.74×10 - 5 Scm -1 . The Al - Si / SiC composite bonded by this synchronous reaction bonding method had a good bonding interface, no pollution, no defects, and had a high bonding strength. The shear strength of the Al - Si / SiC composite bonded by the synchronous reaction bonding method in Example 5 was 45.13 MPa.

[0088] Example 6

[0089] (1) Preparation of Al-Si alloy particles: According to the Al-Si binary phase diagram, weigh Al particles and Si particles according to a certain mass ratio and mechanically mix them. Place them in a water-cooled copper crucible and melt them 5 - 7 times using a vacuum arc melting device. Each time, turn the ingot 180°. Under vacuum conditions, naturally cool it to room temperature to complete the preparation of the Al-Si metal ingot. Among them, the particle size of the used Si particles is 3 - 5 mm, and the purity is ≥99.9%; the particle size of the Al particles is 1 - 3 mm, and the purity is ≥99.9%. The vacuum degree of the arc melting furnace is 4×10 -3 Pa, the current is 120 A, the cooling water temperature of the copper crucible is 22 °C, and the cooling water pressure is 0.15 MPa. In addition, use a vibratory mill to crush the Al-Si alloy into Al-Si alloy particles with uniform particle size, and the particle size is 3 - 5 mm.

[0090] (2) Preparation of SiC / C porous preform: ① Preparation of mixed powder: Mix SiC powder (particle size 5 μm, purity ≥99.9%), carbon black (particle size 1 - 5 μm, purity ≥99.9%) with 50 wt.% phenolic resin alcohol solution and use ethanol as a solvent to mix evenly with a planetary ball mill, and atomize the prepared slurry into mixed powder with uniform size through atomization granulation; ② Pressing of preform: Load the mixed powder obtained in ① into a rectangular mold of 36.00×52.00 mm, apply a pressure of 10 - 15 MPa to prepare a rectangular tablet sample of 36.00×52.00 mm, and prepare a SiC / C porous preform. Among them, the pore size distribution of the preform is 1.1 μm - 1.5 μm, and the thickness is 7.0 mm.

[0091] The raw materials and their ratios used in Example 6 of this embodiment are shown in Table 6:

[0092]

[0093]

[0094] (3) Preparation of Al-Si / SiC composite material and synchronous reaction joining method: Uniformly spread the uniformly sized Al-Si alloy particles prepared in (1) on the preform of two stacked SiC / C porous preforms prepared in (2), and the placement amount of the Al-Si alloy particles is 1.5 - 2.0 times the theoretically required amount of Al-Si alloy particles to ensure that the porous preform can be completely penetrated by the alloy particles. Place the stacked green body into a vacuum brazing furnace for the preparation of the composite material and the synchronous reaction joining method. The specific process is as follows: Under a vacuum condition of ≤5×10 -3 Pa, heat it to 1200 °C at a rate of 10 °C / min, then heat it to 1300 °C at a rate of 5 °C / min, and then heat it to the welding temperature of 1550 °C at a rate of 2 °C / min, keep it warm for 120 min and then cool it to room temperature with the furnace.

[0095] In Example 6, no residual carbon black particles were found after sintering of the prepared Al-Si / SiC composite material. The particles were evenly distributed in the matrix, distributed interphase, and there was no agglomeration. The conductivity of the composite material prepared in Example 6 was 9.16×10 -5 Scm -1 . The Al-Si / SiC composite material connected by this synchronous reaction bonding method has a good bonding at the bonding interface, no pollution, no defects, and has a high bonding strength. The shear strength of the Al-Si / SiC composite material connected by the synchronous reaction bonding method in Example 6 was 48.29 MPa.

[0096] Example 7

[0097] (1) Preparation of Al-Si alloy particles: According to the Al-Si binary phase diagram, Al particles and Si particles were weighed and mechanically mixed in a certain mass ratio, placed in a water-cooled copper crucible, and melted 5 - 7 times using a vacuum arc melting equipment. Each time, the ingot was flipped 180°. Under vacuum conditions, it was naturally cooled to room temperature to complete the preparation of the Al-Si metal ingot. Among them, the particle size of the used Si particles was 3 - 5 mm, and the purity was ≥99.9%; the particle size of the Al particles was 1 - 3 mm, and the purity was ≥99.9%. The vacuum degree of the arc melting furnace was 5×10 -3 Pa, the current was 180 A, the cooling water temperature of the copper crucible was 23°C, and the cooling water pressure was 0.2 MPa. In addition, a vibratory mill was used to crush the Al-Si alloy into Al-Si alloy particles with a uniform particle size, and the particle size was 3 - 5 mm.

[0098] (2) Preparation of SiC / C porous preform: ① Preparation of mixed powder: SiC powder (particle size 5 μm, purity ≥99.9%), carbon black (particle size 1 - 5 μm, purity ≥99.9%) and 50 wt.% phenolic resin alcohol solution were mixed evenly with ethanol as the solvent using a planetary ball mill, and the prepared slurry was atomized into mixed powder with a uniform size through atomization granulation; ② Pressing of the preform: The mixed powder obtained in ① was loaded into a rectangular mold of 36.00×52.00 mm, and a pressure of 10 - 15 MPa was applied to prepare a rectangular tablet sample of 36.00×52.00 mm, and a SiC / C porous preform was prepared. The pore size distribution of the preform was 400 nm - 1.2 μm, and the thickness was 10.0 mm.

[0099] The raw materials and their ratios used in Example 7 are shown in Table 7:

[0100] Name Particle size Ratio (wt.%) Al 1 - 3 mm 8.00 Si 3 - 5 mm 92.00 SiC 5 μm 73.50 Carbon black 1 - 5 μm 18.50 Phenolic resin - 8.00

[0101] (3) Preparation and synchronous reaction bonding method of Al-Si / SiC composites: Evenly lay the uniformly sized Al-Si alloy particles prepared in (1) on the green body of the SiC / C porous preform prepared in (2) consisting of two stacked pieces, and the placement amount of Al-Si alloy particles is 1.5 - 2.0 times the theoretically required amount of Al-Si alloy particles to ensure that the porous preform can be completely penetrated by the alloy particles through melting. Place the stacked green body into a vacuum brazing furnace to carry out the preparation and synchronous reaction bonding method of the composites. The specific process is as follows: Under a vacuum condition of ≤ 5×10 -3 Pa, heat up to 1200 °C at a rate of 10 °C / min, then heat up to 1300 °C at a rate of 5 °C / min, and then heat up to the welding temperature of 1600 °C at a rate of 2 °C / min. After holding for 120 min, cool down to room temperature with the furnace.

[0102] In Example 7, no residual carbon black particles were found after sintering the prepared Al-Si / SiC composites. The particles were evenly distributed in the matrix, interspersed, and there was no agglomeration. The conductivity of the composites bonded in Example 7 was 3.19×10 - 5 Scm -1 . For the Al-Si / SiC composites bonded by this synchronous reaction bonding method, the bonding at the interface is good, without pollution and defects, and has a relatively high bonding strength. The shear strength of the Al-Si / SiC composites bonded by the synchronous reaction bonding method in Example 7 was 56.67 MPa.

[0103] Example 8

[0104] (1) Preparation of Al-Si alloy particles: According to the Al-Si binary phase diagram, weigh Al particles and Si particles according to a certain mass ratio and mix them mechanically. Place them in a water-cooled copper crucible and melt them 5 - 7 times using a vacuum arc melting device. Each time, turn the ingot 180°. Under vacuum conditions, cool down to room temperature naturally to complete the preparation of the Al-Si metal ingot. Among them, the particle size of the used Si particles is 3 - 5 mm, and the purity ≥ 99.9%; the particle size of the Al particles is 1 - 3 mm, and the purity ≥ 99.9%. The vacuum degree of the arc melting furnace is 4×10 -3 Pa, the current is 230 A, the cooling water temperature of the copper crucible is 23 °C, and the cooling water pressure is 0.15 MPa. In addition, use a vibratory mill to crush the Al-Si alloy into Al-Si alloy particles with a uniformly sized particle size, and the particle size is 3 - 5 mm.

[0105] (2) Preparation of SiC / C porous preform: ① Preparation of mixed powder: SiC powder (particle size 5 μm, purity ≥ 99.9%) and carbon black (particle size 1 - 5 μm, purity ≥ 99.9%) are mixed evenly with 8 wt.% phenolic resin using ethanol as a solvent in a planetary ball mill, and the obtained slurry is atomized into uniformly sized mixed powder through atomization granulation; ② Pressing of preform: The mixed powder obtained in ① is filled into a rectangular mold of 36.00×52.00 mm, and a pressure of 10 - 15 MPa is applied to prepare a rectangular tablet sample of 36.00×52.00 mm, thus preparing a SiC / C porous preform. The pore size distribution of the preform is 800 nm - 1.5 μm, and the thickness is 10.0 mm.

[0106] The raw materials and their ratios used in Example 8 are shown in Table 8:

[0107] Name Particle size Ratio (wt.%) Al 1 - 3 mm 10.00 Si 3 - 5 mm 90.00 SiC 5 μm 82.50 Carbon black 1 - 5 μm 9.50 Phenolic resin - 8.00

[0108] (3) Preparation of Al - Si / SiC composite material and synchronous reaction joining method: The uniformly sized Al - Si alloy particles prepared in (1) are evenly laid on the preform of two stacked SiC / C porous preforms prepared in (2), and the amount of Al - Si alloy particles placed is 1.5 - 2.0 times the theoretically required amount of Al - Si alloy particles to ensure that the porous preform can be completely penetrated by the alloy particles. The stacked green bodies are placed in a vacuum brazing furnace for the preparation of the composite material and the synchronous reaction joining method. The specific process is as follows: Under a vacuum condition of ≤ 5×10 -3 Pa, it is heated to 1200℃ at a rate of 10℃ / min, then heated to 1300℃ at a rate of 5℃ / min, and then heated to the welding temperature of 1600℃ at a rate of 2℃ / min, and held for 120 min and then cooled to room temperature with the furnace.

[0109] No residual carbon black particles were found in the sintered Al - Si / SiC composite material prepared in Example 8. The particles are evenly distributed in the matrix, inter - phase distributed, and there is no agglomeration. The conductivity of the composite material joined in Example 8 is 6.65×10 -4 Scm -1 . For the Al - Si / SiC composite material joined by this synchronous reaction joining method, the joining interface has good bonding, no pollution, no defects, and has a high bonding strength. The shear strength of the Al - Si / SiC composite material joined by the synchronous reaction joining method in Example 8 is 62.78 MPa.

[0110] Example 9

[0111] In Example 9, the preparation and the synchronous reaction joining process of the Al-Si / SiC composite material refer to Example 1, with the only difference being that in the preparation of the SiC / C porous preform in step (2), the particle size of the SiC powder is 10 μm.

[0112] No residual carbon black particles were found after sintering the Al-Si / SiC composite material prepared in Example 9. The particles are evenly distributed in the matrix, interspersed, and there is no agglomeration. The conductivity of the composite material prepared in Example 9 is 5.97×10 -4 S cm -1 . For the Al-Si / SiC composite material joined by this synchronous reaction joining method, the joining interface has good bonding, no pollution, no defects, and has a relatively high bonding strength. The shear strength of the Al-Si / SiC composite material joined by the synchronous reaction joining method in Example 9 is 73.28 MPa.

[0113] Example 10

[0114] In Example 10, the preparation and the synchronous reaction joining process of the Al-Si / SiC composite material refer to Example 1, with the only difference being that in the preparation of the SiC / C porous preform in step (2), the particle size of the SiC powder is 50 μm.

[0115] No residual carbon black particles were found after sintering the Al-Si / SiC composite material prepared in Example 10. The particles are evenly distributed in the matrix, interspersed, and there is no agglomeration. The conductivity of the composite material prepared in Example 10 is 5.14×10 -5 Scm -1 . For the Al-Si / SiC composite material joined by this synchronous reaction joining method, the joining interface has good bonding, no pollution, no defects, and has a relatively high bonding strength. The shear strength of the Al-Si / SiC composite material joined by the synchronous reaction joining method in Example 10 is 68.53 MPa.

[0116] Example 11

[0117] In Example 11, the preparation and the synchronous reaction joining process of the Al-Si / SiC composite material refer to Example 1, with the only difference being that in step (3) of the preparation and the synchronous reaction joining method of the Al-Si / SiC composite material, the sintering temperature is 1600 °C and the holding time is 90 min.

[0118] No residual carbon black particles were found after sintering the Al-Si / SiC composite material prepared in Example 11. The particles are evenly distributed in the matrix, interspersed, and there is no agglomeration. The conductivity of the composite material prepared in Example 11 is 8.87×10 -5 S cm -1。The Al-Si / SiC composite material joined by this synchronous reaction joining method has a well-bonded interface, no pollution, no defects, and a relatively high bonding strength. The shear strength of the Al-Si / SiC composite material joined by the synchronous reaction joining method in this Example 11 is 53.18 MPa.

[0119] Example 12

[0120] In this Example 12, the preparation and synchronous reaction joining process of the Al-Si / SiC composite material refer to Example 1, with the only difference being that: in step (3) of the preparation and synchronous reaction joining method of the Al-Si / SiC composite material, the sintering temperature is 1600 °C and the heat preservation time is 60 min.

[0121] No residual carbon black particles were found after sintering of the Al-Si / SiC composite material prepared in this Example 12. The particles are evenly distributed in the matrix, distributed alternately, and there is no agglomeration. The conductivity of the composite material prepared in this Example 12 is 1.59×10 -5 S cm -1 。The Al-Si / SiC composite material joined by this synchronous reaction joining method has a well-bonded interface, no pollution, no defects, and a relatively high bonding strength. The shear strength of the Al-Si / SiC composite material joined by the synchronous reaction joining method in this Example 12 is 52.87 MPa.

[0122] Example 13

[0123] In this Example 13, the preparation and synchronous reaction joining process of the Al-Si / SiC composite material refer to Example 1, with the only difference being that: in the preparation of Al-Si alloy particles in step (1), the Al content in the Al-Si alloy is different, and its raw material ratio is shown in Table 9, and the others are the same as in Specific Example 1.

[0124] The raw materials and ratios used in Example 13 are shown in Table 9:

[0125] Name Particle size Ratio (wt.%) Al 1 - 3 mm 10.00 Si 3 - 5 mm 90.00 SiC 5 μm 83.42 Carbon black 1 - 5 μm 8.58 Phenolic resin - 8.00

[0126] No residual carbon black particles were found after sintering of the Al-Si / SiC composite material prepared in this Example 13. The particles are evenly distributed in the matrix, distributed alternately, and there is no agglomeration. The conductivity of the composite material prepared in this Example 13 is 5.18×10 - 4 Scm -1 。The Al-Si / SiC composite material joined by this synchronous reaction joining method has a well-bonded interface, no pollution, no defects, and a relatively high bonding strength. The shear strength of the Al-Si / SiC composite material joined by the synchronous reaction joining method in this Example 13 is 73.58 MPa.

[0127] Example 14

[0128] In Example 14, the preparation of the Al-Si / SiC composite material and the process of synchronous reaction bonding refer to Example 1, with the only difference being that in the preparation of Al-Si alloy particles in step (1), the Al content in the Al-Si alloy is different, and its raw material ratio is shown in Table 9, and the others are the same as in Example 1.

[0129] The raw materials and their ratios used in Example 14 are shown in Table 10:

[0130] Name Particle size Ratio (wt.%) Al 1 - 3 mm 4.00 Si 3 - 5 mm 96.00 SiC 5 μm 83.42 Carbon black 1 - 5 μm 8.58 Phenolic resin - 8.00

[0131] No residual carbon black particles were found after sintering the Al-Si / SiC composite material prepared in this Example 14. The particles are evenly distributed in the matrix, interspersed, and there is no agglomeration. The conductivity of the composite material prepared in this Example 14 is 6.34×10 -5 S cm -1 . The Al-Si / SiC composite material bonded by this synchronous reaction bonding method has a good bonding interface, no pollution, no defects, and has a high bonding strength. The shear strength of the Al-Si / SiC composite material bonded by the synchronous reaction bonding method in this Example 14 is 76.91 MPa.

[0132] Example 15

[0133] In Example 14, the preparation of the Al-Si / SiC composite material and the process of synchronous reaction bonding refer to Example 1, with the only difference being that in the preparation of Al-Si alloy particles in step (1), the Al content in the Al-Si alloy is different, and its raw material ratio is shown in Table 9, and the others are the same as in Example 1.

[0134] The raw materials and their ratios used in Example 15 are shown in Table 11:

[0135] Name Particle size Ratio (wt.%) Al 1 - 3 mm 6.00 Si 3 - 5 mm 94.00 SiC 5 μm 83.42 Carbon black 1 - 5 μm 8.58 Phenolic resin - 8.00

[0136] No residual carbon black particles were found after sintering the Al-Si / SiC composite material prepared in this Example 15. The particles are evenly distributed in the matrix, interspersed, and there is no agglomeration. The conductivity of the composite material prepared in this Example 15 is 2.31×10 -5 S cm -1 . The Al-Si / SiC composite material bonded by this synchronous reaction bonding method has a good bonding interface, no pollution, no defects, and has a high bonding strength. The shear strength of the Al-Si / SiC composite material bonded by the synchronous reaction bonding method in this Example 15 is 74.54 MPa.

[0137] Example 16

[0138] In Example 16, the preparation and the simultaneous reaction bonding process of the Al-Si / SiC composite material refer to Example 1, with the difference being only that: in the preparation of the Al-Si alloy particles in step (1), the Al content in the Al-Si alloy is different, and the raw material ratio is shown in Table 12, and the others are the same as in Specific Example 1.

[0139] The raw materials and their ratios used in Example 16 are shown in Table 12:

[0140] Name Particle size Ratio (wt.%) Al 1 - 3 mm 12.00 Si 3 - 5 mm 88.00 SiC 5 μm 83.42 Carbon black 1 - 5 μm 8.58 Phenolic resin - 8.00

[0141] No residual carbon black particles were found after sintering the Al-Si / SiC composite material prepared in this Example 16. The particles are evenly distributed in the matrix, interspersed, and there is no agglomeration. The conductivity of the composite material prepared in this Example 16 is 4.87×10 -4 S cm -1 . For the Al-Si / SiC composite material bonded by this simultaneous reaction bonding method, the bonding interface is well combined, pollution-free, defect-free, and has a high bonding strength. The shear strength of the Al-Si / SiC composite material bonded by the simultaneous reaction bonding method in this Example 16 is 73.14 MPa.

[0142] Example 17

[0143] The difference between this Example 17 and Specific Example 1 is that: in the preparation of the green body in step (2), the C:SiC of the SiC / C porous preform is changed, and the raw material ratio is shown in Table 13, and the others are the same as in Specific Example 1.

[0144] The raw materials and their ratios used in Example 17 are shown in Table 13:

[0145] Name Particle size Ratio (wt.%) Al 1 - 3 mm 8.00 Si 3 - 5 mm 92.00 SiC 5 μm 82.50 Carbon black 1 - 5 μm 9.50 Phenolic resin - 8.00

[0146] No residual carbon black particles were found after sintering the Al-Si / SiC composite material prepared in this Example 17. The particles are evenly distributed in the matrix, interspersed, and there is no agglomeration. The conductivity of the composite material prepared in this Example 17 is 8.71×10 -4 S cm -1 . For the Al-Si / SiC composite material bonded by this simultaneous reaction bonding method, the bonding interface is well combined, pollution-free, defect-free, and has a high bonding strength. The shear strength of the Al-Si / SiC composite material bonded by the simultaneous reaction bonding method in this Example 17 is 63.18 MPa.

[0147] Example 18

[0148] The difference between Example 18 and Specific Example 1 is as follows: In the preparation of the green body in step (2), the C:SiC of the SiC / C porous preform is changed, and the raw material ratio is shown in Table 14. The others are the same as Specific Example 1.

[0149] The raw materials and their ratios used in Example 18 are shown in Table 14:

[0150] Name Particle size Ratio (wt.%) Al 1 - 3 mm 8.00 Si 3 - 5 mm 92.00 SiC 5 μm 73.50 Carbon black 1 - 5 μm 18.50 Phenolic resin - 8.00

[0151] No residual carbon black particles were found in the sintered Al-Si / SiC composite material prepared in this Example 18. The particles are evenly distributed in the matrix, interspersed, and there is no agglomeration. The conductivity of the composite material prepared in this Example 11 is 5.17×10 -4 S cm -1 . For the Al-Si / SiC composite material connected by this synchronous reaction bonding method, the bonding interface is well combined, pollution-free, defect-free, and has a high bonding strength. The shear strength of the Al-Si / SiC composite material connected by the synchronous reaction bonding method in this Example 18 is 51.67 MPa.

[0152] Comparative Example 1

[0153] The difference between this Comparative Example 1 and Specific Example 1 is as follows: In the preparation of the Al-Si / SiC composite material and the synchronous reaction bonding method in step (3), the uniformly sized Al-Si alloy particles prepared in step (1) are laid on the green body of the SiC / C porous preform prepared in step (2). Among them, the amount of Al-Si alloy particles required is calculated theoretically, and the theoretically required Al-Si alloy particles are placed.

[0154] Residual carbon black particles were found in the sintered Al-Si / SiC composite material prepared in this Comparative Example 1, and there is a "undercooked" phenomenon, and the synchronous reaction bonding process cannot be achieved, as Figure 5 shown. The Al-Si alloy particles did not melt and penetrate the green body of the SiC / C porous preform. This phenomenon occurred because during the reactive infiltration process, there was volatilization of Al-Si alloy particles or reaction with the graphite crucible. Therefore, Ti-Si alloy particles 1.5 to 2.0 times the theoretically required Al-Si alloy particles were placed during the reactive infiltration process to ensure complete infiltration of the green body.

[0155] Comparative Example 2

[0156] The difference between this Comparative Example 2 and Specific Example 1 is as follows: In the preparation of the SiC / C porous preform in step (2), SiC:C = 54.5:37.5 (as shown in Table 15).

[0157] The raw materials and their ratios used in this Comparative Example 2 are shown in Table 15:

[0158] Name Particle size Ratio (wt.%) Al 1 - 3 mm 8.00 Si 3 - 5 mm 92.00 SiC 5 μm 54.50 Carbon black 1 - 5 μm 37.50 Phenolic resin — 8.00

[0159] After sintering the Al-Si / SiC composite material prepared in Comparative Example 2, residual carbon black particles were found, and there was an "undercooked" phenomenon, and the integrated connection process could not be achieved. This phenomenon occurred because during the reactive infiltration process, the Al-Si alloy particles did not penetrate the green body of the SiC / C porous preform. Therefore, during the reactive infiltration process, the SiC:C needed to be within a certain range to ensure that the green body could be completely infiltrated.

[0160] Comparative Example 3

[0161] The difference between this Comparative Example 3 and Specific Example 1 is that in step (3), in the preparation and synchronous reaction connection method of the Al-Si / SiC composite material, the sintering temperature was 1400 °C and the heat preservation time was 120 min.

[0162] After sintering the Al-Si / SiC composite material prepared in Comparative Example 3, residual carbon black particles were found, and there was an "undercooked" phenomenon. The Al-Si alloy particles did not penetrate the green body of the SiC / C porous preform. This phenomenon occurred because during the reactive infiltration process, due to the low temperature, the reaction process was incomplete, and the Al-Si alloy particles could not further react with the porous preform, resulting in an "undercooked" phenomenon in the middle.

[0163] Comparative Example 4

[0164] The difference between this Comparative Example 4 and Specific Example 1 is that in step (3), in the preparation and synchronous reaction connection method of the Al-Si / SiC composite material, the vacuum degree was 5 - 30 Pa.

[0165] After sintering the Al-Si / SiC composite material prepared in Comparative Example 4, residual carbon black particles were found. The particles were evenly distributed in the matrix, interspersed, without agglomeration, and its microstructure had no obvious difference from that of Example 1. However, for the Al-Si / SiC composite material prepared in this Comparative Example 4, no interfacial layer was formed, and a dense Al-Si / SiC composite material with a certain connection strength could not be prepared. This was because during the sintering process, due to the low vacuum degree, the connection could not be carried out during the infiltration process of the Al-Si alloy particles.

[0166] Comparative Example 5

[0167] The difference between this Comparative Example 5 and Specific Example 1 is that in step (1), in the preparation of the Al-Si alloy particles, the Al content in the Al-Si alloy was different, and its raw material ratio is shown in Table 16, and the others were the same as Specific Example 1.

[0168] The raw materials and their ratios used in Comparative Example 5 are shown in Table 16:

[0169] Name Particle size Ratio (wt.%) Al 1 - 3 mm 1.00 Si 3 - 5 mm 99.00 SiC 5 μm 83.42 Carbon black 1 - 5 μm 8.58 Phenolic resin - 8.00

[0170] After sintering the Al-Si / SiC composite material prepared in Comparative Example 5, there is no Al element inside it, and there is an "undercooked" phenomenon, and the synchronous reaction connection process cannot be achieved.

[0171] Comparative Example 6

[0172] The difference between this Comparative Example 6 and Specific Example 1 is that: in the preparation of Al-Si alloy particles in step (1), the Al content in the Al-Si alloy is different, and its raw material ratio is shown in Table 17, and the others are the same as Specific Example 1.

[0173] The raw materials and their ratios used in Comparative Example 6 are shown in Table 17:

[0174]

[0175]

[0176] Due to the mismatch between the thermal expansion coefficients of the Al-Si alloy particles and the matrix in the Al-Si / SiC composite material prepared in this Comparative Example 6, there are thermal stresses, which in turn lead to cracks during the synchronous reaction connection process, and the Al-Si / SiC composite material cannot be successfully prepared.

[0177] Table 18 shows the composition and its melting parameters in the preparation of the Al-Si alloy prepared in Examples 1-18 and Comparative Examples 1-6:

[0178]

[0179]

[0180] Table 19 shows the composition of the Al-Si / SiC composite green body and its connection parameters in the synchronous reaction connection method in Examples 1-18 and Comparative Examples 1-4:

[0181]

[0182] As can be seen from the table, the present invention can adjust the contents of Al and SiC in the Al / SiC-based composite material by controlling the mass fraction of Al in the Al-Si alloy and the ratio of SiC powder and carbon black in the green body. The Al content in the green body of the SiC / C porous preform ranges from 2 to 14 wt.%. If the Al content is less than 2 wt.%, the Al content inside the prepared Al-Si / SiC composite material during the synchronous connection process will be relatively low, unable to meet its conductivity requirements. If the Al content is greater than 14 wt.%, its thermal expansion coefficient will be too large, not matching the thermal expansion coefficient of the matrix. There will be thermal stress during the synchronous reaction joining process, and cracks will exist in the prepared composite material, and the synchronous reaction joining process cannot be achieved.

Claims

1. A preparation and synchronous reaction joining method for Al-Si / SiC composites, characterized in that an interfacial phase layer is formed at the joint of the Al-Si / SiC composite, and the composition of the interfacial phase layer is Si phase; the thickness of the interfacial phase layer is 10 - 20 μm; the preparation and synchronous reaction joining method includes: spreading Al-Si alloy particles on at least two stacked SiC / C porous preforms, and through in-situ reaction infiltration sintering, the integrated joining of the SiC-based composite is realized; wherein: the mass fraction of Al in the Al-Si alloy particles is 4 wt.% - 12 wt.%; the SiC / C porous preform contains SiC powder and carbon black, and the mass ratio of the SiC powder to the carbon black is 1:(0.1 - 0.66); the spreading amount of the Al-Si alloy particles is 1.5 - 2.0 times of the theoretically calculated value; The process of in-situ reactive melt infiltration sintering is as follows: under a vacuum condition of ≤5×10 -3 Pa, heat it from room temperature to 1100 - 1200 °C at a rate of 8 - 12 °C / min, then heat it to 1200 - 1300 °C at a rate of 3 - 7 °C / min, and then heat it to the welding temperature of 1600 °C at a rate of 1 - 3 °C / min, and keep it warm for 60 - 120 min.

2. The preparation and synchronous reaction connection method according to claim 1, wherein the particle size of the Al-Si alloy particles is 3 - 5 mm; the preparation process of the Al-Si alloy particles includes: (1) Mixing Al particles and Si particles in proportion and placing them in a water-cooled copper crucible, melting by vacuum arc and cooling to room temperature to obtain an ingot; (2) Repeating step (1) 5 - 7 times and turning the obtained ingot 180° each time to obtain an Al-Si alloy ingot; (3) Crushing the obtained Al-Si alloy ingot to obtain Al-Si alloy particles.

3. The preparation and synchronous reaction connection method according to claim 2, characterized in that The particle size of the Al particles is 1 - 3 mm, and the purity is ≥99.9%; the particle size of the Si particles is 3 - 5 mm, and the purity is ≥99.9%; The parameters of the vacuum arc melting include: the vacuum degree ≤ 8×10 -3 Pa; the current range is 120 - 260 A; the temperature of the cooling water used for the water-cooled copper crucible is 22 - 24 °C, and the pressure of the cooling water used is 0.1 - 0.2 MPa.

4. The preparation and synchronous reaction connection method according to claim 1, wherein, The pore diameter of each SiC / C porous preform is 400 nm - 1.5 μm, and the thickness is 5 - 10 mm; the preparation process of the SiC / C porous preform includes: ball milling, atomizing granulating and forming SiC powder, carbon black and a binder to obtain the SiC / C porous preform.

5. The preparation and synchronous reaction connection method according to claim 4, characterized in that The particle size of the SiC powder is 5 - 50 μm, and the purity is ≥99.9%; the particle size of the carbon black is 1 - 5 μm, and the purity is ≥99.9%; the binder is at least one of phenolic resin, PVB, and PVA; the mass fraction of the binder is 6 - 10 wt.% of the total mass of the SiC powder and the carbon black.

6. The preparation and synchronous reaction connection method according to claim 4, characterized in that The parameters of the ball milling include: the rotation speed is 300 - 400 r / min, and the time is 240 - 300 min; The parameters of the atomizing granulating include: the peristaltic speed is 30 - 60 r / min; the temperature is 90 - 100 °C; The forming method is dry pressing; the pressure of the dry pressing is 10 - 15 MPa, and the time is 30 - 60 seconds.

7. An Al-Si / SiC composite material connected by the preparation and synchronous reaction connection method as described in claim 1, characterized in that, The electrical conductivity of the Al-Si / SiC composite material is 4.78×10 -4 ~9.16×10 -5 S cm -1 ; The shear strength of the Al-Si / SiC composite is 45.13 - 89.74 MPa.

8. An application of the preparation and synchronous reaction joining method for the Al-Si / SiC composite according to claim 1 in the field of semiconductor material joining.

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