A method for joining SiC to nickel-based superalloys using a composite metallic interlayer with partial transient liquid phase f connection

Abstract

Method for joining SiC / SiC composite material to nickel-based superalloy by using composite metal interlayer f The present application is to solve the technical problems of difficult control of joint interface reaction and difficult inhibition of brittle intermetallic compounds in weld structure of Cu-based active metal brazing SiC / SiC composite material to nickel-based superalloy f The composite metal interlayer provided by the present application is directly enriched in SiC / SiC side interface by active elements, forms transient liquid phase during welding, has high relative activity of active elements, can realize interface connection through efficient and fast interface reaction, and simultaneously suppresses brittle intermetallic compounds in the weld due to the low content of active elements in the interlayer, so that the obtained joint has firm interface bonding and plastic and ductile weld structure f The room temperature shear strength of the joint of the present application can reach more than 70 MPa, and the high temperature shear strength at 500 DEG C can reach more than 55 MPa.

Description

Technical Field

[0001] The present invention relates to a method for connecting SiC f / SiC and nickel-based high-temperature alloy method. Background Art

[0002] SiC f / SiC ceramic matrix composite material is a new type of material with excellent high temperature performance. Its characteristics include light weight, high thermal conductivity, low thermal expansion coefficient, high high temperature strength (still maintains good mechanical properties at 1650℃), excellent chemical stability (resistant to chemical corrosion and high temperature oxidation) and high fracture toughness. These properties are derived from the high melting point and thermal stability of SiC matrix and SiC fiber, making it have important application potential in high temperature components of aircraft engines and spacecraft. However, SiC f / SiC composite materials have poor processing performance and are difficult to directly form large-scale complex components, which limits their widespread application in the aerospace field. In contrast, nickel-based high-temperature alloys account for up to 50% of the manufacturing of aircraft engine parts. These alloys have excellent plasticity, weldability and forming properties and are suitable for manufacturing aircraft engine hot end parts with a service temperature of up to 800°C. If SiC f High-quality joining of SiC / SiC and nickel-based superalloys will fully leverage the performance advantages of both materials, significantly expanding their applications in the aviation manufacturing industry and possessing significant engineering value. Therefore, developing reliable joining technologies has become a key research topic.

[0003] Currently, in the manufacturing of aircraft engine parts, SiC f The connection between SiC composite materials and nickel-based high-temperature alloys is usually achieved by mechanical connection or brazing. Brazing has the advantages of less stress concentration in the joint, high process flexibility, good sealing, and light weight compared to mechanical connection in ceramic-metal connection. It is gradually replacing mechanical connection in SiC f / SiC composite materials-nickel-based high-temperature alloy connection. In related reports, Cu-based active brazing filler metal (Cu as the matrix element and adding active elements such as Ti and Zr) has been proven to be a kind of SiC f / SiC composite materials / nickel-based high-temperature alloy connectors compatible solder system, active elements such as Ti and Zr can react with SiC f / SiC interface reaction to form a bond. However, in the brazing process, the traditional powder Cu-based active brazing material must contain at least 10 atomic percent of active metal elements to form a bond between SiC and Cu. fThe SiC surface forms good wetting, and higher content of Ti, Zr and other elements can form a large amount of low-melting intermetallic compounds with Cu, Ni and other elements in the weld, which increases the high-temperature softening tendency of the joint and also increases the room-temperature brittleness of the joint, which is not conducive to the mechanical properties of the joint. Therefore, a SiC f The welding scheme of the SiC-nickel-based high-temperature alloy joint will have great significance for the aviation manufacturing industry. SUMMARY

[0004] The application aims to solve the technical problem of excessive active metal elements in the weld structure during the brazing connection of SiC f The application aims to solve the technical problem of excessive active metal elements in the weld structure during the brazing connection of SiC f The application aims to solve the technical problem of excessive active metal elements in the weld structure during the brazing connection of SiC

[0005] The application aims to solve the technical problem of excessive active metal elements in the weld structure during the brazing connection of SiC f The method for connecting SiC

[0006] I. Cleaning treatment of the base material before welding;

[0007] II. Pre-treatment of the composite intermediate layer: polish the two sides of the metal intermediate layer I to be connected to a smooth and bright oxide-free layer using 800#, 1000# and 1200# metallographic sandpaper in turn, then polish the two sides of the metal intermediate layer II to be connected to a smooth and bright oxide-free layer using 800#, 1000# and 1200# metallographic sandpaper in turn, and then immerse the metal intermediate layer I and the metal intermediate layer II in anhydrous ethanol for ultrasonic cleaning and then dry;

[0008] The metal intermediate layer I is Ti foil or Zr foil, and the thickness is 10-30 mu m;

[0009] The metal intermediate layer II is pure Cu or Cu alloy, and the thickness is 200-500 mu m;

[0010] III. Assembly of the samples to be connected;

[0011] The metal intermediate layer I and the metal intermediate layer II treated in step II are connected together using an organic adhesive I to form a composite intermediate layer; then the composite intermediate layer is placed between the base material SiC f The metal intermediate layer I in the composite intermediate layer is assembled into a sandwich structure between the SiC f / SiC surfaces to be joined, and the metal intermediate layer II to the nickel-based high-temperature alloy surfaces to be joined; an organic adhesive II is used to connect the composite intermediate layer to the parent materials on both sides, and the next step is performed after the organic adhesive is air-dried at room temperature;

[0012] 4. Partial instantaneous liquid phase connection:

[0013] Place the sample to be connected after step 3 into the graphite mold and use the metal block to apply brazing pressure to the sample. f / SiC is located at the top, and the mold containing the sample is sent into a vacuum furnace for partial instantaneous liquid phase connection. The partial instantaneous liquid phase connection is carried out under vacuum, the connection temperature is 990℃~1070℃, the holding time is 0~30min, and the temperature is lowered to 300℃~310℃ and then cooled to room temperature with the furnace to obtain SiC f / SiC-nickel-based high-temperature alloy connectors.

[0014] The beneficial effects of the present invention are:

[0015] 1. Direct brazing of SiC with conventional Cu-based active brazing filler metals f Compared with nickel-based high-temperature alloys, the content of active elements (Ti or Zr) in the composite metal intermediate layer provided by the present invention is greatly reduced. At the same time, since the active elements are directly enriched in SiC f At the interface on the Cu / SiC side, the relative activity of the active elements in the liquid phase formed during welding is higher than the uniform liquid phase formed after the conventional Cu-based active solder is melted, which can achieve efficient interface reaction to form a connection. At the same time, due to the low content of active elements in the intermediate layer, the amount of brittle intermetallic compounds in the weld is significantly reduced, which is conducive to obtaining a high-strength joint.

[0016] 2. Direct brazing of SiC with Cu-based brazing filler metal f Compared to nickel-based superalloys, the method of the present invention allows for reliable joints at lower pressures. Because the metal intermediate layer remains largely intact during the joining process, the weld structure retains strong plastic deformation capabilities. Furthermore, under appropriate welding pressure, the low-melting-point liquid phase in the joint is squeezed out, enabling low-temperature connection while maintaining high-temperature performance. The joints of the present invention can achieve room-temperature shear strength exceeding 70 MPa and high-temperature shear strength exceeding 55 MPa at 500°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the instantaneous liquid phase connection mechanism of the connector portion represented by Example 1;

[0018] Figure 2 SiC prepared in Example 1 f Typical microstructure SEM photos of / SiC-nickel-based high-temperature alloy joints;

[0019] Figure 3 for Figure 2 Medium SiC f High-magnification SEM photo of the reaction layer at the / SiC side interface;

[0020] Figure 4 for Figure 3 Energy spectrum analysis results of midpoint 1;

[0021] Figure 5 for Figure 3 Energy spectrum analysis results of midpoint 2. DETAILED DESCRIPTION

[0022] Specific embodiment 1: This embodiment is a method of using a composite metal intermediate layer to partially instantaneously connect SiC f The method of preparing SiC and nickel-based high-temperature alloy is specifically carried out in the following steps:

[0023] 1. Clean the base material before welding;

[0024] 2. Pretreatment of the composite intermediate layer: Use 800#, 1000# and 1200# metallographic sandpaper to polish the surfaces to be connected on both sides of the metal intermediate layer I until they are smooth, bright and free of oxide. Then use 800#, 1000# and 1200# metallographic sandpaper to polish the surfaces to be connected on both sides of the metal intermediate layer II until they are smooth, bright and free of oxide. Then immerse the metal intermediate layers I and II in anhydrous ethanol for ultrasonic cleaning and then dry.

[0025] The metal intermediate layer I is Ti foil or Zr foil with a thickness of 10 μm to 30 μm;

[0026] The metal intermediate layer II is pure Cu or Cu alloy, with a thickness of 200 μm to 500 μm;

[0027] 3. Assembly of samples to be connected:

[0028] The metal intermediate layer I and the metal intermediate layer II processed in step 2 are connected together using an organic adhesive I to form a composite intermediate layer; and then the composite intermediate layer is placed on the base material SiC processed in step 1. f / SiC and the parent material nickel-based high-temperature alloy are assembled into a sandwich structure, and the metal intermediate layer I in the composite intermediate layer and the SiC f / SiC surfaces to be joined, and the metal intermediate layer II to the nickel-based high-temperature alloy surfaces to be joined; an organic adhesive II is used to connect the composite intermediate layer to the parent materials on both sides, and the next step is performed after the organic adhesive is air-dried at room temperature;

[0029] 4. Partial instantaneous liquid phase connection:

[0030] Place the sample to be connected after step 3 into the graphite mold and use the metal block to apply brazing pressure to the sample. f / SiC is located at the top, and the mold containing the sample is sent into a vacuum furnace for partial instantaneous liquid phase connection. The partial instantaneous liquid phase connection is carried out under vacuum, the connection temperature is 990℃~1070℃, the holding time is 0~30min, and the temperature is lowered to 300℃~310℃ and then cooled to room temperature with the furnace to obtain SiC f / SiC-nickel-based high-temperature alloy connectors.

[0031] Specific embodiment 2: This embodiment differs from the specific embodiment 1 in that the method for cleaning the base material before welding in step 1 is:

[0032] First, use a 600# diamond sandpaper to remove the SiC f The large-scale undulations on the surface of the SiC to be joined make the surface to be joined relatively flat; then diamond grinding pastes with specifications of W3.5, W2.5 and W1 are used in turn to grind the base material SiC f / SiC is polished on a flat glass plate until the surface to be connected is flat and bright;

[0033] The base material nickel-based high-temperature alloy is polished in sequence using 600#, 800#, 1000# and 1200# water sandpaper on an automatic grinding and polishing machine at a speed of 300r / min until the surface to be connected is flat and bright;

[0034] Finally, the polished SiC f The SiC and nickel-based high-temperature alloy are respectively ultrasonically cleaned with anhydrous ethanol for 10 to 20 minutes and then dried for later use. Other aspects are the same as those of the first embodiment.

[0035] Specific embodiment 3: This embodiment differs from specific embodiment 1 or 2 in that the organic binder I in step 3 is ethyl α-cyanoacrylate. Other aspects are the same as specific embodiment 1 or 2.

[0036] Specific embodiment 4: This embodiment differs from specific embodiments 1 to 3 in that the organic binder II in step 3 is α-ethyl cyanoacrylate. Other aspects are the same as specific embodiments 1 to 3.

[0037] Specific embodiment 5: This embodiment differs from specific embodiment 4 in that the metal block in step 4 is a metal molybdenum block. Other aspects are the same as specific embodiment 4.

[0038] Specific embodiment 6: This embodiment differs from specific embodiment 5 in that the brazing pressure applied by the metal molybdenum block to the sample in step 4 is 0.05 MPa to 0.5 MPa. Other aspects are the same as specific embodiment 5.

[0039] Specific embodiment 7: This embodiment differs from specific embodiment 6 in that the vacuum degree used in the partial instantaneous liquid phase connection process in step 4 is ≤1×10 -3 Pa. Other aspects are the same as those of the sixth embodiment.

[0040] Specific embodiment eight: This embodiment differs from specific embodiment seven in that the heating rate in step four is 5°C / min to 20°C / min. Other aspects are the same as specific embodiment seven.

[0041] Specific embodiment nine: The difference between this embodiment and specific embodiment eight is that the cooling rate in step four is 5℃ / min~10℃ / min, and the SiC is obtained after cooling to 300℃~310℃ and then cooling to room temperature with the furnace. f / SiC-nickel-based high-temperature alloy connecting piece. Other aspects are the same as those of the eighth embodiment.

[0042] Specific embodiment 10: The difference between this embodiment and specific embodiment 9 is that the cooling rate in step 4 is 5℃ / min~10℃ / min, and after cooling to 300℃, the SiC f / SiC-nickel-based high-temperature alloy connecting piece. Other aspects are the same as those of the ninth embodiment.

[0043] The present invention is verified by the following examples:

[0044] The purity of the pure Cu sheet, Ti foil and Zr foil used in the following examples is 99.9%; the copper alloy sheet used is white copper (brand: B18, cast) and molybdenum copper alloy (Cu-30Mo dual-phase alloy, rolled); the SiC f / SiC is prepared by 2.5D weaving + PIP process; the grade of nickel-based high-temperature alloy used is GH4169 (cast).

[0045] Example 1: This example is a method of using a composite metal intermediate layer to partially instantaneously connect SiC f The method of preparing SiC and nickel-based high-temperature alloy is specifically carried out in the following steps:

[0046] 1. Cleaning of base material before welding: First, use 600# diamond sandpaper to remove SiC f The large-scale undulations on the surface of the SiC to be joined make the surface to be joined relatively flat; then diamond grinding pastes with specifications of W3.5, W2.5 and W1 are used in turn to grind the base material SiC f / SiC is polished on a flat glass plate until the surface to be connected is flat and bright;

[0047] The base material nickel-based high-temperature alloy GH4169 is polished in sequence using 600#, 800#, 1000# and 1200# water sandpaper on an automatic grinding and polishing machine at a speed of 300r / min until the surface to be connected is flat and bright;

[0048] Finally, the polished SiC f / SiC and nickel-based high-temperature alloys were ultrasonically cleaned with anhydrous ethanol for 10 minutes and then dried for later use;

[0049] 2. Pretreatment of the composite intermediate layer: Use 800#, 1000# and 1200# metallographic sandpaper to polish the surfaces to be connected on both sides of the metal intermediate layer I until they are smooth, bright and free of oxide. Then use 800#, 1000# and 1200# metallographic sandpaper to polish the surfaces to be connected on both sides of the metal intermediate layer II until they are smooth, bright and free of oxide. Then immerse the metal intermediate layers I and II in anhydrous ethanol for ultrasonic cleaning and then dry.

[0050] The metal intermediate layer I is Ti foil with a thickness of 10 μm;

[0051] The metal intermediate layer II is a pure Cu sheet with a thickness of 300 μm;

[0052] 3. Assembly of samples to be connected:

[0053] The metal intermediate layer I and the metal intermediate layer II treated in step 2 are connected together using an organic adhesive I (α-ethyl cyanoacrylate) to form a composite intermediate layer; the composite intermediate layer is then placed on the base material SiC treated in step 1. f / SiC and the parent material nickel-based high-temperature alloy are assembled into a sandwich structure, and the metal intermediate layer I in the composite intermediate layer and the SiC f / SiC surfaces to be joined, and the metal intermediate layer II to the nickel-based high-temperature alloy surfaces to be joined; an organic adhesive II (ethyl α-cyanoacrylate) is used to connect the composite intermediate layer to the parent materials on both sides, and the next step is performed after the organic adhesive is air-dried at room temperature;

[0054] 4. Partial instantaneous liquid phase connection:

[0055] Place the sample to be connected after step 3 into the graphite mold and use the metal molybdenum block to apply the brazing pressure of 0.3MPa to the sample. f / SiC is located at the top, and the mold containing the sample is sent into a vacuum furnace for partial instantaneous liquid phase connection. The vacuum degree used in the partial instantaneous liquid phase connection is ≤1×10 -3 Pa, heating rate is 10℃ / min, connection temperature is 1020℃, holding time is 10min, cooling rate is 5℃ / min, cooling to 300℃ and then cooling to room temperature with the furnace to obtain SiC f / SiC-nickel-based superalloy joint.

[0056] Example 2

[0057] The difference between this example and Example 1 is that the connecting temperature in Step Four is 1000°C. The rest is the same as Example 1.

[0058] Example 3

[0059] The difference between this example and Example 1 is that the connecting temperature in Step Four is 1040°C. The rest is the same as Example 1.

[0060] Example 4

[0061] The difference between this example and Example 1 is that the holding time in Step Four is 20 min. The rest is the same as Example 1.

[0062] Example 5

[0063] The difference between this example and Example 1 is that the thickness of the Ti foil in Step Two is 30 μm. The rest is the same as Example 1.

[0064] Example 6

[0065] The difference between this example and Example 1 is that the metal interlayer II in Step Two is B18 copper alloy sheet. The rest is the same as Example 1.

[0066] Example 7

[0067] The difference between this example and Example 1 is that the metal interlayer II in Step Two is Cu-30Mo alloy sheet. The rest is the same as Example 1.

[0068] Example 8

[0069] The difference between this example and Example 1 is that:

[0070] In Step One, the above polished SiC f / SiC and nickel-based superalloy are cleaned with anhydrous ethanol for 15 min and dried for use;

[0071] The metal interlayer I in Step Two is Zr foil with a thickness of 20 μm.

[0072] The connecting pressure in Step Four is 0.5 MPa and the connecting temperature is 1050°C. The rest is the same as Example 1.

[0073] The joints obtained in the above examples are subjected to mechanical evaluation. The shear strength of three samples in each test is measured and averaged. The shear strength of the joints at room temperature and at 500°C is shown in Table 1.

[0074] Table 1

[0075]

[0076] The principle of the connection method provided by the present invention is described with reference to Example 1 as a typical example and with reference to the accompanying drawings. f / The principle of the connection method of SiC-nickel-based high-temperature alloy connectors is as follows Figure 1 As shown, the connection process in step 4 can be divided into the following four stages:

[0077] (1) Solid phase diffusion stage: Figure 1 As shown in (a), during the heating process, the metal interlayer I / metal interlayer II are tightly attached to each other at some locations due to the pressure, and atomic interdiffusion occurs between the base material / composite interlayer and the metal interlayer I / metal interlayer II.

[0078] (2) Partial melting process: Figure 1 As shown in (b), after solid-phase diffusion, the composition between the metal intermediate layer I and the metal intermediate layer II reaches the position of the lowest liquidus line of Cu-Ti, and local melting occurs first. The metal in the surrounding unmelted area continues to dissolve into the liquid phase. However, since the interface of the nickel-based high-temperature alloy and the metal intermediate layer II does not include a low-melting-point eutectic reaction, no obvious local melting occurs. Solid-phase diffusion still mainly occurs at this interface.

[0079] (3) Liquid phase homogenization stage: Figure 1 As shown in (c), the metal intermediate layer I is completely melted, while the metal intermediate layer II is partially melted; SiC f / SiC forms a liquid phase rich in Cu and Ti elements near the surface. The active elements Ti in the liquid phase react with SiC f / SiC interfacial reaction generates TiC reaction layer to form wetting, while the liquid phase can penetrate into SiC along the gaps in the fiber bundle or other manufacturing defects f / SiC inside; while the diffusion layer at the interface of the nickel-based high-temperature alloy side thickens under the action of temperature and pressure, the gap between the interfaces is bridged, and the connection of the high-temperature alloy / metal intermediate layer II is achieved;

[0080] (IV) Joint tissue formation: Figure 1 As shown in (d), SiC f After the liquid phase on the / SiC side fully reacts, the liquid phase composition becomes homogenous and solidifies isothermally, and finally the connection of the entire joint is completed. If the holding time is insufficient, the SiC f A small amount of discontinuous Ti-Si compounds precipitated at the Ti / SiC side interface.

[0081] Figure 2 SiC prepared in Example 1 fTypical microstructure SEM photos of / SiC-nickel-based high-temperature alloy joints; Figure 3 for Figure 2 Medium SiC f High-magnification SEM photo of the reaction layer at the / SiC side interface; Figure 4 for Figure 3 Energy spectrum analysis results of midpoint 1; Figure 5 for Figure 3 The energy spectrum analysis results of midpoint 2 show that the joint is well connected, there is no obvious welding defect, the weld structure is uniform and dense, the main body is Cu-based solid solution, SiC f There is a dense TiC interface layer and a small amount of blocky Ti5Si3, SiC f There is an infiltrated solidified structure inside the nickel-based high-temperature alloy / SiC; there is a diffusion layer rich in Ni, Fe, Cr and other elements at the interface of the nickel-based high-temperature alloy / intermediate layer.

[0082] SiC prepared by the present invention f / SiC-nickel-based high-temperature alloy joints have the following advantages:

[0083] ① Using partial instantaneous liquid phase joining technology, the weld retains a large amount of Cu-based solid solution structure, has strong plastic deformation ability, and significantly increases the fracture toughness of the joint;

[0084] ② Compared with diffusion welding joints, the present invention does not require high pressure to achieve reliable connection, and has lower requirements on the surface conditions of the parent material, making it suitable for connecting fiber-reinforced composite materials;

[0085] ③ Compared with the brazed joints obtained at the same connection temperature, the joints obtained by the method of the present invention can be used at a higher temperature.

[0086] Experiments show that the room temperature shear strength of the joint prepared by the present invention can reach above 70 MPa, and the high temperature shear strength at 500° C. can reach above 55 MPa.

Claims

1. A method of using a composite metal intermediate layer to partially instantaneously connect SiC f / SiC and nickel-based high-temperature alloy method, characterized in that Partial transient liquid phase bonding of SiC using composite metal interlayer f The method of / SiC and nickel-based high-temperature alloy is carried out in the following steps:

1. Clean the base material before welding; 2. Pretreatment of the composite intermediate layer: Use 800#, 1000# and 1200# metallographic sandpaper to polish the surfaces to be connected on both sides of the metal intermediate layer I until they are smooth, bright and free of oxide. Then use 800#, 1000# and 1200# metallographic sandpaper to polish the surfaces to be connected on both sides of the metal intermediate layer II until they are smooth, bright and free of oxide. Then immerse the metal intermediate layers I and II in anhydrous ethanol for ultrasonic cleaning and then dry. The metal intermediate layer I is Ti foil or Zr foil with a thickness of 10 μm to 30 μm; The metal intermediate layer II is pure Cu or Cu alloy, with a thickness of 200 μm to 500 μm; 3. Assembly of samples to be connected: The metal intermediate layer I and the metal intermediate layer II processed in step 2 are connected together using an organic adhesive I to form a composite intermediate layer; Then the composite intermediate layer is placed on the base material SiC treated in step 1 f / SiC and the parent material nickel-based high-temperature alloy are assembled into a sandwich structure, and the metal intermediate layer I in the composite intermediate layer and the SiC f / SiC surfaces to be joined, and the metal intermediate layer II to the nickel-based high-temperature alloy surfaces to be joined; an organic adhesive II is used to connect the composite intermediate layer to the parent materials on both sides, and the next step is performed after the organic adhesive is air-dried at room temperature; 4. Partial instantaneous liquid phase connection: Place the sample to be connected after step 3 into the graphite mold and use the metal block to apply brazing pressure to the sample. f / SiC is located at the top, and the mold containing the sample is sent into a vacuum furnace for partial instantaneous liquid phase connection. The partial instantaneous liquid phase connection is carried out under vacuum, the connection temperature is 990℃~1070℃, the holding time is 0~30min, and the temperature is lowered to 300℃~310℃ and then cooled to room temperature with the furnace to obtain SiC f / SiC-nickel-based high-temperature alloy connectors.

2. A method according to claim 1 for connecting SiC with a composite metal intermediate layer using a transient liquid phase method f / SiC and nickel-based high-temperature alloy method, characterized in that The method for cleaning the base material before welding in step 1 is: First, use a 600# diamond sandpaper to remove the SiC f The large-scale undulations on the surface of the SiC to be joined make the surface to be joined relatively flat; then diamond grinding pastes with specifications of W3.5, W2.5 and W1 are used in turn to grind the base material SiC f / SiC is polished on a flat glass plate until the surface to be connected is flat and bright; The base material nickel-based high-temperature alloy is polished in sequence using 600#, 800#, 1000# and 1200# water sandpaper on an automatic grinding and polishing machine at a speed of 300r / min until the surface to be connected is flat and bright; Finally, the polished SiC f / SiC and nickel-based high-temperature alloys were ultrasonically cleaned with anhydrous ethanol for 10 to 20 minutes and then dried for later use.

3. The method according to claim 1, wherein the composite metal intermediate layer is partially instantaneous liquid phase connected to SiC f / SiC and nickel-based high-temperature alloy method, characterized in that The organic binder I described in step 3 is ethyl α-cyanoacrylate.

4. A method according to claim 3 for connecting SiC with a composite metal intermediate layer using a transient liquid phase method f / SiC and nickel-based high-temperature alloy method, characterized in that The organic binder II described in step 3 is ethyl α-cyanoacrylate.

5. The method according to claim 1, wherein the composite metal intermediate layer is partially instantaneous liquid phase connected to SiC f / SiC and nickel-based high-temperature alloy method, characterized in that The metal block described in step 4 is a metal molybdenum block.

6. A method according to claim 5 for connecting SiC with a composite metal intermediate layer using a transient liquid phase method f / SiC and nickel-based high-temperature alloy method, characterized in that In step 4, the brazing pressure applied by the metal molybdenum block to the sample is 0.05 MPa to 0.5 MPa.

7. The method according to claim 1, wherein the composite metal intermediate layer is partially instantaneous liquid phase connected to SiC f / SiC and nickel-based high-temperature alloy method, characterized in that The vacuum degree used in the transient liquid phase connection process in step 4 is ≤1×10 - 3 Pa.

8. The method according to claim 1 for connecting SiC with a composite metal intermediate layer by a transient liquid phase method f / SiC and nickel-based high-temperature alloy method, characterized in that The heating rate in step 4 is 5°C / min to 20°C / min.

9. The method according to claim 1, wherein the method comprises a composite metal intermediate layer and a partial transient liquid phase connection of SiC f / SiC and nickel-based high-temperature alloy method, characterized in that The cooling rate in step 4 is 5℃ / min~10℃ / min. After cooling to 300℃~310℃, SiC is obtained by cooling to room temperature. f / SiC-nickel-based high-temperature alloy connectors.

10. A method for transient liquid phase bonding of SiC using a composite metal intermediate layer according to claim 9. f / SiC and nickel-based high-temperature alloy method, characterized in that The cooling rate in step 4 is 5℃ / min~10℃ / min. After cooling to 300℃, SiC is obtained by cooling to room temperature. f / SiC-nickel-based high-temperature alloy connectors.

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