Method for instantaneous liquid phase connection of SiCf / SiC and nickel-based superalloy by using composite metal interlayer part

Abstract

The invention discloses a method for instantly connecting SiCf / SiC and nickel-based superalloy through a composite metal interlayer part in a liquid phase mode. The method aims at solving the technical problems that the interface reaction of a joint of a Cu-based active metal brazing SiCf / SiC composite material and a nickel-based high-temperature alloy is difficult to regulate and control, and brittle intermetallic compounds in a weld joint structure are difficult to inhibit. The composite metal intermediate layer provided by the invention is directly enriched at the SiCf / SiC side interface by means of the active elements, an instantaneous liquid phase is formed in the welding process, the relative activity of the active elements is high, interface connection can be realized through efficient and rapid interface reaction, and meanwhile, due to the fact that the content of the active elements in the intermediate layer is relatively low, the performance of the composite metal is greatly improved. And brittle intermetallic compounds in the welding seam are inhibited, and the obtained joint has firm interface bonding and a plastic and tough welding seam structure. The room-temperature shear strength of the joint can reach 70 MPa or above, and the high-temperature shear strength at the temperature of 500 DEG C can reach 55 MPa or above.

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 aero engines and spacecraft. However, SiC f / SiC composite materials have poor processing performance and are difficult to directly form large-scale complex components, limiting their wide 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 hot-end parts of aircraft engines with a service temperature of up to 800°C. If SiC f The high-quality connection of SiC and nickel-based high-temperature alloys will give full play to the performance advantages of the two materials, significantly expand their application range in the aviation manufacturing industry, and have important engineering value. Therefore, the development of reliable connection technology has become the focus of current research.

[0003] At present, in the manufacturing of aircraft engine parts, SiC f The connection between SiC composites and nickel-based high-temperature alloys is usually made by mechanical connection or brazing. Compared with mechanical connection, brazing has the advantages of less stress concentration in the joint, high process flexibility, good sealing, and light additional weight in the connection between ceramics and metals. It is gradually replacing mechanical connection in SiC f / SiC composite materials-Ni-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 material / nickel-based high-temperature alloy connector compatible solder system, active elements Ti, Zr, etc. can be combined 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. f / SiC surface is well wetted, while high content of Ti, Zr and other elements will form a large number of low melting point metal compounds with Cu, Ni and other elements in the weld, which increases the joint's high temperature softening tendency and also increases the room temperature brittleness of the joint, which is not conducive to the mechanical properties of the joint. Therefore, a SiC solder that can reduce the content of active elements in the solder without increasing the welding temperature and obtain higher room temperature and high temperature strength is developed. f The welding scheme of / SiC-nickel-based high-temperature alloy joints will be of great significance to the aviation manufacturing industry. Summary of the invention

[0004] The present invention aims to solve the problem of current Cu-based active solder brazing connection of SiC f In order to solve the technical problem that excessive active metal elements lead to the presence of many low-melting-point brittle intermetallic compounds in the weld structure during the process of welding SiC / SiC and nickel-based high-temperature alloy, a composite metal intermediate layer is provided to connect SiC f / SiC and nickel-based high-temperature alloy method.

[0005] The present invention utilizes the composite metal intermediate layer to partially instantaneously connect SiC f The method of / SiC and nickel-based high-temperature alloy is carried out in the following steps:

[0006] 1. Clean the base material before welding;

[0007] 2. Pretreatment of the composite intermediate layer: Use 800#, 1000# and 1200# metallographic sandpaper to grind the surfaces to be connected on both sides of the metal intermediate layer I until they are smooth, bright and free of oxide layer, then use 800#, 1000# and 1200# metallographic sandpaper to grind the surfaces to be connected on both sides of the metal intermediate layer II until they are smooth, bright and free of oxide layer, 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 with a thickness of 10 μm to 30 μm;

[0009] The metal intermediate layer II is pure Cu or Cu alloy, and has a thickness of 200 μm to 500 μm;

[0010] 3. Assembly of samples to be connected:

[0011] 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 is connected to the SiC f / SiC surfaces to be connected are connected, and the metal intermediate layer II is connected to the surfaces to be connected of the nickel-based high-temperature alloy; 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 insulation time is 0~30min, and the temperature is reduced 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 metal 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 of the SiC side, the relative activity of the active elements in the liquid phase formed during the welding process 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 middle 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 with nickel-based high-temperature alloys, the method of the present invention can form a reliable connection under lower pressure. Since most of the metal intermediate layer will not melt during the connection process, the weld structure retains a strong plastic deformation ability. At the same time, under appropriate welding pressure, the low-melting point liquid phase in the joint will be squeezed out of the joint, thereby achieving the purpose of low-temperature connection and high-temperature use of the joint. The room temperature shear strength of the joint of the present invention can reach more than 70MPa, and the high-temperature shear strength at 500℃ can reach more than 55MPa. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0018] Figure 2 The SiC prepared in Example 1 f / SiC-Ni-based high-temperature alloy joint typical microstructure SEM photos;

[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 implementation method 1: This implementation method is a method of using a composite metal intermediate layer to partially instantaneously connect SiC f The method of / SiC and nickel-based high-temperature alloy is specifically carried out according to 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 grind the surfaces to be connected on both sides of the metal intermediate layer I until they are smooth, bright and free of oxide layer, then use 800#, 1000# and 1200# metallographic sandpaper to grind the surfaces to be connected on both sides of the metal intermediate layer II until they are smooth, bright and free of oxide layer, then immerse the metal intermediate layer I and the metal intermediate layer 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, and has 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 is connected to the SiC f / SiC surfaces to be connected are connected, and the metal intermediate layer II is connected to the surfaces to be connected of the nickel-based high-temperature alloy; 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 insulation time is 0~30min, and the temperature is reduced 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 implementation method 2: This implementation method is different from the specific implementation method 1 in that the method for cleaning the base material before welding in step 1 is:

[0032] First, use a 600# diamond sand disc to remove the SiC matrix. f The large-scale undulations on the surface to be connected of / SiC make the surface to be connected 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 parent material nickel-based high-temperature alloy is polished in turn 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. The rest is the same as the first specific implementation method.

[0035] Specific implementation method 3: This implementation method is different from specific implementation method 1 or 2 in that the organic binder I described in step 3 is ethyl α-cyanoacrylate. The rest is the same as specific implementation method 1 or 2.

[0036] Specific implementation method 4: This implementation method is different from specific implementation methods 1 to 3 in that the organic binder II in step 3 is ethyl α-cyanoacrylate. The rest is the same as specific implementation methods 1 to 3.

[0037] Specific implementation mode 5: This implementation mode is different from the specific implementation mode 4 in that the metal block described in step 4 is a metal molybdenum block. The rest is the same as the specific implementation mode 4.

[0038] Specific embodiment 6: This embodiment is different 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. The rest is 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 process of partial instantaneous liquid phase connection in step 4 is ≤1×10 -3 Pa. The rest is the same as 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. The rest is the same as specific embodiment seven.

[0041] Specific embodiment 9: This embodiment is different from specific embodiment 8 in that the cooling rate in step 4 is 5°C / min to 10°C / min, and the SiC is obtained after cooling to 300°C to 310°C and then cooling to room temperature with the furnace. f / SiC-nickel-based high-temperature alloy connector. 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°C / min to 10°C / min, and after cooling to 300°C, 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 state) and molybdenum copper alloy (Cu-30Mo dual-phase alloy, rolled state); the SiC f / SiC is prepared by 2.5D weaving + PIP process; the grade of the nickel-based high-temperature alloy used is GH4169 (cast).

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

[0046] 1. Cleaning of base material before welding: First, use a 600# diamond sand disc to remove SiC from the base material. f The large-scale undulations on the surface to be connected of / SiC make the surface to be connected 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 parent material nickel-based high-temperature alloy GH4169 is polished in turn with 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 grind the surfaces to be connected on both sides of the metal intermediate layer I until they are smooth, bright and free of oxide layer, then use 800#, 1000# and 1200# metallographic sandpaper to grind the surfaces to be connected on both sides of the metal intermediate layer II until they are smooth, bright and free of oxide layer, then immerse the metal intermediate layer I and the metal intermediate layer 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 processed in step 2 are connected together using an organic adhesive I (ethyl α-cyanoacrylate) to form a composite intermediate layer; 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 is connected to the SiC f / SiC surfaces to be connected are connected, and the metal intermediate layer II is connected to the surfaces to be connected of the nickel-based high-temperature alloy; 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 apply a brazing pressure of 0.3MPa to the sample using a metal molybdenum block. f / SiC is located at the top. The mold containing the sample is sent into a vacuum furnace for partial instantaneous liquid phase connection. The vacuum degree used for 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 high-temperature alloy connectors.

[0056] Example 2

[0057] The difference between this embodiment and embodiment 1 is that the connection temperature in step 4 is 1000° C. The rest is the same as embodiment 1.

[0058] Example 3

[0059] The difference between this embodiment and embodiment 1 is that the connection temperature in step 4 is 1040° C. The rest is the same as embodiment 1.

[0060] Example 4

[0061] The difference between this embodiment and embodiment 1 is that the connection insulation time in step 4 is 20 minutes. The rest is the same as embodiment 1.

[0062] Example 5

[0063] The difference between this embodiment and embodiment 1 is that the thickness of the Ti foil in step 2 is 30 μm. The rest is the same as embodiment 1.

[0064] Example 6

[0065] The difference between this embodiment and embodiment 1 is that the metal intermediate layer II described in step 2 is a B18 copper alloy sheet. The rest is the same as embodiment 1.

[0066] Example 7

[0067] The difference between this embodiment and embodiment 1 is that the metal intermediate layer II described in step 2 is a Cu-30Mo alloy sheet. The rest is the same as embodiment 1.

[0068] Example 8

[0069] The difference between this embodiment and embodiment 1 is:

[0070] In step 1, the polished SiC f / SiC and nickel-based high-temperature alloys were ultrasonically cleaned with anhydrous ethanol for 15 minutes and then dried for later use;

[0071] The metal intermediate layer I described in step 2 is Zr foil with a thickness of 20 μm;

[0072] In step 4, the connection pressure is 0.5 MPa and the connection temperature is 1050° C. The rest is the same as in Example 1.

[0073] The joints obtained in the above-mentioned embodiments were mechanically evaluated. The shear strength of three samples in each test group was measured and the average value was taken. The shear strength of the joints at room temperature and at a high temperature of 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 by taking Example 1 as a typical example and combining the diagram. f / SiC-Ni-based high temperature alloy connection method principle as follows Figure 1 As shown, the connection process in step 4 can be divided into the following four stages:

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

[0078] (ii) Partial melting process: Figure 1 As shown in (b), after solid phase diffusion, the composition between the metal intermediate layer I / metal intermediate layer II reaches the position of the Cu-Ti lowest liquidus line and local melting occurs first, and 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 / metal intermediate layer II does not include a low melting point eutectic reaction, no obvious local melting occurs, and solid phase diffusion still mainly occurs at this interface;

[0079] (III) Liquid phase homogenization stage: Figure 1 As shown in (c), the final 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. The active element Ti in the liquid phase reacts with SiC f The interfacial reaction of SiC forms a TiC reaction layer, thereby forming wetting. At the same time, 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 realized;

[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 is homogenized and isothermal solidification occurs, and finally the connection of the entire joint is completed. If the insulation time is insufficient, the SiC f A small amount of discontinuous Ti-Si compounds precipitated at the / SiC side interface.

[0081] Figure 2 The SiC prepared in Example 1 f / SiC-Ni-based high-temperature alloy joint typical microstructure SEM photos; 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. It can be seen 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 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 The partial instantaneous liquid phase connection technology is adopted, and the weld retains a large amount of Cu-based solid solution structure, which 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, and is suitable for the connection of 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 of 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 grind the surfaces to be connected on both sides of the metal intermediate layer I until they are smooth, bright and free of oxide layer, then use 800#, 1000# and 1200# metallographic sandpaper to grind the surfaces to be connected on both sides of the metal intermediate layer II until they are smooth, bright and free of oxide layer, then immerse the metal intermediate layer I and the metal intermediate layer 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, and has a thickness of 200 μm to 500 μm; 3. Assembly of samples to be connected: The metal intermediate layer I treated in step 2 is connected with the metal intermediate layer II 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 is connected to the SiC f / SiC surfaces to be connected are connected, and the metal intermediate layer II is connected to the surfaces to be connected of the nickel-based high-temperature alloy; 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 insulation time is 0~30min, and the temperature is reduced 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 by partially instantaneous liquid phase connection using a composite metal intermediate layer 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 sand disc to remove the SiC matrix. f The large-scale undulations on the surface to be connected of / SiC make the surface to be connected 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 parent material nickel-based high-temperature alloy is polished in turn 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 minutes to 20 minutes and then dried for use.

3. A method according to claim 1 for connecting SiC by partially instantaneous liquid phase connection using a composite metal intermediate layer 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 of using a composite metal intermediate layer to partially instantaneously connect SiC f / SiC and nickel-based high-temperature alloy method, characterized in that The organic binder II described in step three is ethyl α-cyanoacrylate.

5. A method according to claim 1 for connecting SiC by partially instantaneous liquid phase connection using a composite metal intermediate layer 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 of using a composite metal intermediate layer to partially instantaneously connect SiC 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 0.05MPa to 0.5MPa.

7. A method according to claim 1 for connecting SiC by partially instantaneous liquid phase connection using a composite metal intermediate layer 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 of claim 1 for connecting SiC by partially instantaneous liquid phase connection using a composite metal intermediate layer 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. A method according to claim 1 for connecting SiC by partially instantaneous liquid phase connection using a composite metal intermediate layer 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 can be obtained by cooling to room temperature with the furnace. f / SiC-nickel-based high-temperature alloy connectors.

10. A method for partially instantaneously liquid-phase bonding 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 with the furnace. f / SiC-nickel-based high-temperature alloy connectors.

Images