A method for joining silicon nitride ceramic to nickel-based superalloy
By using vacuum brazing technology and a composite intermediate layer, the problem of poor mechanical properties of silicon nitride ceramic/nickel-based high-temperature alloy joints was solved, achieving high-temperature resistant joint connections and improving the joint's strength and temperature resistance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HARBIN INST OF TECH
- Filing Date
- 2024-05-28
- Publication Date
- 2026-05-12
AI Technical Summary
Silicon nitride ceramic/nickel-based high-temperature alloy joints have poor mechanical properties and are difficult to connect effectively in high-temperature environments.
A composite intermediate layer is used for partial transient liquid phase connection. The silicon nitride ceramic and nickel-based high-temperature alloy are connected under vacuum conditions by vacuum brazing process. Metal foils such as Ti foil, Cu foil, and Ni foil are used as intermediate layers, and each layer is fixed by adhesive. The heating process is controlled to ensure effective connection.
A good interfacial bond between silicon nitride ceramics and nickel-based superalloys was achieved, resulting in a high-temperature resistant joint and improving the joint's room temperature and high-temperature strength.
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Figure CN118404157B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a method for joining ceramic / nickel-based superalloys. Background Technology
[0002] Ceramics possess excellent high-temperature performance, but their inherent brittleness makes it difficult to fabricate large and complex components. Metals offer good plasticity and are easy to process, but compared to ceramics, their wear resistance and creep resistance are relatively poor. Therefore, combining ceramics and high-temperature alloys to create composite components for high-temperature applications has significant potential value; however, thermal mismatch is the biggest obstacle in the joining process. Partial instantaneous liquid-phase diffusion bonding combines the advantages of brazing and diffusion bonding, producing high-temperature resistant joints with joining temperatures below service temperatures, making it a promising joining method. Based on this method, by introducing a hard intermediate layer and porous and mesh structures, the distribution of residual stress can be further improved, thereby enhancing the joint's connection strength. Summary of the Invention
[0003] The present invention aims to solve the technical problem of poor mechanical properties of high-temperature joints made of silicon nitride ceramics / nickel-based superalloys, and provides a connection method for silicon nitride ceramics / nickel-based superalloys.
[0004] The joining method of the silicon nitride ceramic / nickel-based superalloy of the present invention is carried out according to the following steps:
[0005] 1. Treat the oxide layer and visible coarse scratches on the surface to be welded with water sandpaper, then polish it with 600, 800 and 1000 grit metallographic sandpaper in sequence until there are no obvious scratches on the surface. Finally, polish it with diamond particles with a particle size of 0.5μm to make the metal surface to be welded bright.
[0006] 2. Roughly grind the silicon nitride ceramic substrate on a 400# diamond grinding disc to smooth the sample surface. Then, use W3.5 diamond polishing paste to grind on a flat glass surface until there are no obvious wire cutting marks on the silicon nitride surface to be welded. Finally, use W1 polishing paste to grind until the surface of the silicon nitride ceramic is bright.
[0007] The treated silicon nitride ceramic and nickel-based superalloy were placed together in an ultrasonic cleaner for cleaning.
[0008] 3. Process the intermediate connecting layer into the same shape as the surface of the base material to be welded, then ultrasonically clean the intermediate connecting layer and dry it in an oven;
[0009] The intermediate connecting layer is composed of an upper metal layer, a middle metal layer, and a lower metal layer. The thickness of the upper metal layer is 5μm to 20μm, the thickness of the middle metal layer is 20μm to 500μm, and the thickness of the lower metal layer is 250μm to 600μm. The upper metal layer is Ti foil; the middle metal layer is Cu foil; and the lower metal layer is Ni foil / Cu foil, Ni foil / Mo foil / Ni foil / Cu foil, Ni foam / Cu foil, or Ni mesh / Cu foil.
[0010] 4. Place the lower metal layer, the middle metal layer, and the upper metal layer sequentially on the surface of the base nickel-based superalloy to be welded. Place the base silicon nitride ceramic surface to be welded on the upper metal layer. The Cu foil in the lower metal layer is adjacent to the surface of the base nickel-based superalloy to be welded. The base metal and the intermediate connecting layer, as well as each layer of the intermediate connecting layer, are fixed with an adhesive to form a tight fit between the layers.
[0011] 5. Place the assembled workpieces to be welded in step 4 into a vacuum heating furnace. Under vacuum conditions, raise the temperature from room temperature to 300℃~310℃ and hold for 30min~35min to ensure complete volatilization of the binder. Then raise the temperature to 1100℃~1200℃ and hold for 10min~15min. Finally, slowly lower the temperature to 300℃~310℃ and cool it to room temperature with the furnace to complete the brazing of ceramic and metal. The entire process in step 5 is completed under vacuum conditions.
[0012] The present invention aims to obtain a ceramic-high temperature alloy joint with good interface, and uses a composite intermediate layer for partial transient liquid phase connection to obtain a high temperature resistant joint, realizing a silicon nitride ceramic / GH4169 alloy high temperature resistant joint.
[0013] The method of the present invention is simple to operate. No modification treatment is required on the surface of the sample to be welded before welding to achieve direct brazing of ceramics and metals. Effective connection between ceramics and metals can be achieved by adding an intermediate layer. Attached Figure Description
[0014] Figure 1 This is the assembly drawing of the workpiece to be welded in step four of Experiment 1;
[0015] Figure 2 Microscopic photographs of the joint tissue obtained for experimentation;
[0016] Figure 3 The first line scan energy dispersive spectroscopy elemental composition analysis diagram of the joint obtained in Experiment 1;
[0017] Figure 4 The second line scan energy dispersive spectroscopy elemental composition analysis diagram of the joint obtained in Experiment 1;
[0018] Figure 5 for Figure 2 Energy spectrum elemental composition analysis diagrams at various points;
[0019] Figure 6 Microscopic photographs of the joint tissue obtained in Experiment 2;
[0020] Figure 7 This is the first line scan energy dispersive spectroscopy elemental composition analysis diagram of the joint obtained in Experiment 2;
[0021] Figure 8 The second line scan energy spectrum elemental composition analysis diagram of the joint obtained in Experiment 2. Detailed Implementation
[0022] Specific Implementation Method 1: This implementation method is a joining method for silicon nitride ceramic / nickel-based superalloys, specifically carried out according to the following steps:
[0023] 1. Treat the oxide layer and visible coarse scratches on the surface to be welded with water sandpaper, then polish it with 600, 800 and 1000 grit metallographic sandpaper in sequence until there are no obvious scratches on the surface. Finally, polish it with diamond particles with a particle size of 0.5μm to make the metal surface to be welded bright.
[0024] 2. Roughly grind the silicon nitride ceramic substrate on a 400# diamond grinding disc to smooth the sample surface. Then, use W3.5 diamond polishing paste to grind on a flat glass surface until there are no obvious wire cutting marks on the silicon nitride surface to be welded. Finally, use W1 polishing paste to grind until the surface of the silicon nitride ceramic is bright.
[0025] The treated silicon nitride ceramic and nickel-based superalloy were placed together in an ultrasonic cleaner for cleaning.
[0026] 3. Process the intermediate connecting layer into the same shape as the surface of the base material to be welded, then ultrasonically clean the intermediate connecting layer and dry it in an oven;
[0027] The intermediate connecting layer is composed of an upper metal layer, a middle metal layer, and a lower metal layer. The thickness of the upper metal layer is 5μm to 20μm, the thickness of the middle metal layer is 20μm to 500μm, and the thickness of the lower metal layer is 250μm to 600μm. The upper metal layer is Ti foil; the middle metal layer is Cu foil; and the lower metal layer is Ni foil / Cu foil, Ni foil / Mo foil / Ni foil / Cu foil, Ni foam / Cu foil, or Ni mesh / Cu foil.
[0028] 4. Place the lower metal layer, the middle metal layer, and the upper metal layer sequentially on the surface of the base nickel-based superalloy to be welded. Place the base silicon nitride ceramic surface to be welded on the upper metal layer. The Cu foil in the lower metal layer is adjacent to the surface of the base nickel-based superalloy to be welded. The base metal and the intermediate connecting layer, as well as each layer of the intermediate connecting layer, are fixed with an adhesive to form a tight fit between the layers.
[0029] 5. Place the assembled workpieces to be welded in step 4 into a vacuum heating furnace. Under vacuum conditions, raise the temperature from room temperature to 300℃~310℃ and hold for 30min~35min to ensure complete volatilization of the binder. Then raise the temperature to 1100℃~1200℃ and hold for 10min~15min. Finally, slowly lower the temperature to 300℃~310℃ and cool it to room temperature with the furnace to complete the brazing of ceramic and metal. The entire process in step 5 is completed under vacuum conditions.
[0030] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the nickel-based high-temperature alloy mentioned in step one is GH4169 nickel-based alloy. Everything else is the same as in Specific Implementation Method One.
[0031] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One or Two in that: in step two, the treated silicon nitride ceramic and nickel-based superalloy are placed together in an ultrasonic cleaner and cleaned with anhydrous alcohol for 10 to 15 minutes respectively. Everything else is the same as in Specific Implementation Method One or Two.
[0032] Specific Implementation Method Four: This implementation method differs from Specific Implementation Methods One to Three in that: in step three, the intermediate connecting layer is processed into the same shape as the surface of the base material to be welded, and then the intermediate connecting layer is ultrasonically cleaned in anhydrous ethanol for 2 to 3 minutes. Everything else is the same as in Specific Implementation Methods One to Three.
[0033] Specific Implementation Method Five: This implementation method differs from Specific Implementation Method Four in that the adhesive used in step four is 502 glue. Everything else is the same as in Specific Implementation Method Four.
[0034] Specific Implementation Method Six: This implementation method differs from Specific Implementation Method Five in that the vacuum degree in step five is 1×10⁻⁶. -2 Below Pa. Everything else is the same as in Specific Implementation Method Five.
[0035] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Method Six in that, in step five, the temperature is first raised from room temperature to 300℃~310℃ at a rate of 10℃ / min and then maintained at that temperature for 30min~35min. Everything else is the same as in Specific Implementation Method Six.
[0036] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Method Seven in that, in step five, the temperature is subsequently increased to 1100℃~1200℃ at a heating rate of 10℃ / min and held for 10min~15min. Everything else is the same as in Specific Implementation Method Seven.
[0037] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Method One in that, in step five, the temperature is reduced to 300℃~310℃ at a rate of 5℃ / min. Everything else is the same as in Specific Implementation Method One.
[0038] Specific Implementation Method Ten: This implementation method differs from Specific Implementation Method Eight in that, in step five, the temperature is subsequently increased to 1100°C at a rate of 10°C / min and held for 10 minutes. Everything else is the same as in Specific Implementation Method Eight.
[0039] The invention was verified using the following experiments:
[0040] Experiment 1: This experiment demonstrates a method for joining silicon nitride ceramics and nickel-based superalloys, specifically carried out according to the following steps:
[0041] 1. Use water sandpaper to treat the oxide layer and visible coarse scratches on the metal base material GH4169 nickel-based high-temperature alloy. Then, use 600, 800 and 1000 metallographic sandpaper to polish the surface until there are no obvious scratches. Finally, use diamond particles with a particle size of 0.5μm to polish the metal surface to be welded to make it bright.
[0042] 2. Roughly grind the silicon nitride ceramic substrate on a 400# diamond grinding disc to smooth the sample surface. Then, use W3.5 diamond polishing paste to grind on a flat glass surface until there are no obvious wire cutting marks on the silicon nitride surface to be welded. Finally, use W1 polishing paste to grind until the surface of the silicon nitride ceramic is bright.
[0043] The treated silicon nitride ceramic and nickel-based superalloy were placed together in an ultrasonic cleaner and cleaned with anhydrous ethanol for 10 minutes.
[0044] 3. Process the intermediate connecting layer into the same shape as the surface of the base material to be welded, then put the intermediate connecting layer into anhydrous ethanol for ultrasonic cleaning for 2 minutes, and put it into an oven to dry.
[0045] The intermediate connecting layer is composed of an upper metal layer, a middle metal layer, and a lower metal layer; wherein the upper metal layer is a Ti foil with a thickness of 8 μm; the middle metal layer is a Cu foil with a thickness of 100 μm; and the lower metal layer is a Ni foil / Cu foil, wherein the Ni foil has a thickness of 200 μm and the Cu foil has a thickness of 100 μm.
[0046] 4. Place the lower metal layer, the middle metal layer, and the upper metal layer sequentially on the surface of the nickel-based superalloy base material to be welded. Place the silicon nitride ceramic base material to be welded on the upper metal layer. The Cu foil in the lower metal layer is adjacent to the surface of the nickel-based superalloy base material to be welded. The base material and the intermediate connecting layer, as well as each layer of the intermediate connecting layer, are fixed with 502 glue to form a tight fit between the layers. The assembly sequence is GH4169 alloy / Cu foil / Ni foil / Cu foil / Ti foil / Si3N4.
[0047] 5. Place the assembled workpiece from step four into a vacuum heating furnace. Under vacuum conditions, first raise the temperature from room temperature to 300℃ at a rate of 10℃ / min and hold for 30 minutes to ensure complete evaporation of the 502 adhesive; then raise the temperature to 1100℃ at a rate of 10℃ / min and hold for 10 minutes; finally, lower the temperature to 300℃ at a rate of 5℃ / min, and allow it to cool to room temperature with the furnace to complete the brazing of the ceramic and metal. The entire process in step five is completed under vacuum conditions, with a vacuum level of 1×10⁻⁶. -2 Below Pa.
[0048] Figure 1 This is the assembly drawing of the workpiece to be welded in step four of Experiment 1, where 1 is Si3N4 ceramic, 2 is the upper layer metal, 3 is the middle layer metal, 4 is the lower layer metal, and 5 is the nickel-based high-temperature alloy GH4169.
[0049] Figure 2 Microscopic images of the joint structure obtained in Experiment 1 show that the silicon nitride ceramic / GH4169 alloy joint exhibits good interfacial bonding and no obvious microcracks under the bonding conditions. The joint's room temperature shear strength is 65 MPa, and its high-temperature strength at 800℃ is 58 MPa.
[0050] Figure 3 The first line scan energy dispersive spectroscopy elemental composition analysis diagram of the joint obtained in Experiment 1. Figure 4 The second line scan energy dispersive spectroscopy elemental composition analysis diagram of the joint obtained in Experiment 1. Figure 5 for Figure 2 The energy dispersive spectroscopy (EDS) elemental composition analysis at various points shows that the main microstructure of the joint weld is a nickel-copper based solid solution with a small amount of Ti-Cu-Ni compounds, and the joint has high-temperature resistance.
[0051] Experiment 2: This experiment differs from Experiment 1 in that:
[0052] 3. Process the intermediate connecting layer into the same shape as the surface of the base material to be welded, then put the intermediate connecting layer into anhydrous ethanol for ultrasonic cleaning for 2 minutes, and put it into an oven to dry.
[0053] The intermediate connecting layer is composed of an upper metal layer, a middle metal layer, and a lower metal layer. The upper metal layer is a Ti foil with a thickness of 20 μm; the middle metal layer is a Cu foil with a thickness of 20 μm; and the lower metal layer is a Ni foil / Mo foil / Ni foil / Cu foil, where the Cu foil has a thickness of 20 μm, each Ni foil has a thickness of 20 μm, and the Mo foil has a thickness of 200 μm.
[0054] IV. Place the lower, middle, and upper metal layers sequentially on the nickel-based superalloy substrate surface to be welded. Place the silicon nitride ceramic substrate surface to be welded on the upper metal layer. The Cu foil in the lower metal layer should be adjacent to the nickel-based superalloy substrate surface to be welded. The substrate and the intermediate connecting layer, as well as each layer of the intermediate connecting layer, are fixed with 502 adhesive to form a tight fit between the layers. The assembly sequence is GH4169 alloy / Cu foil / Ni foil / Mo foil / Ni foil / Cu foil / Ti foil / Si3N4. Everything else is the same as in Experiment 1.
[0055] After connection, the silicon nitride ceramic / GH4169 alloy joint showed no obvious microcracks, the room temperature shear strength of the joint was 108 MPa, and the high temperature strength of the joint at 800℃ was 75 MPa.
[0056] Figure 6 The image shows a microscopic photograph of the joint structure obtained in Experiment 2, indicating that the overall connection surface of the joint is well connected. The introduction of the Mo intermediate layer did not affect the connection of the joint, and the microstructure is similar to that in Experiment 1.
[0057] Figure 7 This is the first energy spectrum elemental composition analysis diagram of the joint obtained in Experiment 2. Figure 8 The second energy spectrum elemental composition analysis diagram of the joint obtained in Experiment 2 shows that the joint is still a Cu-based solid solution and a small amount of TiCuNi intermetallic compound. However, the replacement of the Ni interlayer with the Mo interlayer reduces the gradient difference in thermal expansion coefficients between the base materials, thereby improving the connection strength of the joint.
[0058] Experiment 3: This experiment differs from Experiment 1 in that:
[0059] 3. Process the intermediate connecting layer into the same shape as the surface of the base material to be welded, then put the intermediate connecting layer into anhydrous ethanol for ultrasonic cleaning for 2 minutes, and put it into an oven to dry.
[0060] The intermediate connecting layer is composed of an upper metal layer, a middle metal layer, and a lower metal layer. The upper metal layer is a Ti foil with a thickness of 8 μm; the middle metal layer is a Cu foil with a thickness of 100 μm; and the lower metal layer is a Cu foil / Ni foam with a Cu foil thickness of 100 μm and a Ni foam thickness of 500 μm.
[0061] IV. Place the lower, middle, and upper metal layers sequentially on the nickel-based superalloy substrate surface to be welded. Place the silicon nitride ceramic substrate surface to be welded on the upper metal layer. The Cu foil in the lower metal layer should be adjacent to the nickel-based superalloy substrate surface to be welded. The substrate and the intermediate connecting layer, as well as each layer of the intermediate connecting layer, are fixed with 502 adhesive to form a tight fit between the layers. The assembly sequence is GH4169 alloy / Cu foil / Ni foam / Cu foil / Ti foil / Si3N4. Everything else is the same as in Experiment 1.
[0062] After connection, the silicon nitride ceramic / GH4169 alloy joint showed no obvious microcracks, and the room temperature shear strength of the joint was 105 MPa.
[0063] Experiment 4: This experiment differs from Experiment 1 in that:
[0064] 3. Process the intermediate connecting layer into the same shape as the surface of the base material to be welded, then put the intermediate connecting layer into anhydrous ethanol for ultrasonic cleaning for 2 minutes, and put it into an oven to dry.
[0065] The intermediate connecting layer is composed of an upper metal layer, a middle metal layer, and a lower metal layer. The upper metal layer is a Ti foil with a thickness of 15 μm; the middle metal layer is a Cu foil with a thickness of 100 μm; and the lower metal layer is a Cu foil / Ni mesh with a Cu foil thickness of 100 μm and a Ni mesh thickness of 300 μm.
[0066] IV. Place the lower, middle, and upper metal layers sequentially on the nickel-based superalloy substrate surface to be welded. Place the silicon nitride ceramic substrate surface to be welded on the upper metal layer. The Cu foil in the lower metal layer should be adjacent to the nickel-based superalloy substrate surface to be welded. The substrate and the intermediate connecting layer, as well as each layer of the intermediate connecting layer, are fixed with 502 adhesive to form a tight fit between the layers. The assembly sequence is GH4169 alloy / Cu foil / Ni mesh / Cu foil / Ti foil / Si3N4. Everything else is the same as in Experiment 1.
[0067] After connection, the silicon nitride ceramic / GH4169 alloy joint showed no obvious microcracks, and the room temperature shear strength of the joint was 116 MPa.
Claims
1. A method for joining silicon nitride ceramic / nickel-based superalloys, characterized in that... The joining method for silicon nitride ceramics / nickel-based superalloys is performed according to the following steps:
1. Use water sandpaper to treat the oxide layer and visible coarse scratches on the metal base material GH4169 nickel-based high-temperature alloy. Then, use 600, 800 and 1000 metallographic sandpaper to polish the surface until there are no obvious scratches. Finally, use diamond particles with a particle size of 0.5μm to polish the metal surface to be welded to make it bright.
2. Roughly grind the silicon nitride ceramic substrate on a 400# diamond grinding disc to smooth the sample surface. Then, use W3.5 diamond polishing paste to grind on a flat glass surface until there are no obvious wire cutting marks on the silicon nitride surface to be welded. Finally, use W1 polishing paste to grind until the surface of the silicon nitride ceramic is bright. The treated silicon nitride ceramic and nickel-based superalloy were placed together in an ultrasonic cleaner and cleaned with anhydrous ethanol for 10 minutes.
3. Process the intermediate connecting layer into the same shape as the surface of the base material to be welded, then put the intermediate connecting layer into anhydrous ethanol for ultrasonic cleaning for 2 minutes, and put it into an oven to dry. The intermediate connecting layer is composed of an upper metal layer, a middle metal layer, and a lower metal layer. The upper metal layer is a Ti foil with a thickness of 20 μm; the middle metal layer is a Cu foil with a thickness of 20 μm; and the lower metal layer is a Ni foil / Mo foil / Ni foil / Cu foil, where the Cu foil has a thickness of 20 μm, each Ni foil has a thickness of 20 μm, and the Mo foil has a thickness of 200 μm.
4. Place the lower metal layer, middle metal layer, and upper metal layer sequentially on the nickel-based superalloy base material to be welded. Place the silicon nitride ceramic base material to be welded on the upper metal layer. The Cu foil in the lower metal layer is adjacent to the nickel-based superalloy base material to be welded. The base material and the intermediate connecting layer, as well as each layer of the intermediate connecting layer, are fixed with 502 glue to form a tight fit between the layers. The assembly sequence is GH4169 alloy / Cu foil / Ni foil / Mo foil / Ni foil / Cu foil / Ti foil / Si3N4.
5. Place the assembled workpiece from step four into a vacuum heating furnace. Under vacuum conditions, first raise the temperature from room temperature to 300℃ at a rate of 10℃ / min and hold for 30 minutes to ensure complete evaporation of the 502 adhesive; then raise the temperature to 1100℃ at a rate of 10℃ / min and hold for 10 minutes; finally, lower the temperature to 300℃ at a rate of 5℃ / min, and allow it to cool to room temperature with the furnace to complete the brazing of the ceramic and metal. The entire process in step five is completed under vacuum conditions, with a vacuum level of 1×10⁻⁶. -2 Below Pa; After connection, the silicon nitride ceramic / GH4169 alloy joint has a room temperature shear strength of 108 MPa and a high temperature strength of 75 MPa at 800℃.