CN-118404157-B - Connection method of silicon nitride ceramic/nickel-based superalloy

Abstract

A connection method of silicon nitride ceramics/nickel-based superalloy relates to a connection method of ceramics/nickel-based superalloy. The invention aims to solve the technical problem that the existing silicon nitride ceramic/nickel-based superalloy high-temperature-resistant joint is poor in mechanical property. The invention aims to obtain a ceramic-superalloy joint with good interface, a composite intermediate layer is adopted for partial transient liquid phase connection, an intermediate connecting layer consists of upper metal, middle metal and lower metal, wherein the upper metal is Ti foil, the middle metal is Cu foil, the lower metal is Ni layer and related metal layer, and the high-temperature-resistant joint is obtained, so that the silicon nitride ceramic/GH 4169 alloy high-temperature-resistant joint is realized. The method is simple to operate, the direct brazing of the ceramic and the metal can be realized without any modification treatment on the surface of the sample to be welded before welding, and the effective connection of the ceramic and the metal can be realized through the addition of the intermediate layer.

Inventors

• ZHANG JIE
• WEN YUE
• SUN LIANGBO
• LIU CHUNFENG

Assignees

• 哈尔滨工业大学

Dates

Publication Date

20260512

Application Date

20240528

Claims (1)

1. 1. The connecting method of the silicon nitride ceramic/nickel-based superalloy is characterized by comprising the following steps of: 1. Treating an oxide layer of a surface to be welded and macroscopic coarse scratches of a metal base metal GH4169 nickel-based superalloy by using water sand paper, polishing the surface of the metal base metal GH4169 nickel-based superalloy by using No. 600, no. 800 and No. 1000 metallographic sand paper in sequence until no obvious scratches exist on the surface, and polishing the metal surface to be welded by using diamond particles with the granularity of 0.5 mu m to make the metal surface to be welded bright; 2. Coarsely grinding a base material silicon nitride ceramic on a 400# diamond grinding disc to grind the surface of a sample flat, grinding the sample flat on a piece of flat glass by using a W3.5 diamond grinding paste until the surface to be welded of the silicon nitride has no obvious linear cutting trace, and grinding the sample flat by using a W1 diamond grinding paste until the surface of the silicon nitride ceramic is bright; Placing the processed base metal silicon nitride ceramics and the base metal nickel-based superalloy into an ultrasonic cleaner together, and cleaning for 10min by using absolute ethyl alcohol; 3. Processing the intermediate connecting layer into the shape identical to the surface of the parent metal to be welded, then placing the intermediate connecting layer into absolute ethyl alcohol, ultrasonically cleaning for 2min, and placing into an oven for drying; The middle connecting layer consists of an upper layer metal, a middle layer metal and a lower layer metal, wherein the upper layer metal is Ti foil with the thickness of 20 mu m, the middle layer metal is Cu foil with the thickness of 20 mu m, the lower layer metal is Ni foil/Mo foil/Ni foil/Cu foil with the thickness of 20 mu m, the thickness of each Ni foil is 20 mu m, and the thickness of each Mo foil is 200 mu m; 4. Sequentially placing a lower metal layer, a middle metal layer and an upper metal layer on the surface to be welded of the base metal nickel-based superalloy, placing a base metal silicon nitride ceramic surface to be welded on the upper metal layer, wherein a Cu foil in the lower metal layer is next to the surface to be welded of the base metal nickel-based superalloy, fixing the base metal, the middle connecting layer and each layer of the middle connecting layer through 502 glue, and forming tight fit among the layers, wherein the assembly sequence is GH4169 alloy/Cu foil/Ni foil/Mo foil/Ni foil/Cu foil/Ti foil/Si 3 N 4 ; 5. Placing the workpiece to be welded assembled in the step four into a vacuum heating furnace, firstly raising the temperature from room temperature to 300 ℃ at 10 ℃ per minute under vacuum condition and preserving heat for 30min to ensure that 502 glue is completely volatilized, then raising the temperature to 1100 ℃ at the temperature raising rate of 10 ℃ per minute and preserving heat for 10min, finally lowering the temperature to 300 ℃ at the temperature of 5 ℃ per minute, and finally cooling to room temperature along with the furnace to finish the brazing of ceramic and metal, wherein the whole process of the step five is finished under vacuum condition, and the vacuum degree is below 1X 10 -2 Pa; After the connection is completed, the room temperature shear strength of the silicon nitride ceramic/GH 4169 alloy joint is 108MPa, and the high temperature strength of the joint at 800 ℃ is 75MPa.

Description

Connection method of silicon nitride ceramic/nickel-based superalloy Technical Field The invention relates to a method for connecting ceramic/nickel-based superalloy. Background Ceramics have excellent high temperature properties but are difficult to manufacture into large, complex components due to inherent brittleness. The metal material has good plasticity and is easy to process and form, but compared with ceramics, the metal material has relatively poor wear resistance and creep resistance. Therefore, the preparation of ceramic and superalloy into composite components by joining and application to high temperature applications would have significant application value, but the problem of thermal mismatch is the biggest obstacle in the joining process. The partial transient liquid phase diffusion method has the advantages of brazing and diffusion connection, can obtain a high-temperature-resistant joint with the connection temperature lower than the service temperature, and is a connection method with development prospect. Based on the method, the distribution of residual stress is further improved by introducing the hard intermediate layer and the porous and net-shaped structure, so that the improvement of the joint can be realized, and the connection strength of the joint is improved. Disclosure of Invention The invention aims to solve the technical problem that the existing silicon nitride ceramic/nickel-based superalloy high-temperature resistant joint is poor in mechanical property, and provides a connecting method of the silicon nitride ceramic/nickel-based superalloy. The connecting method of the silicon nitride ceramic/nickel-based superalloy is carried out according to the following steps: 1. Treating an oxide layer of a surface to be welded and macroscopic coarse scratches of a metal base metal nickel-based superalloy with water sand paper, sequentially polishing the surface of the metal base metal nickel-based superalloy with No. 600, no. 800 and No. 1000 metallographic sand paper until no obvious scratches exist on the surface, and polishing with diamond particles with the granularity of 0.5 mu m to make the surface to be welded of the metal bright; 2. Coarsely grinding a base material silicon nitride ceramic on a 400# diamond grinding disc to grind the surface of a sample flat, grinding the sample flat on a piece of flat glass by using a W3.5 diamond grinding paste until the surface to be welded of the silicon nitride has no obvious linear cutting trace, and grinding the sample flat by using a W1 diamond grinding paste until the surface of the silicon nitride ceramic is bright; Putting the processed base metal silicon nitride ceramics and the base metal nickel-based superalloy into an ultrasonic cleaner for cleaning; 3. Processing the intermediate connecting layer into the shape identical to the surface to be welded of the base material, ultrasonically cleaning the intermediate connecting layer, and putting the intermediate connecting layer into an oven for drying; The middle connecting layer consists of upper metal, middle metal and lower metal, wherein the thickness of the upper metal is 5-20 mu m, the thickness of the middle metal is 20-500 mu m, and the thickness of the lower metal is 250-600 mu m, the upper metal is Ti foil, the middle metal is Cu foil, the lower metal is Ni foil/Cu foil, ni foil/Mo foil/Ni foil/Cu foil, ni foam/Cu foil or Ni net/Cu foil; 4. Sequentially placing a lower metal layer, a middle metal layer and an upper metal layer on the surface to be welded of the base metal nickel-base superalloy, placing a base metal silicon nitride ceramic surface to be welded on the upper metal layer, wherein a Cu foil in the lower metal layer is next to the surface to be welded of the base metal nickel-base superalloy; 5. Placing the workpiece to be welded assembled in the step four into a vacuum heating furnace, heating the workpiece to be welded to 300-310 ℃ from room temperature under vacuum conditions, preserving heat for 30-35 min to ensure complete volatilization of the adhesive, heating the workpiece to 1100-1200 ℃ and preserving heat for 10-15 min, slowly reducing the temperature to 300-310 ℃ and cooling the workpiece to room temperature along with the furnace to finish brazing of ceramic and metal, and finishing the whole process of the step five under vacuum conditions. The invention aims to obtain a ceramic-superalloy joint with good interface, adopts a composite intermediate layer to carry out partial instantaneous liquid phase connection to obtain a high-temperature-resistant joint, and realizes the high-temperature-resistant joint of silicon nitride ceramic/GH 4169 alloy. The method is simple to operate, the direct brazing of the ceramic and the metal can be realized without any modification treatment on the surface of the sample to be welded before welding, and the effective connection of the ceramic and the metal can be realized through the addition of the intermediate