Welding method for heterogeneous material assembly

Abstract

The invention provides a heterogeneous material assembly welding method which comprises the following steps: preparing brazing filler metal and a middle layer by adopting a cold spraying method, and selecting a brazing process; firstly, brazing filler metal is cold-sprayed and deposited on the surfaces of metal material parts and components; the surface of the brazing filler metal coating is cleaned, ground and polished, and a middle layer material in the brazing filler metal design structure is deposited through cold spraying; the metal parts and components obtained after cold spraying are sequentially assembled with brazing filler metal and a ceramic-based composite material, and the assembled to-be-welded assembly is placed in a vacuum furnace and welded in a vacuum state; and cooling and then taking out the heterogeneous material connecting assembly. The method has the beneficial effects that effective welding of complex structure heterogeneous material assemblies with large differences can be achieved, the problem that direct welding of ceramic matrix composites and metal material complex structure assemblies such as titanium alloys and high-temperature alloys is prone to cracking is solved, high practical value is achieved, and the production requirement of engineering application is met.

Description

Technical Field

[0001] The invention relates to the field of welding of heterogeneous material components, and in particular to a connection component of a ceramic-based composite material and a metal material. Background Art

[0002] Ceramic-based composite materials have excellent properties such as light weight, high strength, high temperature resistance and corrosion resistance, and have great application prospects in hot-end components in the aerospace field. Titanium alloys, high-temperature alloys and other alloys have been widely used in the aerospace field. For parts and components with complex structures, there is a demand for connecting ceramic-based composite materials with metal materials such as titanium alloys and high-temperature alloys, but direct welding is prone to cracking and cannot weld parts and components with complex structures.

[0003] The invention is aimed at welding heterogeneous material components, adopts a cold spraying method to prepare the brazing material and the intermediate layer, and selects a brazing process. The invention can effectively realize the welding connection of relatively complex structural components. Summary of the invention

[0004] The purpose of the present invention is to solve the problem of easy cracking when directly welding complex structural components of ceramic-based composite materials and metal materials such as titanium alloys and high-temperature alloys, and to provide a welding method for heterogeneous material components, which can achieve effective welding of complex structural heterogeneous material components with large differences and has high practical value.

[0005] The cold spraying method is used to prepare the brazing material and the intermediate layer, and the brazing process is selected. The invention can effectively realize the welding connection of more complex structural components and meet the production needs of engineering applications.

[0006] The present invention provides a method for welding heterogeneous material components, which is characterized by:

[0007] First, the brazing material is cold sprayed and deposited on the surface of metal parts and components.

[0008] The surface of the brazing filler metal coating is cleaned and polished if necessary, and the intermediate layer material in the brazing filler metal design structure is cold sprayed and deposited.

[0009] The cold-sprayed metal parts and components are assembled with brazing filler metal and ceramic-based composite materials in sequence. The assembled components to be welded are placed in a vacuum furnace and welded according to the set temperature curve under vacuum.

[0010] After cooling down, remove the heterogeneous material connection components.

[0011] In the process of the present invention, the matters needing attention are:

[0012] It is necessary to carry out brazing test experiments on the brazing filler metal and intermediate layer materials used for welding heterogeneous materials to preliminarily determine the range of the brazing filler metal composition, neutral layer material, and brazing process parameters.

[0013] It is necessary to determine the cold spraying process parameters by conducting cold spraying tests on the determined composition of the brazing filler metal, neutral layer, etc.

[0014] Before soldering, spray solder resist on the contact part of the fixture.

[0015] The beneficial effects of the present invention are:

[0016] The present invention provides a method for welding heterogeneous material assemblies, which can achieve effective welding of heterogeneous material assemblies with complex structures that have large differences. It is designed to solve the problem of easy cracking when directly welding complex structural assemblies of ceramic-based composite materials and metal materials such as titanium alloys and high-temperature alloys. It has high practical value and meets the production needs of engineering applications. DETAILED DESCRIPTION

[0017] The present invention will be further explained below in conjunction with specific implementation schemes, but the present invention is not limited thereto.

[0018] Example 1

[0019] Select SiC / SiC ceramic matrix composite material and GH3536 to weld the combustion chamber components, which is completed in the following steps:

[0020] (1) First, Au-Cu-Ti based solder was deposited by cold spraying on the welding area of ​​GH3536. The solder composition (mass percentage) was as follows: Ti: 3-6 wt.%, Au: 68-75 wt.%, Cu: 20-28 wt.%. Spherical particles were used for cold spraying with a particle size range of 20-50 μm. The working gas was N 2 , gas temperature is room temperature to 200°C, gas pressure is 1.5 to 4.0 MPa, spraying distance is 20 to 50 mm, spray gun moving speed is 600 to 1000 mm / s. Deposition thickness is 30 to 60 μm.

[0021] (2) Clean the surface of the brazing material coating and cold spray Mo particles. Spherical particles with a particle size range of 30 to 50 μm are used. The working gas is N 2 , gas temperature 400~800℃, gas pressure 3.5~6.0MPa, spraying distance 20~50mm, spray gun moving speed 800~1200mm / s; deposition thickness is 50~80μm.

[0022] (3) Spray solder resist on the fixture and parts to be welded.

[0023] (4) The coated GH3635 parts are assembled with the mixed paste Au-Cu-Ti based solder and SiC / SiC ceramic based composite materials in sequence, and the assembled components to be welded are placed in a vacuum furnace with a vacuum degree of not less than 2×10 -4 Entrust.

[0024] (5) The temperature gradient adopted during the assembly and welding of the above-mentioned specimens is as follows: starting from room temperature, heating to 250℃~350℃ at a heating rate of 10℃ / min~20℃ / min, keeping warm for 10min~20min, then heating to 800℃~900℃ at a heating rate of 5℃ / min~15℃ / min, keeping warm for 10min~20min, then heating to 950℃~1100℃ at a heating rate of 5℃ / min, keeping warm for 10min, and cooling to room temperature at a cooling rate of 5~10℃ / min.

[0025] The tensile strength test of the SiC / SiC and GH3536 brazed joint obtained in step (5) shows that the room temperature tensile strength of the joint is not less than 100 MPa, the strength is relatively high and there are no obvious defects such as pores and unwelded joints.

[0026] Example 2

[0027] SiC / SiC ceramic matrix composite material and TC4 are selected to weld the ring assembly, which is completed in the following steps:

[0028] (1) First, cold spraying was performed on the TC4 soldering area to be soldered to deposit Ag-Cu-Ti based solder. The solder composition (mass percentage) was as follows: Ti: 0.5-6 wt.%, Ag: 50-80 wt.%, Cu: 20-45 wt.%. Spherical particles were used for cold spraying with a particle size range of 20-50 μm. The working gas was N 2 , gas temperature room temperature ~ 200 ℃, gas pressure 1.0 ~ 3.0MPa, spraying distance 20 ~ 50mm, spray gun moving speed 600 ~ 1000mm / s. Deposition thickness is 20 ~ 100μm.

[0029] (2) Clean the surface of the brazing material coating and cold spray Cu particles. Spherical particles with a particle size range of 30 to 50 μm are used. The working gas is N 2 , gas temperature room temperature ~ 200 ℃, gas pressure 1.5 ~ 5.0MPa, spraying distance 20 ~ 50mm, spray gun moving speed 600 ~ 1000mm / s. Deposition thickness is 50 ~ 120μm.

[0030] (3) Spray solder resist on the fixture and parts to be welded.

[0031] (4) The coated TC4 component is assembled with the foil-shaped Ag-Cu-Ti based solder and the SiC / SiC ceramic based composite material in sequence. The assembled components to be welded are placed in a vacuum furnace with a vacuum degree of not less than 2×10 -4 Entrust.

[0032] (5) The temperature gradient adopted during the assembly and welding of the above-mentioned specimens is as follows: starting from room temperature, heating to 250°C~350°C at a heating rate of 10°C / min~20°C / min, keeping warm for 10min~20min, then heating to 750°C~900°C at a heating rate of 3°C / min~8°C / min, keeping warm for 10min~20min, and then cooling to room temperature at a cooling rate of 5~10°C / min.

[0033] The tensile strength test of the SiC / SiC and TC4 brazed joint obtained in step (5) shows that the room temperature tensile strength of the joint is not less than 70 MPa, the strength is relatively high and there are no obvious defects such as pores and unwelded joints.

[0034] Matters not covered by the present invention are known technologies.

[0035] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for welding heterogeneous material components, characterized in that: The brazing material and the intermediate layer are prepared by cold spraying method, and the brazing process is selected; Firstly, cold spray deposits the brazing material on the surface of metal parts and components; Clean, grind and polish the surface of the brazing material coating, and cold spray deposit the intermediate layer material in the brazing material design structure; The cold-sprayed metal parts and components are assembled with brazing materials and ceramic-based composite materials in sequence, and the assembled components to be welded are placed in a vacuum furnace and welded under vacuum conditions; after cooling, the heterogeneous material connection components are taken out.

2. The method for welding heterogeneous material components according to claim 1, characterized in that: Conduct brazing test on the solder and intermediate layer materials used for welding heterogeneous materials to preliminarily determine the range of solder composition, neutral layer material and brazing process parameters; then, conduct cold spray test on the determined solder and neutral layer material composition to determine the cold spray process parameters; spray solder resist on the contact part of the fixture before welding.