SiO2-BN composite ceramic and Invar alloy brazing method

A technology of composite ceramics and brazing method, which is applied in the direction of welding equipment, metal processing equipment, metal material coating technology, etc., can solve the problems of unsatisfactory plastic deformation capacity and poor shear strength of welded joints, so as to improve mechanical properties, The effect of increasing plastic deformation capacity and relieving residual stress

Active Publication Date: 2018-07-20
HARBIN INST OF TECH
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  • Summary
  • Abstract
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  • Claims
  • Application Information

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Problems solved by technology

[0004] The purpose of the invention is to solve the problem of directly welding SiO2 with AgCuTi solder. 2 - When BN composite ceramics and Invar alloy, due to the excessive dissolution of Fe and Ni elements in Invar into the weld and react with Ti element to form a large area of ​​brittle compound bands, the plastic deformation ability of the welded joint is not ideal, and the shear strength is poor problem, while providing an improved SiO 2 -BN composite ceramics and Invar alloy brazing joint method

Method used

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  • SiO2-BN composite ceramic and Invar alloy brazing method
  • SiO2-BN composite ceramic and Invar alloy brazing method
  • SiO2-BN composite ceramic and Invar alloy brazing method

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specific Embodiment approach 1

[0011] Specific embodiment one: this embodiment is a kind of SiO 2 -The brazing method of BN composite ceramics and Invar alloy is specifically completed according to the following steps:

[0012] First, the graphene layer was grown vertically on the surface of the Invar alloy by plasma-enhanced chemical vapor deposition method, and then AgCuTi solder and SiO 2 -BN composite ceramic vacuum brazing.

[0013] As a new two-dimensional material, graphene has advantages that other materials cannot match: extremely high strength, excellent electrical conductivity, and extremely low resistivity, making it widely used in functional materials, material chemistry, supercapacitors and other fields. Now, in the field of material processing, especially in the field of welding, graphene has been successfully introduced into the welding process to play the role of its excellent properties. At present, experiments have proved that graphene can have a good affinity with active elements such ...

specific Embodiment approach 2

[0016] Specific embodiment two: the difference between this embodiment and specific embodiment one is: the growth graphene layer on the surface of the Invar alloy is carried out according to the following steps:

[0017] 1. Pre-treatment: firstly grind the Invar alloy with sandpaper, ultrasonically clean it after grinding, and then polish it to obtain the polished Invar alloy, which is stored in acetone;

[0018] 2. Growth of graphene layer: ①. Place the polished Invar alloy on the workbench of the furnace cavity of the plasma-enhanced chemical vapor deposition vacuum device, and vacuum the furnace cavity to 10 -1 Below Pa, feed hydrogen gas at a flow rate of 40-50 sccm, adjust the pressure in the furnace chamber to 500 Pa, and then raise the temperature to 500-800 °C at a pressure of 500 Pa and a hydrogen flow rate of 40-50 sccm; ② Turn on the radio frequency power supply and adjust the radio frequency The power is 125W-200W, and the carbon source gas and argon gas are introd...

specific Embodiment approach 3

[0020] Embodiment 3: The difference between this embodiment and Embodiment 2 is that the carbon source gas described in Step 2 ② and ③ is methane. Others are the same as in the second embodiment.

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Abstract

The invention discloses a SiO2-BN composite ceramic and Invar alloy brazing method, relates to a method for improving mechanical performances of a dissimilar material brazing joint, and aims to solvethe problems of bad plastic deformation capacity of welding joints caused by excessive dissolving of Fe and Ni elements in Invar to welding lines and generation of large-area brittle compound strips due to reaction with Ti elements in direct welding of SiO2-BN composite ceramic and Invar alloys by AgCuTi brazing filler metal in the prior art and weak shearing strength. The brazing method comprisesthe following steps: firstly, a plasma reinforced chemical vapor deposition method is used for in-situ vertical growth of graphene layers on the surfaces of Invar alloys; and then, the AgCuTi brazingfiller metal is adopted for vacuum brazing with the SiO2-BN composite ceramic. The brazing method has the advantage that the joint shearing strength reaches above 23 MPa. The brazing method is mainlyused for brazing the SiO2-BN composite ceramic and the Invar alloys.

Description

technical field [0001] The invention relates to a method for improving the mechanical properties of brazed joints of dissimilar materials. Background technique [0002] SiO 2 -BN composite ceramics have excellent mechanical properties, corrosion resistance, dielectric properties, and thermal shock resistance, and can be successfully used as constituent materials for missile radomes and other large aerospace components. But SiO 2 -BN has a low linear expansion coefficient and low plastic deformation ability, and is relatively brittle, making it difficult to be processed into parts with complex shapes. Therefore, we need to connect the composite ceramics with metal materials to play the role of complementary advantages of the two. At present, the main metal material of the transitional connecting ring of the missile radome is Invar alloy, which has good plasticity and has a low linear expansion coefficient at 400°C, realizing SiO 2 -The reliable connection of BN ceramics a...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B23K1/008C23C16/26C23C16/513
CPCB23K1/008C23C16/26C23C16/513
Inventor 张丽霞田成龙宋亚南孙湛冯吉才
Owner HARBIN INST OF TECH
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