High-temperature sealing gum, and preparation method and application thereof

Abstract

The invention relates to high-temperature sealing gum, which includes, by weight, 50-80 parts of glass powder, 5-40 parts of Ag/Cu alloy powder and 10-20 parts of a dispersant. The glass powder is prepared by crushing SiO2 glass and/or boron oxide glass. By adding the Ag/Cu alloy powder and the dispersant to the glass powder, the high-temperature sealing gum can seal or connect metal materials, ceramic materials or both, has excellent chemical stability and thermal stability, can effectively seal the material from room temperature to 1000 DEG C; meanwhile, after the high-temperature sealing gum is cured, thermal-expansion coefficient can be adjusted according to the content of oxides in the glass powder, ratio of silver in the Ag/Cu alloy powder and addition amount of the Ag/Cu alloy powder and can be changed optionally in the range of 7.3*10<-6> - 16.1*10<-6>/K, thus satisfying sealing demand on materials in different thermal-expansion coefficients.

Description

technical field [0001] The invention relates to the field of sealing materials, in particular to a high-temperature sealant and its preparation method and application. Background technique [0002] Materials are the basis for the survival and development of human beings. As one of the three pillars of contemporary civilization, they play an important role in enhancing national defense and military strength, improving the quality of national life, and developing the national economic foundation. Ceramics and ceramic-based composite materials are particularly important. A class of structural materials generally have excellent mechanical properties such as high melting point, low density, and high strength, and excellent physical and chemical stability at high temperatures. However, due to the high brittleness of ceramic materials, it is difficult to process them into complex components, so the scope of use is limited. Restricted, compared with metal materials with good ductili...

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Problems solved by technology

[0003] Sealants that can be used for ceramic materials at high temperatures must have a thermal expansion coefficient that matches the ceramic material to be sealed, good interface bonding, and high chemical and thermal stability. The sealant with organic matter as the main material will be carbonized when the temperature is greater than 500 ° C, so it cannot withstand too high a temperature. Therefore, the research on high-temperature sealing materials mainly focuses on ceramic seals with glass or other metal oxides as the main component. glue direction

[0004] Glass materials have good adhesion and wettability, and are cheap, and can be used to seal the interface densely. However, the thermal cycle performance and thermal shock performance of traditional glass materials are poor, and the thermal expansion coefficients of glass materials are uniform. Smaller, usually around 10×10 -6 K -1 Next, when the thermal expansion coefficient of the sealed interface does not match the sealing material, stress will be generated between the sealed interface and the sealing material, causing the sealant to crack and cannot be sealed. For example, the high temperature resistant sealant disclosed in CN105524560A is made of silicic acid Sodium, boric acid, metal oxides, aluminum hydroxide, asbestos powder and water are the main components, and can be cured and sealed at a high temperature of about 700 ° C. However, it cannot be guaranteed that the sealing effect can still be maintained at higher temperatures. Other existing technologies, Such as the lanthanum antimonate nanosphere high-temperature sealant disclosed in CN106497461A, the preparation method is complicated, the cost is high, it is not suitable for large-scale production and use, and it cannot guarantee that it can meet the demand for sealing materials at high temperatures greater than 700 ° C.

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