Silicon nitride whisker combined silicon carbide porous ceramic and production method thereof

Abstract

The invention relates to silicon nitride whisker combined silicon carbide porous ceramic and a production method thereof. According to the technical scheme, the production method comprises: adding a foam stabilizer into deionized water, and magnetically stirring for 12-24 h to obtain foam stabilizer solution; adding a catalyst, isobutene-maleic anhydride copolymer and ceramic powder into the foam stabilizer solution, and mechanically stirring for 5-15 min to obtain silicon nitride / silicon carbide ceramic slurry; adding a foaming agent into the silicon nitride / silicon carbide ceramic slurry, stirring, carrying out injection molding, demolding, drying, and holding the temperature of 1150-1400 DEG C for 2-6 h to obtain the silicon nitride whisker combined silicon carbide porous ceramic. The silicon nitride whisker combined silicon carbide porous ceramic and the production method thereof have the advantages that the preparation process is simple, has low equipment requirements, and is easy to control, low in pollution and synthetic temperature and low in production cost; the produced silicon nitride whisker combined silicon carbide porous ceramic has high porosity, high strength and good toughness and has a great industrial prospect.

Description

technical field [0001] The invention belongs to the technical field of porous ceramics. It specifically relates to a silicon nitride whisker-bonded silicon carbide porous ceramic and a preparation method thereof. Background technique [0002] Silicon carbide porous ceramics have the characteristics of high porosity, low thermal conductivity, small bulk density and large specific surface area, and also have high strength, corrosion resistance, high temperature resistance, low thermal expansion coefficient, good thermal shock resistance and good biocompatibility excellent performance. These excellent properties make silicon carbide porous ceramics have broad application prospects in the fields of environmental protection, energy chemical industry, metallurgy, filtration and separation, tail gas treatment and biomedicine. Silicon nitride is an important structural ceramic material with a strength up to 1.7GPa and a fracture toughness up to 11MPa m 1 / 2 . The thermal expansio...

AI Technical Summary

Problems solved by technology

This method has the following disadvantages: (1) Organic substances are highly toxic, such as monomeric acrylamide and cross-linking agent N,N´-methylenebisacrylamide, etc., which are irritating to eyes, skin, mucous membranes and respiratory tract, and will harm The health of operators; (2) The combustion of organic matter in the sintering process will produce a large amount of waste gas, which will seriously pollute the environment; (3) This method consumes a large amount of organic matter and has high cost, which is not suitable for large-scale production

This method has the following disadvantages: (1) The process is complicated, such as two atmospheres of argon and nitrogen are required; (2) The sintering temperature is relatively high, as high as 1700~1800°C

(3) Si 3 N 4 The dosage is 70wt%, the cost is high, and it is not suitable for large-scale production

This method also has the following problems: (1) The process is complicated, if it needs to be kept in an air atmosphere at 400-600°C for 2-6 hours for debinding; (2) A large amount of organic matter such as monomers and cross-linking agents are added during the gelation process , the gas produced by pyrolysis will pollute the atmosphere; (3) the cross-linking agent methylenebisacrylamide is toxic and harmful to humans and the environment; (4) the sintering temperature is high, and it still needs Up to 1300~1500℃

[0006] The above results show that the preparation of silicon nitride combined with silicon carbide porous ceramics has problems such as complex process, large amount of organic matter, large pollution, low porosity, low strength and high synthesis temperature.

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