Method for preparing porous silicon carbide ceramic

Abstract

The invention belongs to the field of inorganic non-metallic materials and relates to a method for preparing porous silicon carbide ceramic. The method comprises that alkaline silica sol and silicon carbide ceramic powder are subjected to ball milling mixing to form silicon carbide ceramic water-based suspension slurry, a surfactant is added into the silicon carbide ceramic water-based suspension slurry, the mixture is stirred and foams at designed multiplying power, the foaming slurry is added with a coagulation accelerator, the mixture is stirred to form uniform slurry, the uniform slurry is poured into a mold without hydroscopicity, the alkaline silica sol is gelation-cured under the action of the coagulation accelerator, the blank is subjected to mold release and drying, then the blank is immersed with a certain amount of a C source-containing solution, and after solvent volatilization, the blank is subjected to reactive sintering at a high temperature in an argon protective atmosphere to produce the porous silicon carbide ceramic. The method has simple processes, low equipment requirements, uniform aperture distribution, controllable porosity and less pollution and can be used for industrial production of the porous silicon carbide ceramic with high porosity.

Description

technical field [0001] The invention belongs to the field of inorganic non-metallic materials, and relates to a method for preparing porous silicon carbide ceramics. Background technique [0002] Porous silicon carbide ceramics have the advantages of good chemical stability, thermal stability, corrosion resistance and high mechanical strength. Using the uniform permeability of foam ceramics, various filters, separation devices, fluid distribution components, mixing components, etc. can be manufactured; using its developed specific surface area, various porous electrodes, catalyst carriers, heat exchangers, etc. can be made; Its application has been widely used in metallurgy, chemical industry, environmental protection, energy, biology, aerospace and other departments. With the attention of the material science community, this has become a very active research field. The scope of application of porous silicon carbide ceramics is still being further developed, and the applic...

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Problems solved by technology

However, these traditional methods for preparing porous ceramics usually need to add a large amount of organic pore-forming agents and binders. When organic matter is cracked at high temperature, a large amount of volatiles will be generated, causing environmental pollution and other problems. In addition, these pore-forming agents are expensive and have a large loss, resulting in The preparation cost of porous silicon carbide ceramics is relatively high