Silicon carbide porous ceramic and preparation method thereof

Abstract

The invention discloses silicon carbide porous ceramic and a preparation method thereof. The silicon carbide porous ceramic is characterized by comprising the following components in percentage by weight: 30 to 45 percent of silicon carbide powder, 5 to 10 percent of carbon powder, 35 to 50 percent of silicon powder and 3 to 12 percent of adhesive phenol resin. The method comprises the following steps of: ball-milling the silicon carbide powder, the carbon powder and the silicon powder and wet-mixing to obtain mixed powder; adding the adhesive phenol resin for granulation; performing compression molding; drying a molded green body and then placing into an air furnace to remove adhesives; sintering the green body according to a reaction sintering process after the adhesives are removed; and recrystallizing a product obtained by the reaction sintering at the high temperature of over 2,000 DEG C and removing silicon to obtain a single-phase porous silicon carbide material. The porous silicon carbide material prepared by the invention has the characteristics of controllable porosity, high strength, high corrosion resistance and high thermal stability, can be widely used as a filteringmaterial in high temperature atmospheres and corrosive atmospheres and a carrier material for a chemical reaction and can be used for high-temperature heat insulation.

Description

technical field [0001] The invention relates to a porous ceramic and a preparation method thereof, in particular to a silicon carbide porous ceramic and a preparation method thereof. Background technique [0002] Silicon carbide porous ceramics have the characteristics of low thermal expansion coefficient, low density, high temperature resistance, corrosion resistance, oxidation resistance and thermal shock resistance, and are widely used as heat insulation materials, filter materials, chemical catalyst carriers, heat insulation and sound insulation materials, etc. The common process methods are as follows: [0003] 1) The method of adding a pore-forming agent. For example, She Jihong et al. used silicon carbide, alumina and carbon powder as raw materials, and carbon powder as a pore-forming agent. After being pressed into a green body, it was oxidized at a high temperature in an air furnace to form an oxidized surface on the surface of silicon carbide. Silicon, silicon oxi...

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Problems solved by technology

[0008] Among the various methods for preparing silicon carbide porous materials at present, either the requirements for raw materials are relatively high, or the process is too complicated, and when the porosity of the finished product reaches more than 50%, the strength is often lower than 40MPa, which limits the porous carbonization. Wide application of silicon materials

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