Preparation of Hierarchically Porous Silicon Carbide Ceramics by Gel Casting and Carbothermal Reduction

Abstract

The method for preparing hierarchical porous silicon carbide ceramics by gel injection molding and carbothermal reduction comprises the following steps: adding phenolic resin, ethylene glycol, and silicon monoxide particles into a container in sequence and stirring, adding benzenesulfonyl chloride to continue stirring, and then using a water pump Carry out vacuum degassing to obtain a uniformly mixed slurry; then put the mixed slurry into an oven to obtain a cured body containing silicon monoxide particles; then put the cured body into a tube furnace, pass through a protective gas to raise the temperature and then keep it warm Finally, a carbide body containing silicon monoxide particles is obtained; finally, the carbide body is placed in a graphite crucible containing silicon oxide particles, and a porous silicon carbide ceramic is made after feeding a protective gas into a multifunctional furnace to raise the temperature and then keep warm; the present invention Using cheap phenolic resin and other raw materials to prepare lightweight, pore-tunable hierarchical porous silicon carbide ceramics by gel injection molding and carbothermal reduction preparation methods, the structure is uniform and complex shape samples can be prepared, the cost is low, and it is more convenient for actual production and application.

Description

technical field [0001] The invention relates to the technical field of preparation of porous silicon carbide materials, in particular to a method for preparing hierarchical porous silicon carbide ceramics through gel injection molding and carbothermal reduction. Background technique [0002] Porous silicon carbide ceramics have low density, large specific surface area, excellent thermal shock resistance and oxidation resistance, as well as high temperature resistance and chemical corrosion resistance, and are widely used in filters, heat insulation, separation membranes, catalysts Carriers, bioceramics and other component materials. There are many preparation methods of porous silicon carbide ceramics, including organic foam impregnation method, foaming method, adding pore-forming agent method, solid-state sintering method, extrusion molding method, sol-gel method, gel injection molding, etc. [0003] The pore size of porous silicon carbide (SiC) ceramics prepared by organi...

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Problems solved by technology

In this process, the shape, particle size and distribution of powder particles, the content and types of various additives, and the sintering temperature have a direct impact on the formation, porosity, pore size distribution, and pore size of the microporous body, which is difficult to control

The extrusion method relies on a well-designed porous metal mold to form holes. The shape and size of the holes can be precisely designed according to the needs, but it cannot prepare porous materials with complex structures and small pore sizes.

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