A kind of preparation method of low temperature sintered porous silicon carbide ceramics

Abstract

The invention relates to a method for preparing porous silicon carbide ceramic through low temperature sintering. The method comprises the steps of (1) mixing SiC powder, SiC sintering aid, absolute ethyl alcohol and polyvinyl alcohol and then grinding, drying to obtain a SiC porous ceramic sintering raw material; (2) preparing a multi-channel tubular test piece through an extruding forming machine, putting into a 200 DEG C muffle furnace, preburning for 2 hours, and cooling along with the muffle furnace, so as to prepare a multi-channel tubular SiC porous ceramic blank; (3) putting the multi-channel tubular SiC porous ceramic blank prepared in step (2) into a tube furnace, heating up to 200DEG C at the speed of 6 DEG C per minute in a nitrogen atmosphere, then heating up to 1200-1300DEG C at the speed of 9 DEG C per minute, preserving heat for 2 hours, and cooling down to room temperature along with the furnace, so as to prepare the SiC porous ceramic. The method has the beneficial effects of having highly connected voidage and high breaking strength, improving the usability, being capable of sintering at lower temperature, and saving energy.

Description

technical field [0001] The invention belongs to the field of material science and engineering, and in particular relates to a method for preparing low-temperature sintered porous silicon carbide ceramics. Background technique [0002] SiC porous ceramic refers to a ceramic material that has been fired at high temperature and has a large number of interconnected pores. It is widely used in filter materials, catalyst carriers, etc. Compared with organic filter materials, SiC porous ceramics are used as filter materials in environmental protection fields such as sewage treatment and high-temperature gas dedusting. Deformation, high separation efficiency, strong anti-pollution ability, simple operation, easy cleaning and many other advantages will become the key component materials and development trends of membrane separation technology in the field of environmental protection. [0003] Silicon carbide is a non-metallic inorganic compound artificial material bonded by covalent...

AI Technical Summary

Problems solved by technology

The foaming method is mainly suitable for the preparation of closed-pore materials, and has high requirements for raw materials, and the process is not easy to control; the sol-gel method has low productivity and the shape of the product is limited; the shape of the product by the organic foam impregnation method is limited, and the product Ingredient density is not easy to control

The method of adding a pore-forming agent is easy to form complex shapes and is convenient for mass continuous production. It has become the main preparation method of silicon carbide porous ceramics for filtration, but its performance is closely related to the type and amount of pore-forming agents and binders, which can easily lead to porosity in products. Poor distribution uniformity, low porosity, low strength