Porous silicon carbide ceramic and preparation method thereof

Abstract

The invention relates to a ceramic material, in particular to a porous silicon carbide ceramic and a preparation method thereof. The porous silicon carbide ceramic is characterized by including the following components by weight: 70-80 parts of silicon carbide ceramic aggregate, 20-25 parts of a binder, 5-10 parts of a pore-forming agent, 5-10 parts of a sintering aid and 5-10 parts of a dispersant. The invention also provides a preparation method of the porous silicon carbide ceramic, and the method includes the steps of: firstly mixing the binder with water in a ratio of 1:1, then adding theremaining raw materials and fully mixing the substances, and then performing aging for 3-4h to obtain a mixture, then subjecting the mixture to compression moulding to obtain a green body, and then drying and sintering the green body to obtain a silicon carbide refractory material finished product. The porous silicon carbide ceramic provided by the invention has a good mechanical structure and isconducive to preparation of porous silicon carbide ceramics with complex shapes and high performance.

Description

technical field [0001] The invention relates to a ceramic material, in particular to a porous silicon carbide ceramic and a preparation method thereof. Background technique [0002] Due to the advantages of low density, high temperature resistance, corrosion resistance, high permeability, good oxidation resistance and thermal shock resistance, porous silicon carbide ceramics are widely used in high temperature gas filter materials, catalyst carriers, gas combustion chamber media and refractory materials. It has broad application prospects. At present, the porous ceramics that have been widely used are mostly oxide ceramics, but they have disadvantages such as poor high-temperature performance and insufficient corrosion resistance, and porous silicon carbide ceramics can just make up for these deficiencies; in addition, many special fields require porous ceramic materials. The performance of silicon carbide puts forward higher requirements, and the advantages of silicon carb...

AI Technical Summary

Problems solved by technology

In the existing methods for preparing porous silicon carbide ceramic materials, some processes are relatively simple, but the pore size and porosity cannot be effectively controlled, and it is difficult to prepare porous ceramics with a porosity higher than 80% and oriented pores; some processes require Exclude organic matter in the preparation process to form a pore structure. Although the porosity and pore size are controllable within a certain range, it is also difficult to prepare porous silicon carbide ceramics with high porosity. In addition, the exclusion of organic matter is not friendly to the environment; using polycarbosilane as Precursors enable the preparation of porous SiC ceramics at lower temperatures, but are expensive to prepare

On the other hand, the above-mentioned preparation method is difficult to realize the preparation of porous silicon carbide ceramics with complex shapes. To prepare parts with complex shapes, large subsequent mechanical processing is required, which greatly increases the production cost.

In addition, due to the poor sintering performance of silicon carbide, the mechanical properties of porous silicon carbide ceramics prepared by existing methods are low. When the porosity of the finished product reaches 50%, the strength is often lower than 40MPa, which severely limits the porous carbonization. Application of silicon ceramics