Preparation of oriented hole silicon carbide porous ceramic

Abstract

The invention discloses a preparation method of a porous silicon-carbide ceramic provided with oriented pores. Firstly, according to weight percentage, 0 to 30 percent of carbon powder, 0 to 50 percent of silicon powder and 0 to 60 percent of silica are added into the 10 to 100 percent of the basic material of silicon-carbide; wherein, the granularity of the silicon-carbide is W3.5 to P220, and one granularity or two granularities are adopted for graduation; then the equally mixed materials are processed through powder accumulation or normal ceramic forming process to obtain a green compact which is put into a graphite crucible or a saggar; the graphite crucible or saggar is placed into a vacuum sintering furnace provided with a temperature field with a temperature grade from 15 to 30 DEG C / cm, and then the temperature is raised to 1900 to 2500 DEG C in an argon environment and with pressure of 0.2 to 1 multipliedby 10 <5>Pa, and the insulation work for the graphite crucible or saggar is preserved for 0.5 to 3 hours; finally the temperature naturally falls down under air protection and the sintered body is taken out, namely, the recrystallization porous silicon-carbide ceramic provided with oriented pores is obtained.

Description

technical field [0001] The invention relates to a preparation method of a recrystallized silicon carbide porous ceramic with a directional arrangement pore structure that can be used as a filter product or a catalyst carrier. Background technique [0002] Silicon carbide ceramic material has hardness second only to diamond, extremely high thermal conductivity, relatively low thermal expansion coefficient, excellent thermal shock resistance and creep resistance, high temperature strength and wear resistance, high chemical stability, It is insoluble in common acids and mixed acids, and does not react with boiling hydrochloric acid, sulfuric acid, and hydrofluoric acid. Silicon carbide also has semiconductor properties and has the characteristics of a negative temperature coefficient. Therefore, as a high-temperature ceramic with excellent performance, it has broad application prospects in industrial fields related to thermal engineering, combustion, chemical industry, and env...

AI Technical Summary

Problems solved by technology

The inherent excellent performance of silicon carbide cannot be fully utilized

[0006] During the preparation process of reaction sintering, it is difficult to obtain a material with high porosity due to the volume expansion of silicon carbide produced by the reaction, or the filling of the pores of the green body by excess reactants (such as metal silicon), and the use temperature of the material is limited

The pores of the porous (foam) silicon carbide ceramics produced by the prior art are all randomly oriented, and the relevant properties of the material are isotropic.

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