Silicon carbide-cordierite composite ceramic kiln furniture and preparation method thereof

Abstract

The invention relates to silicon carbide-cordierite composite ceramic kiln furniture and belongs to the technical field of ceramic kiln furniture. The kiln furniture comprises, by weight, 40-65% of silicon carbide particles, 35-60% of cordierite fine powder less than or equal to 0.074mm, wherein the two components are 100 parts and serve as a reference, additionally, 2-8% of silicon metal powder less than or equal to 0.074mm, 5-20% of silica sol or aluminum-silicon sol with a solid content of 25%-30%, and 1-5% of a binding agent. The preparation method includes evenly mixing the raw materials according to the formula, ageing the materials for 12-24 hours, molding, natural drying, baking the materials at a temperature of 110 DEG C for 8-12 hours, heating the materials to the temperature of 1320-1460 DEG C, and preserving heat for 6-12 hours. The high temperature oxidation resistance of the obtained silicon carbide-cordierite composite ceramic kiln furniture is 0.2% -0.5% (quality change percentage after heat preservation for 20 hours at the temperature of 1200 DEG C reached at a speed of 300 DEG C per hour), the normal temperature breaking strength is 40-55MPa, the frequency of thermal shock stability is 150-200 times (water cooling after thermal treatment at a temperature of 1100 DEG C), and the coefficient of thermal expansion is 4.1-5.0 (*10<-6> DEG C <-1>).

Description

technical field [0001] The invention belongs to the technical field of ceramic kiln furniture, in particular to a silicon carbide-cordierite composite ceramic kiln furniture and a preparation method thereof. Background technique [0002] Ceramic kiln furniture is a refractory material used for load-bearing, transportation and protection of fired products in the firing process of ceramic products. Whether its performance is stable or not is directly related to the quality of the fired ceramic product, and affects the overall production cost. [0003] At present, common ceramic kilns have several types such as silicon carbide, cordierite, corundum-mullite and mullite-cordierite. [0004] Since the discovery of silicon carbide in 1891, after more than one hundred years of development, silicon carbide materials have become widely used non-oxide ceramics. It has high strength at room temperature and high temperature, high thermal conductivity (the thermal conductivity reaches 6...

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Problems solved by technology

It has high strength at room temperature and high temperature, high thermal conductivity (the thermal conductivity reaches 65w / (m k) under heat treatment at 500°C), and small thermal expansion coefficient (0~1400°C is 4.8×10-6 ℃-1), good thermal shock stability, excellent high temperature wear resistance, strong chemical corrosion resistance and other advantages; there are also insufficient toughness at room temperature, poor high temperature oxidation resistance, and production costs Relatively high disadvantages, such as a method for preparing pure silicon carbide kiln furniture using different particle sizes of silicon carbide (Chinese patent application CN 1821179A, silicon carbide kiln furniture and its preparation process), the disadvantages of this method are: (1) a large amount of silicon carbide is used Micropowder will greatly increase the specific surface area of ​​silicon carbide per unit mass, resulting in aggravated deterioration of the product's high temperature oxidation resistance; (2) The cost of raw materials is high, which in turn increases the production cost of the enterprise, which is not conducive to the efficiency of the enterprise

Cordierite has been widely used because of its small coefficient of thermal expansion, not easily deformed, strong resistance to rapid cooling and rapid heating, good thermal shock stability, easy source of raw materials, and stable composition; but its firing temperature is narrow, and production is difficult to control. Add certain high-temperature-resistant materials to increase the service temperature of cordierite materials

Cordierite ceramic kiln furniture prepared by pouring molding with silicon micropowder, alumina micropowder, magnesia fine powder, calcined kaolin, etc. as the matrix, with mullite, andalusite, and silicon carbide as the aggregate CN 1415575A, a method for manufacturing cordierite kiln furniture), the disadvantages of this method are: (1) the use intensity is low, and the consumption of ceramic products per unit mass is too large; (2) the use temperature is low, no Conducive to the preparation of higher-grade ceramic products

(3) Pouring, smearing or vibration molding is adopted, and the porosity of the product is too large, which will lead to poor high-temperature wear resistance and erosion resistance of the obtained cordierite ceramic products