Low-expansion high-strength thin-wall cordierite honeycomb ceramic and preparation method thereof

Abstract

The invention discloses low-expansion high-strength thin-wall cordierite honeycomb ceramic and a preparation method thereof. Content of cordierite in ceramic is greater than 95%, and the ceramic is prepared from the following chemical components in percentage by mass: 47.5-52.5% of SiO2, 32.7-37.7% of Al2O3 and 11.5-15.5% of MgO; porosity of honeycomb ceramic is greater than or equal to 16%, and awater absorption rate is 14%-30%; bending strength of the honeycomb ceramic is greater than or equal to 1.6 MPa; and a thermal expansion coefficient at the room temperature of 800 DEG C is smaller than or equal to 5*10<-7>/DEG C. According to the preparation method, aluminum hydroxide prepared by a special preparation method is led, so that the product has low CTE (Coefficient of Thermal Expansion), high strength and low cost.

Description

technical field [0001] The invention belongs to the technical field of preparation of inorganic non-metallic materials, and relates to a cordierite honeycomb ceramic and a preparation method thereof, in particular to a low-expansion high-strength thin-walled cordierite honeycomb ceramic and a preparation method thereof. Background technique [0002] It is well known that internal combustion engine systems emit exhaust gases containing hydrocarbons and oxygenated compounds (nitrogen oxides and nitrogen monoxide) due to the combustion of hydrocarbon fuels, which contribute to air pollution. The automobile industry has long been committed to purifying automobile exhaust gas and reducing air pollution. One of the technologies is to install catalytic converters for post-treatment of exhaust gas. Cordierite honeycomb ceramics have long been preferred as the carrier of catalysts in catalytic converters for purifying automobile exhaust, because honeycomb ceramics with cordierite str...

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Problems solved by technology

In addition, another technique for reducing the CTE of honeycomb ceramics in the current technology is to introduce more raw kaolin. Generally, the amount of raw kaolin is ≥ 12% by mass, such as CN1329581A. Higher, the greater the number of microcracks in the product, and the closure of microcracks during heating will reduce the CTE of the product

[0005] However, the current technology of introducing boehmite (particle size ≤ 0.5 μm) to reduce the particle size of aluminum source to obtain lower CTE and higher strength honeycomb ceramics greatly increases the production cost, because the price of aluminum source with very fine particle size, such as boehmite , which is 3-5 times that of the coarser aluminum source (particle size 1-6μm), so the improvement of the performance of this thin-walled honeycomb ceramic is at the cost of increasing the production cost; and the introduction of microcracks by increasing the amount of raw kaolin reduces the The CTE method of the product will not increase the cost of raw materials, but the introduction of too much raw material will reduce the pass rate of the product sintering process. In addition, the introduction of more raw material will cause more microcracks in the product and reduce the strength of the product. High-strength thin-walled products are unfavorable

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