Cylindrical mullite-sheet shape alumina composite powder and preparation method thereof

Abstract

The invention relates to cylindrical mullite-sheet shape alumina composite powder and a preparation method thereof. The preparation method comprises the following steps: uniformly mixing 60-88wt% of mullite powder and 12-40wt% of aluminium fluoride powder to obtain mixed powder; adding deionized water in the mixed powder according to the mass ratio of (0.01-0.05):1, uniformly mixing the materials, ageing a mixture, and compacting the mixture to obtain a base substrate; then placing the base substrate in an enclosed alumina crucible, insulating the material for 2-16 hours at the condition of 1400-1650 DEG C, and cooling the material to room temperature to obtain the cylindrical mullite-sheet shape alumina composite powder. The Al2O3 content in the mullite powder is greater than or equal to 71.8wt%, and particle size is less than or equal to 80 mm. The AlF3 content in the aluminum fluoride powder is greater than or equal to 98wt%, and particle size is less than or equal to 80 mm. The cylindrical mullite-sheet shape alumina composite powder has the characteristics of simple preparation technology, easiness in control, low cost and high yield; and the cylindrical mullite-sheet shape alumina composite powder produced by the method has the advantages of high purity and easy large-scale production.

Description

technical field [0001] The invention belongs to the technical field of columnar mullite-flaky alumina. Specifically relates to a columnar mullite-flaky alumina composite powder and a preparation method thereof. Background technique [0002] Columnar mullite has excellent characteristics such as high melting point, high strength, good thermal shock resistance, small thermal conductivity, small thermal expansion coefficient and good chemical stability. with SiC, BN and Si 3 N 4 Compared with non-oxide whisker / columnar crystals, mullite columnar crystals not only have various excellent properties, but also have low price, and can be used in harsher oxidizing environments. Flaky alumina not only has the advantages of high melting point, high hardness, good mechanical properties and corrosion resistance, but also has a special two-dimensional sheet structure. Therefore, the composite powder of columnar mullite and flaky alumina not only has the respective advantages of mullit...

AI Technical Summary

Problems solved by technology

Although these methods have their own advantages, there are still some disadvantages: most of the sol-gel methods use alkoxides as raw materials, which are expensive; at the same time, the hydrolysis rates of alkoxides are different, the process is complicated, difficult to control, and the yield is low. and high cost of preparation

Although the molten salt method can produce the required columnar mullite or flaky alumina at low temperature, the volatilization of the molten salt seriously endangers human health and pollutes the environment, and the product has high impurity content and low yield, which leads to price expensive

The columnar mullite or flaky alumina prepared by the mineral decomposition method and oxide doping method has high impurity content, which seriously affects the performance of the product

[0004] Therefore, the shortcomings of the current preparation technology of columnar mullite-flaky alumina are: complex process, low yield, high cost, low product purity, etc., which limit the application of columnar mullite-flaky alumina in the industry. Scale application

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