Preparation method and use of nano-SiC whisker

Abstract

The invention discloses a preparation method of a nano-SiC whisker. The preparation method has a whisker yield of 100%. The preparation method adopts a uniform mixture of a commercial carbon source and rice husk lime as raw materials. The preparation method comprises the following steps of heating the uniform mixture to a high temperature of 1500 DEG C in an inert atmosphere, carrying out heat preservation at the temperature for a certain time, after the reaction, heating the reaction products mainly comprising nano beta-SiC whiskers which have smooth surfaces or are provided with granules on the surface thereby forming beading structures to a temperature of 700 DEG C in air, and carrying out heat preservation for 120min to remove residual carbon so that a high-purity SiC whisker product is obtained, wherein the high-purity SiC whisker product has the diameter of 200-400nm and the length of dozens of microns. SiC has a series of excellent properties and thus SiC can be widely used, for example, SiC can be used for a reinforcing phase of a composite material and for increasing a heat transfer coefficient of a hot fluid. The SiC whisker having a beading structure can be used for reinforcement of a composite material. Compared with the traditional smooth fibers, the SiC whisker has better effects. The SiC whisker can greatly improve a heat transfer coefficient of a hot fluid.

Description

technical field [0001] The invention relates to a method for preparing high-quality silicon carbide whiskers by using rice husks and commercial carbon sources as raw materials, and two applications of the prepared silicon carbide whiskers. Background technique [0002] As a ceramic material with superior performance, SiC has excellent characteristics such as high Young's modulus, high temperature strength, low specific gravity, strong chemical stability, corrosion resistance, and thermal shock resistance, so it has a wide range of uses. SiC has more than two hundred crystal forms and various forms, including particles, whiskers, fibers, and bulk SiC. Different morphologies have an important impact on its performance. Considering different usage purposes, it is very important to select the corresponding SiC material to make full use of its excellent performance. [0003] As a crystal form of SiC, β-SiC is very important in academia and industry, and has important and extensi...

AI Technical Summary

Problems solved by technology

The addition of catalyst can promote the reaction to a certain extent, but it has limited effect on improving the yield of SiC whiskers

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