Method for preparing silicon carbide whisker by laser irradiation of nano silicon carbide powdered material

Abstract

The invention provides a method for preparing silicon carbide whisker by using laser irradiating nano silicon carbide powder material which belongs to the nano technique field. The method includes steps as follows: (1) preparing a caking agent solution for processing granulation to SiC nano powder granule; (2) preparing nano SiC powder pressing block by using cool isostatic pressing theory; (3) scanning irradiation by using a laser along the pressing block diameter direction, the scanning irradiation region is cut and opened an aperture, a uniform compact scan irradiation layer is formed on two walls in the aperture inside, and beta-SiC whisker can be obtained in the scan irradiation layer; wherein, parameter of the laser is that: a laser facula diameter is 0.2mm-0.3mm, a laser scan speed is 0.04m / min-0.2m / min, a laser power is 250W-450W. The new method provided by the invention for preparing beta-SiC nano whisker has advantages of short preparing period, simple method, high purity whisker and good quality whisker.

Description

technical field [0001] The invention relates to a method for silicon carbide whiskers, belonging to the field of nanotechnology. Background technique [0002] β-SiC nano-whiskers are not only quasi-one-dimensional nano-semiconductor materials with special optical and electrical properties, but also the highest hardness and strength of all known whisker-like materials. SiC nano whiskers do not react with most metals and are easy to form super composite materials with high hardness, high toughness, high wear resistance, high temperature resistance, high temperature creep resistance and low thermal expansion coefficient, especially in the preparation of nano optoelectronics Devices, high-strength small-size composite components and thin composite components, and surface nano-reinforced composite materials have very attractive application prospects. [0003] At present, the methods commonly used to prepare SiC whiskers at home and abroad mainly include: arc discharge method; re...

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Problems solved by technology

Among them, the arc discharge method, the resistance heating evaporation method and the floating catalyst method can all prepare β-SiC nano whiskers in large quantities, but they have the disadvantage of introducing catalysts to affect the purity. Although the carbon nanotube limited reaction method has high purity, the cost of raw materials is too high.

After searching the literature, it was found that Wang Qibao and others pointed out in the article "Research on the Synthesis of β-SiC Whiskers and Growth Mechanism of Rice Husks" published in "New Chemical Materials", 1996; (2): 21-24, that SiC whiskers were prepared from rice husks. The disadvantage is that the synthesized SiC whisker content is less than 30%. At the same time, Ning Shufan and others published "SiC whisker preparation method and In the article "Application", it is pointed out that the disadvantages of preparing SiC whiskers by CVD are that the price of raw materials is high, and SiC tiny particle by-products are easily generated during thermal decomposition, the output is small, and the preparation cycle is long.

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