Synthesis method of beta-SiC micro-powder and whiskers

Abstract

The invention relates to the technical field of solid phase synthesis of silicon carbide micro-powder and especially relates to a synthesis method of beta-SiC micro-powder and whiskers. The synthesis method of the beta-SiC micro-powder and whiskers utilizes crushed and uniformly mixed carbon and silicon raw materials as reaction raw materials and is characterized by comprising the following steps of filling the reaction raw materials into a vacuum resistance furnace, closing the vacuum resistance furnace, carrying out vacuum-pumping on the vacuum resistance furnace so that the pressure in the vacuum resistance furnace is below 100Pa, supplying power to the vacuum resistance furnace to heat it to a temperature of 1400-1500K, carrying out heat preservation, stopping the power supply when the pressure in the vacuum resistance furnace is below 10Pa for more than 60min, and carrying out natural cooling to obtain the product. The synthesis method realizes accurate control of beta-SiC micro-powder and whisker synthesis conditions, has a simple process and a low production cost, and can realize industrial synthesis of the beta-SiC micro-powder and whiskers. The beta-SiC micro-powder and whiskers obtained by the synthesis method has high integrity, high purity and good quality.

Description

(1) Technical field [0001] The invention relates to the technical field of solid-phase synthesis of silicon carbide micropowder, in particular to a method for synthesizing β-SiC micropowder and whiskers. (2) Background technology [0002] β-SiC powder and whiskers have a very broad market demand in the production fields of optical instruments, electronic devices, ultra-precision grinding machine metal products, advanced refractory materials, and structural ceramic materials. At present, there are three methods for synthesizing β-SiC micropowder and whiskers: solid-phase method, liquid-phase method and gas-phase method. Solid-phase methods include Acheson method, ESK method, shaft furnace method and high-temperature converter method, multi-core furnace method, carbon-silicon direct reaction method and self-propagating method, etc.; liquid-phase method has been developed since the 1980s, including many There are mainly precipitation methods (direct precipitation method, unif...

AI Technical Summary

Problems solved by technology

The Acheson method is the most important SiC production method, but this method has low technical level, backward production method, serious pollution, low thermal efficiency, high energy consumption, unsafe production (easy to spray furnace), low product quality, and low product added value , CO gas is not recovered, which is contrary to the current national energy conservation and emission reduction policies

In recent years, countries have tried to change this high-energy, high-pollution, low-yield SiC production method, such as increasing the size of the production furnace, changing the power supply method of the electrode, and collecting and reusing CO gas, which has achieved certain energy-saving effects. Fundamentally change its backward status

[0004] However, none of the above methods considers the synthesis of SiC micropowders and whiskers under vacuum conditions, and cannot accurately control the synthesis temperature, atmosphere and pressure of SiC micropowders and whiskers. The synthesis temperature is high, so that the synthesis of β-SiC basically depends on technical experience. It has caused a certain degree of randomness in the production, and it is difficult to synthesize high-purity micron-sized β-SiC powder and whiskers at one time.

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