INFLUENCE OF ENERGY ON PHASE COMPOSITION OF END-PRODUCT OBTAINED BY VACUUM-FREE ELECTRIC ARC SYNTHESIS OF CUBIC SILICON CARBIDE

• Main Authors: Aleksandr Y Pak, Gennadii Ya Mamontov, Ol’ga A Bolotnikova
• Format: Article
• Language: English
• Published: Peoples’ Friendship University of Russia (RUDN University) 2018-12-01
• Series: RUDN Journal of Engineering Researches
• Subjects: карбид кремния; безвакуумный метод; электродуговой синтез; влияние прекурсоров; рентгеновская дифрактометрия; электронная микроскопия
• Online Access: http://journals.rudn.ru/engineering-researches/article/view/18913
• ISSN: 2312-8143; 2312-8151

The paper describes the scientific and technical basis of the vacuum-free plasma method for obtaining silicon carbide realized by DC arc discharge between graphite electrodes. In a series of experiments the energy supplied to the system was changed by increasing the duration of arc discharge with the constant value of current intensity (165 A); two precursor types were used: a mixture of silicon powder with X-ray amorphous carbon in the microfiber form in the first case and with carbon powder in the second case; the mass ratio in the initial mixture was Si:C = 2:1. As a result of the evaluation of the synthesis product quantitative composition, the experimental parameters that allow to achieve the maximum content of the target silicon carbide phase (up to 45%) are determined. Moreover, it was possible to determine the parameters when the only impurity phase in the product was graphite; as a result, the purification of the product from unbound carbon and thereby obtaining silicon carbide with ~99% content was successfully performed by atmospheric furnace heating at a temperature of 900 °C. This result is ensured by two factors: the presence of carbon fibers in the initial reagents mixture and a sufficient level of the supplied energy of about 216 kJ/g.