PROCEEDINGS OF THE RUSSIAN HIGHER SCHOOL
ACADEMY OF SCIENCES

The paper presents the results of a study of the synthesis of a highly dispersed silicon carbide powder by combining exo- and endothermic reactions (synthesis from elements and carbothermic reduction) using carbon nanofibers as carbon material. The reaction products were studied by the X-ray phase and elemental analyses as well as by scanning electron microscopy using the local energy-dispersive X-ray microanalysis. The specific surface of the samples was determined by the BET method. A sedimentation analysis was performed.  The thermo-oxidative stability was studied by synchronous thermogravimetry (TG) and differential scanning calorimetry (DSC). The material obtained under optimal conditions is represented by one phase - high-temperature modification silicon carbide. An average size of aggregated particles is 6.3…7.2 μm. The specific surface area of the samples is up to 8 m² /g. The content of impurities is insignificant (no more than 4 % by weight). Optimal conditions for the synthesis of silicon carbide with the use of NFC(s) as a reducing agent and carbidizer are the following: the mass ratio of reagents according to SiC carbide stoichiometry, the mass ratio of charges of 1:1, and the process in argon at 1800 °C.

1. Grigor'ev O.N. Keramika i kermety na osnove beskislorodnykh tugoplavkikh soedinenii [Ceramics and cermets based on anoxic refractory compounds]. Poroshkovaya metallurgiya – Powder Metallurgy and Metal Ceramics, 2012, no. 11/12, pp. 100–116. (In Russian).
2. Monteverde F., Savino R., Fumo M.D.S. Dynamic oxidation of ultra-high temperature ZrB₂–SiC under high enthalpy supersonic flows. Corrosion Science, 2011, vol. 53, pp. 922–929. doi: 10.1016/j.corsci.2010.11.018.
3. Kosolapova T.Ya., ed. Svoistva, poluchenie i primenenie tugoplavkikh soedinenii [Properties, production and application of refractory compounds]. Moscow, Metallurgiya Publ., 1986. 928 p.
4. Gruner W., Stolle S., Wetzig K. Formation of CO_х species during the carbothermal reduction of oxides of Zr, Si, Ti, Cr, W, and Mo. International Journal of Refractory Metals & Hard Materials, 2000, vol. 18, pp. 137–145.
5. Sivasankaran S., Kumar K. A novel sonochemical synthesis of nano-crystalline silicon carbide ceramic powder and its characterization. International Journal of Recent Scientific Research, 2015, vol. 6, pp. 2630–2633.
6. Gubernat A., Pichor V., Lach R., Zientara D., Sitarz M., Springwald M. Low-temperature synthesis of silicon carbide powder using shungite. Boletin de la Sociedad Espanola De Ceramica y Vidrio, 2017, vol. 56, iss. 1, pp. 39–46.
7. Kuvshinov G.G., Krutskii Yu.L., Orishith A.M., Chukanov I.S., Varfolomeeva A.S., Afonin Yu.V., Zaikovskii V.I. , Kuvshinov D.G. Morphology of silicon carbide synthesized using laser ablation of a mixture of nanofibrous carbon with. Nanotechnologies in Russia, 2012, vol. 7, pp. 385–391.
8. 8 Sychev A.E., Merzhanov A.G. Samorasprostranyayushchiisya vysokotemperaturnyi sintez nanomaterialov [Self-propagating high-temperature synthesis of nanomaterials]. Uspekhi khimii – Russian Chemical Reviews, 2004, vol. 73, no. 2, pp. 157–170. (In Russian).
9. Saeedifar Z., Nourbakhsh A.A., Kalbasi R.J., Karamian E. Low-temperature magnesiothermic synthesis of mesoporous silicon carbide from an MCM-48/polyacrilamid nanocomposite precursor. Journal of Materials Science and Technology, 2013, vol. 29, pp. 255–260.
10. Hosseini B., Nourbacksh A.A., MacKenzie K.J.D. Magnesiothermal synthesis of nanostructured SiC from natural zeolite (clinoptilolite)and mesoporous carbon CMK-1. Ceramics International, 2015, vol. 41, pp. 8809–8813. doi: doi.org/10.1016/j.ceramint.2015.03.107.
11. Polyakh O.A., Rudneva V.V. Plazmometallurgicheskoe proizvodstvo karbida kremniya dlya kompozitsionnogo nikelirovaniya i khromirovaniya [Plasma-metallurgical production of silicon carbide for composite nickel plating and chrome plating]. Moscow, Nauka Publ., 2006. 188 p.
12. Kuvshinov G.G., Mogilnykh Yu.I., Kuvshinov D.G., Yermakov D.Yu., Yermakova M.A., Salanov A.N., Rudina N.A. Mechanism of porous filamentous carbon granule formation on catalytic hydrocarbon decomposition. Carbon, 1999, vol. 37, pp. 1239–1246.
13. Samsonov G.V., ed. Fiziko-khimicheskie svoistva okislov [Physico-chemical properties of oxides]. Moscow, Metallurgiya Publ., 1978. 472 p.
14. Blott S.J., Pye K. Gradistat: a grain size distribution and statistics package for the analysis of unconsolidated sediments. Earth Surface Processes and Landforms, 2001, vol. 26, pp. 1237–1248.