The influence of reaction parameters on the free Si and C contents in the synthesis of nano-sized SiC
S. Larpkiattaworna, , , P. Ngernchuklina, W. Khongwonga, N. Pankurddeea and S. Wadab
aThailand Institute of Scientific and Technological Research, 196 Phahonyothin Rd., Chatuchak, Bangkok 10900, Thailand bMaterial Science Department, Chulalongkorn University, Bangkok, Thailand
Received 16 November 2004; revised 16 June 2005; revised 30 June 2005. Available online 5 October 2005.
Uniform nano-sized beta-silicon carbide (β-SiC) powder was synthesized from the reaction of silicon (Si) and carbon black (C). Mixed Si and C-black powder were pressed into pellets and the influence of four parameters, temperature (1250, 1300 and 1350 °C), heating rate (20 and 50 °C/min), soaking time (1 and 3 h) and atmosphere (vacuum and argon), were tested. It was found that higher temperatures, higher heating rates and longer soaking times in a vacuum system lead to lower free Si content in the SiC powder created. Temperature was the parameter with the greatest influence on the Si content of the SiC powder. This study also found that the Si–C reaction occurs through gas–solid (SiO–C) and solid–solid (Si–C) reactions that occur simultaneously.
Keywords: SiC powder; Synthesis; Si–C reaction; Free Si; Reaction parameters