本文以不同粒径的硅粉和纳米碳黑为原料，采用微波加热在真空下合成SiC微粉，研究了反应温度、反应时间和原料粒径对反应产物的物相、SiC 生成率及其形貌的影响。结果表明，反应温度达到1000°C时，Si和C开始反应生成SiC；在1200°C时反应30 min即可基本实现Si和C的充分反应，得到平均粒径约为100 nm的SiC微粉，且SiC的生成率达到95%以上。此外，本文还对Si和C的固相反应扩散机制进行了初步探索。%Ultrafineβ-SiC powders were synthesized by microwave in vacuum. The starting materials are silicon powders of different particle sizes and nanometer carbon black. The effects of reaction temperature, reaction time and the particle size of initial silicon powder on the phase, productivity, particle size and morphology of the synthesized SiC powder were studied. The results show thatβ-SiC began to be synthesized when the temperature reaches 1000°C. When the temperature reaches 1200°C and reacting time is 30 min, silicon can completely react with carbon black to form SiC. The average particle size of the synthesizedβ-SiC powder is about 100 nm, and the producing rate can reach above 95%. The diffusion mechanism of the solid-state reaction between Si and C was also explored briefly.
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