| Abstrakt: |
In this study, carbothermic reduction of rice husk silica (SiO2) was performed for the production of Si/SiO2/SiC composites. The carbothermic reduction was carried out in an atmospheric tube furnace at 1350 °C with two boats, namely the alumina boat (AB) and the charcoal boat (CB). For the reduction reaction, SiO2 was directly put into the CB, whereas in the case of AB, SiO2 was mixed with activated carbon (AC) in different fractions. The products obtained were characterized using X-ray diffraction (XRD) analysis, Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS). The CB treatment yielded a hard solid product, whereas three different products stacked in layers were obtained from AB reduced SiO2. Hybrid Si/SiO2/SiC composites with novel floral morphology were obtained from CB and the upper layer of AB, having hexagonal rods with spherical tips and string-bead structure, respectively. The middle layer of AB reduced SiO2 yielded SiO2/SiC composites with a combination of nanowhiskers and micro-bead morphology. The product from the lower layer of AB showed characteristics of β-SiC whiskers with an average grain size of 27.95 nm along with some remnant of SiO2 and carbon. Highlights: Carbothermic reduction of rice husk silica to produce Si/SiO2/SiC composites The reduction was performed in an atmospheric tube furnace using carbon and alumina boats Si/SiO2/SiC composites were produced with novel morphologies, along with SiO2/SiC and β − SiC [ABSTRACT FROM AUTHOR] |
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