SYNTHESIS OF NANOSIZE SILICON CARBIDE POWDER BY CARBOTHERMAL REDUCTION OF SiO₂

Abstract

A mixture of silicon carbide nano-particles and nano-whiskers has been synthesized through solid state reduction of silica by graphite employing high energy planetary ball milling for 25 h and subsequent heat treatment at 1300-1700°C in dynamic argon atmosphere. Effects of process conditions on the thermal behavior, phase composition and morphology of the samples were investigated using DTA/TGA, XRD and SEM, technique, respectively. DTA/TGA analysis shows that silicon carbide starts to form at ~ 1250°C. Analysis of the XRD patterns indicates that the phase composition of the sample heat treated at 1300°C for 2 h mainly consists of SiO2 together with small amount of β-SiC. Nano-crystalline silicon carbide phase with a mean crystallite size of 38 nm was found to be dominate phase on heat treatment temperature at ~ 1500°C. Substantial SiO2 was still remained in the above sample. SEM studies reveal that the sample heat treated at 1500°C for 2 h contains nano-particles and nano-whisker of β-SiC with a mean diameter of almost ~ 85 nm. The results obtained were also showed that the characteristics of the synthesized SiC particles strongly depend on the mechanical activation and heat treatment conditions.

Fluorescent Silicon Carbide Nanoparticles

“…The width of each box indicates the range of particle sizes that can be fabricated with the respective technique to date. The main techniques are laser ablation, [ 18–24 ] milling, [ 25–28 ] various etching techniques, [ 17,29,30–37,38–41 ] and thermal reduction of Si‐ and C‐based precursors. [ 42–44 ]…”

“…Mechanical ball milling creates particles in the size range from tens of nanometers to microns. [ 25,27,45 ] Steel, [ 25,26,45 ] tungsten carbide, [ 27,28 ] or zirconia [ 27 ] balls are commonly used as milling media. The milling process also leads to a degradation of the milling medium and can introduce impurities like iron, tungsten, or zirconium onto the surface of the milled particles which necessitates cleaning with strong acids.…”

“…The result of the synthesis process is often a porous SiC matrix, [ 65 ] which is then purified and further processed, for instance, to create isolated NPs. Carbothermal synthesis has been used for synthesis of complex nanostructures such as high aspect ratio nanowires [ 26,57,66–70 ] and rings. [ 18 ] The created particles are usually tens of nanometers or larger in size, and consist of 3C‐SiC.…”

Production of Silicon Carbide via Grinding and Heat Treatment Process

“…SiC is a commonly used ceramic material with a tetrahedral structural unit similar to diamond and with attractive properties such as high strength, stiffness, good wear and corrosion resistance and semi-conductivity, which are mainly characteristic of covalent bonded ceramic materials. It is a promising material for thermo-mechanical and electronic applications [1].…”