Effect of decomposition of chemically precipitated Al(OH)(3) on nano silicon carbide experimental and reaxff molecular dynamic study

Abstract

Chemically precipitated Al(OH)(3) on SiC particles is effective and economical additives as sintering aids for silicon carbide materials. Nanocomposite SiC powder was produced by chemically precipitated Al(OH)(3) via heterogeneous nucleation. Produced powder was calcined under controlled atmosphere at 1350 degrees C for 1 h. Effect of calcination of Al(OH)(3) on the nano sized SiC particles was investigated experimentally by using XRD, Thermogravimetric Analysis and Transmission Electron Microscope. Molecular dynamic study using ReaxFF reactive force field was performed to understand the mechanism of Al2O3 and SiC interaction at elevated temperatures under oxygen free environment. The experimental analyses showed that polymorphic transition sequence of alumina, which was precipitated on the SiC nanoparticles, was retarded to the relatively higher temperatures. Molecular dynamic study revealed that silicon site was more prone to oxidation and silicon atoms preferred to react with Al-O species.