SYNTHESIS AND CHARACTERIZATION OF MULLITE COATINGS

In the current paper, an attempt is made to synthesize a mullite EBC on a SiC substrates using sol-gel synthesis. Two general procedures were practiced for preparing mullite gel. First, by ageing the Aluminium Nitrate Nona Hydrate and Tetra Ethyl Ortho Silicate (TEOS) in solution of Ethyl Alcohol at various temperatures and Second, by preparing Aluminium Isopropoxide from continuous stirring of Aluminium Chloride (AlCl3) with 2-Propanol in different amounts in Refluxing vessel for 24 hrs and then mixing it with TEOS at various pH values. Characterization of the synthesized mullite has been performed by X-Ray Diffraction (XRD), Fourier Transformation Infra-Red Spectroscopy (FTIR) as well as Scanning Electron Microscopy (SEM). The effects of variations in the processing parameters such as pH, ageing temperatures, amount of propan-2-ol and calcinations temperatures have been discussed.