CHEMICAL PROCESSING OF ADVANCED LITHIUM ALUMINOSILICATE CERAMIC SYSTEM

ABSTRACT:During the past few decades, new developments in the use of ceramics in more advanced technological applications have drawn considerable attention. It is reported that certain ceramic compositions in the lithium aluminosilicate system have low thermal expansion coefficient and high degree of thermal shock resistance making them useful in specific applications. Being a novel technology for the chemical synthesis of ceramics, the sol-gel method was applied in this work. This process is based on the chemical hydrolysis and condensation reactions starting from molecular or colloidal precursors. Lithium aluminosilicate with molar composition Li20 : A1203 : 3Si02 was selected to be prepared via sol-gel technique. Tetraethoxysilane (TEOS), Lithium chloride [LiCl2 . H20] and Aluminum nitrate [Al(NO3)3 9H20] were used as precursors in this ceramic synthesis. The effect of CH3COOH, H3PO4 and HNO3 acid catalysts on the synthesis method was studied. The prepared ceramic was analyzed by TGA, DSC, DTA, XRD, IR and SEM. The results were given, explained and discussed.