Decomposition characteristics of a mixture of aluminum-tri-sec butoxide (ASB) and tetraethyl orthosilicate (TEOS) in ethyl acetate solution by microwave pyrolysis was examined. The decomposed product was used as a second-stage precursor in the preparation of pure mullite (3Al(2)O(3). 2SiO(2)). Mullite-zirconia composites were obtained, using the above mixture along with zirconium-iso-propoxide as starting materials. Pellets of mullite and mullite-zirconia composites were sintered in a microwave oven using beta-SiC as a secondary heater.