Innovations in synthesis and processing of ceramic materials

There are two main keys for step function advances in ceramic materials science, i.e., new materials and new processing techniques. This paper focuses on new synthesis and processing techniques. Since 1991, we have been very active in the synthesis of various ceramics, metals and semiconductor powders using microwave-assisted solvothermal process. The main advantages of microwave-sol vothermal (M-S) process over the conventional process are: (a) it can lead to energy savings through rapid heating to the temperature of treatment and enhanced kinetics of phase formation by one to two orders of magnitude, (b) it can lead to formation of new phases and (c) it can eliminate metastable phases. These advantages of the M-S process will be illustrated with several examples of ceramic materials synthesized by this process. Ceramic powders including nanopowders of different sizes and shapes can be synthesized by the novel M-S process. These powders can then be processed by microwave sintering to achieve good mechanical properties. Nanocomposite sol-gel processing is another innovative technology developed at Penn State to obtain well densified materials of alumina, mullite and cordierite with applications for abrasive grains, electronic substrates etc.