A New Approach to Ceramic Liquid-Phase Sintering Paradigms

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The major assumption of isothermal changes in the "old" liquid-phase sintering model is notsuitable for the actual processings. This project proposes to use the transmission electron microscope (TEM) to observe the actual nanometer events. The observed TEM data will be used to change the "old" quantitative expressions as developed by Kingery in 1959. Observations of microsctructural changes and rates of change during the heating-up process, with emphasis on material distribution and distribution changes, will be made. Quantitative expressions will be formulated for the processes during the heating-up process with additives. These processes develop ultimately into liquid-phase sintering. The study will begin with the Al2O3-TiO2 system. %%%% This project examines the heating-up process with the presence of actives. Microscopic observations in nanoscales will be made of the microstructural changes and their rates of change with emphasis on material distribution and distribution changes. The study begins with the hypothesis that the focal point should be on the distribution, crystallinity, and properties of boundaries and surface "phases", which are present to allow acclerated material transfer. This study challenges the applications of the quantitative expressions the PI developed many years ago. This study aims to develop new expressions which will have a profound effect in catalyzing rapid and innovative advances, not only in ceramic processing, but also in ceramic sciences as well as in powder metallurgy.