| Abstract Scope |
The driving force for sintering and densification is the exchange of solid-vapor surface energy for solid-solid surface energy. Therefore, the solid-vapor surface energy must be related to the amount of measurable surface area, which may be measured by nitrogen adsorption (i.e., B.E.T. method). The potential to promote sintering of different powders should then be related to the reduction in surface energy resulting from the exchange of solid-vapor surface energy for solid-solid surface energy. It is proposed that it may be possible to identify a critical surface area necessary to promote sintering for a given powder chemistry based on the ratio of SV:SS surface energy, with respect to time, temperature, and initial surface area. Results suggest a majority of the powders (i.e., Al<sub>2</sub>O<sub>3</sub>, Y<sub>2</sub>O<sub>3</sub>, and CaO) evaluated displayed a linear reduction in surface area with increasing temperature, while CeO2 exhibited non-linear behavior proposed to be polymorphism at elevated temperatures. |