SURFACE ENERGY OF CERAMIC MATERIALS

Abstract

Abstract : The concepts, experimental techniques, and theoretical analyses of the surface energy of solid ceramic materials are reviewed with the aim of condensing a large mass of unrelated data into a concise form for comparison and evaluation. It is shown that various experimental methods can be applied to the measurement of surface energy, but, that each of these has certain limitations which are often unstated. Furthermore, it is shown that theoretical analyses and empirical correlations, while sometimes rather imprecise, can be used to approximate surface energies, particularly as functions of temperature. While a few materials have been discussed in considerable detail (such as MgO, Al2O3 and some alkali halides), a review of the literature notes that there is a great paucity of information on the surface energies of many solids of interest. Improvements and extensions of experimental and empirical techniques are suggested that will help to fill the voids in the present understanding of ceramic solid surfaces, and specific analyses of experimental methods are forwarded. It is shown in the report that the proper use of thermodynamic techniques offers considerable potential for the measurement and interpretation of solid surface energies of a large number of materials that are poorly understood at present. In addition, the further development of thermodynamic methods presents an opportunity to investigate solid surface energies of nonbrittle materials, thus overcoming one of the basic limitations of the use of mechanical methods.