Rapid Nondiffusional Penetration of Oxide Melts along Grain Boundaries of Oxide Ceramics

Interaction of the liquid phase with the grain boundaries of solids and a rapid mass transport in solids were studied in the present work with a CuO ceramic melt of the Bi2O3system as an example. Anomalously rapid penetration of the liquid phase along the grain boundaries of a solid ceramic material was observed. The velocity and activation energy of the process were each determined. A mechanism for the development of a grain-boundary liquid channel in the kinetic mode, when the channel growth rate is reaction-limited, was proposed. This mechanism leads to the formation of a liquid-channel grain-boundary structure (LGBS) in solids. It was demonstrated that liquid can interact with one-dimensional as well as two-dimensional defects in solids.