Stability and Surface Energies of Wetted Grain Boundaries in Aluminum Oxide

• Published in: Journal of the American Ceramic Society 1994-02, Vol.77 (2), p.444-453
• Main Authors: Kim, Doh-Yeon, Wiederhorn, Sheldon M., Hockey, Bernard J., Handwerker, Carol A., Blendell, John E.
• Format: Article
• Language: English
• Subjects: 360202 - Ceramics, Cermets, & Refractories- Structure & Phase Studies; ALUMINIUM COMPOUNDS; ALUMINIUM OXIDES; CHALCOGENIDES; Condensed matter: structure, mechanical and thermal properties; CORUNDUM; Exact sciences and technology; GRAIN BOUNDARIES; INTERFACES; Liquid thin films; MATERIALS SCIENCE; MICROSTRUCTURE; MINERALS; OXIDE MINERALS; OXIDES; OXYGEN COMPOUNDS; Physics; SAPPHIRE; Solid surfaces and solid-solid interfaces; Solid-fluid interfaces; STABILITY; Surface energy; thermodynamic properties; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Wetting
• ISSN: 0002-7820; 1551-2916
• DOI: 10.1111/j.1151-2916.1994.tb07013.x

The stability of a calcium‐aluminum‐silicate liquid film between two near‐basal plane surfaces of sapphire at 1650°C was studied. Samples were prepared having an average basal misorientation across the interface of 6–7° about < 〈1010〉. The interfaces varied in orientation from 0° to ∼38° to the [0001] direction. Three types of interfaces were observed: faceted, solid‐liquid interfaces; low‐angle grain boundaries consisting of aligned arrays of dislocations; and boundaries consisting of alternating regions of dislocations and faceted solid‐liquid interfaces. The type of interface observed depended on the orientation of the interface and could be predicted by using a construction based on Wulff shapes. Because the type of interface depends on crystal alignment and interface angle, these results suggest an absolute method of determining the surface free energy of wetted boundaries.