Anisotropic Properties in Textured Ceramics

Abstract

Preferred orientation results from processing of many ceramic and intermetallic materials. Preferred orientation of crystals, anisometric grain shapes and oriented defects can enhance or compromise the performance of ceramic components. The limited research to date on textured ceramics has focused on either materials for structural applications or for high temperature superconductors. The goal for this paper is to describe new areas of opportunity in research on texture and anisotropy in ceramic and intermetallic materials. These opportunities include investigations of new or at least poorly understood mechanisms, new topics for texture and anisotropy correlations and improvements in performance for existing applications. Examples given in this paper include layered ceramics, textures in diffusion studies, and orientation and anisotropy in materials with electromechanical applications. Layered aluminum oxide materials possessing particles separated by size, and thereby shape can be produced using centrifugal processing. Refractory metal disilicides, materials proposed for high temperature applications beyond current use as heating elements in high temperature furnaces, have shown growth of phases with preferred crystal orientation and anisometric grain shapes. Piezoelectric and electrostrictive materials, widely employed as sensors and actuators, have properties that are strongly influenced by crystal orientation. Orientation assessment and correlation with properties in these materials will be discussed.