Ceramic materials are currently being used in many applications and account for about $26 B of the U.S. economy in low value-added products (glass, refactories, cement, whitewares, etc.) and nearly $4 B of high value-added components (chip carriers, waveguides, capacitors, cutting tools, etc.). There are many new applications of ceramics in high technology engineering systems which will result in significant growth of the ceramics business if the materials research triad Structure-Property-PROCESSING moves from the laboratory to the manufacturing plant. Each component can be classified by function (e.g., thermal, mechanical, electromagnetic, optical, biological, and nuclear); configuration (e.g., film, monolith, composite, porous, and single crystal); or processing route (e.g., powder processing, glass forming, and crystal growth). The opportunities are greatest for those components which have a well established processing science base or an unique fabrication method.
Thirty years of research have shown that the critical physical/chemical properties are strongly related to the structure on one or more levels: few angstroms - crystal structure and phases; 10–100 Å - boundary or grain boundary layers or phases; 1 μm - microstructure (grain size, porosity, interpenetrating phases, etc.); and macro-structure including joining, shape and dimensional tolerances. The major focus of this overview relates to issues of reliability and reproducibility in processing polycrystalline ceramics and the relationship between processing and the control of the structure and properties. Examples considered are those of high value-added components where design and functionality justify improved material characteristics.