MOBILITY CONTROL OF CERAMIC GRAIN-BOUNDARIES AND INTERFACES

Grain boundary mobility and grain-liquid boundary mobility in ceramics vary vastly from material to material. Their characteristics are sensitive to the crystal structure, the nature of bonding, orientation. stoichiometry and composition. More directly, mobility can be lowered by decreasing the interfacial energy and anisotropy or increasing solute drag, liquid viscosity, particle pinning and grain interlocking. Judicious doping and scavenging emerge as especially effective methods for mobility control. Static and dynamic grain growth data of zirconia, alumina, and silicon nitride are cited to support the above proposition.