Structure,. Properties, and Formation Models of Optical Ceramics

摘要

The structure, properties, and formation mechanisms of Y_l,01A0Y2,35a saer ncedra_2m lL_ics_u__() are investigated. Their microhardness and fracture toughness are determined. It is shown that the change in mechanical properties is related both to the grain size and grain boundary structure. Processes of plastic deformation of crystals by mechanical twinning are considered. Mechanisms of formation and motion of twins in crystals with FCC structure are determined. It is shown that the realization of similar mechanisms in crystals with HCP structure results in the phase transformations. Models of the formation and motion of twin boundaries are proposed which result in pore healing when preparing monolithic Samples of highly transparent ceramics.