Grain boundary engineering of highly deformable ceramics

Conference · Sat Jul 01 04:00:00 EDT 2000

OSTI ID:20104661

Mecartney, M L

Highly deformable ceramics can be created with the addition of intergranular silicate phases. These amorphous intergranular phases can assist in superplastic deformation by relieving stress concentrations and minimizing grain growth if the appropriate intergranular compositions are selected. Examples from 3Y-TZP and 8Y-CSZ ceramics are discussed. The grain boundary chemistry is analyzed by high resolution analytical TEM is found to have a strong influence on the cohesion of the grains both at high temperature and at room temperature. Intergranular phases with a high ionic character and containing large ions with a relatively weak bond strength appear to cause premature failure. In contrast, intergranular phases with a high degree of covalent character and similar or smaller ions than the ceramic and a high ionic bond strength are the best for grain boundary adhesion and prevention of both cavitation at high temperatures and intergranular fracture at room temperature.

• Research Organization: Univ. of California, Irvine, CA (US)
• Sponsoring Organization: Oak Ridge National Laboratory; Los Alamos National Laboratory; National Science Foundation
• OSTI ID: 20104661
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
DEFORMATION
FLOW STRESS
FRACTURE PROPERTIES
GRAIN BOUNDARIES
PLASTICITY
SILICON OXIDES
YTTRIUM OXIDES
ZIRCONIUM OXIDES