Ceramics: 1. Shear and dilatation effects

Journal Article · Fri Feb 28 23:00:00 EST 1986 · J. Am. Ceram. Soc.; (United States)

OSTI ID:5684937

Chen, I -W; Morel, P E.R.

Transformation plasticity in ZrO/sub 2/-containing ceramics generally exhibits shear and dilation effects of comparable magnitude. The coupling between external stresses and crystallographic strains assists the tetragonal-monoclinic transformation, which, via shear localization, gives rise to macroscopic shear and dilatant deformation. Application of a yield criterion based on both shear and dilatation effects correctly correlates deformation data from tension, compression, bending, and indentation, and further delineates a crack-tip process zone comparable to the one observed experimentally. Similar shear and dilatation effects in microcracking due to transformation plasticity are explored. These findings suggest that the strength of the ultimate transformation-toughened structural ceramics should be yield limited and sensitive to the stress state. Strategies for fracture control are recommended.

• Research Organization: Dept. of Nuclear Engineering and Dept. of Materials Science and Engineering, Massachusetts Inst. of Technology, Cambridge, MA 02139
• DOE Contract Number: FG02-84ER45154
• OSTI ID: 5684937
• Journal Information: J. Am. Ceram. Soc.; (United States), Journal Name: J. Am. Ceram. Soc.; (United States) Vol. 69:3; ISSN JACTA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360203* -- Ceramics
Cermets
& Refractories-- Mechanical Properties
BENDING
CERAMICS
CHALCOGENIDES
COMPRESSION
CRYSTALLOGRAPHY
DEFORMATION
DILATANCY
FRACTURE MECHANICS
MECHANICAL PROPERTIES
MECHANICS
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
PLASTICITY
RECOMMENDATIONS
SHEAR
STRAINS
STRESSES
TRANSITION ELEMENT COMPOUNDS
ULTIMATE STRENGTH
ZIRCONIUM COMPOUNDS
ZIRCONIUM OXIDES