Thermally activated martensitic transformations in Mg-PSZ

Journal Article · Mon Apr 01 00:00:00 EST 1996 · Journal of the American Ceramic Society

DOI:https://doi.org/10.1111/j.1151-2916.1996.tb08523.x· OSTI ID:247908

Behrens, G; Heuer, A H ^[1]

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1. Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Materials Science and Engineering

The thermally activated, stress-assisted martensitic tetragonal {yields} monoclinic (t {yields} m) and tetragonal {yields} orthorhombic (t {yields} o) transformations in a high-toughness Mg-PSZ were investigated by monitoring the phase assemblage with Raman spectroscopy after a variety of heat treatments and loading conditions. After a short anneal at 1,000 C, which transforms m- and o-ZrO{sub 2} to the t polymorph, isothermal t {yields} m and t {yields} o transformations occur at room temperature during the months following the anneal. The transformation rates in the annealed samples are greatly enhanced under external stress. Alternatively, samples containing regions of significant residual stress, introduced by indentation for example, and then annealed at relatively low temperatures, underwent additional thermally activated transformation in the stressed regions. The thermodynamics and kinetics of this complex transformation ``plasticity,`` and its effect on mechanical properties, are discussed.

• Sponsoring Organization: USDOE
• OSTI ID: 247908
• Journal Information: Journal of the American Ceramic Society, Vol. 79, Issue 4; Other Information: DN: Presented at the 95th annual meeting of the American Ceramic Society, Minneapolis, MN (US), April 16, 1992; PBD: Apr 1996
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ZIRCONIUM OXIDES
CRYSTAL-PHASE TRANSFORMATIONS
MAGNESIUM OXIDES
RAMAN SPECTROSCOPY
X-RAY DIFFRACTION
NEUTRON DIFFRACTION
HEAT TREATMENTS
TETRAGONAL LATTICES
MONOCLINIC LATTICES
ORTHORHOMBIC LATTICES
STRESSES
STRAINS
STRESS RELAXATION
THERMODYNAMICS
KINETICS
MECHANICAL PROPERTIES