A critical assessment of flow and cavity formation in a superplastic yttria-stabilized zirconia

Journal Article · Mon Aug 01 04:00:00 EDT 1994 · Acta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-7151(94)90216-X· OSTI ID:6977209

Ma, Y; Langdon, T G ^[1]

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1. Univ. of Southern California, Los Angeles, CA (United States)

Tensile tests were performed on specimens of high purity 3Y-TZP (tetragonal ZrO[sub 2] stabilized with [approximately]3 mol% of Y[sub 2]O[sub 3]) at temperatures from 1,623 to 1,803 K. Superplastic-like flow was achieved with elongations of up to > 400%. The experiments show that the stress exponent, n, is [approximately] 3.0--3.4 and the activation energy for flow, Q, is [approximately] 602 [+-] 20 kJ mol[sup [minus]1]. Internal cavities developed in all specimens during flow, and quantitative measurements were taken of the cavity shapes and sizes over a range of experimental conditions. The results demonstrate that there is an increase in the extent of cavitation with (i) decreasing temperature at constant strain rate and (ii) increasing strain rate at constant temperature. The influence of strain rate on cavitation in 3Y-TZP is the opposite of most superplastic metals, and the difference arises because of an inhibition in the diffusion growth process in 3Y-TZP.

• OSTI ID: 6977209
• Journal Information: Acta Metallurgica et Materialia; (United States), Journal Name: Acta Metallurgica et Materialia; (United States) Vol. 42:8; ISSN 0956-7151; ISSN AMATEB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202 -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
360203* -- Ceramics
Cermets
& Refractories-- Mechanical Properties
CERAMICS
CHALCOGENIDES
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
FLOW STRESS
MECHANICAL PROPERTIES
OXIDES
OXYGEN COMPOUNDS
PLASTICITY
STRESSES
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES
ZIRCONIUM COMPOUNDS
ZIRCONIUM OXIDES