Crack resistance and fatigue of transforming ceramics; Materials in the ZrO sub 2 -Y sub 2 O sub 3 -Al sub 2 O sub 3 system

Journal Article · Fri Feb 01 00:00:00 EST 1991 · Journal of the American Ceramic Society; (USA)

DOI:https://doi.org/10.1111/j.1151-2916.1991.tb06882.x· OSTI ID:5663396

Grathwohl, G; Liu, T ^[1]

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1. Kernforschungszentrum Karlsruhe, Univ. Karlsruhe, Karlsruhe (DE)

Crack resistance characteristics and fatigue properties have been studied in four types of Y{sub 2} O{sub 3}-TZP ceramics including one containing Al{sub 2}O{sub 3}. The largely linear-elastic behavior connected with the very small transformation zone ({lt}4 {mu}m) explains the absence of any resistance-curve behavior and the flaw-controlled strength. The crack resistance shows high sensitivity to environment-induced subcritical crack growth. This influence is also operative in both types of fatigue experiments, i.e., under static and cyclic stresses, leading to reduced fatigue thresholds compared with K{sub ic}. While for static conditions a benefit is observed from enhanced t-m ZrO{sub 2} transformation, cyclic stresses provoke an additional fatigue effect. However, if the cyclic stresses are restricted to subthreshold values, cyclic stress-induced effects in the process zone provide an improvement of the materials being visible as a strengthening effect.

• OSTI ID: 5663396
• Journal Information: Journal of the American Ceramic Society; (USA), Vol. 74:2; ISSN 0002-7820
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM OXIDES
MECHANICAL PROPERTIES
YTTRIUM OXIDES
ZIRCONIUM OXIDES
CERAMICS
CRACKING
FATIGUE
STRESSES
ALUMINIUM COMPOUNDS
CHALCOGENIDES
CHEMICAL REACTIONS
DECOMPOSITION
OXIDES
OXYGEN COMPOUNDS
PYROLYSIS
THERMOCHEMICAL PROCESSES
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
ZIRCONIUM COMPOUNDS
360203* - Ceramics
Cermets
& Refractories- Mechanical Properties