Investigation of creep in (Al2O3 + ZrO2)-ceramics by ultrasonic surface waves

Journal Article · Fri May 01 04:00:00 EDT 1992 · Acta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-7151(92)90074-O· OSTI ID:5002097

Schneider, D; Krell, A; Weiss, T; Reich, T H ^[1]

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1. Zentralinstitut fuer Festkoerperphysik und Werkstoff-Forschung, Dresden (Germany)

The creep damage in inhomogeneously deformed regions of ceramic bending specimens was examined by measuring the propagation velocity of ultrasonic surface waves. Using ultrasonic equipment with a noncontact generation of surface waves by laser impulses and applying the Fourier transformation technique for analyzing the surface waves dispersion, the procedure finally results in the surface wave velocity depending on the frequency in a desired surface region of a specimen. The measurement of the surface wave disperison enables the evaluation of a microstructural gradient produced by inhomogeneously distributed creep porosity perpendicular to that surface. The porosity is then estimated using relationships between elastic parameters and porosity within the framework of a theory of elasticity in heterogeneous materials. The ultrasonic method has been applied to investigate the creep behavior of (Al2O3 + 11 vol pct ZrO2) ceramics with two different glass contents of 1 and 4 vol pct. At equal deformation strain, creep porosity rises in the material with increasing content of amorphous phase. 18 refs.

• OSTI ID: 5002097
• Journal Information: Acta Metallurgica et Materialia; (United States), Journal Name: Acta Metallurgica et Materialia; (United States) Vol. 40:5; ISSN 0956-7151; ISSN AMATE
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360203* -- Ceramics
Cermets
& Refractories-- Mechanical Properties
ACOUSTIC TESTING
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CERAMICS
CHALCOGENIDES
CREEP
CRYSTAL STRUCTURE
DEFORMATION
FOURIER TRANSFORMATION
INTEGRAL TRANSFORMATIONS
MATERIALS TESTING
MECHANICAL PROPERTIES
MICROSTRUCTURE
NONDESTRUCTIVE TESTING
OXIDES
OXYGEN COMPOUNDS
POROSITY
RESIDUAL STRESSES
STRESSES
TESTING
TRANSFORMATIONS
TRANSITION ELEMENT COMPOUNDS
ULTRASONIC TESTING
ZIRCONIUM COMPOUNDS
ZIRCONIUM OXIDES