Creep behavior of superplastic Y-TZP/Al{sub 2}O{sub 2} composite: An examination of the possibility for diffusion creep

Conference · Sat Jul 01 04:00:00 EDT 2000

OSTI ID:20104665

Sosa, S S; Langdon, T G

The creep characteristics of a high purity superplastic Y-TZP/Al{sub 2}O{sub 3} composite were studied. The test samples had a uniform initial grain size of essentially equiaxed grains and the phase distribution was also uniform. Creep tests were conducted at elevated temperatures in tension and measurements were taken after testing to determine the average size and shape of the grains. The creep curves showed the existence of a primary stage of creep and then a transition into a steady-state region where the strain rate remained reasonably constant. Observations by scanning electron microscopy revealed an elongation of the alumina grains with the grain strain essentially matching the overall strain within the sample. There was some grain growth after testing at the lower stresses. Preliminary observations using an atomic force microscope revealed direct evidence for the occurrence of some grain boundary sliding within the samples. The results are compared with earlier data reported for Y-TZP/Al{sub 2}O{sub 3} composites and they are analyzed using the interface reaction-controlled diffusion creep model.

• Research Organization: Univ. of Southern California, Los Angeles, CA (US)
• Sponsoring Organization: US Department of Energy
• DOE Contract Number: FG03-92ER45472
• OSTI ID: 20104665
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM OXIDES
COMPOSITE MATERIALS
CREEP
EXPERIMENTAL DATA
GRAIN BOUNDARIES
PLASTICITY
YTTRIUM OXIDES
ZIRCONIUM OXIDES