The grain size dependency of compressive deformation of a superplastic 3 mol% yttria stabilized tetragonal zirconia

G. Q. Tong, Kang Cheung Chan, L. Gao, Z. R. Lin

Research output: Journal article publicationJournal articleAcademic researchpeer-review

12 Citations (Scopus)

Abstract

The compressive behavior of a medium purity 3 mo1% yttria stabilized tetragonal zirconia (3YTZ) was investigated with three different initial grain sizes at the temperature of 1723 K. It was found that the strain rate sensitivity exponent increases from 0.45 to 0.55 when the initial grain size increases from 0.5 to 1.1 μm and that the grain size exponent is about 2.0. Microstructural measurements revealed that grains retained the essentially equiaxed nature even after large plastic strain and that the instantaneous grain size had a linear relationship with true strain at the specified initial strain rates. Transmission electron microscope observation demonstrated that an amorphous phase concentrated at multiple points and that no amorphous phase formed at two-grain boundaries. Like Al2O3, the SiO2content had a significant effect on superplastic 3YTZ characteristics. It is considered that grain boundary sliding (GBS) should play a dominant role in 3YTZ superplasticity and that the presence of an amorphous phase at triple or multiple points could effectively release the stress concentration caused by GBS and thereby facilitate superplastic deformation.
Original languageEnglish
Pages (from-to)263-269
Number of pages7
JournalMaterials Science and Engineering A
Volume336
Issue number1-2
DOIs
Publication statusPublished - 25 Oct 2002

Keywords

  • Activation energy
  • Amorphous phase
  • Concurrent grain growth
  • Grain boundary sliding

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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