Accession Number : ADA224505

Title :   Tetragonal Phase in the System ZrO2-Y2O3

Corporate Author : CASE WESTERN RESERVE UNIV CLEVELAND OH DEPT OF METALLURGY AND MATERIALS SCIENCE

Personal Author(s) : Lanteri, V. ; Heuer, A. H. ; Mitchell, T. E.

PDF Url : ADA224505

Report Date : 1985

Pagination or Media Count : 13

Abstract : Precipitates of the high-ZrO2 tetragonal distorted-fluorite phase in the system ZrO2-Y2O3 appear to be quite different from those observed in other well-studied partially stabilized zirconias (Mg-PSZ). In this paper, we discuss the nature of the tetragonal phase in Y2O3 partially stabilized zirconia (Y-PSZ) single crystals. We note that three versions of the phase diagram exist, which differ in detail mainly at the high-ZrO2 region; our work thus also sheds light on the subsolidus phase equilibria in this system. Scott 4 described a metastable 'nontransformable' high-Y2O3-content tetragonal ZrO2 solid solution (t-ZrO2), which he and other workers suggested formed from the cubic ZrO2 solid solution (c-ZrO2) via a displacive phase transformation; the nontransformability relates to its reluctance to undergo the stress-assisted martensitic transformation to monoclinic symmetry found in lower-Y2-O3-content t-ZrO2. (JES)

Descriptors :   *PHASE TRANSFORMATIONS, SINGLE CRYSTALS, EQUILIBRIUM(GENERAL), PRECIPITATES, SYMMETRY, PHASE DIAGRAMS, ZIRCONIUM OXIDES, STABILIZATION, PHASE STUDIES

Subject Categories : Physical Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE