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Cubic‐to‐Tetragonal ( t ') Transformation in Zirconia‐Containing Systems
Author(s) -
Sheu TzerShin,
Tien TsengYing,
Chen IWei
Publication year - 1992
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1992.tb05546.x
Subject(s) - tetragonal crystal system , materials science , metastability , phase (matter) , diffusionless transformation , crystallography , mineralogy , thermodynamics , martensite , crystal structure , chemistry , metallurgy , microstructure , physics , organic chemistry
The coexistence of the cubic fluorite and tetragonal phases in rapidly quenched samples was studied in the ZrO 2 ‐MO 1.5 systems for M = Sc, In, Y, and rare earths (R). Spontaneous transformation from metastable cubic phase was triggered at room temperature by a mechanical force. Isolated tetragonal platelets in the cubic matrix were bounded by [101] habit planes and contained anti‐phase boundaries. The tetragonality decreased with stabilizer content and vanished at around 18 mol% for M = Y and R, 23 mol% for M = Sc, and 25 mol% for M = In, all at room temperature. With increasing temperature, the tetragonality initially increased because of anisotropic thermal expansion, then decreased rapidly, after reaching a maximum, as the temperature for the tetragonal‐to‐cubic transformation was approached. Being a first‐order martensitic transformation, the cubic‐to‐tetragonal transformation is accompanied by a discontinuous change of tetragonality and a hysteresis loop as the temperature or composition passes through the equilibrium value.