Premium
Crystallite and Grain‐Size‐Dependent Phase Transformations in Yttria‐Doped Zirconia
Author(s) -
Suresh Arun,
Mayo Merrilea J.,
Porter Wallace D.,
Rawn Claudia J.
Publication year - 2003
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.1151-2916.2003.tb00025.x
Subject(s) - crystallite , monoclinic crystal system , materials science , tetragonal crystal system , yttria stabilized zirconia , grain size , cubic zirconia , phase (matter) , surface energy , crystallography , differential scanning calorimetry , mineralogy , thermodynamics , composite material , chemistry , metallurgy , crystal structure , ceramic , physics , organic chemistry
In pure zirconia, ultrafine powders are often observed to take on the high‐temperature tetragonal phase instead of the “equilibrium” monoclinic phase. The present experiments and analysis show that this observation is one manifestation of a much more general phenomenon in which phase transformation temperatures shift with crystallite/grain size. In the present study, the effect of crystallite (for powders) and grain (for solids) size on the tetragonal → monoclinic phase transformation is examined more broadly across the yttria–zirconia system. Using dilatometry and high‐temperature differential scanning calorimetry on zirconia samples with varying crystallite/grain sizes and yttria content, we are able to show that the tetragonal → monoclinic phase transformation temperature varies linearly with inverse crystallite/grain size. This experimental behavior is consistent with thermodynamic predictions that incorporate a surface energy difference term in the calculation of free‐energy equilibrium between two phases.