Premium
Grain‐Size‐Dependent Transformation Behavior in Polycrystalline Tetragonal Zirconia
Author(s) -
Becher Paul F.,
Swain Michael V.
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.tb07832.x
Subject(s) - tetragonal crystal system , crystallite , materials science , grain size , monoclinic crystal system , crystallography , mineralogy , thermodynamics , composite material , metallurgy , crystal structure , chemistry , physics
Experimental observations of the tetragonal phase transformation behavior in polycrystalline zirconias and the related toughening contribution are presented. An analysis which considers transformation thermodynamics and residual stresses is developed to describe the influence of grain size on tetragonal‐to‐monoclinic transformation temperature. The model is based on the promotion of the transformation by local internal tensile stress concentrations whose effects scale with grain size. The analysis is supported by observations of the martensite start temperature–grain size behavior in polycrystalline tetragonal zirconia containing 12 mol% ceria (12CeTZP). Next, the analysis considers the grain‐size‐dependent behavior of the transformation‐toughening contribution, Δ K T , and the transformation zone size, r T . The tetragonal‐to‐monoclinic ( t ‐to‐ m ) formation temperature, M s , increases with increase in tetragonal grain size, d . Experimental results for zirconia‐12 mol% ceria (12CeTZP) and 2YTZP ceramics illustrate the predicted forms of the grain size dependencies for Δ K T and r T . The analytical model also describes the temperature dependence of the transformation‐toughening contribution Δ K T observed in 2 mol% yttriadoped polycrystalline tetragonal zirconias (2YTZP).