Uniaxial Compression Experiments on PZT 95/52Nb Ceramic: Evidence for an OrientationDependent, ''Maximum Compressive Stress'' Criterion for Onset of the F(R1)()A(O) Polymorphic Phase Transformation
Abstract
Some time ago we presented evidence that, under nonhydrostatic loading, the F{sub R1} {r_arrow} A{sub O} polymorphic phase transformation in unpoled PZT 95/52Nb ceramic began when the maximum compressive stress equaled the hydrostatic pressure at which the transformation otherwise took place. More recently, we showed that this simple stress criterion did not apply to nonhydrostatically compressed, poled ceramic. However, unpoled ceramic is isotropic, whereas poled ceramic has a preferred crystallographic orientation and is mechanically anisotropic. If we further assume that the transformation depends not only on the magnitude of the compressive stress, but also its orientation relative to some feature(s) of PZT 95/52Nb's crystallography, then these disparate results can be qualitatively resolved. In this report, we first summarize the existing results for unpoled and poled ceramic. Using our orientationdependent hypothesis and these results, we derive simple arithmetic expressions that accurately describe our previouslyobserved effects of nonhydrostatic stress on the transformation of unpoled ceramic. We then go on to test new predictions based on the orientationdependent model. It has long been known that the transformation can be triggered in uniaxial compression: the model specifically requires a steadily increasing axial stress to drive the transformation of a randomlyoriented polycrystal to completion. Wemore »
 Authors:
 Publication Date:
 Research Org.:
 Sandia National Labs., Albuquerque, NM (US); Sandia National Labs., Livermore, CA (US)
 Sponsoring Org.:
 US Department of Energy (US)
 OSTI Identifier:
 3862
 Report Number(s):
 SAND990077
TRN: AH200113%%37
 DOE Contract Number:
 AC0494AL85000
 Resource Type:
 Technical Report
 Resource Relation:
 Other Information: PBD: 1 Jan 1999
 Country of Publication:
 United States
 Language:
 English
 Subject:
 36 MATERIALS SCIENCE; NIOBIUM ALLOYS; CERAMICS; COMPRESSION; CRYSTALLOGRAPHY; HYDROSTATICS; ORIENTATION; PHASE TRANSFORMATIONS; POLYCRYSTALS; MATHEMATICAL MODELS
Citation Formats
Carlson, L.W., Grazier, J.M., Holcomb, D.J., Montgomery, S.T., and Zeuch, D.H. Uniaxial Compression Experiments on PZT 95/52Nb Ceramic: Evidence for an OrientationDependent, ''Maximum Compressive Stress'' Criterion for Onset of the F(R1)()A(O) Polymorphic Phase Transformation. United States: N. p., 1999.
Web. doi:10.2172/3862.
Carlson, L.W., Grazier, J.M., Holcomb, D.J., Montgomery, S.T., & Zeuch, D.H. Uniaxial Compression Experiments on PZT 95/52Nb Ceramic: Evidence for an OrientationDependent, ''Maximum Compressive Stress'' Criterion for Onset of the F(R1)()A(O) Polymorphic Phase Transformation. United States. doi:10.2172/3862.
Carlson, L.W., Grazier, J.M., Holcomb, D.J., Montgomery, S.T., and Zeuch, D.H. 1999.
"Uniaxial Compression Experiments on PZT 95/52Nb Ceramic: Evidence for an OrientationDependent, ''Maximum Compressive Stress'' Criterion for Onset of the F(R1)()A(O) Polymorphic Phase Transformation". United States.
doi:10.2172/3862. https://www.osti.gov/servlets/purl/3862.
@article{osti_3862,
title = {Uniaxial Compression Experiments on PZT 95/52Nb Ceramic: Evidence for an OrientationDependent, ''Maximum Compressive Stress'' Criterion for Onset of the F(R1)()A(O) Polymorphic Phase Transformation},
author = {Carlson, L.W. and Grazier, J.M. and Holcomb, D.J. and Montgomery, S.T. and Zeuch, D.H.},
abstractNote = {Some time ago we presented evidence that, under nonhydrostatic loading, the F{sub R1} {r_arrow} A{sub O} polymorphic phase transformation in unpoled PZT 95/52Nb ceramic began when the maximum compressive stress equaled the hydrostatic pressure at which the transformation otherwise took place. More recently, we showed that this simple stress criterion did not apply to nonhydrostatically compressed, poled ceramic. However, unpoled ceramic is isotropic, whereas poled ceramic has a preferred crystallographic orientation and is mechanically anisotropic. If we further assume that the transformation depends not only on the magnitude of the compressive stress, but also its orientation relative to some feature(s) of PZT 95/52Nb's crystallography, then these disparate results can be qualitatively resolved. In this report, we first summarize the existing results for unpoled and poled ceramic. Using our orientationdependent hypothesis and these results, we derive simple arithmetic expressions that accurately describe our previouslyobserved effects of nonhydrostatic stress on the transformation of unpoled ceramic. We then go on to test new predictions based on the orientationdependent model. It has long been known that the transformation can be triggered in uniaxial compression: the model specifically requires a steadily increasing axial stress to drive the transformation of a randomlyoriented polycrystal to completion. We show that when the stress is held constant during uniaxial compression experiments, the transformation stops, supporting our hypothesis. We close with a discussion of implications of our model, and ways to test it using poled ceramic.},
doi = {10.2172/3862},
journal = {},
number = ,
volume = ,
place = {United States},
year = 1999,
month = 1
}

Some time ago we presented evidence that, under nonhydrostatic loading, the F{sub R1} {r_arrow} A{sub O} polymorphic transformation of unpoled PZT 95/52Nb (PNZT) ceramic began when the maximum compressive stress equaled the hydrostatic pressure at which the transformation otherwise took place. Recently we showed that this simple criterion did not apply to nonhydrostatically compressed, poled ceramic. However, unpoled ceramic is isotropic, whereas poled ceramic has a preferred crystallographic orientation and is mechanically anisotropic. If we further assume that the transformation depends not only on the magnitude of the compressive stress, but also its orientation relative to some feature(s) of PNZT'smore »

Uniaxial compression experiments on lead zirconate titanate 95/52Nb ceramic: Evidence for an orientationdependent, ''maximum compressive stress'' criterion for onset of the ferroelectric to antiferroelectric polymorphic transformation
Recently we showed that, under nonhydrostatic loading, the F{sub R1}{yields}A{sub O} polymorphic transformation of unpoled lead zirconate titanate 95/52Nb (PNZT) ceramic began when the maximum compressive stress equaled the hydrostatic pressure at which the transformation otherwise occurred. More recently we showed that this criterion seemed not to apply to poled ceramic. However, unpoled ceramic is isotropic whereas poled ceramic is not. If we further assume that the transformation depends on both the stress magnitude and its orientation relative to PNZT's structure, these disparate results can be resolved. This modified hypothesis makes two predictions for transformation of unpoled ceramic under uniaxialmore » 
Hydrostatic and triaxial compression experiments on unpoled PZT 95/52Nb ceramic: The effects of shear stress on the F[sub R1] [yields] A[sub O] polymorphic phase transformation
Hydrostatic and constantstressdifference (CSD) experiments were conducted at RT on 3 different sintering runs of unpoled, Nbdoped leadzirconatetitanate ceramic (PZT 95/52Nb) in order to quantify influence of shear stress on displacive, martensiticlike, firstorder, rhombohedral [r arrow] orthorhombic phase transformation. In hydrostatic compression at RT, the transformation began at about 260 MPa, and was usually incompletely reversed upon return to ambient. Strains associated with the transformation were isotropic, both on first and subsequent hydrostatic cycles. Results for CSD tests were quite different. First, the confining pressure and mean stress at which the transition begins decreased linearly with increasing stress difference. Second,more » 
Hydrostatic and triaxial compression experiments on unpoled PZT 95/52Nb ceramic: The effects of shear stress on the F{sub R1} {yields} A{sub O} polymorphic phase transformation
Hydrostatic and constantstressdifference (CSD) experiments were conducted at RT on 3 different sintering runs of unpoled, Nbdoped leadzirconatetitanate ceramic (PZT 95/52Nb) in order to quantify influence of shear stress on displacive, martensiticlike, firstorder, rhombohedral {r_arrow} orthorhombic phase transformation. In hydrostatic compression at RT, the transformation began at about 260 MPa, and was usually incompletely reversed upon return to ambient. Strains associated with the transformation were isotropic, both on first and subsequent hydrostatic cycles. Results for CSD tests were quite different. First, the confining pressure and mean stress at which the transition begins decreased linearly with increasing stress difference. Second, themore » 
Hydrostatic and triaxial compression experiments on unpoled PZT 95/52Nb ceramic: The effects of shear stress on the [ital F][sub [ital R]1][r arrow]A[sub 0] polymorphic phase transformation
We conducted a series of hydrostatic and constant shear stress experiments at room temperature on three different sintering runs of unpoled, niobiumdoped leadzirconatetitanate ceramic (PZT 95/52Nb) in order to quantify the influence of shear stress on the displacive (possibly martensitic), firstorder, rhombohedral[r arrow]orthorhombic phase transformation. Inter and intrabatch variations were detected, but some generalizations can be made. In hydrostatic compression at room temperature, the transformation began at approximately 260 MPa, and was usually incompletely reversed upon return to ambient conditions. Strains associated with the transformation were isotropic, both on the first and subsequent hydrostatic cycles. Results for the constant shearmore »