y|7 BHall, D. A.
Steuwer, A.
Cherdhirunkorn, B.
Withers, P. J.
Mori, T.2005eTexture of poled tetragonal PZT detected by synchrotron X-ray diffraction and micromechanics analysis206-210aMaterials Science and Engineering a-Structural Materials Properties Microstructure and Processing4091-2oferroelectricity
domain switching
texture
synchrotron x-ray
micromechanics
ceramics
behavior
strain
field
modelNov 15The texture and lattice elastic strain due to electrical poling of tetragonal PZT (lead zirconate titanate) ceramics have been measured using high energy synchrotron X-ray diffraction. It is shown that XRD peak intensity ratios associated with crystal planes of the form {002}, {112} and {202} exhibit a linear dependence on cos(2) Psi, where Psi represents the orientation angle between the plane normal and the macroscopic poling axis. The observed dependence of texture and lattice strain on the grain orientation can be understood on the basis that the macroscopic strain due to poling is the average of the poling strains of all the individual grains. (c) 2005 Elsevier B.V. All rights reserved.://000234033900029-994LS
Times Cited:1
Cited References Count:11 0921-5093ISI:000234033900029Mori, T
Univ Manchester, Ctr Mat Sci, Manchester M1 7HS, Lancs, England
Univ Manchester, Ctr Mat Sci, Manchester M1 7HS, Lancs, EnglandEnglishaGJd|7!BHall, D. A.
Steuwer, A.
Cherdhirunkorn, B.
Withers, P. J.
Mori, T.2005qMicromechanics of residual stress and texture development due to poling in polycrystalline ferroelectric ceramics249-260.Journal of the Mechanics and Physics of Solids532xferroelectric ceramic
domain conversion
synchrotron x|79Clausen, B.
Lorentzen, T.
Bourke, M. A. M.
Daymond, M. R.1999KLattice strain evolution during uniaxial tensile loading of stainless steel17-24aMaterials Science and Engineering a-Structural Materials Properties Microstructure and Processing2591neutron diffraction
time-of-flight
self-consistent
polycrystal deformation
elastic-plastic modeling
austenitic stainless steel
metal matrix composites
neutron-diffraction
rietveld refinement
predictionJan 15Applied and residual lattice strains were determined by neutron diffraction during a tensile test of a weakly textured austenitic stainless steel and were compared to the predictions of a self-consistent polycrystal deformation model. Parallel to the tensile axis the model predictions are generally within the resolution of the diffraction measurements, but perpendicular to the tensile axis discrepancies are noted. Discrepancies between model and measurements were greater for the residual lattice strains than during loading. It is postulated that this is because the model does not predict reverse plasticity during unload. (C) 1999 Elsevier Science S.A. All rights reserved.://000078049400003.157FF
Times Cited:55
Cited References Count:15 0921-5093ISI:000078049400003Clausen, B
Univ Calif Los Alamos Natl Lab, Neutron Scattering Ctr, LANSCE, POB 1663,Mail Stop H805, Los Alamos, NM 87545 USA
Univ Calif Los Alamos Natl Lab, Neutron Scattering Ctr, LANSCE, Los Alamos, NM 87545 USA
Riso Natl Lab, Mat Res Dept, DK-4000 Roskilde, DenmarkEnglish |7JDaymond, M. R.
Bourke, M. A. M.
VonDreele, R. B.
Clausen, B.
Lorentzen, T.1997Use of Rietveld refinement for elastic macrostrain determination and for evaluation of plastic strain history from diffraction spectra 1554-1562Journal of Applied Physics824polycrystalsAug 15TMacrostrain variations in engineering components are frequently examined using neutron diffraction, at both reactors and pulsed sources. It is desirable to minimize the sampling volume in order to maximize the spatial resolution, although this increases the required measurement time. At reactors, macrostrain behavior is inferred from a single lattice reflection (deemed to be representative of the bulk response). At a pulsed source, a complete diffraction pattern is recorded and accordingly it is natural to fit the entire diffraction spectra using a Rietveld [J. Appl. Cryst. 2, 65 (1969)] refinement. This means that an idealized crystal structure is fit to the measured distorted crystal structure, which includes deviation of the measured lattice reflections from the ideal due to elastoplastic strain anisotropies, which are dependent on the particular lattice reflection (hk1) considered. We show that elastic macrostrains calculated from lattice parameter changes in Rietveld refinements (without accounting for hk1 dependent anisotropies) are almost identical to the bulk elastic response and are comparable to the response obtained from a single lattice reflection typically used by practitioners at a steady state source. Moreover good refinements on the complete pattern are obtained with short measurement times compared to what is required for good statistics for single reflections. By incorporating a description of the elastic strain anisotropy expected in cubic materials into the Rietveld code, an empirical prediction of plastic strain history is possible. The validity of these arguments is demonstrated by analysis of a uniaxial tensile load test and a reanalysis of previously reported data taken on a deformed stainless steel ring. The plastic strain predictions compare favorably with a finite element model. (C) 1997 American Institute of Physics.://A1997XQ79700009.Xq797
Times Cited:99
Cited References Count:17 0021-8979ISI:A1997XQ79700009Daymond, MR
Los Alamos Natl Lab,Manuel Lujan Jr Neutron Scattering Ctr,Los Alamos,Nm 87545
Riso Natl Lab,Dept Mat,Dk-4000 Roskilde,DenmarkEnglish|7Lebensohn, R. A.
Tome, C. N.1993A Self-Consistent Anisotropic Approach for the Simulation of Plastic-Deformation and Texture Development of Polycrystals - Application to Zirconium Alloys 2611-2624Acta Metallurgica Et Materialia419SepVWe present in this work a visco-plastic self-consistent (VPSC) anisotropic approach for modeling the plastic deformation of polycrystals, together with a thorough discussion of the assumptions involved and the range of application of such approach. We use the VPSC model for predicting texture development during rolling and axisymmetric deformation of Zirconium alloys, and to calculate the yield locus and the Lankford coefficient of rolled Zircaloy sheet. We compare our results with experimental data and find that they are in good agreement with the available experimental evidence. We also compare the VPSC predictions with the ones of a Full Constraints approach and observe that they differ both quantitatively and qualitatively: according with the predictions of the VPSC scheme, deformation is accommodated mostly by the soft systems, the twinning activity is much lower, and fewer systems are active, in average, per grain. These results are a consequence of having accounted for the grain interaction with its surroundings, which is a crucial aspect when modeling plastically anisotropic materials.://A1993LR48400009/Lr484
Times Cited:250
Cited References Count:34 0956-7151ISI:A1993LR48400009Lebensohn, Ra
Unr,Conicet,Inst Fis Rosario,27 Febrero 210 Bis,Ra-2000 Rosario,Argentina
Unr,Fac Ciencias Exactas Ingn & Agrimensura,Ra-2000 Rosario,Argentina
Atom Energy Canada Ltd,Whiteshell Labs,Reactor Mat Res Branch,Pinawa R0E 1L0,Manitoba,CanadaEnglish|7&Nikolov, S.
Lebensohn, R. A.
Raabe, D.2006tSelf-consistent modeling of large plastic deformation, texture and morphology evolution in semi-crystalline polymers 1350-1375.Journal of the Mechanics and Physics of Solids547micromechanics
constitutive behavior
polymer
self-consistent
texture
high-density polyethylene
crystallographic texture
constitutive model
behavior
polycrystals
simulation
alloysJulA self-consistent model for semi-crystalline polymers is proposed to study their constitutive behavior, texture and morphology evolution during large plastic deformation. The material is considered as an aggregate of composite inclusions, each representing a stack of crystalline lamellae with their adjacent amorphous layers. The deformation within the inclusions is volume-averaged over the phases. The interlamellar shear is modeled as an additional slip system with a slip direction depending on the inclusion's stress. Hardening of the amorphous phase due to molecular orientation and, eventually, coarse slip, is introduced via Arruda-Boyce hardening law for the corresponding plastic resistance. The morphology evolution is accounted for through the change of shape of the inclusions under the applied deformation gradient. The overall behavior is obtained via a viscoplastic tangent self-consistent scheme. The model is applied to high density polyethylene (HDPE). The stress-strain response, texture and morphology changes are simulated under different modes of straining and compared to experimental data as well as to the predictions of other models. (c) 2006 Elsevier Ltd. All rights reserved.://000237914500003-047YL
Times Cited:1
Cited References Count:34 0022-5096ISI:000237914500003Nikolov, S
Max Planck Inst Eisenforsch GmbH, Max Planck Str 1, D-40237 Dusseldorf, Germany
Max Planck Inst Eisenforsch GmbH, D-40237 Dusseldorf, Germany
Los Alamos Natl Lab, Los Alamos, NM 87545 USAEnglish ~|7;Tome, C. N.
Maudlin, P. J.
Lebensohn, R. A.
Kaschner, G. C.2001nMechanical response of zirconium - I. Derivation of a polycrystal constitutive law and finite element analysis 3085-3096Acta Materialia4915texture
polycrystal modeling
self-consistent approach
texture development
crystallographic texture
deformation
model
plasticity
prediction
behavior
alloysSep 3Stimulating the forming of anisotropic polycrystals, such as zirconium, requires a description of the anisotropy of the aggregate and the single crystal, and also of their evolution with deformation (texture development and hardening). Introducing the anisotropy of the single crystal requires the use of polycrystal models that account for inhomogeneous deformation depending on grain orientation. In particular, visco-plastic self-consistent models have been successfully used for describing strongly anisotropic aggregates. As a consequence, using a polycrystal. constitutive law inside finite element (FE) codes represents a considerable improvement over using empirical constitutive laws, since the former provides a physically based description of anisotropy and its evolution.
In this work we develop a polycrystal constitutive description for pure Zr deforming under quasi-static conditions at room and liquid nitrogen temperatures, We use tensile and compressive experimental data obtained from a clock-rolled Zr sheet to adjust the constitutive parameters of the polycrystal model. Twinning is accounted for in the description. The polycrystal model is implemented into an explicit FE code, assuming a full polycrystal at the position of each integration point. The orientation and hardening of the individual grains associated with each element is updated as deformation proceeds. We report preliminary results of this methodology applied to simulate the three-dimensional deformation of zirconium bars deforming under four-point bend conditions to maximum strains of about 20%. A critical comparison between experiments and predictions is done in a second paper Published by Elsevier Science Ltd on behalf of Acta Materialia Inc.://000170652100022.466NR
Times Cited:37
Cited References Count:27 1359-6454ISI:000170652100022Tome, CN
Los Alamos Natl Lab, MST-8 MS G755, Los Alamos, NM 87545 USA
Los Alamos Natl Lab, Los Alamos, NM 87545 USA
Inst Fis Rosario, RA-2000 Rosario, ArgentinaEnglish|7Solas, D. E.
Tome, C. N.2001KTexture and strain localization prediction using a N-site polycrystal model737-753#International Journal of Plasticity175evisco-plastic material
polycrystal model
self-consistent
normal grain-growth
3 dimensions
deformationMost polycrystal models of plastic deformation rely on the assumption that, strain and stress are uniform within the domain of each grain. Comparison between measured and predicted textures suggests that this assumption is realistic for most single-phase aggregates and crystal symmetries. In this paper, we implement a self-consistent N-site model that allows one to account for strain localization and local misorientation near grain boundaries. We apply this model to face centered cubic (fcc) and hexagonal close packed (hcp) aggregates, and analyze the similarities and differences with a one-site model that assumes uniform stress and strain-rate within a grain. We find that the assumption of uniformity is justified in first order. We discuss the implications of the N-site model for the simulation of systems with hard inclusions, orientation correlations, and recrystallization mechanisms. (C) 2001 Elsevier Science Ltd. All rights reserved.://000168786500004.433XT
Times Cited:11
Cited References Count:18 0749-6419ISI:000168786500004Tome, CN
Univ Calif Los Alamos Natl Lab, MST-8,MS G755, Los Alamos, NM 87545 USA
Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USAEnglishg|7Tome, C. N.1999eSelf-consistent polycrystal models: a directional compliance criterion to describe grain interactions723-738=Modelling and Simulation in Materials Science and Engineering75&texture development
deformation
alloysSepRViscoplastic self-consistent polycrystal models have been successful in addressing and explaining features of plastic deformation which cannot be treated with the Taylor condition of isostrain. In particular, these models have been applied to the simulation of plastic deformation and texture development in materials with hexagonal, trigonal, orthorhombic and triclinic symmetry.
An important assumption required to solve the equilibrium equation within self-consistent formulations is that the strain-rate varies Linearly with the stress in the homogeneous effective medium surrounding the inclusion. The characteristic of such a linear relation has been a matter of debate and two extreme cases can be identified: the tangent and the secant approaches. The secant approach has associated with it a stiffer inclusion-matrix interaction than the tangent approach and is closer to the Taylor approach.
In this work we perform a systematic study of the implications of both assumptions on the response of cubic and hexagonal materials (texture development, system activity, stress and strain-rate deviations). In addition, we argue that the strength of the matrix-inclusion interaction should not be constant but should depend on the capability of each orientation to accommodate the particular deformation mode imposed externally. As a consequence, we propose a relative directional compliance (RDC) criterion for defining a variable interaction between grain and matrix depending on their relative compliances and compare the predictions of the RDC approach with the predictions of the secant and the tangent schemes.://000083820600006.258CM
Times Cited:18
Cited References Count:13 0965-0393ISI:000083820600006Tome, CN
Univ Calif Los Alamos Natl Lab, MST-8,MS G755, Los Alamos, NM 87545 USA
Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USAEnglish|7 JLebensohn, R. A.
Turner, P. A.
Signorelli, J. W.
Canova, G. R.
Tome, C. N.1998lCalculation of intergranular stresses based on a large-strain viscoplastic self-consistent polycrystal model447-465=Modelling and Simulation in Materials Science and Engineering64+plastic-deformation
zirconium
texture
creepJulWe present here an extension of the viscoplastic self-consistent (VPSC) polycrystal model for the calculation of the intergranular Cauchy stresses in an aggregate. This method, which is based on the self-consistent treatment of incompressible aggregates proposed in 1987 by Molinari el al, is formulated using the inclusion formalism and full anisotropy is incorporated into it. The complete stress state in the grains is obtained by computing the deviatoric and the hydrostatic local deviations with respect to the overall corresponding magnitudes applied to the polycrystal. The extended VPSC model, followed by an elastic self-consistent unloading, is used to obtain the intergranular residual strains in the aggregate after large plastic deformation. The texture evolution and the hardening of the material are explicitly taken into account in the model. As an application, the model is used to predict intergranular residual states in Incoloy-800 plate after uniaxial deformation.://000076004600011.121GH
Times Cited:11
Cited References Count:21 0965-0393ISI:000076004600011TLebensohn, RA
Univ Nacl Rosario, CONICET, Inst Fis Rosario, 27 Febrero 210 Bis, RA-2000 Rosario, Santa Fe, Argentina
Univ Nacl Rosario, CONICET, Inst Fis Rosario, RA-2000 Rosario, Santa Fe, Argentina
Ecole Natl Super Phys Grenoble, GPM2, F-38402 St Martin Dheres, France
Univ Calif Los Alamos Natl Lab, Ctr Mat Sci, Los Alamos, NM 87545 USAEnglishQ|7
2Tome, C. N.
Wenk, H. R.
Canova, G. R.
Kocks, U. F.1991]Simulations of Texture Development in Calcite - Comparison of Polycrystal Plasticity Theories11865-118757Journal of Geophysical Research-Solid Earth and Planets96B7&slip system activity
transitions
shearJul 10Deformation modelling based on polycrystal plasticity theory has been applied to several rocks. Recently it has been demonstrated that rate sensitivity and heterogeneous deformation can have a significant influence on the activation of slip systems and corresponding texture development. In this study previous predictions for pure shear deformation of calcite with the rigid-plastic fully constrained Taylor theory are compared with those from a visco-plastic Taylor theory, a relaxed Taylor theory and a visco-plastic self-consistent theory. In the case of calcite, texture simulations for all models are similar and conclusions based on earlier data remain valid. There are some quantitative differences and these will be discussed. A new procedure for dealing with mechanical twinning is proposed; it requires the volume fraction of twin reoriented grains to match the twinning fraction given by the twinning shears.://A1991FW81900015.Fw819
Times Cited:16
Cited References Count:28 0148-0227ISI:A1991FW81900015Tome, Cn
Univ Nacl Rosario,Inst Fis Rosario,27 Febrero 210 Bis,Ra-2000 Rosario,Argentina
Fac Sci Metl,Phys & Mecan Mat Lab,F-57045 Metz,France
Univ Calif Los Alamos Sci Lab,Ctr Mat Sci,Los Alamos,Nm 87545
Univ Calif Berkeley,Dept Geol & Geophys,Berkeley,Ca 94720English -ray
diffraction
residual stress
texture development
model
behaviorFebThis paper presents micromechanics based analysis of elastic strain and changes in the texture of poled polycrystalline ferroelectric PZT ceramics for direct comparison with synchrotron Xray measurements. The grains are modelled as spherical inclusions. to which transformation strains are assigned depending on the fractions of different ferroelectric domains. Eshelby's inclusion problem with the classical self-consistent method is applied to evaluate the elastic state of the grains. In particular, the elongation due to lattice elastic strain is calculated as a function of inclination T relative to the polar axis. The ratio of diffraction peak intensties. corresponding to the domain fractions, is also expressed as a function of T. This analysis identifies the special;] character of the (I 1 1) reflection, for which the lattice strain along (I 1 1) in the stress free state is independent of ferroelectric domain population and hence unaffected by poling. The elongation due to the lattice strain parallel to (I 1 1) and peak intensity ratio are expressed in terms of the overall macroscopic strain of a poled specimen, each having a cos(2) Psi dependence. (C) 2004 Elsevier Ltd All rights reserved.://000226555700001-891BG
Times Cited:7
Cited References Count:12 0022-5096ISI:000226555700001Hall, DA
Univ Manchester, Ctr Mat Sci, Grosvenor St, Manchester M1 7HS, Lancs, England
Univ Manchester, Ctr Mat Sci, Manchester M1 7HS, Lancs, EnglandEnglisho|7"BHall, D. A.
Steuwer, A.
Cherdhirunkorn, B.
Mori, T.
Withers, P. J.2006ZAnalysis of elastic strain and crystallographic texture in poled rhombohedral|7+Daymond, M. R.
Tome, C. N.
Bourke, M. A. M.2000'Intergranular strains in textured steel54-59IEcrs 5: Proceedings of the Fifth European Conference on Residual Stresses347-3`diffraction elastic constant
elastic modulus
intergranular stress
neutron diffraction
zircaloy-2Tensile specimens were machined from heat treated austenitic stainless steel plate prior to and after 70% reduction by uni-directional rolling. In addition to a specimen from the as-received plate, two specimens were cut from the rolled plate, with axes parallel and perpendicular to the rolling direction respectively. In situ measurements of the strain response of multiple hkl lattice planes to an applied uniaxial tensile load were made using neutron diffraction. The experimental results are compared with predictions from a self-consistent Hill-Hutchinson model. The measured texture in the plate was approximately 3 times random, however its effect on the hkl response was small compared to the residual strains left by rolling. The apparent elastic modulus and Poisson's ratios of the planes is affected by the residual strains, which is attributed to the effect of micro-plasticity. Interpretation of residual stress measurements is considered in light of these results.://000168535100009DBs06M
Times Cited:0
Cited References Count:7
Materials Science Forum 0255-5476ISI:000168535100009Daymond, MR
Rutherford Appleton Lab, ISIS Facil, Chilton OX11 0QX, Oxon, England
Univ Calif Los Alamos Natl Lab, Los Alamos Neutron Sci Ctr, Los Alamos, NM 87545 USA
Univ Calif Los Alamos Natl Lab, Mat Sci & Technol Div, Los Alamos, NM 87545 USAEnglish2|7
+Daymond, M. R.
Tome, C. N.
Bourke, M. A. M.2000IMeasured and predicted intergranular strains in textured austenitic steel553-564Acta Materialia482zdeformation mechanisms
residual stress
neutron diffraction
plasticity
mechanical properties
rietveld refinement
zircaloy-2Jan 24Tensile specimens were machined from heat-treated austenitic stainless steel plate prior to and after 70% reduction by uni-directional rolling. In addition to a single specimen cut from the as-received plate, two specimens were cut from the rolled plate, with axes parallel and perpendicular to the rolling direction, respectively. In situ measurements of the strain response of multiple hkl lattice planes to an applied uniaxial tensile load were made using neutron diffraction, to macroscopic plastic strains of around 1%. The experimental results are compared with predictions from a self-consistent Hill-Hutchinson model. The measured texture in the plate was approximately three Limes random; however, its effect on the hid response was small compared to the residual strains left by rolling. The apparent elastic modulus of the planes is affected by the residual strains, which is attributed to the effect of micro-plasticity. Interpretation of residual stress measurements, for both single peak and Rietveld measurements is considered in light of these results. (C) 2000 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved.://000085318200016.284ER
Times Cited:30
Cited References Count:21 1359-6454ISI:000085318200016Daymond, MR
Rutherford Appleton Lab, ISIS Facil, Didcot OX11 0QX, Oxon, England
Univ Calif Los Alamos Natl Lab, Los Alamos Neutron Sci Ctr, Los Alamos, NM 87545 USA
Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USAEnglish|7DClausen, B.
Leffers, T.
Lorentzen, T.
Pedersen, O. B.
Van Houtte, P.1999jThe resolved shear stress on the non-active slip systems in Taylor/Bishop-Hill models for fcc polycrystals91-96Scripta Materialia421itheory and modelling
mechanical properties
constitutive equations
crystal structure
resolved shear stressDec 17://000084716100015-273PM
Times Cited:0
Cited References Count:11 1359-6462ISI:000084716100015Clausen, B
Univ Calif Los Alamos Natl Lab, Mail Stop H805, Los Alamos, NM 87545 USA
Riso Natl Lab, Mat Res Dept, DK-4000 Roskilde, Denmark
Katholieke Univ Leuven, Dept MTM, B-3001 Heverlee, BelgiumEnglish|7%Clausen, B.
Leffers, T.
Lorentzen, T.2003kOn the proper selection of reflections for the measurement of bulk residual stresses by diffraction methods 6181-6188Acta Materialia5120micromechanical modeling
residual stresses
austenitic steels
rolled stainless-steel
self-consistent
intergranular strains
plastic-deformation
polycrystals
grainDec 8The suitability of various reflections for diffraction measurement of bulk residual stresses in austenitic steel after plane-strain deformation is investigated by self-consistent calculations. Earlier findings (for tensile-deformed fcc materials) that 311 is particularly well suited was not confirmed. In the present calculations 111 and 422 turned out to be the best (least bad) reflections. The new results have led us to reconsider the earlier findings. (C) 2003 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.://000187219700013-753ET
Times Cited:5
Cited References Count:20 1359-6454ISI:000187219700013Clausen, B
CALTECH, Dept Mat Sci, Pasadena, CA 91125 USA
CALTECH, Dept Mat Sci, Pasadena, CA 91125 USA
Riso Natl Lab, Dept Mat Res, DK-4000 Roskilde, DenmarkEnglish|74Lorentzen, T.
Daymond, M. R.
Clausen, B.
Tome, C. N.2002ALattice strain evolution during cyclic loading of stainless steel 1627-1638Acta Materialia506bauschinger effect
neutron diffraction
elasto-plastic self-consistent model
rietveld refinement
diffraction
polycrystals
stresses
textureApr 2A uniaxial tension/compression test specimen was cycled between fixed total strain limits of 0.4% for eight successive cycles. The sample was loaded using a dedicated Instron hydraulic load frame on the ENGIN station of the PEARL beam line at the ISIS facility of the Rutherford Appleton Laboratory. The load frame was aligned to allow simultaneous monitoring of longitudinal and transverse lattice strain components. There was a strong experimental hkl-dependency of the lattice strain response in both the effective stiffness and in the lattice strain loop hysteresis. The experimental data were compared with numerical predictions obtained from a self-consistent elasto-plastic model for the simulation of polycrystal deformation. A cyclic hardening law was developed and implemented into the modelling scheme, providing theoretical predictions in good agreement with experimental observations. (C) 2002 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.://000174972400032.541EN
Times Cited:12
Cited References Count:17 1359-6454ISI:0001749724000328Daymond, MR
Rutherford Appleton Lab, ISIS Facil, Didcot OX11 0QX, Oxon, England
Rutherford Appleton Lab, ISIS Facil, Didcot OX11 0QX, Oxon, England
Riso Natl Lab, Mat Res Dept, DK-4000 Roskilde, Denmark
Los Alamos Natl Lab, LANSCE 12, Los Alamos, NM 87545 USA
Los Alamos Natl Lab, MST 8, Los Alamos, NM 87545 USAEnglish Hester, Sch Mat, Ctr Mat Sci, Manchester M1 7HS, Lancs, EnglandEnglish+gp|7H!Bhattacharya, K.
Ravichandran, G.20039Ferroelectric perovskites for electromechanical actuation 5941-5960Acta Materialia5119ferroelectricity
perovskites
piezoelectricity
ferroelectric domains
modeling
lead-zirconate-titanate
pbtio3 single-crystals
thin-films
fracture-mechanics
barium-titanate
piezoelectric properties
phase-t|7$7Canova, G. R.
Fressengeas, C.
Molinari, A.
Kocks, U. F.1988GEffect of Rate Sensitivity on Slip System Activity and Lattice Rotation 1961-1970Acta Metallurgica368Aug://000238468100019-055RM
Times Cited:2
Cited References Count:21 1359-6454ISI:000238468100019Hall, DA
Univ Manchester, Sch Mat, Ctr Mat Sci, Grosvenor St, Manchester M1 7HS, Lancs, England
Univ Manch|74Lorentzen, T.
Faurholdt, T.
Clausen, B.
Danckert, J.1998XCharacterization of residual stresses generated during inhomogeneous plastic deformation243-2521Journal of Strain Analysis for Engineering Design333Fresidual stresses
plastic deformation
fe technique
neutron diffractionMayResidual stresses generated by macroscopic inhomogeneous plastic deformation are predicted by an explicit finite element (FE) technique. The numerical predictions are evaluated by characterizing the residual elastic strains by neutron diffraction using two different (hkl) reflections. Intergranular residual elastic strains between subsets of grains are predicted numerically and verified by neutron diffraction. Subsequently, the measured residual strain profiles in the test samples are modified by the intergranular strains and compared to the engineering predictions of the FE technique. Results compare well and verify the capability of the numerical technique as well as the possibilities of experimental validation using neutron diffraction. The presented experimental and numerical approach will subsequently be utilized for the evaluation of more complicated plastic deformation processes resembling forming operations.://000075262600007-108JK
Times Cited:2
Cited References Count:16 0309-3247ISI:000075262600007Lorentzen, T
Riso Natl Lab, Dept Mat Res, DK-4000 Roskilde, Denmark
Riso Natl Lab, Dept Mat Res, DK-4000 Roskilde, Denmark
Univ Aalborg, Dept Prod, Aalborg, DenmarkEnglish|7%Clausen, B.
Lorentzen, T.
Leffers, T.1998Self-consistent modelling of the plastic deformation of FCC polycrystals and its implications for diffraction measurements of internal stresses 3087-3098Acta Materialia469May 22Using a self consistent scheme we model the development of elastic lattice strains during uniaxial loading for selected families of grains with specific orientations. These lattice strains vary dramatically for the different grain orientations, and most families of grains show a high degree of non-linearity at the start of the plastic regime. The 311 reflection does, however, respond almost linearly to loading, and therefore it constitutes a suitable reflection for characterization of macroscopic stresses and strains by diffraction for the given conditions. As a consequence of the high degree of non-linearity in the lattice strain response during loading highly anisotropic intergranular residual lattice strains develop during unloading. The evaluation of the model predictions by neutron diffraction is exemplified by selected results from in-situ loading experiments performed on austenitic stainless steel specimens. As a necessary condition for the proper understanding of the results we have included a description of the slip pattern resulting from the model applied and its relation to the slip patterns derived from the upper-bound Taylor model and the lower-bound Sachs model. (C) 1998 Acta Metallurgica Inc.://000074101700013.Zt576
Times Cited:73
Cited References Count:26 1359-6454ISI:000074101700013Clausen, B
Riso Natl Lab, Mat Res Dept, DK-4000 Roskilde, Denmark
Riso Natl Lab, Mat Res Dept, DK-4000 Roskilde, Denmark
Tech Univ Denmark, Dept Solid Mech, DK-2800 Lyngby, DenmarkEnglishh|7Clausen, B.
Lorentzen, T.1997kExperimental evaluation of a polycrystal deformation modeling scheme using neutron diffraction measurements 2537-2541TMetallurgical and Materials Transactions a-Physical Metallurgy and Materials Science2812textureDecThe uniaxial behavior of aluminum polycrystals is simulated using a rate-independent incremental self-consistent elastic-plastic polycrystal deformation model, and the results are evaluated by neutron diffraction measurements. The elastic strains deduced from the model show good agreement with the experimental results for the 111 and 220 reflections, whereas the predicted elastic strain level for the 200 reflection is, in general, approximately 10 pct too low in the plastic regime.://000071486400011-Yr348
Times Cited:21
Cited References Count:9 1073-5623ISI:000071486400011Clausen, B
Univ Calif Los Alamos Natl Lab, Lujan Ctr, POB 1663, Los Alamos, NM 87545 USA
Riso Natl Lab, Dept Mat Res, DK-4000 Roskilde, Denmark
Riso Natl Lab, Engn Sci Ctr Struct Characterisat & Modelling, DK-4000 Roskilde, DenmarkEnglish to ISI>://A1988P863300008.P8633
Times Cited:40
Cited References Count:19 0001-6160ISI:A1988P863300008~Canova, Gr
Lab Phys & Mecan Met,Cnrs,Ua 1215,Ile Saulcy,F-57045 Metz,France
Univ Calif Los Alamos Natl Lab,Los Alamos,Nm 87545English|7%3Canova, G. R.
Kocks, U. F.
Tome, C. N.
Jonas, J. J.1985*The Yield Surface of Textured Polycrystals371-397.Journal of the Mechanics and Physics of Solids334://A1985AQJ6700004.Aqj67
Times Cited:59
Cited References Count:31 0022-5096ISI:A1985AQJ6700004wUniv Calif Los Alamos Natl Lab,Ctr Mat Sci,Los Alamos,Nm 87545
Mcgill Univ,Dept Met Engn,Montreal H3a 2a7,Quebec,CanadaEnglish|7&BTome, C.
Canova, G. R.
Kocks, U. F.
Christodoulou, N.
Jonas, J. J.1984UThe Relation between Macroscopic and Microscopic Strain-Hardening in Fcc Polycrystals 1637-1653Acta Metallurgica3210://A1984TS01000007.Ts010
Times Cited:98
Cited References Count:39 0001-6160ISI:A1984TS01000007@Tome, C
Mcgill Univ,Dept Met Engn,Montreal H3a 2a7,Quebec,CanadaEnglishI|7'0Canova, G. R.
Kocks, U. F.
Tome, C.
Jonas, J. J.19832The Uniform Multiaxial Deformation of PolycrystalsA28-a28Journal of Metals358://A1983RF21000233,Rf210
Times Cited:0
Cited References Count:0 0148-6608ISI:A1983RF21000233*Mcgill Univ,Montreal H3a 2a7,Quebec,CanadaEnglish|7(8Huber, J. E.
Fleck, N. A.
Landis, C. M.
McMeeking, R. M.19993A constitutive model for ferroelectric polycrystals 1663-1697.Journal of the Mechanics and Physics of Solids478ttwinning
crystal plasticity
ferroelectric switching
elastic energy
ceramics
discontinuity
continuum
behavior
surfaceAugA constitutive model is developed for the non-linear switching of ferroelectric polycrystals under a combination of mechanical stress and electric field. It is envisaged that the polycrystal consists of a set of bonded crystals and that each crystal comprises a set of distinct crystal variants. Within each crystal the switching event, which converts one crystal variant into another, gives rise to a progressive change in remanent strain and polarisation and to a change in the average linear electromechanical properties. It is further assumed that switching is resisted by the dissipative motion of domain walls. T |7AHall, D. A.
Evans, J. D. S.
Oliver, E. C.
Withers, P. J.
Mori, T.2007In-situ neutron diffraction study of the rhombohedral to orthorhombic phase transformation in lead zirconate titanate ceramics produced by uniaxial compression41-52Philosophical Magazine Letters871mcrystallographic texture
ferroelectric ceramics
electric energy
solid-solution
temperature
transitions
strainJanThe martensitic transformation from the rhombohedral to the orthorhombic phase in a lead zirconate titanate (Zi-/Ti = 95/5) ceramic has been Studied under uniaxial compressive stress using neutron diffraction. Ferroelastic domain switching in the rhombohedral phase was observed by monitoring the pseudo-cubic {111}(p) diffraction peaks, whereas the development of the orthorhombic phase texture was revealed most clearly by examining the charges in the {200}(p) reflections under stress. Rhombohedral grains having the (100)(p) direction along the compression axis transformed most efficiently, by the development of the c-axis of the orthorhombic phase along this direction. The transformation strain along this direction was most dominant and determined as -1.1 x 10(-2), whereas the lateral strains were measured as 1.0 x 10(-3). In contrast to the case of hydrostatic compression, Under uniaxial stress the transformation proceeded progressively as the applied compressive stress increased beyond a level of 200 MPa, up to a maximum orthorhombic phase fraction of 70% at a stress of 400 MPa. Pronounced hysteresis was observed upon unloading, indicating that the frictional stress required to move a rhombohedral/orthorhombic interface is approximately 150 MPa. By monitoring the lattice strain, it was found that the total stress along (100)(p) remained approximately constant during the progress of the transformation. This is Caused by an increase in the residual tensile stress within {100}(p)-oriented grains owing to the difference between their transformation strain and that of the surroundings. The above tensile stress is balanced by compressive residual stresses in the Surrounding grains.://000244388300006-138UH
Times Cited:0
Cited References Count:16 0950-0839ISI:000244388300006Hall, DA
Univ Manchester, Sch Mat, Manchester M1 7HS, Lancs, England
Univ Manchester, Sch Mat, Manchester M1 7HS, Lancs, England
AWE Aldermaston, Reading RG7 4PR, Berks, England
Rutherford Appleton Lab, ISIS, Didcot OX11 0QX, Oxon, EnglandEnglish|7:da Fonseca, J. Q.
Oliver, E. C.
Bate, P. S.
Withers, P. J.2006cEvolution of intergranular stresses during in situ straining of IF steel with different grain sizes26-32aMaterials Science and Engineering a-Structural Materials Properties Microstructure and Processing4371intergranular stresses
neutron diffraction
crystal plasticity
neutron-diffraction
deformation
polycrystals
dislocation
texture
metalsNov 10Despite its significant effect on metal deformation, grain size is not usually considered when modelling the evolution of intergranular stresses. This paper presents an experimental in situ straining neutron diffraction study of deformation in two interstitial free steels with different grain sizes, one with 80 mu m and one with 350 mu m. These were compared against the predictions of crystal plasticity finite element modelling, which is scale insensitive. Only small differences in the evolution of both mean grain family elastic strains and peak width were detected. These were attributed to local texture effects. (c) 2006 Elsevier B.V. All rights reserved.://0002418986000059Sp. Iss. SI
103PG
Times Cited:0
Cited References Count:24 0921-5093ISI:000241898600005da Fonseca, JQ
Manchester Mat Sci Ctr, Grosvenor St, Manchester M1 7HS, Lancs, England
Manchester Mat Sci Ctr, Manchester M1 7HS, Lancs, England
Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, EnglandEnglish|7+Oliver, E. C.
Daymond, M. R.
Withers, P. J.2005REffects of texture and anisotropy on intergranular stress development in zirconium 1553-1558,Icotom 14: Textures of Materials, Pts 1and 2495-497@texture
anisotropy
zirconium
neutron diffraction
residual stressThe influence of texture and anisotropy on the generation of intergranular stresses in clock-rolled zirconium is investigated using neutron diffraction and elastoplastic self-consistent modelling. Comparison between experimental data and model calculations indicates that the operation mainly of prismatic and basal slip explains the trends in intergranular stress evolution during in-plane tensile and through-thickness compressive deformation, whilst twinning plays a significant role during in-plane compression.://000231284400238MPart 1&2
Bcu61
Times Cited:1
Cited References Count:8
Materials Science Forum 0255-5476ISI:0002312844002388Oliver, EC
Rutherford Appleton Lab, ISIS Neutron Scattering Facil, Chilton OX11 0QX, Didcot, England
Rutherford Appleton Lab, ISIS Neutron Scattering Facil, Chilton OX11 0QX, Didcot, England
Queens Univ, Dept Mech & Mat Engn, Kingston, ON K7L 3N6, Canada
Manchester Mat Sci Ctr, Manchester M1 7HS, Lancs, EnglandEnglish|74Oliver, E. C.
Mori, T.
Daymond, M. R.
Withers, P. J.2004uNeutron diffraction study of stress-induced martensitic transformation and variant change in Fe-Pd shape memory alloy328-332aMaterials Science and Engineering a-Structural Materials Properties Microstructure and Processing3781-2pneutron diffraction
martensitic transformation
shape memory alloy
fe-pd
residual stresses
strain evolution
steelJul 25Neutron diffraction spectra were recorded during tensile testing of Fe-30.5 at.% Pd shape memory alloy at temperatures above M, and below M-f. Peak intensity changes indicate that the application of tensile stress to initially fully austenitic material results in the preferential martensitic transformation of grains oriented with austenite <100> parallel to the tensile axis. Tensile stress applied to initially fully martensitic material causes the greatest extent of reorientation in those variants oriented with martensite <001> lying parallel to the tensile axis. These results are interpreted using a simple elasticity-based theory. Additionally, diffraction peak shifts provide information on the development of lattice strain in differently oriented grain families during loading. This indicates that above M, the alloy exhibits high single crystal elastic anisotropy. Below M-f the apparent stiffnesses of different grain families suggest that axially compressive internal stresses develop in those grain families in which most variant reorientation occurs. These stresses act to reverse the variant changes upon subsequent unloading. (C) 2004 Elsevier B.V. All rights reserved.://0002233299000619Sp. Iss. SI
846QE
Times Cited:1
Cited References Count:12 0921-5093ISI:000223329900061Oliver, EC
Rutherford Appleton Lab, ISIS Facil, Didcot OX11 0QX, Oxon, England
Rutherford Appleton Lab, ISIS Facil, Didcot OX11 0QX, Oxon, England
Univ Manchester, Manchester Mat Sci Ctr, Manchester M1 7HS, Lancs, England
UMIST, Manchester M1 7HS, Lancs, EnglandEnglish|71Mori, T.
Oliver, E. C.
Daymond, M. R.
Withers, P.2004;Micromechanics of stress-induced martensitic transformation479-483aMaterials Science and Engineering a-Structural Materials Properties Microstructure and Processing3781-2omartensitic phase transformation
shape memory alloys (sma)
thermodynamics
mean field analysis
fe-pd
fe-pd alloyJul 25This work proposes that the structure of a twinned martensite plate is dependent upon temperature and stress. The uniaxial tensile stress required to induce the formation of a martensite plate is predicted to be smaller than that calculated under the assumption that the plate has a fixed structure subject to the criterion of invariant plane strain (IPS). Using a mean field method, the analysis is extended to non-dilute martensite volume fraction in order to obtain a stress-strain curve for the deformation of a single crystal. The curve shows a decrease in stress as transformation progresses. The implication of this result is discussed. (C) 2004 Elsevier B.V. All rights reserved.://0002233299000919Sp. Iss. SI
846QE
Times Cited:0
Cited References Count:10 0921-5093ISI:000223329900091Oliver, EC
Univ Manchester, Manchester Mat Sci Ctr, Grosvenor St, Manchester M1 7HS, Lancs, England
Univ Manchester, Manchester Mat Sci Ctr, Manchester M1 7HS, Lancs, England
UMIST, Manchester M1 7HS, Lancs, England
Rutherford Appleton Lab, ISIS Facil, Didcot OX11 0QX, Oxon, EnglandEnglish|7BOliver, E. C.
Kobayashi, N.
Mori, T.
Daymond, M. R.
Withers, P. J.2003IMechanical energy criterion for stress-induced martensitic transformation 1013-1019Scripta Materialia4910[martensitic phase transformation
shape memory alloys (sma)
thermodynamics
fe-pd
fe-pd alloyNovIt is proposed on the basis of equilibrium thermodynamics that the microstructure of a stress-induced twinned martensite plate adheres to the criterion of mechanical free energy minimisation, rather than that of invariant plane deformation. This lowers the predicted transformation stress. To demonstrate the proposal, an Fe-Pd shape memory alloy is considered. (C) 2003 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.://000185266200015-720NE
Times Cited:3
Cited References Count:12 1359-6462ISI:0001852662000155Oliver, EC
Rutherford Appleton Lab, ISIS Facil, Didcot OX11 0QX, Oxon, England
Rutherford Appleton Lab, ISIS Facil, Didcot OX11 0QX, Oxon, England
Univ Manchester, Inst Sci & Technol, Ctr Mat Sci, Manchester M1 7HS, Lancs, England
Tokyo Inst Technol, Dept Innovat & Engn Mat, Yokohama, Kanagawa 2268502, JapanEnglish|74Oliver, E. C.
Daymond, M. R.
Withers, P. J.
Mori, T.2002HStress induced martensitic transformation studied by neutron diffraction489-494GEcrs 6: Proceedings of the 6Th European Conference on Residual Stresses404-4Imartensitic transformation
neutron diffraction
residual stress
trip steelNeutron diffraction is an ideal tool for the study of stress induced martensitic transformation. The method is well established for the measurement of internal stress in two phase materials, since its selectivity allows the partitioning of stress between phases and grain families to be determined. A material undergoing a stress induced phase transformation is an example of a two phase material in which the volume fractions vary during the loading history; as such, internal stress plays a crucial role in its mechanical behaviour. In addition to the determination of internal stress, the neutron method gives information on the evolving texture of the material, and thus the preferred martensite variants which develop under loading. Moreover, by Rietveld refinement of the diffraction spectra, phase volume fractions may be determined.
This paper presents results and analysis of neutron diffraction studies into stress induced martensitic transformation. In Fe-Ni-C TRIP (TRansformation Induced Plasticity) steel, the development of internal stress under uniaxial tensile loading reveals the reinforcing role of the growing martensite phase. The observed load transfer contributes to the strain hardening of the material, suppressing strain localisation and preventing necking. This identifies the role of internal stress in the origin of TRIP. Moreover, the evolution of texture shows that austenite grains with <100> parallel to the tensile axis transform preferentially. The data is interpreted using a model based on infinitesimal deformation theory.://000177256900076DBu87K
Times Cited:1
Cited References Count:5
Materials Science Forum 0255-5476ISI:000177256900076Oliver, EC
Rutherford Appleton Lab, ISIS Facil, Didcot OX11 0QX, Oxon, England
Rutherford Appleton Lab, ISIS Facil, Didcot OX11 0QX, Oxon, England
Univ Manchester, Manchester Mat Sci Ctr, Manchester M13 9PL, Lancs, England
UMIST, Manchester M60 1QD, Lancs, EnglandEnglish|71Daymond, M. R.
Bourke, M. A. M.
Von Dreele, R. B.1999qUse of Rietveld refinement to fit a hexagonal crystal structure in the presence of elastic and plastic anisotropy739-747Journal of Applied Physics852diffraction
strain
polycrystalsJan 15When multiple elastic diffraction peaks are obtained from an x-ray or neutron source, data analysis is commonly performed using a Rietveld refinement applied to the entire pattern, rather than simply performing single peak fits. In the simplest case the crystal structure is assumed to be ideal despite the presence of stresses which, coupled with the elastic and plastic anisotropy of individual grains, can result in a nonisotropic response of the polycrystal. A first step to account for this anisotropy in the refinement is to include an anisotropic strain parameter. In an earlier work [J. Appl. Phys. 82, 1554 (1997)] we included elastic anisotropy into a Rietveld refinement and discussed its validity in the elastic and plastic regimes for a cubic crystal structure. Here we extend the discussion to include anisotropy in hexagonal crystal structures. The agreement between single peak fits and the Rietveld refinement modeled single peak positions is considered for hexagonal close packed beryllium in the presence of an applied compressive load, in both the elastic and plastic regime (to similar to 1% plastic strain). Agreement is found to be good in the elastic and early plastic regime, where only basal slip is assumed to be active. At higher loads, where prism slip and/or basal fracture are also assumed to be active, agreement is poorer for some diffraction planes. The implications for residual stress measurements are considered. (C) 1999 American Institute of Physics. [S0021-8979(99)03502-1].://000077792600015.152TJ
Times Cited:37
Cited References Count:21 0021-8979ISI:000077792600015Daymond, MR
Rutherford Appleton Lab, ISIS, Didcot OX11 0QX, Oxon, England
Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USAEnglish he constitutive model for the progressive switching of each crystal draws upon elastic-plastic crystal plasticity theory, and a prescription is given for the tangent moduli of the crystal, for any assumed set of potentially active transformation systems. A self-consistent analysis is used to estimate the macroscopic response of tetragonal crystals (representative of lead titanate) under a variety of loading paths. Also, the evolution of the 'switching surface' in stress-electric field space is calculated. Many of the qualitative features of ferroelectric switching, such as butterfly hysteresis loops, are predicted by the analysis. (C) 1999 Elsevier Science Ltd. All rights reserved.://000080301400003.196GV
Times Cited:80
Cited References Count:37 0022-5096ISI:000080301400003Fleck, NA
Univ Cambridge, Dept Engn, Trumpington St, Cambridge CB2 1PZ, England
Univ Cambridge, Dept Engn, Cambridge CB2 1PZ, England
Univ Calif Santa Barbara, Dept Mech & Environm Engn, Santa Barbara, CA 93106 USAEnglish3oҐ|7)%Holden, T. M.
Tome, C. N.
Holt, R. A.1998Experimental and theoretical studies of the superposition of intergranular and macroscopic strains in Ni-based industrial alloys 2967-2973TMetallurgical and Materials Transactions a-Physical Metallurgy and Materials Science2912%zircaloy-2
zirconium
stresses
textureDecMeasurements of the strain response to applied stress in polycrystalline MONEL-400 by neutron diffraction are modeled with the elastoplastic self-consistent (EPSC) theory. The strains in the different crystallographic orientations of grains, which are generated in the tensile test experiments, are shown to be caused by the anisotropy of elastic and plastic deformation with respect to crystallographic orientation. On the basis of the description of the results in the theory, the origin of a number of anomalies of a general nature in measurements by both neutron and X-ray diffraction can be understood. The theory is used to calculate which crystallographic reflections are least sensitive to intergranular effects under uniaxial tension.://000077771700011.152HU
Times Cited:11
Cited References Count:19 1073-5623ISI:000077771700011qHolden, TM
Natl Res Council Canada, Chalk River Labs, Neutron Program Mat Res, Chalk River, ON K0J 1J0, Canada
Natl Res Council Canada, Chalk River Labs, Neutron Program Mat Res, Chal k River, ON K0J 1J0, Canada
Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA
AECL Res, Chalk River Labs, Fuel Channels Div, Chalk River, ON K0J 1J0, CanadaEnglish>|7.
Kamlah, M.2001aFerroelectric and ferroelastic piezoceramics - modeling of electromechanical hysteresis phenomena219-268&Continuum Mechanics and Thermodynamics134phenomenological constitutive law
electroelastic greens-function
hexagonal infinite medium
finite-element model
thermodynamical formulation
deformation-behavior
multilayer actuators
ceramic actuators
pzt
equationsAugoThis paper deals with the constitutive modeling of ferroelectric and ferroelastic piezoceramics which are of gaining importance for modern sensing and actuation applications. First, the basic properties of these materials will be discussed in terms of their microstructure. Then, the recent literature on constitutive modeling is looked at, considering both microscopic and phenomenological approaches. Next. a simplifying constitutive model is presented describing the main large signal hysteresis phenomena of piezoceramics. The model was developed for purposes of structural mechanics analyses by means of the finite element method and its benefits to the understanding of complex residual stress and poling states in piezoceramic devices are demonstrated. Finally, a thermodynamically based and microscopically motivated constitutive model for piezoceramics will be sketched.://000170760100001/468LX
Times Cited:46
Cited References Count:110 0935-1175ISI:000170760100001Kamlah, M
Forschungszentrum Karlsruhe, Inst Mat Forsch 2, Postfach 3640, D-76021 Karlsruhe, Germany
Forschungszentrum Karlsruhe, Inst Mat Forsch 7|7++Turner, P. A.
Christodoulou, N.
Tome, C. N.19955Modeling the Mechanical Response of Rolled Zircaloy-2251-265#International Journal of Plasticity113deformationAn elastoplastic self-consistent model has been implemented to perform a systematic study of the response of rolled Zircaloy-2 subjected to mechanical loading. The intergranular stresses induced by cooling the material from 898 K to room temperature are calculated, accounting for the experimental texture, and compared with experimental data. The elastoplastic response in tension and compression along the rolling and the transverse directions of the sheet is predicted and compared against the results of uniaxial tensile and compressive tests performed in the same material. The role of the internal stresses on the yield stress and the elastoplastic transition is analyzed, and information about the active deformation systems in the individual grains is inferred from the comparison. Indirect inference of the parameters describing the deformation mechanisms is the only available means, because it is not possible to grow single crystals of these alloys. The results of this study demonstrate the adequacy of self-consistent schemes for predicting intergranular stresses and the significance of the latter on the mechanical behavior of the material.://A1995QU94300003.Qu943
Times Cited:44
Cited References Count:22 0749-6419ISI:A1995QU94300003qAecl Res,Reactor Mat Res Branch,Pinawa,Mb R0E 1L0,Canada
Univ Nacl Rosario,Conicet,Ifir,Ra-2000 Rosario,ArgentinaEnglish(|7-Turner, P. A.
Tome, C. N.1994;A Study of Residual-Stresses in Zircaloy-2 with Rod Texture 4143-4153Acta Metallurgica Et Materialia42128grain-interaction stresses
zirconium alloys
polycrystalsDec3The development of high grain-to-grain interactions in Zircaloy-2 polycrystals is due to the anisotropy of the thermal, elastic and plastic properties of the constituent grains. These residual stresses modify the mechanical performance of the material, as well as its response under neutron irradiation. Here we simulate the evolution of internal stresses in Zircaloy-2 with rod texture, when the aggregate is cooled down from the annealing temperature, and also when it is subjected to tensile and compressive deformation. We implement for that purpose an elasto-plastic self-consistent scheme that accounts for grain interactions, and compare our predictions with experimental determinations of residual strains obtained by neutron diffraction. Our results are in good quantitative agreement with the experimental evidence, and represent a qualitative improvement over the predictions of the more rigid upper-bound approach. We discuss the role that slip and twinning systems play in the macroscopic response of the aggregate and in the evolution of internal stresses.://A1994PQ61900022.Pq619
Times Cited:52
Cited References Count:18 0956-7151ISI:A1994PQ61900022Turner, Pa
Unr,Conicet,Inst Fis Rosario,27 Febrero,210 Bis,Ra-2000 Rosario,Argentina
Aecl,Res,Reactor Mat Res Branch,Pinawa R0E 1L0,Mb,CanadaEnglish '2, D-76021 Karlsruhe, GermanyEnglish?/Hutchings, M. T.2005NIntroduction to the Characterization of Residual Stress by Neutron DiffractionTaylor & Francis?4Cullity, B. D.1978Elements of X-Ray Diffraction545 Reading, Mass.Addison-Wesley Publishing Co.J?5Young, R. A.1993The Rietveld MethodOxford Univ PrP?6Mura, T.1987M?2
Warren, B. E.1990X-Ray DiffractionDover Publications 1#Micromechanics of Defects in SolidsSpringer3?7Lodini, A.
Fitzpatrick, M. F.200i3RAnalysis of Residual Stress by Diffraction Using Neutron and Synchrotron RadiationTaylor & Francis|?8Clyne, T. W.
Withers, P. J.1993*An Introduction to Metal Matrix CompositesCambridge University Press?9Rogan, R. C.2004vInvestigation of the Multiscale Constitutive Behavior of Ferroelectric Materials Using Advanced Diffraction TechniquesW `?:
Burcsu, E.2001:Investigation of Large Strain Actuation in Barium T?;Clausen, B.1997fCharacterisation of Polycrystal Deformation by Numerical Modeling and Neutron Diffraction MeasurementsTechnical University of Denmarkd?<%Larson, A. C.
Von Dreele, R. B.2000.General Structure Analysis System. Report LAURLos Alamos National Laboratoryx?=Kurzydlowski, K. J.1995?The Quantitative Description of the Microstructure of Materials CRC Pressg?>Ottosen, N. S.
Ristinmaa, M.2005&The Mechanics of Constitutive ModelingElsevierz??Nemat-Nasser, S.
Hori, M.1999<Micromechanics: overall properties of heterogenous materialsElsevier\?@Lemaitre, J.2001%Handbook of materials behavior modelsAcademic Pressy?AEshelby, J. D.1961&Elastic inclusions and inhomogeneities89–140Progress in Solid Mechanics2?BEshelby, J. D.1957XThe Determination of the Elastic Field of an Ellipsoidal Inclusion, and Related Problems376-396XProceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences2411226JSTOR?CHutchinson, J. W.1970BElastic-Plastic Behaviour of Polycrystalline Metals and Composites247-272XProceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences3191537JSTOR?ECanova, G. R.
Kocks, U. F.1984NThe development of deformation textures and resulting properties of fcc metals 573–579^ ^Seventh Int. Conf. on Textures of Materials. Soc. for Materials Science. Netherlands (1984) ppmV?GLandolt-Börnstein, N. D.2Functional Relationships in Science and Technology Group III17 ransitions
domain-structures
force microscopy
lattice-dynamicsNov 25There has been a recent surge of activity in ferroelectric materials motivated by the desire for materials capable of large strains for actuator applications. New materials have been developed and systematic attempts to exploit underlying domains have been pursued. New experimental methods have probed the material at the atomistic and domain scales. Significant advances have been made in the theoretical understanding of the origins of ferroelectricity, nature of domain patterns and their overall behavior. Modern methods of synthesis with controlled texture and composition have opened the possibility of exploiting the inherent microscopic features of these materials. This paper provides some snapshots of the recent advances in theory and experiment, and points to open issues and opportunities for the future. (C) 2003 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.://000186603200013/743ZF
Times Cited:14
Cited References Count:127 1359-6454ISI:000186603200013yRavichandran, G
CALTECH, Div Engn & Appl Sci, Pasadena, CA 91125 USA
CALTECH, Div Engn & Appl Sci, Pasadena, CA 91125 USAEnglishT?IJona, F.
G. Shirane1962Ferroelectric crystalsPergamon Pressc?JJaffe, B.
Cook, W. R.
Jaffe, H.1971Piezoelectric ceramicsBlackwell Synergy?KLines, M. E.
Glass, A. M.1978CPrinciples and Applications of Ferroelectrics and Related PhenomenaUniversity Press, Oxford /|7LQNoheda, B.
Gonzalo, J. A.
Cross, L. E.
Guo, R.
Park, S. E.
Cox, D. E.
Shirane, G.2000jTetragonal-to-monoclinic phase transition in a ferroelectric perovskite: The structure of PbZr0.52Ti0.48O3 8687-8695Physical Review B6113lead-zirconate-titanate
powder profile refinement
crystal-structure
first-principles
neutron-scattering
pzt
pbtio3
batio3
instabilities
temperaturesApr 1=The perovskitelike ferroelectric system PbZr1-xTixO3 (PZT) has a nearly vertical morphotropic phase boundary (MPB) around x = 0.45-0.50. Recent synchrotron x-ray powder diffraction measurements by Noheda et al. [Appl. Phys. Lett. 74, 2059 (1999)] have revealed a monoclinic phase between the previously established tetragonal and rhombohedral regions. In the present work we describe a Rietveld analysis of the detailed structure of the tetragonal acid monoclinic PZT phases on a sample with x = 0.48 for which the lattice parameters are, respectively, a(1) = 4.044 Angstrom, c(t) = 4.138 Angstrom, at 325 K, and a(m) = 5.721 Angstrom, b(m) = 5.708 Angstrom, c(m) = 4.138 Angstrom, beta = 90.496 degrees, at 20 K. In the tetragonal phase the shifts of the atoms along the polar [001] direction are similar to those in PbTiO3 but the refinement indicates that there are, in addition, local disordered shifts of the Pb atoms of similar to 0.2 Angstrom perpendicular to the polar axis. The monoclinic structure can be viewed as a condensation along one of the (110) directions of the local displacements present in the tetragonal phase. It equally well corresponds to a freezing-out of the local displacements along one of the (100) directions recently reported by Corker et al.[J. Phys.: Condens. Matter 10, 6251 (1998)] for rhombohedral PZT. The monoclinic structure therefore provides a microscopic picture of the MPB region in which one of the ''locally'' monoclinic phases in the "average" rhombohedral or tetragonal structures freezes out, and thus represents a bridge between these two phases.://000086597400026/306LD
Times Cited:203
Cited References Count:49 1098-0121ISI:000086597400026Noheda, B
Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA
UAM, Dept Fis Mat, Madrid 28049, Spain
Penn State Univ, Mat Res Lab, University Pk, PA 16802 USA
Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USAEnglish|7M-Munoz-Saldana, J.
Schneider, G. A.
Eng, L. M.2001uStress induced movement of ferroelastic domain walls in BaTiO3 single crystals evaluated by scanning force microscopy L402-L410Surface Science4801-2single crystal surfaces
growth
nucleation
piezoelectric effect
surface stress
electrically polar substances
barium-titanate ceramics
r-curve behavior
ferroelectric domains
electron-microscopy
measurement signals
configuration
surfaceMay 30We report on the quantitative investigation of lateral domain wall motion in BaTiO3 single crystals subjected to a compressive unidirectional mechanical stress. Simultaneous to the mechanical testing, the single crystals prepared by the modified exaggerated growth method were characterized by scanning force microscopy and piezoresponse force microscopy (PFM) which allow both topographical details and the true three-dimensional ferroelectric domain configuration to be reproduced simultaneously. Stress induced domain formation is initiated at the sample surface followed by the forward- and lateral-domain growth both perpendicular and parallel to the direction of induced stress. Knowing the crystallographic orientation of the BaTiO3 single crystal (from Kikuchi patterns) clearly associates our experimental observations with a 90 degrees domain switching process, in accordance with a theoretical model. Additionally. 180 degrees ferroelectric domain boundaries (a-domains) were detected with PFM which are not visible from the sample topography. The formation of these newly formed domains is driven by the compensation of the positive surface charge arising from the ferroelastic growth of C+ domains. (C) 2001 Published by Elsevier Science B.V.://000169276900004.442GM
Times Cited:15
Cited References Count:24 0039-6028ISI:000169276900004Munoz-Saldana, J
Tech Univ Hamburg Harburg, Adv Ceram Grp, D-21073 Hamburg, Germany
Tech Univ Hamburg Harburg, Adv Ceram Grp, D-21073 Hamburg, Germany
Univ Technol Dresden, Inst Appl Photophys, D-01062 Dresden, GermanyEnglish?NCross, L. E.1993FFerroelectric ceramics: tailoring properties for specific applications1–86Ferroelectric Ceramics|7OKisi, E. H.
Howard, C. J.1998WElastic constants of tetragonal zirconia measured by a new powder diffraction technique 1682-1684'Journal of the American Ceramic Society816temperatureJunVElastic constants for 12 mol% Ce-doped tetragonal zirconia have been determined from peak shifts in neutron diffraction patterns recorded under applied uniaxial stress. When these diffraction data are combined with a measured value of Young's modulus, a complete set of elastic constants is obtained. The values are c(11) = 327, c(12) = 100, c(13) = 62, c(33) = 264, c(44) = 59, and c(66) = 64 (units: GPa). These are the first reported results using a new technique for the measurement of elastic constants for anisotropic materials via neutron diffraction measurements on polycrystalline samples.://000074277600037.Zv175
Times Cited:15
Cited References Count:10 0002-7820ISI:000074277600037Kisi, EH
Univ Newcastle, Dept Mech Engn, Callaghan, NSW 2308, Australia
Univ Newcastle, Dept Mech Engn, Callaghan, NSW 2308, Australia
Australian Nucl Sci & Technol Org, Neutron Scattering Grp, Menai, NSW 2234, AustraliaEnglish#|7P Khalal, A.
Khatib, D.
Jannot, B.1999BElastic and piezoelectric properties of BaTiO3 at room temperature343-347Physica B-Condensed Matter2711-4Welastic properties
piezoelectric properties
batio3
lattice dynamics
shell model
phononsNovWe have calculated the phonon dispersion curves of barium titanate (BaTiO3) at room temperature. A lattice dynamical formalism using the shell model is used. This microscopic model includes the short-range interactions of axially symmetric type and the long-range Coulomb interactions and taking into account the electronic polarizability of constituent ions. Zone center phonon and a few phonons in the first Brillouin zone are used for fitting. The values of relevant parameters are critically analyzed. A calculation of the elastic and piezoelectric properties is presented and compared with the available experimental data. (C) 1999 Elsevier Science B.V. All rights reserved.://000084152100038-263YD
Times Cited:0
Cited References Count:20 0921-4526ISI:000084152100038Khatib, D
Univ Ibn Zohr, Fac Sci, Lab Phys Solide Theor, BP 28-S, Agadir 80000, Morocco
Univ Ibn Zohr, Fac Sci, Lab Phys Solide Theor, Agadir 80000, Morocco
Univ Bourgogne, Fac Sci Mirande, Equipe Opt Mat, Phys Lab, F-21011 Dijon, FranceEnglish|7Q,Gnaupel-Herold, T.
Brand, P. C.
Prask, H. J.1998gCalculation of single-crystal elastic constants for cubic crystal symmetry from powder diffraction data929-935"Journal of Applied Crystallography31residual-stresses
polycrystalDec 1ZIn this work a method is developed that allows the computation of the single-crystal elastic constants for crystals of cubic symmetry from the diffraction elastic constants. The diffraction elastic constants can be obtained by measuring the hkl-dependent lattice strain response to an applied stress. Because of their hkl dependence they represent, partially, the anisotropic nature of the single-crystal elastic constants. The computation of the single-crystal elastic constants is carried out by a least-squares refinement which fits the calculated diffraction elastic constants to the measured ones.://0000780678000165Part 6
157ND
Times Cited:17
Cited References Count:27 0021-8898ISI:000078067800016Gnaupel-Herold, T
Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA
Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA
Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USAEnglishh?R Sachs, G.1928#Zur Ableitung einer Fliessbedingung734–6Z. Ver. Dtsch. Ing72\F?S
Taylor, G. I.1938Plastic strain in metalsJ. Inst. Metals62S 307|7UJohnson, M. W.
Daymond, M. R.2002`An optimum design for a time-of-flight neutron diffractometer for measuring engineering stresses49-57"Journal of Applied Crystallogra phy35FebA method is described for optimizing the design of a time-of-flight neutron diffractometer designed to measure lattice parameters. Such diffractometers are now used extensively by engineers and materials scientists for measuring strain within metallic and ceramic components. The method presented relies on the identification of a figure of merit (FOM) that accurately describes the performance of such an instrument. For the first time, an FOM for an instrument exhibiting non-Gaussian peak shapes is described, and the methods by which this FOM may be maximized are described. Although the instrument described is based on the time-of-flight technique, the FOM derived may equally well be used to optimize a reactor-based instrument. While measuring peak position is a straightforward example, it is shown that similar figures of merit may be found for other peak shape parameters, and thus other types of instrumentation.://0001734410000095Part 1
514LM
Times Cited:18
Cited References Count:15 0021-8898ISI:000173441000009Daymond, MR
Rutherford Appleton Lab, ISIS Facil, Didcot OX11 0QX, Oxon, England
Rutherford Appleton Lab, ISIS Facil, Didcot OX11 0QX, Oxon, EnglandEnglish?VFDann, J. A.
Daymond, M. R.
Edwards, L.
James, J. A.
Santisteban, J. R.2004]A comparison between Engin and Engin-X, a new diffractometer optimized for stress measurement E511-E514 Physica B3501-3|7WRietveld, H. M.1969?A Profile Refinement Method for Nuclear and Magnetic Structures65-&"Journal of Applied Crystallography2://A1969D4976000057Part 2
D4976
Times Cited:4866
Cited References Count:15 0021-8898ISI:A1969D497600005English 4itanatePh.D."California Institute of Technology