Principles of equal-channel angular pressing as a processing tool for grain refinement

https://material.karlov.mff.cuni.cz/people/janecek/studenti/FyzMetNano/Estrin_AM61_2013_782.pdf

Extreme grain refinement by severe plastic deformation: A wealth of challenging science

We present a critical review that encompasses the fundamentals and state-of-the-art knowledge of barium titanate-based piezoelectrics. First, the essential crystallography, thermodynamic relations, and concepts necessary to understand piezoelectricity and ferroelectricity in barium titanate are discussed. Strategies to optimize piezoelectric properties through microstructure control and chemical modification are also introduced. Thereafter, we systematically review the synthesis, microstructure, and phase diagrams of barium titanate-based piezoelectrics and provide a detailed compilation of their functional and mechanical properties. The most salient materials treated include the (Ba,Ca)(Zr,Ti)O3, (Ba,Ca)(Sn,Ti)O3, and (Ba,Ca)(Hf,Ti)O3 solid solution systems. The technological relevance of barium titanate-based piezoelectrics is also discussed and some potential market indicators are outlined. Finally, perspectives on productive lines of future research and promising areas for the applications of these ma...

BaTiO3-based piezoelectrics: Fundamentals, current status, and perspectives

Fatigue and microstructure of ultrafine-grained metals produced by severe plastic deformation

Cyclic deformation and fatigue properties of very fine-grained metals and alloys

The formation of PSB-like shear bands in cyclically deformed ultrafine grained copper processed by ECAP

Low sintering temperature and high piezoelectric properties of Li-doped (Ba,Ca)(Ti,Zr)O3 lead-free ceramics

Large strain induced by the alignment of defect dipoles in (Bi3 +,Fe3 +) co-doped Pb(Zr,Ti)O3 ceramics

The non-doped and 0.5, 1.0, 2.0, and 5.0 mol% Er3+-doped 0.75Pb(Mg1/3Nb2/3)O3-0.25PbTiO3 (called PMN-PT) transparentceramics have been fabricated. The optical absorption spectra, photoluminescence excitation and emission spectra, and the up-conversion luminescence spectra under the excitation of
980 nm laser were investigated. The up-conversion luminescence of Er3+-doped PMN-PT transparent ceramics changes from yellowish green to reddish orange with increasing the Er3+ doping concentration. The dependence of visible up-conversion luminescence on the laser power was measured. The up-conversion
luminescence saturation is observed for Er3+ 5.0 mol%-doped PMN-PT. A possible up-conversion luminescence mechanism is proposed, which depends on Er3+ concentration. The up-conversion emission is mainly due to excited state absorption for lightly Er3+-doped PMN-PT transparent ceramics, while the
energy-transfer processes are for highly doped ones.

NIR to Visible Up‐conversion Luminescence of Er3+‐Doped PMN‐PT Transparent Ceramics

Textured Pb(Mg1/3Nb2/3)0.675Ti0.325O3 (PMN-PT) ceramics were prepared by the templated grain growth method with 3% plate-like BaTiO3 as templates. The degree of grain orientation was about 81% by calculating from the XRD pattern. Temperature dependence of electric field induced strain was measured for both untextured and textured PMN-PT ceramics. The results show that the electric field induced strain for textured PMN-PT ceramics is much larger and more stable than that for untextured PMN-PT ceramics in a wide temperature range. The contribution from the piezoelectric effect and electrostrictive effect to the strain was analyzed, and it was found that textured PMN-PT ceramics exhibited electrostrictive coefficient Q33 as high as 5.19 × 10−2 m4 C−2 and it was comparable to that of PMN-PT single crystals. The electrostrictive effect contributed the main part of the enhancement of electric field induced strain for textured PMN-PT ceramics.

Guorong Li

Papers

The formation of PSB-like shear bands in cyclically deformed ultrafine grained copper processed by ECAP

Low sintering temperature and high piezoelectric properties of Li-doped (Ba,Ca)(Ti,Zr)O3 lead-free ceramics

Large strain induced by the alignment of defect dipoles in (Bi3 +,Fe3 +) co-doped Pb(Zr,Ti)O3 ceramics

NIR to Visible Up‐conversion Luminescence of Er3+‐Doped PMN‐PT Transparent Ceramics

Contribution to the large and stable electric field induced strain for textured Pb(Mg1/3Nb2/3)0.675Ti0.325O3 ceramics