5th International Conference and Expo on Ceramics and Composite Materials June 03-04, 2019 London, UK

Kenji Uchino is the pioneer in “piezoelectric actuators”, is the Founding Director of International Center for Actuators and Transducers, Professor of EE and MatSE, and Distinguished Faculty of Schreyer Honors College at The Penn State University. He was the Founder and Senior Vice President of Micromechatronics Inc., State College, PA from 2004 till 2010, and Associate Director at Office of Naval Research-Global from 2010 till 2014. After his PhD degree from Tokyo Institute of Technology, Japan, he became Research Associate in 1976 at this university. Then, he joined Sophia University, Japan as an Associate Professor in 1985. He was recruited from The Penn State in 1991. He has authored 570 papers, 75 books and 31 patents in the ceramic actuator area. 48 papers/books have been cited more than 100 times, leading to his average h-index 70. He is the Fellow of American Ceramic Society and IEEE. He is currently the IEEE UFFC Distinguished Lecturer.

The perovskite ceramics are current primary piezoelectric materials widely commercialized and applied to various devices such as sensors and actuators. This paper reviews the piezoelectric perovskite history and forecasts the future development trend. BaTiO3 (BT) ceramics were discovered during World War II independently in three countries, US, Japan and Russia. Following the methodology taken for the BT discovery, the perovskite isomorphic oxides such as PbTiO3, PbZrO3 and their solid solutions were intensively studied. In particular, the discovery of super piezoelectricity in the Pb(Zr,Ti)O3 (PZT) system is noteworthy. In parallel to the PZT-based ternary solid solutions development, complex perovskite structure materials were synthesized and investigated in the 1950s. Among them, huge dielectric permittivity

was reported in Pb(Mg1/3Nb2/3)O3 (PMN), which became major ceramic compositions for high-K capacitors in the 1980s. It is noteworthy to introduce two epoch-making discoveries in the late 1970s, relating with electromechanical couplings in the relaxor ferroelectrics: electrostrictive actuator materials, and high k piezoelectric single crystals. The author’s group focused on the single crystal Pb(Zn1/3Nb2/3)O3-PbTiO3 solid solution system, which has a phase diagram similar to the PZT system.

Figure: Changes in electromechanical coupling factors with PT faction x in (1–x) Pb (Zn_1/3Nb_2/3) O₃-xPbTiO₃.

 

P N de Aza has received her Doctoral degree in Chemistry-Ceramin 1995. She did a Postdoctoral stage at the IRC in Biomaterials at the Queen Mary College, University of London, UK working on in vitro and in vivo behavior of bioceramics. At this moment, she is the Chair of the Materials Science, Optic and Electronic Technology Department, Professor of Materials Science and Metallurgical Engineering and Researcher at the Bioengineering Institute at the Miguel Hernandez

de Elche University.

Bone tissue engineering provides an alternative way to repair diseased or damaged tissue and to recover its original state and function. In the tissue engineering approach, a highly porous artificial material, or scaffold, is employed as a template to facilitate the cell attachment, proliferation, and differentiation. Therefore, these materials must satisfy the requirements of biocompatible, osteoconductivity, controlled degradation, and provide adequate mechanical properties. A new route for obtaining bioactive ceramic materials, to improve the ingrowth of new bone into implants (osseintegration), is presented. This consitits of attaining eutectoid structures from selected systems bearing in mind the different bioactive behaviour of the phases. To this purpose the subsystem silicocarnotite- α-tricalcium phosphate was chosen because of the

first is bioactive and the second resorbable. The eutectoid material is formed by lamellae type microstructure of alternate layers of silicocarnotite and α-triclacium phosphate. The eutectoid material, in vitro esperiments, tranforms dissolving the α-tricalcium phosphate phase and forming, by pseudomorphic transformation of the silicocarnotite lamellae, a porous structure of hydroxyapatite, that mimic porous bone. The procedure developed by the authors opens the opportunity to obtain a new family of bioactive materials, with improved osseointegration, for which the general name of bioeutectoid® is proposed.

Sergey Sokovnin has his expertise in pulse power technique, radiation technology and nanotechnology. He has developed a method for production of nano powders, including evaporation of a target by a pulsed electron beam, condensation of the vapor of the material in a low-pressure gas, and deposition of nano powders on a large cold square crystallizer. By this method, it is possible to produce oxide nano powders with the characteristic size of 3-5 nm and nano powder agglomerates with the characteristic size of 20-200 nm having the specific surface of up to 338 m2/g at the production rate of up to 10 g/h and the specific energy consumption of less than 120 Wh/g.

By method of pulsed electron beam evaporation in vacuum of targets from bulk state compounds of plain and complex oxides (ZnO-Zn, Al2O3, SiO2, CeO2,YSZ (Y2O3-8% Gd2O3 est.) and also fluorides (CaF2 and BaF2) nano powders (NPs) with a high specific surface were produced. The morphology magnetic, thermal and luminescence characteristics of NPs were measured. Than have studied the properties of ZnO ceramics sintered from the ZnO-Zn NPs to establish the influence of NPs prehistory on the luminescence and dilatometry properties properties of ceramics produced from them. Pressing was performed on uniaxial presses: static and the magnetic pulsed one. Sintering of ceramics was produced in air by heating to 1200°C in 60 min. Maximal density of the ceramics did not exceed 81, 25% of the theoretical density. The behavior of the shrinkage curves of ZnO-Zn NPs depends on their prehistory. The suppression of the ultraviolet emission in NP obtained by electron beam evaporation, and in ceramics sintered of them was established. Besides, two types of ZnO ceramics were fabricated and characterized by XRD, SEM methods. The radioluminescence spectra were measured within the 300-550K range.The thermostimulated luminescence (TSL) glow-curves were measured after X-ray irradiation at 300K. It was concluded that the complex overlapping peak within the 320-450 K temperature range consists of two components (~360-375K and 400-420K). The ratio of component intensities differs in both ceramics. The positions of high temperature TSL components (480-520K) also differ in both samples; therefore not only sintering conditions but also the properties of the initial powder are very important for characteristics of TSL. A linear dependence of peak intensity on irradiation dose was observed up to ~3 kGy for ceramic 1 and up to 9 kGy for ceramic 2.

Kenji Uchino is the pioneer in “piezoelectric actuators”, is the Founding Director of International Center for Actuators and Transducers, Professor of EE and MatSE, and Distinguished Faculty of Schreyer Honors College at The Penn State University. He was the Founder and Senior Vice President of Micromechatronics Inc., State College, PA from 2004 till 2010, and Associate Director at Office of Naval Research-Global from 2010 till 2014. After his PhD degree from Tokyo Institute of Technology, Japan, he became Research Associate in 1976 at this university. Then, he joined Sophia University, Japan as an Associate Professor in 1985. He was recruited from The Penn State in 1991. He has authored 570 papers, 75 books and 31 patents in the ceramic actuator area. 48 papers/books have been cited more than 100 times, leading to his average h-index 70. He is the Fellow of American Ceramic Society and IEEE. He is currently the IEEE UFFC Distinguished Lecturer.

Antiferroelectrics (AFE) can exhibit a ‘shape memory function controllable by electric field’, with huge isotropic volumetric expansion associated with the AFE to Ferroelectric (FE) phase transformation. In the Pb0.99Nb0.02[(Zr0.6Sn0.4)1-yTiy]0.98O3 (PNZST) system, the shape memory function is observed in the intermediate range between high temperature AFE and low temperature FE, or low Ti-concentration AFE and high Ti-concentration FE. In the AFE multilayer actuators (MLA’s), the crack is initiated in the center of a pair of internal electrodes under cyclic electric field, rather than the edge area of the internal electrodes in normal piezoelectric MLA’s. The two-sublattice polarization coupling model is proposed to explain: (1) isotropic volume expansion during the AFE-FE transformation, and (2) piezoelectric anisotropy. We introduce latching relays and mechanical clampers as possible unique applications of shape memory ceramics.