TY  - THES
T1  - Time-resolved diffraction experiments on piezoelectric actuators
A1  - Rödl,Florian
Y1  - 2010/06/29
N2  - One of the most important features of many common functional ceramics is piezoelectricity, a phenomenon which is not fully under-stood so far. Especially the time-dependent response and its role in the deterioration of properties due to fatigue has not been much investigated. The present work focuses especially on time-resolved X-ray-diffraction, but also uses static methods to improve the understanding of dynamic processes that occur during switching in piezoelectric actuators and how they change with increasing fatigue. Micro-tensile tests were performed on the electrode material; the flow stress strongly depends on the temperature. A new synchrotron-based method was developed to study actuators in-situ during switching on timescales of microseconds. The results show different relaxation processes depending on the sample position. In a pre-stressed actuator, only one 90° domain relaxation can be found in the active area. In an actuator without prestress, we can find two different 90° domain relaxation processes. In the inactive area of the actuator, only slow processes can be seen as no domain processes occur. Close to the electrode edge, high mechanical stresses yield defect relaxations which could be a reason for stronger fatigue in this area. In this work it was shown that synchrotron experiments can be used to study the domain processes in piezoelectric materials. Future experiments could use this method to study the influence of fatigue on domain processes.
KW  - Röntgenweitwinkelstreuung
KW  - PZT
KW  - Zeitauflösung
KW  - Piezokeramiken
CY  - Saarbrücken
PB  - Universitäts- und Landesbibliothek
AD  - Postfach 151141, 66041 Saarbrücken
UR  - http://scidok.sulb.uni-saarland.de/volltexte/2010/3167
ER  -