| Autor: |
Suchanicz J; Department of Mechanical Engineering and Agrophysics, University of Agriculture in Krakow, Balicka 120, 31-120 Krakow, Poland., Wąs M; Department of Bioprocess Engineering, Power Engineering and Automation, University of Agriculture in Krakow, Balicka 116, 31-120 Krakow, Poland., Kluczewska-Chmielarz K; Institute of Technical Sciences, University of the National Education Commission, Podchorazych 2, 30-084 Krakow, Poland., Jagło G; Institute of Technical Sciences, University of the National Education Commission, Podchorazych 2, 30-084 Krakow, Poland., Brzezińska D; Institute of Materials Engineering, Faculty of Science and Technology, University of Silesia in Katowice, 75 Pułku Piechoty 1a, 41-500 Chorzow, Poland., Rosiek R; Institute of Technical Sciences, University of the National Education Commission, Podchorazych 2, 30-084 Krakow, Poland., Stachowski G; Astronomical Observatory, Jagiellonian University, Orla 171, 30-244 Krakow, Poland., Sokolowski M; Faculty of Computer Science, Electronics and Telecommunications, AGH University of Science & Technology, 30-059 Krakow, Poland. |
| Abstrakt: |
The mechanical properties of Mn- and Fe-doped Na 0.5 Bi 0.5 TiO 3 ceramics in unpoled and poled states were examined and analyzed for the first time through measurements of Young's modulus, the elastic modulus, Poisson's number, compressibility modulus K, hardness, fracture toughness and bending strength on one hand and by stress-strain measurements on the other hand. It was found that both the introduction of Fe and Mn ions into Na 0.5 Bi 0.5 TiO 3 and E-poling lead to improvements in their mechanical properties. The additives also cause improvement of the piezoelectric properties. The stress-strain curves revealed a changing mechanical response with the Mn and Fe doping of the NBT. With the doping, there was a decrease in coercive stress, which enhanced the remnant strain. In contrast, the E-poling led to an increase in the coercive stress, which reduced the remnant strain. Induced internal stresses associated with non-180° domain switching were determined. It was found that the investigated materials displayed significant ferroelastic deformation and large remnant polarization even under external stress of 180-250 MPa. Modification of NBT by Mn and Fe ions and E-poling were found to be effective ways of improving actuator performance and controlling operating stresses in order to minimize irreversible fatigue damage. The results suggest that the investigated materials could replace PZT ceramics in actuator applications where high blocking stress is required. |
