To better understand the generation of electric power for piezoelectric Pb Zr Ti O3(PZT)ceramic plate(?25 mm),an attempt was made to investigate experimentally and numerically electricpower generation characteristics ...To better understand the generation of electric power for piezoelectric Pb Zr Ti O3(PZT)ceramic plate(?25 mm),an attempt was made to investigate experimentally and numerically electricpower generation characteristics during cyclic bending under various loading fixtures(?0–?20 mm),i.e.,different contact areas.Increasing the load-contact area on the PZT ceramic leads to a nonlinear decrease in the generated voltage.Decreasing contact area basically enhances the generated voltage,although the voltage saturates during loading when the contact area is less than?5 mm.A similar voltage is generated for?0 and?5 mm,which is attributed to strain status(ratio of compressive and tensile strain)and material failure due to different stress distribution in the PZT ceramic.On the basis of the obtained electric generation voltage,suitable loading conditions are clarified by loading with the?5 mm fixture,which generates a higher voltage and a longer lifetime of the PZT ceramic.From this approach,it is appeared that the area contact with the area ratio of 0.04(?5 mm/?20 mm)is suitable to obtain the high efficiency of the electric voltage.展开更多
Clear experimental evidence for phase transitions was shown in titanium doped lead magnesium niobate compositional disordered ferroelectric ceramics. One is the diffused phase transition around the temperature of diel...Clear experimental evidence for phase transitions was shown in titanium doped lead magnesium niobate compositional disordered ferroelectric ceramics. One is the diffused phase transition around the temperature of dielectric permittivity maxima, which is often assumed as the characteristics of relaxor ferroelectrics. Another is a first order transition from frequency dispersion relaxor ferroelectrics to normal ferroelectrics, corresponding to a zero field spontaneous polar micro macrodomain switching. According to the x ray diffraction, thermal analysis and transmission electron microscope results, it is pointed out that the relaxor state corresponds to a coexistence of cubic parent phase and nucleating rhombohedral ferroelectric microregion which is similar to a precursor martensite. After the spontaneous relaxor normal ferroelectrics transition, the lower symmetry phase is sure to be a long range rhombohedral phase. Thus a dynamic behavior of polar microregions is suggested to explain the phenomena, which is more similar to a stress induced martensitic transformations from cubical stabilized perovskite parent phase.展开更多
The relationship between composition and the electric mechanical properties for La2O3-doped lead niobium stibium zirconate titanate(La2O3-doped PNSZT) piezoelectric ceramics,in which there are tetragonal and rhombohed...The relationship between composition and the electric mechanical properties for La2O3-doped lead niobium stibium zirconate titanate(La2O3-doped PNSZT) piezoelectric ceramics,in which there are tetragonal and rhombohedral coexistent phases, was studied. A series of piezoelectric ceramics with good properties was obtained, having dielectric constants (ε= 1500 ~ 2500), plane electromechanical coupling factor(Kp = 0.45 ~ 0.65), mechanical quality factor( Qm = 500 ~ 1600). These materials are used for making ultrasonic sensor and filter, and marine acoustic launching and receiving device, and so on. It has been explored that the influence of composition on the lattice constant and phase composition of La2O3-doped PNSZT piezoelectric ceramics by XRD(X-ray diffraction) . The character of dielectric constant changing of La2O3-doped PNSZT piezoelectric ceramics before polarization and after polarization was studied. The affecting mechanism about composition on the electric machine properties of phase coexistent La2O3-doped PNSZT piezoelectric ceramics was analyzed and discussed.展开更多
采用传统的固相反应法制备了(Ba_(0.85)Ca_(0.15))(Ti_(0.9)Zr_(0.1))O_(3)(BCZT)以及掺杂Al-Mg-Ca玻璃粉的BCZT无铅压电陶瓷。首先研究了预烧温度对BCZT陶瓷粉体的影响,其次研究了掺杂Al-Mg-Ca玻璃粉对BCZT无铅压电陶瓷的烧结性能、介...采用传统的固相反应法制备了(Ba_(0.85)Ca_(0.15))(Ti_(0.9)Zr_(0.1))O_(3)(BCZT)以及掺杂Al-Mg-Ca玻璃粉的BCZT无铅压电陶瓷。首先研究了预烧温度对BCZT陶瓷粉体的影响,其次研究了掺杂Al-Mg-Ca玻璃粉对BCZT无铅压电陶瓷的烧结性能、介电性能和压电性能的影响。最后通过正交试验确定了其烧结工艺。结果显示BCZT粉体的最佳预烧温度在1100℃。掺杂Al-Mg-Ca玻璃粉能够有效降低BCZT陶瓷的烧结温度。通过烧结工艺正交实验获得了最佳烧结工艺:1100℃预烧,1350℃烧结,升温速度为2℃/min,保温时间为7 h,在110 min降温至800℃。验证正交试验所得到的结果是掺杂Al-Mg-Ca玻璃粉的BCZT陶瓷的居里温度点的介电常数为12228,压电常数d_(33)为425 p C/N。展开更多
Ba0.85Ca0.15Ti0.9Zr0.1O3 （BCTZ） lead-free piezoelectric ceramics co-doped with CeO2 （x=0.1 wt.%, 0.2 wt.%, 0.3 wt.%, 0.4 wt.%, 0.5 wt.%） and Li2CO3 （0.6 wt.%） were prepared by conventional solid-state reaction m...Ba0.85Ca0.15Ti0.9Zr0.1O3 （BCTZ） lead-free piezoelectric ceramics co-doped with CeO2 （x=0.1 wt.%, 0.2 wt.%, 0.3 wt.%, 0.4 wt.%, 0.5 wt.%） and Li2CO3 （0.6 wt.%） were prepared by conventional solid-state reaction method. Influence of CeO2 doping amount on the piezoelectric properties, dielectric properties, phase composition and microstructure of prepared BCTZ lead-free piezoelectric ceramics doped with Li2CO3 were investigated by X-ray diffraction （XRD） and scanning electron microscopy （SEM） and other analytical methods. The results showed that the sintered temperature of BCTZ lead-free piezoelectric ceramics doped with CeO2 decreased greatly when Li2CO3 doping amount was 0.6 wt.%;a pure perovskite structure of BCTZ lead-free piezoelectric ceramics co-doped with Li2CO3 and CeO2 and sintered at 1050 ℃ could also be obtained. The piezoelectric constant （d33）, the relative permit-tivity （εr） and the planar electromechanical coupling factor （kp） of BCTZ ceramics doped with Li2CO3 increased firstly and then de-creased, the dielectric loss （tanδ） decreased firstly and then increased and decreased at last when CeO2 doping amount increased. The influence of CeO2 doping on the properties of BCTZ lead-free piezoelectric ceramics doped with Li2CO3 were caused by“soft effect”and “hard effect”piezoelectric additive and causing lattice distortion. When CeO2 doping amount （x） was 0.2 wt.%, the BCTZ ceramics doped with Li2CO3 （0.6 wt.%） and sintered at 1050 ℃ possessed the best piezoelectric property and dielectric property with d33 of 436 pC/N, kp of 48.3%,εr of 3650, tanδof 1.5%.展开更多
文摘To better understand the generation of electric power for piezoelectric Pb Zr Ti O3(PZT)ceramic plate(?25 mm),an attempt was made to investigate experimentally and numerically electricpower generation characteristics during cyclic bending under various loading fixtures(?0–?20 mm),i.e.,different contact areas.Increasing the load-contact area on the PZT ceramic leads to a nonlinear decrease in the generated voltage.Decreasing contact area basically enhances the generated voltage,although the voltage saturates during loading when the contact area is less than?5 mm.A similar voltage is generated for?0 and?5 mm,which is attributed to strain status(ratio of compressive and tensile strain)and material failure due to different stress distribution in the PZT ceramic.On the basis of the obtained electric generation voltage,suitable loading conditions are clarified by loading with the?5 mm fixture,which generates a higher voltage and a longer lifetime of the PZT ceramic.From this approach,it is appeared that the area contact with the area ratio of 0.04(?5 mm/?20 mm)is suitable to obtain the high efficiency of the electric voltage.
文摘Clear experimental evidence for phase transitions was shown in titanium doped lead magnesium niobate compositional disordered ferroelectric ceramics. One is the diffused phase transition around the temperature of dielectric permittivity maxima, which is often assumed as the characteristics of relaxor ferroelectrics. Another is a first order transition from frequency dispersion relaxor ferroelectrics to normal ferroelectrics, corresponding to a zero field spontaneous polar micro macrodomain switching. According to the x ray diffraction, thermal analysis and transmission electron microscope results, it is pointed out that the relaxor state corresponds to a coexistence of cubic parent phase and nucleating rhombohedral ferroelectric microregion which is similar to a precursor martensite. After the spontaneous relaxor normal ferroelectrics transition, the lower symmetry phase is sure to be a long range rhombohedral phase. Thus a dynamic behavior of polar microregions is suggested to explain the phenomena, which is more similar to a stress induced martensitic transformations from cubical stabilized perovskite parent phase.
文摘The relationship between composition and the electric mechanical properties for La2O3-doped lead niobium stibium zirconate titanate(La2O3-doped PNSZT) piezoelectric ceramics,in which there are tetragonal and rhombohedral coexistent phases, was studied. A series of piezoelectric ceramics with good properties was obtained, having dielectric constants (ε= 1500 ~ 2500), plane electromechanical coupling factor(Kp = 0.45 ~ 0.65), mechanical quality factor( Qm = 500 ~ 1600). These materials are used for making ultrasonic sensor and filter, and marine acoustic launching and receiving device, and so on. It has been explored that the influence of composition on the lattice constant and phase composition of La2O3-doped PNSZT piezoelectric ceramics by XRD(X-ray diffraction) . The character of dielectric constant changing of La2O3-doped PNSZT piezoelectric ceramics before polarization and after polarization was studied. The affecting mechanism about composition on the electric machine properties of phase coexistent La2O3-doped PNSZT piezoelectric ceramics was analyzed and discussed.
文摘采用传统的固相反应法制备了(Ba_(0.85)Ca_(0.15))(Ti_(0.9)Zr_(0.1))O_(3)(BCZT)以及掺杂Al-Mg-Ca玻璃粉的BCZT无铅压电陶瓷。首先研究了预烧温度对BCZT陶瓷粉体的影响,其次研究了掺杂Al-Mg-Ca玻璃粉对BCZT无铅压电陶瓷的烧结性能、介电性能和压电性能的影响。最后通过正交试验确定了其烧结工艺。结果显示BCZT粉体的最佳预烧温度在1100℃。掺杂Al-Mg-Ca玻璃粉能够有效降低BCZT陶瓷的烧结温度。通过烧结工艺正交实验获得了最佳烧结工艺:1100℃预烧,1350℃烧结,升温速度为2℃/min,保温时间为7 h,在110 min降温至800℃。验证正交试验所得到的结果是掺杂Al-Mg-Ca玻璃粉的BCZT陶瓷的居里温度点的介电常数为12228,压电常数d_(33)为425 p C/N。
基金supported by Project of Combination of Producing,Learning and Studying of Guangdong Province and Education Department(2011B090400027)
文摘Ba0.85Ca0.15Ti0.9Zr0.1O3 （BCTZ） lead-free piezoelectric ceramics co-doped with CeO2 （x=0.1 wt.%, 0.2 wt.%, 0.3 wt.%, 0.4 wt.%, 0.5 wt.%） and Li2CO3 （0.6 wt.%） were prepared by conventional solid-state reaction method. Influence of CeO2 doping amount on the piezoelectric properties, dielectric properties, phase composition and microstructure of prepared BCTZ lead-free piezoelectric ceramics doped with Li2CO3 were investigated by X-ray diffraction （XRD） and scanning electron microscopy （SEM） and other analytical methods. The results showed that the sintered temperature of BCTZ lead-free piezoelectric ceramics doped with CeO2 decreased greatly when Li2CO3 doping amount was 0.6 wt.%;a pure perovskite structure of BCTZ lead-free piezoelectric ceramics co-doped with Li2CO3 and CeO2 and sintered at 1050 ℃ could also be obtained. The piezoelectric constant （d33）, the relative permit-tivity （εr） and the planar electromechanical coupling factor （kp） of BCTZ ceramics doped with Li2CO3 increased firstly and then de-creased, the dielectric loss （tanδ） decreased firstly and then increased and decreased at last when CeO2 doping amount increased. The influence of CeO2 doping on the properties of BCTZ lead-free piezoelectric ceramics doped with Li2CO3 were caused by“soft effect”and “hard effect”piezoelectric additive and causing lattice distortion. When CeO2 doping amount （x） was 0.2 wt.%, the BCTZ ceramics doped with Li2CO3 （0.6 wt.%） and sintered at 1050 ℃ possessed the best piezoelectric property and dielectric property with d33 of 436 pC/N, kp of 48.3%,εr of 3650, tanδof 1.5%.
