多铁材料掺杂BNT基无铅压电陶瓷的制备及性能研究

发布时间：2019-03-06 13:39

【摘要】：PZT铅压电陶瓷长期以来占据着压电陶瓷材料的重要地位,随着社会的进步,人们环保意识的增强,研究和开发具有高性能的无铅压电陶瓷是一个具有重要意义的研究课题。Bi_(0.5)Na_(0.5)Ti O_3(BN T)压电陶瓷因其优异的压电和介电性能成为铅基压电陶瓷的最具潜力的替代品之一。本文将通过离子掺杂以及添加新组元的两种方式对0.935Bi_(0.5)Na_(0.5)Ti O_3-0.065BT(BNT-BT6.5)进行改性,具体内容如下:(1)通过多铁材料Sr_3Cu Nb_2O_9掺杂对BNT-BT6.5无铅压电陶瓷得到单一的钙钛矿结构,通过铁电分析,当x=0.003,外加电场为60k V/cm时,矫顽场和剩余极化强度分别为18.41 k V/cm和29.11μC/cm~2并且陶瓷样品具有最大的单极应变系数S_(m ax)=0.29%和最大的等效压电常数d~*_(33)=483 pm/V。(2)0.994BNTBT-0.006SCN陶瓷具有优异的储能性能以及明显的弛豫行为。通过电滞回线对储能分析,随着外加电场的增加,样品的电滞回线的最大极化强度呈非线性增加。外加电场由20 k V/cm增加到60 k V/cm,最大极化强度由7.5μC/cm~2增加到34.05μC/cm~2。当外加电场为60 k V/cm时,储能密度W_1为0.62J/cm~3,储能效率η为0.54。(3)通过多铁材料Bi Mn O_3掺杂对BNT-BT6.5无铅压电陶瓷得到单一的钙钛矿结构,多铁材料Bi Mn O_3的掺入明显的促进了晶粒的生长,并且使晶界更加明显,晶粒饱满圆润,气孔减少,陶瓷致密度增加。当x=0.015时,压电常数d_(33)取得最大值210 p C/N,机电耦合系数K_p同为最大值为0.41,介电常数取得最大值1880,介电损耗最小0.020。通过弛豫行为分析,认为陶瓷内部存在弥散相变,并且陶瓷内部弛豫转变就是弥散相变。(4)采用复合离子(Fe_(1/2)Ta_(1/2))~(4+)对BNT-BT6.5无铅压电陶瓷B位取代,所有的样品均形成单一纯的钙钛矿结构。通过SEM分析,随着FT掺杂量的增加,晶粒尺寸先增大后减小,并且晶界逐渐明显,气孔减少,形成致密度较高的压电陶瓷。当x=0.006时,晶粒尺寸最大,3μm~6μm,并且晶界明显,晶粒大小均匀,没有气孔。通过电学性能分析。当x=0.006时,综合性能最佳:d_(33)=225 p C/N,K_p=40%,ε=1500,tanθ=0.025。通过铁电性能分析,随着FT掺杂量的增加,矫顽场逐渐降低,剩余极化强度先增加后降低。当x=0.006时,E_c=30 k V/cm,,P_r=33.19μC/cm~2(5)BNT-BT6.5-PZT复合压电陶瓷通过XRD分析,当PZT掺杂量小于0.09时,样品均形成单一纯的钙钛矿结构,PZT完全进入BNT-BT6.5的晶格内。通过SEM分析,随着PZT含量的增加,晶粒尺寸逐渐增大,晶粒的尺寸的均匀性也有所提高,气孔逐渐减小,致密度增大,并且出现棱角分明的晶粒,提高陶瓷性能。压当x=0.06时,综合性能最佳:d_(33)=195 p C/N,K_p=40%,ε=1734,tanθ=0.026。BNT-BT6.5-PZT基复合压电陶瓷的研究是一个具有研究价值的研究方向。
[Abstract]:PZT lead piezoelectric ceramics have occupied an important position of piezoelectric ceramics for a long time. With the progress of society, people's awareness of environmental protection has been enhanced. The research and development of lead-free piezoelectric ceramics with high performance is an important research subject. Bi _ (0.5) Na_ (0.5) Ti O _ 3 (BN T) piezoelectric ceramics have excellent piezoelectric and dielectric properties. It has become one of the most potential alternatives to lead-based piezoelectric ceramics. In this paper, 0.935Bi _ (0.5) Na_ (0.5) Ti O_3-0.065BT (BNT-BT6.5) was modified by ion doping and adding new components. The main contents are as follows: (1) single perovskite structure was obtained by doping lead-free BNT-BT6.5 piezoelectric ceramics with multi-iron material Sr_3Cu Nb_2O_9. By ferroelectric analysis, when xx0.003and applied electric field was 60k V/cm, the perovskite structure was obtained. The coercive field and the residual polarization intensity are 18.41 k V/cm and 29.11 渭 C / cm~2, respectively. The ceramic samples have the maximum unipolar strain coefficient S _ (m ax) = 0.29% and the maximum equivalent piezoelectric constant d _ (33) = 483. Pm/V. (2) 0.994BNTBT-0.006SCN ceramics have excellent energy storage properties and obvious relaxation behavior. The maximum polarization intensity of the hysteresis loop increases non-linearly with the increase of the applied electric field through the energy storage analysis of the hysteresis loop pair. The applied electric field increased from 20 k V/cm to 60 kV / cm, and the maximum polarization intensity increased from 7.5 渭 C / cm~2 to 34.05 渭 C / cm~2.. When the applied electric field is 60 k V/cm, the energy storage density is 0.62 J 路cm ~ (3) and the energy storage efficiency 畏 is 0.54. (3) the single perovskite structure of BNT-BT6.5 piezoelectric ceramics doped with Bi Mn O _ (3) is obtained. The addition of multi-iron material Bi Mn O ~ (3 +) obviously promoted the grain growth, and made the grain boundary more obvious, the grain size was full and round, the porosity decreased, and the density of ceramics increased. When x = 0.015, the maximum value of piezoelectric constant d _ (33) is 210 p C _ (n), the electromechanical coupling coefficient K _ (p) is 0.41, the maximum dielectric constant is 1880 and the dielectric loss is 0.020. Through the analysis of relaxation behavior, it is concluded that there exists dispersion phase transition in the ceramics. The internal relaxation transition is dispersion phase transition. (4) lead-free piezoelectric BNT-BT6.5 ceramics are replaced by complex ions (Fe_ (1) _ (1) Ta_ (1) ~ (2) ~ (4). All the samples formed a single pure perovskite structure. By SEM analysis, the grain size increases first and then decreases with the increase of FT doping content, and the grain boundary is obvious gradually, the porosity decreases, and the piezoelectric ceramics with high density are formed. When the grain size is 0.006, the grain size is the largest, 3 渭 m ~ 6 渭 m, and the grain boundary is obvious, the grain size is uniform and there are no pores. The electrical properties are analyzed. When x = 0.006, the comprehensive properties are as follows: d33 = 225 p C 路N, K = 40%, 蔚 = 1500, tan 胃 = 0.025. The ferroelectric properties show that the coercive field decreases and the residual polarization intensity increases first and then decreases with the increase of FT doping content. When x = 0.006, E_c=30 k V 路cm, P = 33.19 渭 C / cm~2 (5) BNT-BT6.5-PZT composite piezoelectric ceramics are analyzed by XRD. When the doping amount of PZT is less than 0.09, all the samples form a single pure perovskite structure, and when the doping amount of PZT is less than 0.09, all the samples form a single pure perovskite structure. PZT fully enters the lattice of BNT-BT6.5. According to SEM analysis, with the increase of PZT content, the grain size increases gradually, the uniformity of grain size increases, the porosity decreases gradually, the densification increases, and the crystal grains with distinct edges and angles appear to improve the properties of ceramics. The composite piezoelectric ceramics with D33 = 195p C, K = 40%, 蔚 = 1734, tan 胃 = 0.026.BNT-BT6.5-PZT-based composite piezoelectric ceramics are the most valuable research directions when the pressure is 0.06.The results show that the composite piezoelectric ceramics based on D33 = 195p C + N, K = 40%, 蔚 = 1734, tan 胃 = composite piezoelectric ceramics are of great value.
【学位授予单位】：贵州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ174.1

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