【作者】 徐青；

【导师】 孙清池；

【作者基本信息】 天津大学 ， 材料学， 2014， 硕士

【摘要】 近年来，由于压电马达、压电变压器、压电换能器以及超声电机的普遍使用，大功率压电陶瓷材料逐渐成为了近期的研究热点。本文旨在探讨研制超声电机用大功率低损耗压电陶瓷，要求材料不仅具有较好的压电介电性能，而且具有低的介电损耗。为了实现上述要求，实验选取一种性能较好的三元系锑锰锆钛酸铅PMS-PZT压电陶瓷配方，在此基础上进行掺杂改性、制备工艺等方面的研究。本文采用传统固相法制备了Pb1.02(Mn1/3Sb2/3)x(Zr0.47Ti0.48)(1-x)/0.95O3三元系压电陶瓷，讨论了不同的锰锑掺杂量对体系综合性能的影响，结合X射线衍射（XRD）对试样的晶相分析，以及由扫描电子显微镜（SEM）观察到的试样表面微观形貌，断定：该体系压电陶瓷的准同型相界位于x=0.05附近，此时获得最佳的综合性能：压电系数d33=340pC/N，机械品质因数Kp=0.585，相对介电常数εT33/ε0=1369，介电损耗tanδ=0.31%，居里温度Tc=320℃。在上述配方Pb1.02(Mn1/3Sb2/3)0.05Zr0.47Ti0.48O3的基础上，对体系进行了制备工艺的探索和优化。具体包括：极化工艺、合成方法、成型方式。最佳的极化条件为：3kV/mm的极化电场，140℃硅油中极化20min，保压降温至120℃，选取合适的极化条件能有效地提升压电陶瓷的压电介电性能；传统固相氧化物是最佳的合成方法，简单易行，且能获得优异的性能；最佳的成型方式为冷等静压成型，成型压力为360MPa，与干压成型样品相比，冷等静压成型样品具有较小的晶粒和较高的密度，使材料的介电损耗大幅度的降低，进一步实现了综合性能的提升。工艺的改进使体系的性能进一步提升，各项参数为：d33=353pC/N，tanδ=0.20%，εT33/ε0=1659。本文还对上述配方进行了掺杂改性的研究。探讨了二氧化铈（CeO2）的掺杂含量对性能的影响，实验表明CeO2在该体系中表现为硬性掺杂，对性能无明显的提升作用，仅使介电损耗tanδ有微小的下降；研究了两种烧结方式：正立式和倒扣式，对CeO2掺杂的PMS-PZT的性能的影响；对体系进行了钙铁氧化物的掺杂，适量钙铁氧化物的加入能保证体系具有较好的压电介电性能，且能在一定程度上提高体系的居里温度。更多还原

【Abstract】 Recently, research works on high-power piezoelectric ceramics become aninteresting and popular topic due to their increasing application in piezoelectricmotors, transformers, piezoelectric transducers and other fields. Consequently, it isdesirable for high-power piezoelectric ceramics to be possessed with excellentcomprehensive performances, specifically, a low dielectric loss, a high mechanicalquality factor, a high piezoelectric constant and a high planar coupling factor. In orderto achieve that goal, a kind of PMS-PZT ternary system piezoelectric ceramic withgood properties was selected. The doping effect and preparation technology were alsostudied in the paper.Pb1.02(Mn1/3Sb2/3)x(Zr0.47Ti0.48)(1-x)/0.95O3(with composition x=0.01,0.03,0.05,0.07)ceramics were fabricated through a conventional solid-state reaction method. Then,the effect of MnSb content to the performance was studied. Besides, in considerationof the sample phase measured by X-ray diffraction (XRD), and the surfacemicrostructure by scanning electron microscope (SEM), we can deduced that TheMorphotropic Phase Boundary (MPB) in PMS-PZT system was observed near theregion of x=0.05. The optimum comprehensive properties turned out to be:piezoelectric coefficient d33=340pC/N, mechanical quality factor Kp=0.585, dielectricloss tanδ=0.31%, relative dielectric constant εT33/ε0=1369, and Curie temperatureTc=320℃.The effect of poling technique, two kind of pressing methods and differentsynthesized methods were researched about the material with the best formula. Theoptimized dc electric field was3kv/mm and best polarization temperature were140℃.After poling in that condition for20minutes, lower the temperature to120℃andremove the polarization electric field in the end. The study of poling technique showthat increasing poling temperature is an effective method to improve polarization.Experiments results showed that the traditional oxide method was beneficial forexcellent properties. Compared with dry pressed ceramics, the ceramics through coldisostatic compaction have smaller crystal grain and higher density, and thus optimizedielectric properties and piezoelectric properties. Cold isostatic compaction wasconcluded as the appropriate molding method in our experiment, and the best moldingpressure was360MPa. The property parameters are listed as follows: d33=353pC/N,εT33/ε0=1659, tanδ=0.20%. In the end, the doping modification of cerium oxide (CeO2) and2CaO-Fe2O3onPb1.02(Mn1/3Sb2/3)0.05Zr0.47Ti0.48O3piezoelectric ceramics were also carried outrespectively. Specifically, the influence of CeO2content was studied, and theexperiment showed that CeO2served as the hard dopant in this system. In addition,the influence of sintering methods on properties were also studied aboutPb1.02(Mn1/3Sb2/3)0.05Zr0.47Ti0.48O3ceramics doped with CeO2. Specimens sintered in anerected crucible turned out to have better comprehensive performance than those in anupturned crucible. The research of PMS-PZT doped with different content of2CaO-Fe2O3can be concluded that the moderate content of2CaO-Fe2O3couldimprove Tc of PMS-PZT.更多还原