0-3 PZT/PVDF 压电复合材料的制备及其性能

采用溶液混合法制备PZT/PVDF压电复合材料。首先用水热法制备出适合溶液混合的PZT陶瓷粉末,并根据陶瓷粉末对PVDF的吸收量,选择乙醇作为PVDF的溶剂进行混合,然后烘干制备PZT/PVDF复合粉末,再成型极化。实验结果表明,这种复合方法提高了PZT陶瓷颗粒在PVDF有机基体中的分散度,使材料内部均匀,结构致密,从而提高了PZT/PVDF压电复合材料的压电和介电性能。      

压电陶瓷粒度分布对锆钛酸铅/聚偏氟乙烯复合材料电性能的影响

将不同粒度的锆钛酸铅(PZT)陶瓷粉进行复配,制成不同粒度分布的PZT陶瓷颗粒,然后与聚偏氟乙烯(PVDF)复合制备不同PZT粒度分布的PZT/PVDF复合材料,研究了复合材料的介电性能和压电性能。结果表明,当陶瓷颗粒体积分数高达70%时,双峰分布复合材料的压电系数可达75 pC·N-1。这是由于双峰分布复合材料中大陶瓷颗粒保持了完整的钙钛矿结构,小陶瓷颗粒填充在大颗粒之间,陶瓷颗粒彼此联接,形成了更多的电-力耦合通道,有效地实现了压电效应的传递。大陶瓷颗粒完整的钙钛矿结构以及大、小颗粒的协同堆砌效应,提高了PZT/PVDF复合材料的电性能。     

改性PZT/PVDF体系压电复合材料的介电和压电性能

采用复合材料模压工艺,制备了体积分数不同的改性PZT(含铌的钛锆酸铅)/PVDF(聚偏二氟乙烯)压电复合材料。采用扫描电镜对材料的形貌进行了分析,并利用HP4294A,Z-3A型准静态测试仪等系统地研究了改性PZT体积分数对材料介电、压电性能的影响。结果显示,在改性PZT体积分数为70%时,获得了性能优良的压电复合材料。在压电陶瓷高含量区(>0.5),部分压电陶瓷颗粒相互联接,形成了类似0-3(3-3)型复合连通形式,是复合材料获得优良压电、介电性能的主要原因。     

0-3型PZT/PVDF压电复合材料制备及性能研究

利用固相法制备了掺杂有Nb2O5的PZT95/5压电陶瓷,采用固化、冷等静压、溶液混合法制备0-3型PZT/PVDF压电复合材料,经过对这几种方法的分析、比较后发现溶液混合法制备的样品中PZT微粉的分散性要优于前两种制备方法;这几种制备方法中PVDF均有晶相转变,但没有较为明显的β相PVDF存在,对复合材料的电性能的影响不大.     

PZN-PZT压电陶瓷及其PVDF压电复合材料的制备和性能

采用固相烧结法合成了PZN-PZT(铌锌锆钛酸铅)三元系压电陶瓷烧结块材和粉末,并采用XRD、SEM等测试方法对其结构和性能进行了分析。PZN-PZT常压烧结陶瓷具有优良的压电性能,PZN-PZT颗粒粒径在0.5~4 μm之间,颗粒形态不太规整。采用溶液共混法将PZN-PZT粒子均匀分散于PVDF基体中,制备了PZN-PZT/PVDF 0-3型压电复合材料。研究了PZN-PZT质量分数、极化电场等因素对该压电复合材料压电和介电性能的影响。实验结果表明,选用压电活性更高的压电陶瓷粉末进行复合,可有效提高压电复合材料的压电性能。增加PZN-PZT质量分数、提高极化电压均有利于复合材料压电性能的提高。     

高介电常数PVDF/PZT/Terfenol-D复合材料的介电性能研究

以聚偏氟乙烯(PVDF)为聚合物基体,PZT为陶瓷相,稀土铁合金粒子Tedenol-D为添加组分,运用聚合物熔融压片法制备了聚合物体积含量为30%的0.3PVDF/(0.7-f)PZT/fTerfenol-D三相复合材料.研究了Tedenob-D的体积含量、频率对复合材料介电性能的影响.结果显示:Tedenol-D粒子的加入,可以提高0.3PVDF/0.7PZT复合材料的介电常数,PVDF/PZT/Terfenol-D复合材料具有介电常数高、介电损耗小的特点.     

镧掺杂PZN-PZT陶瓷及其PVDF压电复合材料的制备与性能

采用固相烧结法合成了不同镧掺杂量的PZN-PZT压电陶瓷和粉体．并用XRD分析了陶瓷的晶相，扫描电镜观察到PZN-PZT陶瓷粉体形态不太规整，颗粒粒径主要分布在1～4μm之间．将PZN-PZT粒子均匀分散于PVDF基体中，制备了PZN-PZT/PVDF压电复合材料．研究了镧掺杂量对PZN-PZT陶瓷及复合材料压电性能的影响．结果表明，适量的镧掺杂可有效提高复合材料的压电性能，当镧掺杂量为4％（摩尔分数）时，复合材料的压电性能最好，压电常数d33值为36pC/N。     

颗粒分散型纳米复合材料的研究

采用溶胶-凝胶法制备了粒径为30～50nm锆钛酸铅PZT纳米压电粉体.将PZT纳米粉分散于环氧树脂中得到具有0-3连通性的颗粒分散型纳米复合材料.讨论了影响PZT纳米粉体合成、纳米粉体分散均匀性和压电复合材料性能的主要因素,包括pH值、粘度、超声波分散与柠檬酸三铵分散、PZT纳米粉的含量等.     

0-3型PZN-PZT/PVDF压电复合材料的制备工艺条件优化

采用固相法合成了性能良好的PZN-PZT陶瓷粉体.将压电陶瓷粉体分散于PVDF基体中,制备了0-3型PZN-PZT/PVDF压电复合材料.研究了复合材料的复合工艺、极化参数与压电陶瓷的含量对复合材料压电性能的影响.结果表明,溶液混合工艺较好,且当极化电场强度为6kV·mm-1、温度为110℃进行极化20min时,陶瓷粉体质量分数为90%的复合材料的压电性能最好,压电常数d33值达35.9 pC·N-1.     

0-3型陶瓷/聚合物压电复合材料的压电性能研究

采用溶液共混法和热压法分别制备了PZN-PZT/PI、PZN-PZT/PVDF 0-3型压电复合材料,所得材料具有较高的压电常数和良好的可柔性加工性能。并研究分析了无机压电陶瓷种类、含量,压电聚合物类型、制备工艺与极化参数对压电系数d₃₃的影响,在一定程度上提供了提高0-3型聚合物/陶瓷压电复合材料的压电性能的途径。      

PZT/P VDF 压电复合材料的制备及其性能研究

用氧化物一步合成法制备了PZT 粉末, X 射线衍射测试结果显示, 它是Zr/T i 为52∶48 的纯四方钙钛矿型结晶相, 并用SEM 观察了PZT 粉末的形貌; 用热分析仪测试了PVDF 的固化温度; 在自制模具上采用模压/烧结工艺获得了六种含PZT 不同体积含量的PZT/ PVDF 复合材料; 对其介电性和压电性的测试表明, 随着PZT体积含量的增加, 电性能参数呈非线性增大, 当PZT 的体积份数超过70% 时, 介电常数E和压电常数d₃₃值迅速增加, PZT 体积份数达到90% 时, 其电性能参数与纯PZT 值接近, 但此时复合材料的脆性较大, 已没有实用价值。     

25 MHz ultrasonic transducers with lead- free piezoceramic, 1-3 PZT fiber-epoxy composite, and PVDF polymer active elements

This paper presents the fabrication and characterization of single-element ultrasonic transducers whose active elements are made of lead-free piezoceramic, 1-3 PZT/polymer composite and PVDF film. The lead free piezoelectric KNNLT- LS(K_0.44Na_0.52Li_0.04)(Nb_0.84Ta_0.10S_0.06b)O₃ powders and ceramics were prepared under controlled humidity and oxygen flow rate during sintering. Due to its moderate longitudinal piezoelectric charge coefficient (175 pC/N) and k_t of 0.50, the KNN-LT-LS composition may be a good candidate for highfrequency transducer applications. PZT fibers with 25 μm diameter formed by the viscose suspension spinning process were incorporated into epoxy to fabricate 1-3 composites with the averaged k_t = 0.64 and d₃₃ = 400 pC/N. Using KNN-LS-LT ceramic, 1-3 PZT fiber composite, and PVDF film, 3 different unfocused single element transducers with center frequencies of 25 MHz were fabricated. The acoustic characterization of the transducers demonstrated that wideband and low insertion loss could be obtained employing KNN-LS-LT ceramic. The ?6 dB bandwidth and insertion loss were 70% and ?21 dB, respectively. In comparison, the insertion loss of the ceramic transducer was much smaller than those made with 1-3 composite and PVDF film. This was attributed to closer electrical impedance match to 50 Ω and higher thickness coupling coefficient of the ceramic transducer.     

Influence of polarization on properties of 0–3 cement-based PZT composites

In this paper, studies on a new 0–3 type cement-based PZT (lead zirconate titanate) composite are presented. Using a normal mixing and compacting method, up to 50 vol.% PZT ceramic powder can be easily incorporated into the composites. The behaviors of the cement-based PZT composites under different polarizing conditions have been investigated on the piezoelectric properties both theoretically and experimentally. It shows that cement-based PZT composites have their own unique characteristics. There is a good potential for the application of 0–3 type cement based piezoelectric composites in civil engineering.     

Microwave Hydrothermal Synthesis PZT of Nanometer Crystal

It was focused on the applications and developments of microwave hydrothermal synthesis piezoelectric ceramic powder. The microwave hydrothermal vessel was designed and manufactured. The microwave hydrothermal synthesis system was established and the PZT piezoelectric ceramic powder was synthesized. XRD and TEM have been used to characterize the products in detail. The diameter of the PZT powder particle is from 40 to 60 nm.     

具有大驱动位移的复合结构型PZT压电陶瓷

采用PZT作为基体材料,通过化学还原的方法制备了具有大位移驱动能力的复合结构型压电陶瓷。研究了其预制应力的分布,探索了还原制备工艺,测试了驱动性能。结果表明,复合结构的优化设计方案是,还原层厚度比率为0.3;与普通压电陶瓷驱动器相比,复合结构型PZT压电陶瓷具有较低的谐振频率,驱动位移量提高3倍多;还原层相结构中存在二次氧化的基体相,表明其还原工艺仍需改进。      

Piezoelectric composites of PZT and some semi-crystalline polymers

Piezoelectric composites of PZT ceramics and several semi-crystalline polymers have been produced by embedding slender PZT rods (4 volume percent) in the polymers. The observed dielectric constants were considerably lower than that of pure PZT. The hydrostatic piezoelectric voltage coefficients of the composites were larger than PZT, even though the composite hydrostatic piezoelectric strain coefficients were lower. Composite figures of merit ranged from one-third to six times that of PZT.     

Performance enhancements in poly(vinylidene fluoride)-based piezoelectric films prepared by the extrusion-casting process

The extrusion-casting process can realize large-area and continuous preparation of polymer-based films. In this paper, five different types of polyvinylidene fluoride (PVDF)-based piezoelectric films: PVDF, PVDF/PZT, PVDF/PZT@105, PVDF/PZT/BNNS and PVDF/PZT@105/BNNS were prepared by the extrusion-casting process. The mechanical, dielectric, thermal conductivity and piezoelectric properties were studied. It is found that PZT particles can well improve the dielectric performance and also the mechanical stability under variable temperature conditions. PZT powders modified by titanate coupling reagent (UP-105) can further improve the performance of the PVDF/PZT@105 films by improving the combination and dispersion of organic and inorganic phases. The addition of boron nitride nanosheets (BNNS) can improve the thermal conductivity of the films and the breakdown strength. The piezoelectric coefficient (d₃₃) of PVDF/PZT@105/BNNS composite film can reach 21pC/N, compared with the neat PVDF film (4pC/N) and PZT/PVDF (9pC/N) film realizing great improvement.