复合工艺对压电复合材料性能的影响

采用直接混合和溶液混合两种不同的复合工艺,将铌锌锆钛酸铅（PZN—PZT）压电陶瓷粉体分散于有机聚偏二氟乙烯（PVDF）基体中,制备了0—3型PZN—PZT／PVDF压电复合材料。研究了复合工艺对压电复合材料性能的影响。结果表明,采用溶液混合法能有效地改善陶瓷的分散性及复合材料的压电性,当陶瓷质量分数为90％时,压电复合材料的压电常数d33达到33．4pC·N^-1。     

陶瓷-聚合物相压电复合材料研究进展

本文介绍了陶瓷-聚合物相压电复合材料的研究进展及其性能的影响因素.从陶瓷压电相的性能和复合材料的微观结构出发分别综述了0-3、1-3型陶瓷-聚合物相压电复合材料的制备工艺及其对性能的影响.重点介绍了陶瓷压电粉体最新合成方法的进展情况。     

陶瓷粉体粒度对PZN—PZT／PVDF压电复合材料性能的影响

将铌锌锆钛酸铅（PZN—PZT）压电陶瓷粉体分散于聚偏二氟乙烯（PVDF）基体中,制备出0-3型PZN—PZT／PVDF压电复合材料。文中研究了PZN—PZT陶瓷不同粒度对复合材料的压电性、介电性、铁电性的影响。结果表明,当陶瓷粒度为100～150目时,压电复合材料的综合性能最佳,压电常数d33达到23．10pC／N,剩余极化强度Pr达到5．131μC·era2,矫顽场Ec为45．7lkV·cm^-1,介电常数ε。为192．86,介电损耗tanδ为0．10。     

不同压电陶瓷体积分数对1-3-2型压电复合材料性能的影响

以环氧树脂为基体,铌镁锆钛酸铅[0.375Pb(Mg1/3Nb2/3)O3·0.375PbTiO3·0.25PbZrO3,PMN]为压电功能体,采用切割-浇注法制备了1-3-2型压电复合材料.分析讨论压电陶瓷体积分数(φ,下同)对1-3-2型压电复合材料压电性能、介电性能及声阻抗的影响.结果表明:随着PMN的φ的增加,复合材料的压电应变常数(d33)和声阻抗(2)增大;相对介电常数(εr)几乎呈线性增加,且当PMN的φ为47.47%时,复合材料的εr=1 660,远小于纯PMN陶瓷的(εr=4000).压电电压常数(g33)及介电损耗(tan δ)则呈下降趋势;与PMN相比较,1-3-2型压电复合材料厚度方向的谐振明显增强,机械品质因数(Qm)显著降低;随着PMN的φ的增加,复合材料的平面机电耦合系数(Kp)减小,而厚度机电耦合系数(Kt)增加.     

基于1-3型压电单晶复合材料的高频宽带发射换能器

1-3型压电单晶复合材料结合弛豫铁电单晶与复合材料的优势,具有压电常数高、机电耦合系数极大、声阻抗低等特点,是理想的高频发射换能器压电元件.基于1-3型压电单晶复合材料设计并研制了高频宽带发射换能器,根据理论计算分析了压电单晶复合材料的性能特点,利用有限元建模仿真优化了换能器结构,研制的1-3型压电单晶复合材料发射换能...     

PZT/PVDF体系压电复合材料的介电和压电性能研究

采用复合材料热压工艺,制备了0-3型PZT/PVDF(钛锆酸铅/聚偏二氟乙烯)压电复合材料。系统地研究了PZT体积分数对材料介电、压电性能的影响,并与Furukawa等人的理论预测进行了对比。结果显示在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,部分压电陶瓷颗粒相互联接,形成了类似0-3(1-3)型连通形式,获得了压电和介电性能优良的压电复合材料。     

铅含量对0-3型PZN-PZT/PVDF压电复合材料性能的影响

通过固相烧结法制备PZN-PZT压电陶瓷,采用溶液共混法将PZN-PZT陶瓷粉均匀分散于PVDF有机基体中,制备了PZN-PZT/PVDF 0-3型压电复合材料,测试并研究了材料的性能。实验结果表明,适量的铅过量可以有效抑制焦绿石相的生成,但含铅量过高会降低主晶相的结晶程度,从而影响最终制备的压电复合材料的性能。通过实验得出用Pb过量1.5%的压电陶瓷制备的压电复合材料的性能最好。     

环境湿度对1-3型水泥基压电复合材料性能的影响

用切割-填充法,以硫铝酸盐水泥为基体,铌镁锆钛酸铅[Pb(Mg1/3Nb2/3)O3·PbTiO3·PbZrO3](PMN)为压电功能体制备了1-3型硫铝酸盐水泥基压电复合材料.研究了环境湿度对1-3型水泥基压电复合材料的压电性能和介电性能的影响.结果表明随着相对湿度的增大,压电电压常数g33与机械品质因数Qm 呈非线性减小.湿度对压电应变常数d33以及机电耦合系数Kp和Kt的影响较小.在低频和高频段,当相对湿度低于85%时,介电常数εr基本不受湿度的影响,表现出良好的介频稳定性.     

微细1-3型PZT/环氧树脂压电复合材料的制备及其性能

提出了一种改良型切割-浇注工艺,并利用该工艺制备了锆钛酸铅(lead zirconate titanate,PZT)柱宽为120μm,纵横比大于10的1-3型PZT/环氧树脂压电复合材料,并对制备过程中影响复合材料特性的各种影响因素进行了讨论比较.结果表明:这种复合材料的谐振模式单一,与PZT相比声阻抗大幅降低,前者为31Mrayl,后者仅为4.5～5.5Mrayl.     

压电陶瓷PZN-PZT对压电复合材料性能的影响

本研究采用固相烧结法合成了PZN-PZT压电陶瓷粉体,并用XRD分析了其晶相组成。将PZN-PZT陶瓷粉体与PVDF复合,制备出PZN-PZT/PVDF0-3型压电复合材料,研究了陶瓷质量分数对复合材料铁电性、介电性及压电性的影响。结果表明,复合材料的铁电性、介电性和压电性能随陶瓷含量的增加而增强,当陶瓷含量为90%时,复合材料的剩余极化强度Pr达到5.27μC·cm-2,矫顽场EC为76kV·cm-1,介电常数εr为188,介电损耗tanδ为0.065,压电常数d33则达到33.4pC/N。     

Properties of 0–3 Lead Zirconate Titanate–Polymer Composites Prepared in a Centrifuge

The purpose of this work was to present the electrical and piezoelectric properties of the 0-3 piezoceramic–polymer composites prepared by spinning the lead zirconate titanate (PZT) powders with polyester resin in a centrifuge. PZT powders with average sizes of 55 and 160 μm were used and mixed in the resin with different volumetric percentages. The dielectric and piezoelectric properties such as permittivity, loss angle, electromechanical coupling factor, and piezoelectric coefficient were measured. The mechanical quality factor was calculated. The acoustic impedance was accessed by the echo-shift method. The results were analyzed and fit to mechanical models. Distribution of the ceramic particles in the polyester-resin phase was examined by scanning electron microscopy. Smaller-ceramic-particle composites seemed to form denser samples. Most of the properties showed linearly varying as the volumetric percentage of the ceramic phase. The fabrication using the centrifuging techniques resulted in more homogeneity of the ceramic and polymer phases, and the fabricated samples could be loaded up to 65% or more with the ceramic powders.     

三维编织压电陶瓷基复合材料有效电弹性性能有限元分析

基于三维编织预制件的细观结构,建立了三维编织压电陶瓷基复合材料位移-电耦合场有限元模型,利用电弹性场体积平均思想和有限元方法研究了周期分布三维编织压电陶瓷基复合材料的有效电弹性性能。通过对代表性体积单元施加位移载荷和电载荷边界条件,预测了不同纤维体积分数下三维编织压电陶瓷基复合材料的有效弹性常数、压电常数和介电常数。计算结果表明,三维编织压电陶瓷基复合材料可显著改善压电陶瓷的整体力学性能,且保持了较好的电学性能。     

Fabrication and Characterization of the Piezoelectric Ceramic–Polymer Composites

The modified sol–gel method was used to synthesize lead zirconate titanate nanoparticles, and the lead zirconate titanate nanoparticles and polyvinylidene fluoride were used to prepare piezoelectric nano‐ceramic–polymer composites with 0–3 connectivity type. The composites were successfully prepared by cold‐pressing and curing‐molding methods. X‐ray diffraction and scanning electron microscopy were adopted to characterize the microstructure of the obtained lead zirconate titanate nanoparticles and composites. The normal vibration modes of the lead zirconate titanate nanoparticles were investigated by Fourier transform infrared spectroscopy. The dielectric and piezoelectric properties of the composites were analyzed in detail with respect to different volume fractions of the lead zirconate titanate nanoparticles. It demonstrated that the values of d₃₃ and ε increased with the increase in the content of lead zirconate titanate. The results here pointed to potential and simple methods to fabricate the lead zirconate titanate nanoparticles and the piezoelectric ceramic–polymer composites for piezoelectric applications.     

Electromechanical coupling coefficient and acoustic impedance of 1-1-3 piezoelectric composites

1-1-3 piezoelectric composites consisting of a PZT-5H ceramic, an epoxy resin matrix and a silicone rubber filler were prepared using a modified 'slice and fill' method. The effect of the ceramic volume percentage on the properties of the composite was analyzed both through experiments and simulations. By adopting the 1-1-3 structure, the electromechanical coupling coefficient of the piezoelectric composites could be increased to 0.69, and the acoustic impedance reduced to 6.81. The experimental results further showed that the variation of the ceramic volume percentage had no effect on the electromechanical coupling coefficient of the composites, but only affected the acoustic impedance. The presented piezoelectric composites can be used to design high-performance transducer.     

冲击载荷下2-2型水泥基压电复合材料力电响应特性

研究2-2型水泥基压电复合材料在冲击载荷下的力电响应特征,利用分离式Hopkinson压杆装置进行冲击加载,借助超高速摄影技术观察试样在冲击载荷下的破坏形貌。结果表明:冲击载荷下,压电复合材料具有明显的应变率效应,是应变率敏感材料;压电复合材料的力电响应存在一个临界值,当应力小于该临界值时,试样的电信号与施加载荷之间具有良好的线性关系;动态增强因子可以有效描述压电复合材料压缩强度的率效应规律,在线性范围内,随着应变率的增大,试样的动态增强因子也增大,且具有稳定的增长率;由Maxwell模型得到的压电复合材料应力松弛时间随应变率增大单调递减;冲击载荷下,2-2型水泥基压电复合材料与压电陶瓷的电学失效发生在力学失效之前,且均呈现“爆炸式”破碎,压电陶瓷还伴随着明显的电弧放电现象。     

Novel 1–3 (K,Na)NbO3-based ceramic/epoxy composites with large thickness-mode electromechanical coupling coefficient and good temperature stability

The 1–3 piezoelectric composites are an important type of artificial functional materials for ultrasonic transducers. Currently, there are increasingly strong demands to replace the lead-containing materials. Excellent 1–3 0.96(K_0.48Na_0.52) (Nb_0.96Sb_0.04)O₃?0.03BaZrO₃?0.01(Bi_0.50Na_0.50)ZrO₃ ceramic/epoxy (abbreviated hereafter as KNNS-0.03BZ-0.01BNZ/epoxy) piezoelectric composites were prepared by a modified dice-and-fill technique. Compared to the monolithic KNNS-0.03BZ-0.01BNZ ceramic, the developed composites possess much larger electromechanical coupling coefficient k_t of 0.54–0.67 and piezoelectric voltage coefficient g₃₃ of 64–91 × 10^?3 Vm/N. In addition, these composites also possess other favorable properties such as low values of acoustic impedance Z of 6.9–13.4 Mrayl, dielectric coefficient ε₃₃ of 130–400 and mechanical quality factor Q_m of 1.3–4. More importantly, k_t is weakly temperature-dependence in the common usage temperature range between ?30 °C and 100 °C. The result indicates that the 1–3 KNNS-0.03BZ-0.01BNZ/epoxy piezoelectric composites have a great potential for high-frequency ultrasonic transducers.