压电复合材料中组元介电性对其性能的影响

Effect of Componential Dielectric Properties on the Properties of Piezoelectric Composites

用PVDF分别与5种具有不同介电常数的陶瓷粉体:PMN、PNL、PLS、P4 3、P8制备压电复合材料。首先,将PVDF用N ,N 二甲基甲酰胺溶解,加入一定体积比例的陶瓷粉体,搅拌状态下烘干,热压成片状,旋涂银电极,极化,最后测量其压电和介电性能。研究陶瓷组元介电性能和复合材料性能的关系。结果表明:在极化过程中陶瓷组元的低介电性有助于增强其所分担的极化电场,提高其极化率,制备出性能优良的压电复合材料。通过实验和理论计算,得出复合材料介电常数随陶瓷相体积分数的变化趋势。

Piezoelectric composites was fabricated by using PVDF and five kinds of ceramic powder of different dielectric constant: PMN, PNL, PLS, P4-3, P8. Firstly, using N, N-Dimethyl formamide to dissolve PVDF, adding a certain proportion ceramic powder and drying it. After that, the mixture could be hot-pressed, polarization. At last their piezoelectricity and permittivity were tested. The relationship between permittivity of ceramics and properties of composites were investigated. The experimental results showed that low dielectric coefficient of ceramic could increase the polarization percentage when composites were polarized. Finally, the composites with excellent properties were made. The experimental and theoretic results proved that permittivity of composites increased with volume fractions of ceramic increasing.