锆钛酸铅系压电陶瓷使用寿命评价及高性能、高寿命压电陶瓷研发

Lead Zirconate Titanate as one kind of piezo-ceramic, because of its good piezoelectrical properties and low material cost, is widely used in various electro-mechanical equipments. Piezo-ceramic will undergo an electrical degradation process after applying an electrical field, and the degradation process represents as the decrease of the resistance and the decay of the piezoelectrical properties. This electrical degradation phenomenon severely limits the lifetime and the performance of piezoelectrical products. However, the electrical degradation mechanisms have not been completed and the testing methods of the life-time and the reliability of the piezoelectrical samples are based on the investigating on the leakage current through the samples, currently. However, for different samples, their initial resistance and the leakage current when degraded are very different. Therefore, it will be very difficult to evaluate the life-time and reliability based on current methods. This project aims to investigate the micro mechanisms of the black spot formation and the relationship between the black spot formation and electrical degradation process, improving the current mechanisms of electrical degradation, summarize the relationship between the black spot characterizations and the life-time of piezoelectrical samples under vary environment conditions, develop one type of formula and its manufacturing technologies of piezoelectrical ceramic with high electrical properties and life-time.

锆钛酸铅作为压电陶瓷的一种，因其较好的压电性能，低廉的材料成本，被广泛应用于各种电子机械装置。压电陶瓷在电场的作用下会发生电退化现象，表现为电阻值逐渐减小，压电性能衰退。电退化现象严重地影响了压电产品的寿命与性能。但是目前,对于压电陶瓷电退化的理论尚不完善，且对压电陶瓷产品的使用寿命和可靠性的测试和分析主要是通过工作条件下疲劳实验，对样品的漏电流进行评估。但是对于不同的样品而言，它们的起始电阻值、样品失效时的漏电流大小都有可能不同，这使得对压电陶瓷产品的寿命和可靠性评估非常困难。本项目旨在研究黑斑生长的机理以及其与电退化之间的关系，完善现有的电退化理论；并且总结不同环境因素下黑斑生长与压电陶瓷样品的使用寿命之间的联系，并研发出一种具有优异电学性能和使用寿命的压电陶瓷及其生产工艺。

锆钛酸铅基压电陶瓷，因其较好的压电性能，低廉的材料成本，被广泛应用于各种电子机械装置。压电陶瓷在电场的作用下会发生电退化现象，表现为黑斑生长、电阻值逐渐减小、压电性能衰退，严重地影响了压电产品的寿命与性能。本项目旨在研究黑斑生长的机理以及其与电退化之间的关系，完善现有的电退化理论；并且总结不同环境因素下黑斑生长与压电陶瓷样品的使用寿命之间的联系，并研发出一种具有优异电学性能和使用寿命的压电陶瓷及其生产工艺。. 本项目研究发现，压电陶瓷在直流场下的电退化受载流子种类影响显著，如银离子、氢离子和氧离子等会形成快离子电导，显著加速电退化过程。电退化过程中无明显化学反应发生，但由于物理上的晶粒混乱排列，导致黑斑生长。因此，电退化和黑斑生长对压电常数、介电常数、居里温度、晶粒阻抗等参数无明显影响，但会使陶瓷介电损耗由明显增大。此外，探索了提升压电陶瓷产品工作寿命的制备工艺和配方改进方法，并在实验数据和理论依据基础上，提出了压电陶瓷受温度、湿度、电场等外界因素影响的寿命预测公式，这为压电陶瓷在直流场下应用的寿命预测提供了科学依据，并对压电陶瓷工作寿命提升提供了可行方案。