锆钛酸铅压电陶瓷元件高温老化行为及其微观机制  

High-temperature Aging Behavior of Lead Zirconate Titanate Piezoelectric Ceramic Components and the Corresponding Micro-mechanism

作　　者：王旋 宋凯强 张敏[1] 丛大龙[1] 彭冬 丁星星 白懿心 黄安畏 李忠盛[1] WANG Xuan;SONG Kaiqiang;ZHANG Min;CONG Dalong;PENG Dong;DING Xingxing;BAI Yixin;HUANG Anwei;LI Zhongsheng(Southwest Institute of Technology and Engineering,Chongqing 401329,China)

机构地区：[1]西南技术工程研究所,重庆401329

出　　处：《材料导报》2023年第18期31-38,共8页Materials Reports

摘　　要：长时高温作用会显著加速压电陶瓷元件电学性能的退化,极大地影响压电元件使用寿命。本工作在85、125和150℃下对PZT压电陶瓷元件进行长时老化处理,研究并分析了高温老化过程中PZT陶瓷元件电学性能退化规律及其微观机制。压电常数与介电常数随老化周期延长均退化明显,初期退化速率较慢,后期退化加快并逐渐趋于稳定,介电常数和压电常数退化均符合Boltzmann变化规律。85℃和125℃下老化49 d时,元件介电常数退化率达到最大,分别为31.01%和36.48%;压电常数退化率达到最大,分别为11.57%和19.02%。PZT压电元件介电性能退化主要由表面Ag电极内结构退化、Ag/PZT界面弱化及PZT陶瓷退极化三方面所贡献,其中界面弱化和陶瓷退极化占主导。长时高温作用促使Ag电极逐渐缓慢氧化生成Ag2S,晶粒收缩产生大量孔洞,导致Ag电极致密度下降和Ag/PZT界面分层,降低了Ag/PZT的电容率;此外,长时高温作用加速了PZT陶瓷电畴转向无序状态,促进氧空位位移钉扎电畴壁,导致了PZT压电元件介电性能退化。Long-term exposure to high temperature considerably accelerates the degradation of the electrical properties of piezoelectric ceramic components,which greatly affects their service life.In this study,lead-zirconate-titanate(PZT)piezoelectric ceramic components were subjected to long-term aging treatment at 85,125,and 150℃,and the degradation law and micro-mechanism of the electrical properties of the PZT ceramic components were studied and analyzed during the high-temperature aging.The piezoelectric and dielectric constants both degraded significantly with an extended aging cycle.The initial degradation rate was slow,whereas the later degradation accelerated and gradually stabilized.The rates of degradation of the dielectric and piezoelectric constants both conformed to the Boltzmann law.The maximum dielectric constant degradation rates reached 31.01%and 36.48%,and the maximum piezoelectric constant degradation rates reached 11.57%and 19.02%at 85℃and 125℃,respectively,after aging treatment for 49 days.The dielectric performance degradation of the PZT piezoelectric components was mainly attributed to the following:degradation of the internal structure of the Ag electrode on the surface,weakening of the Ag/PZT interface,and depolarization of the PZT ceramic,with the latter two being the dominant factors.The long-term high-temperature effect promoted the gradual and slow oxidation of the Ag electrode in generating Ag2 S,and crystal grain shrinkage produced numerous pores.This in turn led to a decrease in the density of the Ag electrode and delamination of the Ag/PZT interface,which reduced the permittivity.In addition,the long-term high temperature accelerated the process whereby PZT ceramic domains were transformed into disordered states.It also promoted the displacement of oxygen vacancy to pin the domain wall and led to complete degradation of the dielectric performance of the PZT piezoelectric components.

关 键 词：Ag电极 PZT陶瓷 高温老化行为 表面氧化 界面弱化 退极化 

分 类 号：TM282[一般工业技术—材料科学与工程]