高性能铌酸钾钠基无铅压电陶瓷温度稳定性研究

项目名称： 高性能铌酸钾钠基无铅压电陶瓷温度稳定性研究

项目编号： No.50802038

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 金属学与金属工艺

项目作者： 臧国忠

作者单位： 聊城大学

项目金额： 22万元

中文摘要： 本项目采用传统的电子陶瓷固溶烧结工艺，研制出温度稳定性较高的铌钽酸盐无铅压电陶瓷。通过两步法制备工艺，大幅度展宽了KNN基陶瓷两相共存的温度范围，其中制备的(Na0.52K0.435Li0.045)Nb0.87Sb0.08Ta0.05O3陶瓷d33高达350pC/N以上， 介电损耗仅为1.8%，且在-40℃#65293;80℃#28201;度范围内，d33的变化低于15%。已超过本基金申请书预期成果（-40℃#65293;80℃#20869;，压电常数d33在300pC/N以上，介电损耗tan?小于2%）的目标。同时，提出了一些寻找KNN基压电陶瓷准同型相结构的新方法，研究发现，(Na0.65K0.35)NbO3陶瓷室温下也存在两相共存的结构，且压电性能与(Na0.5K0.5)NbO3陶瓷相近，是值得深入研究的另一体系。研究还发现，通过构造五价元素进行B位替代，可大幅度提高材料的压电常数，尤其是平面机电耦合系数。另外，本项目对(Bi0.5Na0.5)TiO3、BaTiO3无铅压电陶瓷体系也做了一定的研究，取得了一些较好的研究结果。

中文关键词： 无铅压电陶瓷；温度稳定性；压电应变常数；准同型相界

英文摘要： Lead-free KNN piezoceramics with high performance and good temperature stability were fabricated by the solid-state sintering processing. The temperature range for the coexistence of two phases was broadened through a two-step preparing technology and a piezoelectric strain constant d33 higher than 350 pC/N, a dielectric loss tan? as low as 1.8% were obtained for (Na0.52K0.435Li0.045)Nb0.87Sb0.08Ta0.05O3 ceramics. Even more, the variation of d33 was lower than 15% during -40℃80℃which is better than expected in the project application (-40℃80℃#65292;d33 higher than 300pC/N, tan? lower than 2%). During the research process, some new methods for searching new morphotropic phase boundary (MPB) structure were proposed and similar to (Na0.5K0.5)NbO3, it was found that the (Na0.65K0.35)NbO3 ceramics have MPB structure and good piezoelectrical properties and, this composition is another promising lead-free candidate for investigation besides (Na0.5K0.5)NbO3 system. For KNN ceramics, doping with constructed quinquevalent element at B site can greatly enhance the piezoelectric constants especially the electromechanical coupling coefficient. In addition, some research work have also been done on (Bi0.5Na0.5)TiO3、BaTiO3 lead-free ceramics and some good results were obtained.

英文关键词： Lead-free piezoceramics; Temperature stability;piezoelectric strain constant;morphotropic phase boundary