K0.5Na0.5NbO3-LiSbO3–BiFeO3无铅压电陶瓷的烧结特性

Sintering Characteristics of Lead-Free K_(0.5)Na_(0.5)NbO_3-LiSbO_3-BiFeO_3 Piezoelectric Ceramics

采用传统无压固相烧结法制备0.996(0.95K0.5Na0.5NbO3-0.05LiSbO3)-0.004BiFeO3[0.996(0.95KNN-0.05LS)-0.004BF]无铅压电陶瓷,着重研究烧结保温时间对陶瓷结构、压电性能与介电性能和Curie温度TC的影响。结果表明:随着烧结保温时间的延长,陶瓷趋于形成更稳定的四方相结构,陶瓷的压电性能指标则先升高后降低,但变化幅度都不大,陶瓷的Curie温度和相对介电常数εr随烧结保温时间的变化也不大,表明该体系陶瓷具有较宽的烧结保温时间范围。在1 100℃烧结3 h,0.996(0.95KNN-0.05LS)-0.004BF无铅压电陶瓷具有较好的综合性能:压电常数d33=262 pC/N,平面机电耦合系数kp=52%,TC=360℃,εr=1 594,介电损耗tanδ=2.12%,表明该体系陶瓷具有良好的实用前景。

0.996（0.95K0.5Na0.5NbO3-0.05LiSbO3）-0.004BiFeO3（0.996（0.95KNN-0.05LS）-0.004BF）lead-free piezoelectric ceramics were prepared by the traditional ceramic processing.Effects of sintering time t on the microstructure,piezoelectric and dielectric properties,and Curie temperature TC of the ceramics were mainly investigated.Results show that with increasing of sintering time,the ceramic has a more stable tetragonal phase structure,and its piezoelectric property data first increase and then decrease.But neither of these changes is very evident,and TC and relative dielectric constant εr of the ceramics do not change demonstrably either.This indi-cates that the ceramics can be well sintered at a wide range of sintering time.When sintered at 1 100 ℃ for 3 h,0.996（0.95KNN-0.05LS）-0.004BF ceramics have good electric properties： piezoelectric constant d33 = 262 pC/N,planar electromechanical coupling factor kp = 52%,TC = 360 ℃,εr = 1 594,dielectric loss tan δ = 2.12%.This indicates that the ceramics have promising prospects for application in many fields.