流延法制备铌酸钾钠基无铅压电陶瓷的性能研究

Research of Potassium-sodium Niobate Based Lead-free Piezoelectric Ceramics Prepared by Tape Casting Process

通过流延成型技术,以片状K0.5Na0.5NbO3(简称为KNN)粉体为模板,结合掺杂改性后的基料粉体(K0.45Na0.55)0.98Li0.02(Nb0.77Ta0.18Sb0.05)O3-0.005Ba ZrO3(简称为KNNLST-BZ)流延制备出KNN基无铅压电陶瓷,研究了不同的工艺参数(烧结温度、烧结次数)对于KNNLST-BZ织构化陶瓷的电学性能、显微结构的影响。结果表明:模板含量为20wt%的KNNLST-BZ织构化陶瓷在1145℃下保温2 h呈现出优异的性能:压电常数d33=204 p C/N,横向机电耦合系数k31=23%,剩余极化强度Pr=26μC/cm2,矫顽场Ec=1.2 k V/mm。同时该织构化陶瓷在1145℃下烧结2次能得到更优的电学性能:d33=248 p C/N,k31=32.54%,Pr=38μC/cm2,Ec=1.2 k V/mm,介电损耗tanδ=6.38%,机械品质因数Qm=16.76,介电常数εT33/ε0=913.7,横向伸缩振动频率常数N1=2244。

The potassium-sodium niobate based lead-free piezoelectric ceramics were fabricated by tape casting process using K0. 5Na0. 5NbO3（ abbreviated as KNN） plate-like powder as template particles,（ K0. 45Na0. 55）0. 98Li0. 02（ Nb0. 77Ta0. 18Sb0. 05）O3-0. 005 Ba ZrO3（ abbreviated as KNNLST-BZ） as base powder. The influence of different process parameters such as sintering temperature,sintering times on the electronic properties of the textured KNNLST-BZ ceramics was studied. The results show that high performance of the textured KNNLST-BZ ceramics with the template contents for 20wt% sintered at 1145 ℃ for 2 h were obtained： piezoelectric constant d33= 204 p C / N,transverse electromechanical coupling factor k31= 23%,remnant polarization Pr= 26 μC / cm2 and coercive field Ec= 1. 2 k V / mm. At the same time,the textured KNNLST-BZ ceramics after sintered 2 times at 1145 ℃ exhibits the better performance： d33= 248 p C / N,k31=32. 54%,Pr= 38 μC / cm2,Ec= 1. 2 k V / mm,dielectric loss tanδ = 6. 38%,mechanical quality factor Qm=16. 76,dielectric constant εT33/ ε0= 913. 7,and transverse stretching vibration frequency constant N1= 2244.