铌酸钾钠基无铅压电陶瓷烧结及极化工艺优化

Optimization of Sintering and Polarization Process of Potassium Sodium Niobate-Based Lead-Free Piezoelectric Ceramics

采用传统固相法在烧结温度1110~1150℃内成功制备了(K_(0.5)Na_(0.5))_(0.98)Li_(0.02)Nb_(0.77)Ta_(0.18)Sb_(0.05)O_(3)(LTS-KNN)无铅压电陶瓷,所有样品结晶性良好,无第二相产生。在1130℃下烧结的压电陶瓷致密度良好,陶瓷表现出较好的压电性能。通过调节极化电场与极化温度可改善陶瓷的极化程度,进而优化陶瓷的压电性能。实验结果表明,在烧结温度为1130℃,极化电场为3 kV/mm,极化温度为60℃时,陶瓷的压电性能达到最佳,即压电常数d_(33)=310 pC/N,机电耦合系数k_(p)=48%。

The(K_(0.5)Na_(0.5))_(0.98)Li_(0.02)Nb_(0.77)Ta_(0.18)Sb_(0.05)O_(3)(LTS-KNN)lead-free piezoelectric ceramics are successfully prepared by the traditional solid-state method at the sintering range of 1110-1150℃.All samples show good crystallinity without second phase.The piezoelectric ceramics sintered at 1130℃ are well-densified and have good piezoelectric properties.By adjusting the polarization electric field and polarization temperature,the polarization degree of the ceramics can be improved,and the piezoelectric properties are optimized.The experimental results show that when the sintering temperature is 1130℃,the polarization electric field is 3 kV/mm and the polarization temperature id 60℃,the best piezoelectric performances have been obtained,that is,the piezoelectric constant d_(33)=310 pC/N,the electromechanical coupling coefficient k_(p)=48%.