助烧剂CuAlO_2掺杂(K_(0.5)Na_(0.5))NbO_3陶瓷的微观形貌及介电性能研究

Effects of CuAlO2sintering aid additive on the microstructure and dielectric properties of(K_(0.5)Na_(0.5))NbO_3 lead-free ceramics

目的以偏铝酸亚铜(CuAlO_2简称CA)为助烧剂对铌酸钾钠陶瓷(KNN)进行烧结特性改善并研究掺杂陶瓷的微观结构及介电性能。方法采用传统固相法制备了不同含量CA助烧剂作为第二组元的掺杂铌酸钾钠陶瓷。结果 XRD结果表明烧结温度为1 085℃时KNN-xCA陶瓷样品具有正交相钙钛矿结构;SEM结果表明CuAlO_2助烧剂抑制KNN陶瓷晶粒生长,掺杂系数x=0.01时,KNN-xCA陶瓷晶粒均匀。在20~500℃温度范围内,掺杂系数x=0.01时,KNN-xCA样品的介电损耗较小(≤5%),介电常数较大(≥1 000),介电温度变化率较小,介电性能最佳。结论不同含量的偏铝酸亚铜(CuAlO2)掺杂改善了(1-x)(K0.5Na0.5)NbO3-xCuAlO_2(KNN-xCA,x=0.005,0.010,0.015,0.020)陶瓷的烧结性能,微观形貌及介电性能。

Purposes--To optimize the sintering character of the （K0.5Na0.5）NbO3（KNN） ceramics and to investigate the effects of CuA102 （CA） additives as a sintering aid on the phase structure, mi- crostructure, dielectric properties of the KNN-.rCA ceramics. Methods--The doped KNN ceramics were prepared by the solid-state process with the different contents of the sintering aid CuA102 as the second components. Results--The KNN-xCA ceramics had an orthorhombic perovskite structure at the sintering temperature of 1 085 ℃ ; the sintering aid CuA102 inhibited grain growth of the KNN ce- ramics and the KNN-~A ceramics samples with 0.01 tool CA content doped show better densification and the cubic grain shape. In the temperature range of 20 ℃ to 500 ℃, the KNN-xCA ceramics sam- ples with 0.01 tool CA content doped show that besides smaller temperature change rate and the best dielec- tric properties, the dielectric loss was small（≤5%） and the dielectric constant was larger （≥1 000）. Conclu- sion-The doping of sintering aid CuA102 can effectively optimize the sintering character, microstruc- ture, dielectric properties of the KNN-xCA （or=0. 005, 0. 010, 0. 015, 0. 020） ceramics.