ZnO-B2O3玻璃对Li2Zn3Ti4O12-CaTiO3复合陶瓷低温烧结及性能的影响

采用传统固相反应法制备0.94Li₂Zn₃Ti₄O₁₂-0.06CaTiO₃(LZT-CT)复合陶瓷,采用高温熔融法制备ZnO-B₂O₃(ZB)玻璃;以ZB玻璃为烧结助剂,研究了添加不同质量分数(x=0.5%、1.0%、1.5%、2.0%和2.5%)的ZB玻璃对LZT-CT复合陶瓷的烧结特性、物相组成、微观结构以及微波介电性能的影响。结果表明:ZB玻璃能有效地将LZT-CT复合陶瓷的烧结温度从1 175 ℃降低到875 ℃,并促进了LZT-CT复合陶瓷的致密化。当ZB玻璃掺量x≤2.5%时,LZT-CT复合陶瓷中除了LZT、CT相,没有出现其他新相。随着ZB玻璃添加量增加,复合陶瓷的体积密度、介电常数(ε_r)、品质因数(Q×f)均先增加后减小,谐振频率温度系数(τ_f)变化不大,在(-2.25~4.51)×10^-6/℃波动。当ZB玻璃掺量为2.0%时,LZT-CT复合陶瓷在875 ℃烧结2 h,获得最大体积密度(4.22 g/cm³)以及优异的微波介电性能,ε_r=23.9,Q×f=58 595 GHz,τ_f=-0.14×10^-6/℃。

Effect of ZnO-B2O3 Glass on Low Temperature Sintering and Properties of Li2Zn3Ti4O12-CaTiO3 Composite Ceramics

The 0.94Li₂Zn₃Ti₄O₁₂-0.06CaTiO₃ (LZT-CT) composite ceramics were prepared by the traditional solid-state reaction method, and ZnO-B₂O₃(ZB) glass was synthesized by high temperature melting method. The sintering characteristics, phase compositions, microstructures and microwave dielectric properties of LZT-CT composite ceramics with different mass fraction (x=0.5%, 1.0%, 1.5%, 2.0% and 2.5%) of ZB glass were investigated in detail. The results indicate that, the ZB glass effectively decreases the sintering temperature of the LZT-CT composite ceramics from 1 175 ℃ to 875 ℃ and also promotes the densifiction. There are no new phases in addition to the LZT and CT phase when ZB glass addition x≤2.5%. With the increase of ZB glass addition, the densification temperature of composite ceramics decreases gradually, the bulk density, relative permittivity (ε_r), quality factor (Q×f) initially increase and then decrease, and the temperature coefficient of resonance frequency (τ_f) is stable, fluctuated between -2.25×10^-6/℃ and 4.51×10⁶/℃. When added 2.0%ZB glass, LZT-CT composite ceramics sintered at 875 ℃ for 2 h obtained maximun bulk density of 4.22 g/cm³, and excellent microwave dielectric properties: ε_r=23.9, Q×f=58 595 GHz, τ_f=-0.14×10^-6/℃.