单晶PMNT/环氧树脂压电复合材料的研制

Fabrication and Performances of Single Crystal PMNT/Epoxy Piezoelectric Composite

采用1-3型复合结构,沿表面两个相互垂直的方向切割PMNT单晶陶瓷,在切槽间浇注环氧树脂,制备出新型的1-3型PMNT/环氧树脂压电复合材料。实验测试了复合材料的压电、介电、阻抗和超声回波特性,结果表明其厚度机电耦合系数达到0.75,声速2 985 m/s,声阻抗14.9 MPa.(s.m-3),脉冲回波中心频率0.95 MHz,-6 dB带宽88%,相对介电常数1 423,介电损耗0.014。

Lead magnesium niobate-lead titannate （abbreviated as PMNT） was used to fabricate PMNT/epoxy 1-3 piezoelectric composite, by dicing single crystal PMNT along mutually perpendicular directions on the surface and then filling epoxy into grooves. The piezoelectric, dielectric and electromechanical properties of the composite were determined. It exhibited a thickness electromeehanical coupling coefficient of about 0.75, acoustic velocity of 2 985 m/s, a acoustic impendence of 14.9 MPa · （s . m^-3）, a relative dielectric constant of 1 423 and a dielectric loss of about 0.014. The pulse-echo waveforms of the composites without backing were also measured. It showed a --6 dB bandwidth of 88% at the center frequency of 0.95 MHz.