不同压电陶瓷体积分数对1-3-2型压电复合材料性能的影响

INFLUENCE OF VOLUME FRACTION OF PIEZOELECTRIC CERAMICS ON PROPERTIES OF 1-3-2 PIEZOELECTRIC COMPOSITES

以环氧树脂为基体,铌镁锆钛酸铅[0.375Pb(Mg_(1/3)Nb_(2/3))O_3·0.375PbTiO_3·0.25PbZrO_3,PMN]为压电功能体,采用切割-浇注法制备了1-3-2型压电复合材料。分析讨论压电陶瓷体积分数((?),下同)对1-3-2型压电复合材料压电性能、介电性能及声阻抗的影响。结果表明:随着PMN的(?)的增加,复合材料的压电应变常数(d_(33))和声阻抗(Z)增大;相对介电常数(ε_r)几乎呈线性增加,且当PMN的(?)为47.47%时,复合材料的ε_r=1 660,远小于纯PMN陶瓷的(ε_r=4000)。压电电压常数(g_(33))及介电损耗(tanδ)则呈下降趋势;与PMN相比较,1-3-2型压电复合材料厚度方向的谐振明显增强,机械品质因数(Q_m)显著降低;随着PMN的(?)的增加,复合材料的平面机电耦合系数(K_p)减小,而厚度机电耦合系数(K_t)增加。

1-3-2 piezoelectric composites were fabricated by the cut-filling method, using 0.375Pb（Mg1/3Nb2/3）O3-0.375PbTiO3·0.25PbZrO3（PMN） ceramic as piezoelectric function component and polymer as the matrix. The effects of PMN volume fraction（φ, the same below） on the piezoelectric properties, dielectric properties, the electromechanical coupling coefficients, and acoustic impedance of the composites were studied. The results indicate that as the PMN volume fraction increases, the piezoelectric strain constant （d33） and acoustic impedance （Z） increase evidently, while the piezoelectric voltage constant （g33） and the dielectric loss （tan δ） decrease. The relative dielectric constant （er） increases linearly, when the φ of PMN is 47.47%. The εr of the composite is 1 660, which is far less than that of PMN （4 000）. Compared with PMN piezoelectric ceramic, the thickness direction of the resonator 1-3-2 type piezoelectric composites is strengthened and the electromechanical quality factor （Qm） is decreased. Meanwhile, as the PMN volume fraction increases, the planar electromechanical coupling coefficient （Kp） decreases, and the thickness electromechanical coupling coefficient （Kt） increases.