【摘要】 针对机械品质因数特别低的压电陶瓷材料,提出了一种测量机电耦合系数和机械品质因数的方法,并用来测定了PbNb₂O₆陶瓷的材料参数。在这个方法中,利用低频阻抗分析仪（HP—4192A型）测量压电振子的阻抗随频率的变化,画出导纳圆图,由导纳圆图得出所需的振子参数,然后计算出径向伸缩振动的机电合系数k_p和机电械品质因数Q_m。对于厚度伸缩振动模式,由与上述径向仲缩振动模式相同的步骤得出机械品质因数,并由泛音比法计算机电耦合系数k_s,所需的泛音及基音频率仍然由低频阻抗分析仪测定。更多还原

【Abstract】 A method to determine the electromechanical coupling coefficients and mechanical quality factor Qm of the piezoelectric ceramics with extremely low Qm is proposed and the material parameters of PbNb2O6 ceramics have been measured dy it. In this method, a low frequency impedance analyzer(HP-4192A) is employed to measure the frequency dependence of the impedance of the piezoelectric resonator and thereby an admittance diagram is obtained. The necessary resonator parameters are taken from this diagram and the electromechanical coupling coefficient kp, mechanical quality factor Qm for the radial extension vibration mode are then calculated. As for the thickness extension vibration mode, it is recommended to deter mine the mechanical quality factor Qm by the same procedure as that for the radial extension vibration mode and to calculate the electromechanical coupling coefficient kt by the overtone—ratio with the necessary frequencies measured still by the low frequency impedance analyzer.更多还原