mini piezoceramic for various ultrasonic products
The performance parameters of piezoceramic (1) mechanical quality factor.
The mechanical quality factor is defined as Qm = *2, which represents the extent of energy consumption within the material during vibration conversion. The greater the mechanical quality factor, the smaller the energy loss. The mechanical quality factor can be calculated from the equivalent circuit: Qm =, in which R1 is the equivalent resistance, Ws is the series resonant frequency, and C1 is the equivalent capacitance when the oscillator is resonant. When the ceramic sheet vibrates radially, it can be approximately expressed as Qm =, in which C0 is the static capacitance of the oscillator, unit F; delta f is the difference between the resonant frequency FR and the antiresonant frequency fa, unit Hz; and Qm is a dimensionless physical quantity.
Base electric coupling coefficient.
Electromechanical coupling coefficient K is a comprehensive parameter reflecting the performance of piezoelectric materials, which represents the coupling effect of mechanical energy and electrical energy of piezoelectric materials. The electromechanical coupling coefficient can be defined as K2= (inverse piezoelectric effect) and K2= (positive piezoelectric effect) has no dimension. _Electromechanical coupling coefficient is the reflection of the ability of piezoelectric materials to convert mechanical energy into electrical energy. It is totally different from mechanical efficiency. It is related to the piezoelectric constant, dielectric constant and elastic constant of the material, so the electromechanical coupling constant is a comprehensive parameter.
According to the piezoelectric effect, the piezoelectric ceramics will produce alternating elongation and contraction under the action of alternating electric field, thus forming a forced vibration consistent with the excitation electric field frequency (signal frequency). Piezoelectric ceramic oscillator is called piezoelectric ceramic oscillator for piezoelectric ceramics with certain shape, size and overlay electrode. In fact, the deformation of the resonator is very small, which can generally be regarded as elastic deformation. The elastic modulus is the parameter reflecting the stress and strain in the elastic deformation range. It
Piezoelectric ceramic material is an elastic body, which obeys Hooke's law: within the elastic limit, stress is proportional to strain. When the stress of T (in Pa) is applied to the piezoelectric ceramics, the strain S is S = sT, and the strain S is elastic compliance coefficient, unit m2 / N, unit C is rigid stiffness coefficient, unit Pa.