Application of elastic and dielectric properties of piezoelectric ceramic crystal

    Application of elastic and dielectric properties of piezoelectric ceramic crystal     

  Piezoelectric ceramic is a kind of information functional PZT ceramic material that can transform mechanical energy and electrical energy. In addition to piezoceramic ring crystals properties, piezoelectric ceramic chips also have dielectric properties and elasticity, which are widely used in medical imaging, acoustic sensors, acoustic transducers, ultrasonic motors and other fields. Piezoelectric ceramic is made of its material under the action of mechanical stress, which causes the relative displacement and polarization of the internal positive and negative charge center, and causes the opposite sign of bound charge on the surface of both ends of the material, i.e. piezoelectric effect. Piezoelectric ceramic chips are mainly used to make ultrasonic transducer, underwater acoustic transducer, electroacoustic transducer, ceramic filter, piezoelectric ceramic chip transformer, ceramic frequency discriminator, high voltage generator, infrared detector, surface acoustic wave device, electro-optic device, ignition device, piezoelectric gyroscope, etc. in addition to being used in high-tech fields, it also provides more services for people in daily life and strives to create a better life for people.    

   
     The maximum displacement of the packed PST 1000 / 35 / 200 vs45 is 260 μ m, the rigidity of the piezo ceramic is 150 n / μ m, and the rigidity of the external mechanism is 70 n / μ M. the displacement generated by the above calculation formula is 177 μ M. at this time, the effective thrust of the external mechanism of the piezoelectric ceramic is 12450 n. when the rigidity of the external mechanism is 500 N / μ m, the displacement generated is 60 μ m, and the effective thrust is 30000 n 。  

    
      When the external load changes the mechanical force, the thrust generated by the piezoelectric ceramics depends on the elongation of the piezoelectric ceramics. The following figure is based on the displacement and thrust values of the future core piezoelectric ceramics PST 150 / 5x5 / 20 and PST 150 / 7x7 / 20. It can roughly estimate the thrust and displacement shape variables generated by the two piezoelectric ceramics under the different mechanism stiffness.         

   The abscissa represents the maximum thrust of piezoelectric ultrasonic transducer, the ordinate represents the displacement of piezoelectric ceramics under no-load, and the smech represents the stiffness curve of external mechanism. The intersection point between the stiffness curve and the thrust displacement curve of the external mechanism is the performance parameter when the piezoelectric ceramic resists the external mechanism.      

      When the stiffness of the external mechanism is the same as that of the pzt powder piezo ceramic, the displacement and thrust are half of the Zui large displacement and Zui large thrust. Zui makes great use of the energy efficiency of the piezoelectric ceramic.       

 
When the stiffness of the external load is the same as PST 150 / 5x5 / 20, the piezoelectric ceramic can output a maximum displacement of 10 μ m and a maximum output of 800 n.    

     
   Under the same external mechanical structure, because PST 150 / 7x7 / 20 has greater rigidity, Zui can output larger displacement and output under large driving voltage.