Electromechanical properties of 2-2 cement based piezoelectric composite

A 2-2 type cement based piezoelectric composites were fabricated by dice-and-fill technique. The influences of lead magnesium niobate-lead zirconate-lead titanate (PMN) ceramic volume fraction on the electromechanical properties of the composite were investigated. The results indicate that the planar electromechanical coupling factor K_p of the composite is hardly influenced by the PMN volume fraction, which fluctuates between 35% and 37%, while both the thickness electromechanical coupling factor K_t and the mechanical quality factor Q_m exhibit the trend of increase. When PMN volume fraction is 69.2%, K_t could reach to 49.8%, which is larger than that of the PMN ceramic (K_t = 46%).When PMN volume fraction is 41.7%, Q_m is 4.5, which is also much less than that of the PMN ceramic (Q_m = 70). This means that the composite has wider frequency band and higher sensitivity to be used as transducers. With the increase of PMN volume fraction, the acoustic impedance of the composite also exhibits the trend of increase.