| 摘要 |
PURPOSE:To obtain a vibrator excellent in characteristic by a method wherein a composition of the piezoelectric porcelain used for the vibrator is specified in a plate- shaped thickness direction vibrator which is polarization-treated in the thickness direction. CONSTITUTION:Each powder of PbO, TiO2, SrCO3, MnCO3, Sb2O3 is used as a starting raw material for manufacturing the plate-shaped thickness direction vibrator polarization-treated in the thickness direction. In case where the composition of those powders is expressed by Pb1-xSr<x>Ti1-y(Mn1/3Sb22/3)yO3, the values of (x) and (y) are specified in ranges of 0.009<=x<=0.16 and 0.015<=y<=0.12. Thereafter, the powders are mixed together and then prebaked at 850 deg.C, ground into pieces, pressure-feed-molded at the pressure of 700kg/cm<2>, and cut down in a pole-shape in a prescribed size after being sintered at 1,240-1,300 deg.C. In such a manner, vibrations of longitudinal vibration transverse effect system in a range of frequencies below the thickness vibration resonance frequency is suppressed, the dielectric constant and dielectric loss at the application of a high electric field are both decreased and best suited for an acoustic signal waves transmitting and receiving device for the marine instrumentation system. |
