| 摘要 |
PURPOSE:To obtain piezoelectric ceramics of stable characteristics reducing characteristic change during working and heat treatment by polarizing them at a temperature higher than a temperature arrived on account of the temperature rise in working and heat treatment after the polarization. CONSTITUTION:Polarization is carried out at a temperature higher than a temperature arrived on account of the temperature rise during working and heat treatment after the polarization. For instance, the material powder of PbTi0.44 Zr0.56O3 is calcined and crushed, and then moulded and baked at 1200-1300 deg.C. Next, on the principal face of the sintered object, an electrode is fitted all over, a 5kV/cm polarizing field is applied in the direction of thickness at 200 deg.C for 30 minutes to polarize, and then the object is heat-treated at 180 deg.C for 6 hours. By so doing, the characteristic changes of an electro-mechanical fusion coefficient kt, capacity, etc., during working and heat treatment after polarization can be reduced and piezoelectric ceramics of stable characteristics can be obtained. |
