Temperature stable and fatigue resistant lead-free ceramics for actuators

摘要

Lead-free ceramics with the composition 0.91K_(1/2)Bi_(1/2)TiO_3-0.09(0.82BiFeO_3-0.15NdFeO_3-0.03Nd_(2/3) TiO_3) were prepared using a conventional solid state, mixed oxide route. The ceramics exhibited a high strain of 0.16% at 6kV mm~(-1), stable from room temperature to 175℃, with a variation of ＜10%. The materials were fabricated into multilayer structures by co-firing with Pt internal electrodes. The prototype multilayer actuator exhibited constant strains up to 300 ℃ with a variation of ～15%. The composition showed fatigue resistant behaviour in both monolithic and multilayer form after bipolar loading of 10~6 cycles.