LEAD-FREE PIEZOELECTRIC CERAMIC MULTILAYER ACTUATOR

摘要

PURPOSE: An environmentally-friendly lead-free piezoelectric ceramic multilayer actuator is provided to reduce a failure rate due to interlayer delamination by decreasing the plastic shrinkage mismatch of an inner electrode layer and a ceramic layer. CONSTITUTION: A KNN based lead-free piezoelectric ceramic sheet and an inner electrode are alternatively stacked. The piezoelectric ceramic material is (K,Na)NbO3(KNN), BiNaTiO3(BNT), Bi(Na,K)TiO3(BNKT), or BiKTiO3(BKT). The inner electrode is made of composite materials formed by mixing AgPd alloy and a piezoelectric ceramic material. The composite material includes AgPd alloy of 65 to 95 volume and piezoelectric ceramic materials of 5 to 35 volume. The Ag : Pd of the AgPd alloy is 95:5 to 70:30.