提出了一种新的方法可以使锆钛酸铅压电陶瓷PZT7具有形状记忆效应.用自制的sawyer-Tower电路测试得到PZT7方形样品发生极化反转对应的电场强度大约为130kV/cm.当施加对称的饱和极化电压370V时,PZT7/Si(109/146μm)悬臂梁端部的变形一电场曲线呈现典型的"蝴蝶"形状.在外电场为0时,悬臂梁端部的变形为0.如果施加不对称的极化电压,悬臂梁端部的变形--电场曲线发生明显的变化.不同的反向极化电压使悬臂梁端部产生不同的变形,而且,电压和变形是一一对应的.因此,在外电场为零时,PZT7/Si悬臂梁可以具有多个不同的稳定位置,表现出明显的形状记忆效应.实验表明,对于长度为15.5mm的PZT7/Si悬臂梁而言,当施加的反向极化电压从120V回到0时,悬臂梁端部产生的变形最大,为68.5μm.%The fundamental study about shape memory effect of lead zirconate titanate piezoelectric ceramics (PZT7) was carried out and a new method to make PZT7 material have shape memory effect was presented in this paper. The fabricated piezoelectric actuators are PZT7/Si (100/150μm) cantilevers with width of 5. 5mm and different lengths. The P-E hysteresis loop of PZT7 measured using Sawyer-Tower circuit shows that the co-ercive electric field of PZT7 is about 130kV/cm. When the voltage applied on the piezoelectric cantilever is satu-rated and symmetrical, the curve of piezoelectric strain versus electric field (D-E) is classical butterfly hysteresis one. However, the shape of D-E hysteresis loop has big change if the applied voltage is unsymmetrical. The pi-ezoelectric cantilever may have multistable strain conditions after the applied unsaturated voltage return 0V fromdifferent voltages. Different unsaturated reverse voltages can make PZT7/Si cantilever being on different stable strain conditions. Therefore, unsaturated reverse voltages result in shape memory effect of PZT7. Experiments show that the PZT7/Si cantilever with length of 15.5ram and width of 5.5mm has biggest residual displacement and the tip's displacement is 68.5μm after the applied reverse voltage is changed from 120V to 0V.
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