OPERATIONAL PRINCIPLE, FABRICATION AND DISPLACEMENT CHARACTERISTICS OF A FUNCTIONALLY GRADIENT PIEZOELECTRIC CERAMIC ACTUATOR

In this paper, the theoretical relationship between the bending displa cement at the free end of a functionally gradient material (FGM) actua tor and the FGM coefficient of the sandwich has been derived from the structure of an FGM actuator. FGM actuators based on PNN-PZT piezoelec tric ceramics have been developed by the powder mould stacking press m ethod and their displacement characteristics have also been measured. The results show that the bending displacement at the free end of a 20 mm x 8 mm x 0.7 mm FGM actuator is about 20 mu m when a voltage of 10 00 V is applied. The morphology and the compositional distribution acr oss the profile of the FGM actuator are examined by using SEM and EDS, respectively.