Degradation of the d(33) piezoelectric coefficient for PZT ceramics under static and cyclic compressive loading

The degradation of the d(33) piezoelectric coefficient of PZT ceramics subj ected to compressive stresses along the poling direction was studied in the range from 10 to 70 MPa. in static and cyclic loading. The coefficient was measured making use of the direct piezoelectric effect with the same servo hydraulic test machine used to apply the stresses. The piezoelectric coeffi cient was measured as a function of the amplitude of the applied stress, wh ich allowed us to isolate the intrinsic coefficient and the domain wall con tribution. A hard and a soft piezoelectric ceramic were studied. The hard p iezoelectric material was very resistant to degradation in the range of str ess investigated. The soft material showed significant piezoelectric degrad ation due to stress induced depolarisation. The degradation was significant ly higher for a given stress in cyclic loading than in static loading. (C) 2001 Elsevier Science Ltd. All rights reserved.