The effect of uniaxial stress on the electro-mechanical response of 8/65/35 PLZT

8/65/35 PLZT is characterized under stress and electric field loading above the coercive field. Strain-electric-field and electric-displacement-electric-field hysteresis loops are measured at various compressive stress levels showing the effect of stress on the electro-mechanical coupling. Stress-strain curves are run at zero electric field, showing that depolarization begins at as little as 5 MPa. The limitations of linear constitutive modeling and the limitations of this composition of PLZT as an actuator material are examined. The ''yield'' or ferroelastic switching stress is suggested as a good criteria for assessing the capability of actuator ceramics. This parameter is an indication of the actuation limitations of the material. An equivalence of the slopes of the strain-electric-field curve at several compressive stress levels and the electric-displacement-stress curve at the same stress level is observed. This suggests that the conjugacy of the piezoelectric coefficients may hold during path dependent polarization switching. Copyright (C) 1996 Acta Metallurgica Inc.