Publications
Material model for simulating domain reorientation and phase transformation in triaxial loaded PZT95/5
Explosively driven ferroelectric generators (FEG) are used as pulsed power sources in many applications that require a compact design that delivers a short high-voltage and high-current pulse. A mechanical shock applied to ferroelectrics releases bound electrical charge through a combination of piezoelectric, domain reorientation, and phase transformation effects. Lead-zirconate-titanate (PZT) 95/5 lies near the ferroelectric (FE)-antiferroelectric (AF) phase boundary and readily transforms to AF phase under compression because AF has a smaller unit volume. This makes it a popular choice for FEGs as the FE-AF transformation completely releases all the stored dipole charge. The complexity of piezoelectric, domain reorientation, and phase transformation behaviors under high deviatoric stress makes modeling this FE to AF transformation and the accompanying charge release challenging. The mode and direction of domain reorientation and phase transformation varies significantly with different deviatoric and hydrostatic stress states. Microstructure changes due to domain reorientation and phase alter the piezoelectric properties of the material. Inaccuracies in modeling any one of these phenomena can result in inaccurate electrical response. This work demonstrates a material model that accurately captures the linear piezoelectric, domain reorientation and phase transformation phenomena by using a micromechanical approach to approximate the changes in domain-structure.