Piezoelectric 3–3 composites

Network Modelling of 3-3 Piezocomposite Materials

“…Due to the rapid decrease in d 31 and slow decrease in d 33 , there is an increase in d h compared to the dense material (Fig. 3); as earlier papers have shown in depth [1,9,12]. For example, for a PZT-air composite the d 33 at ∼20% PZT is large while d 31 has significantly reduced (Fig.…”

“…Good correlation between model and experimental data has been observed with this technique. The model offers a number of advantages over current simplistic models [2,8,9,11] which consider a single pore in a piezoceramic matrix. Principally, by modelling a random array of pores the change in properties as the composite system changes from fully interconnected PZT (high density) to fully isolated PZT (low density) can be modelled, as shown by d 33 results (see Fig.…”

“…6. [2,9,12,13]. While the models predict some scatter, the experimental data exhibits a higher degree of scatter which again may be associated with incomplete or variable poling of these porous materials.…”

“…1-3 composites [1,2]), however, there has been less research into 3-3 composites than other areas. Banno [8] derived models for 3-0 and 3-3 connectivity that used a single unit cell and single pore with 4 divisions based on the biphasic composite microstructure of Rittenmyer et al [9], with theoretical findings not fully matching experimental results. Banno highlighted that these differences were related to the microstructure of the porous PZT, which was not fully represented by the unit cell model [8].…”

“…In this paper a model is developed which better represents a porous PZT ceramic in which the porosity in impregnated with air or polymer. While earlier papers considered single pores [2,8,9,11], this paper will use a three-dimensional network to model a PZT material containing a random array of a large number of pores at a predefined volume fraction of porosity. Porous piezoelectric materials are often manufactured by the addition of a polymer that is burnt out during the sintering processes.…”