Optimization of crystal microstructure in piezoelectric ceramics by multiscale finite element analysis

Abstract A multiscale finite element method based on homogenization theory is employed to optimize the microstructure of polycrystalline piezoelectric ceramics so as to maximize the homogenized macrostructural piezoelectric response. This analysis reveals that two specific microstructures, layered or alternating [1 1 1]-oriented structures, result in a piezoelectric response that exceeds that of the single-crystal. The layered structure consists of ordered 120°-rotated layers maximizing d333, while the alternating structure consists of adjacent grains rotated by 180° in three dimensions optimizing d311. These heterogeneous structures maximize the internal strain in polycrystalline aggregates by optimizing electrical and mechanical effects.