Mechanical properties of BaTiO3 open-porosity foams

Barium titanate (BaTiO3) foams synthesized via direct foaming method using silicon-free, rigid polyurethane systems (PU), commercially purchased and lab developed, are being engineered for piezocomposites in sonar applications. The mechanical properties of these foams were measured using confined compression testing to evaluate the suitability of these foams for the intended application. Compressive modulus and collapse strain determined from the experimental data increased with increasing density. Additionally, the foams fabricated using the lab developed PU (LPU) showed a higher mechanical strength due to a higher average density than the foams developed using commercial PU (CPU) system. The data was then fit with a phenomenological model to verify the values of the compressive properties extracted from the experimental data and also to extract additional properties such as tensile strength. Based on these findings, it is proposed that these foams can be successfully incorporated into piezocomposites by infiltrating the foams with polymer.