Epoxy interface method enables enhanced compressive testing of highly porous and brittle materials

The compressive mechanical characterization of highly porous ceramics is problematic due to sensitivity to stress concentrations and localized fractures. In this paper a review of the methods used by the scientific community is done and their typical results, advantages, and shortcomings are discussed. Here, a new methodology that can address some of the problems associated with the current measurement procedures is presented. The proposed method is applied to highly porous barium titanate foams. This procedure produces more consistent data that can be analyzed and interpreted objectively. We show that properties such as the crushing or collapse stress as well as the compressive modulus cannot be extracted correctly by the conventional methods. By contrast, the proposed method collects data that is more accurate, consistent with what is expected of porous ceramics and that yields smaller measurement to measurement variation.