Modeling nonlinear elastic behavior of plasma sprayed ceramics and its evolution with sintering

Plasma sprayed ceramics have nonlinear behavior under compression in small deformations due to partially closing of microcracks existing in the microstructures. Their tangent modulus increases up to a certain value with an increase in compressive stress and indicate a stiffer response. In this paper, the nonlinear behavior of such materials is modeled based on a proposed relation between micrcocracks density and the compressive stress. The comparison between the experimental results and that of the predicted values by the model verifies the suitability of the model. The effect of sintering at high temperature on stress-strain behavior of the plasma sprayed ceramics is modeled and investigated by proposing a relation between the microcracks density as well as porosity and time.