Off Axis Compressive Response of Ice-Templated Ceramics

Abstract

OFF AXIS COMPRESSIVE RESPONSE OF ICE TEMPLATED CERAMICS Rahul Kumar Jujjavarapu Old Dominion University, 2019 Co-Directors: Dr. Oleksandr Kravchenko Dr. Dipankar Ghosh The off-axis compressive behavior of ice-templated ceramic was analyzed using experimental results and micro-mechanical model simulation. Ice-templated ceramics is a versatile processing technique used to manufacture anisotropic ceramic foam by exploiting the anisotropic growth characteristics and lamellar morphology. The ice-templating process results in processing-structure-property relationships determined by the microstructure. The processed alumina samples which were later manufactured by water jet machine from the freeze casting were tested under quasi-static off-axis loading conditions and were used to determine the mechanical properties of the material. Digital image correlation (DIC) was used to measure the strain response of ice-templated ceramic under off-axis loading. DIC results revealed nonhomogenous strain distribution in the material during compression. Specifically, the origin of the localized strain concentration columnar regions, which are oriented in the ice-growth direction. Those regions were found to be the onset failure of in off-axis and 0-degree loading conditions. The experimental results reveal the strong influence of the loading direction on the compressive behavior of the ice-templated ceramic. A Representative Volume Element is developed to predict the behavior of off-axis loading. Micro-mechanical loading results in indicated that buckling of lamella walls were determined as the driving factor of failure. The results of the model compared favorably with the experimental results.