Influence of porosity on elastic properties of Ti2AlC and Ti3SiC2 MAX phase foams

MAX phase foams could have various applications where tailored functional and mechanical properties are required. In this study, Ti2AlC and Ti3SiC2 MAX phase foams with controlled porosity and pore size were produced and characterized. The foams were produced from MAX phase powders by powder metallurgy method using crystalline carbohydrate as a space holder. Foams with overall porosity up to approximately 71 vol% and pore size from 250 μm to 1000 μm were successfully produced; micro-porosity and macro-porosity was characterized. Poisson's ratio and elastic moduli of the foams were measured by resonant ultrasound spectroscopy (RUS) and analyzed as a function of porosity and pore size. Different models were used to fit the experimental data and interpret the effect of pore size and amount of porosity and on elastic properties. It was found that the amount and type of porosity has a larger influence on the elastic properties than the pore size.