Customization of closed-cell aluminum foam properties using design of experiments

The closed-cell aluminum foam processing by liquid melt method using titanium hydride (TiH2) decomposition method is studied for customizing the process variables for explicit requirements. Design of experiments (DOEs) is employed in this study, which is a technique for planning and conducting experiments and analyzing the responses to bring out valid and objective conclusions. In the first stage, four process variables such as, holding time, amount of TiH2, amount of calcium addition and stirring time after calcium addition were adopted to identify the most influencing process variables by using half-fractional factorial design. Holding time and the amount of TiH2 addition were recognized as the significant process variables and those parameters were studied for non-linear relationship at a higher-level design using response surface methodology (RSM). The developed empirical models were used to derive inferences on the influence of these process variables on foam structure like relative density, pore diameter and cell aspect ratio. These structural properties of the foam in turn govern the mechanical property of closed-cell aluminum foam and static compression tests were conducted to study the correlations between them.