Effects of process parameters on additive manufacturing of aluminum porous materials and their optimization using response surface method

This paper deals with the fabrication of porous materials using direct energy deposition, which is a versatile 3D printing technique for metals. To manufacture a porous material, a mixture consisting of AlSi12 powder and a foaming agent (ZrH2) is sprayed onto an aluminum substrate and subsequently fused with the substrate using a high-power laser beam. We examined the effects of the main process parameters, namely the laser power, scanning speed and foaming agent ratio, on the total porosity, average pore size and number of pores of the final product. The results showed that the use of an excessive amount of foaming agent or energy decreases the porosity. In addition, a statistical analysis as well as the optimization of the main process parameters to ensure high porosity was conducted using the response surface method. Based on the central composite design method, the foaming agent ratio was found to have the greatest effect on the porosity, and a porous material with a maximum porosity of 24.83% could be fabricated using the optimal combination of the main process parameters. Finally, a mathematical model was derived to predict the relationship between these parameters and the porosity.