Metal Additive Manufacturing Conference - MAMC 2024

Porous materials have always been a necessary component in application of catalysts, fuel cells or capacitors in the field of energy conversion and storage. They can be obtained by a variety of production methods, however a novel emerging method has been demonstrated by the use of additive manufacturing. With laser powder bed fusion (LPBF) several printing parameters, such as laser power, hatching distance, layer height or beam diameter are available to modify the printing process and to create mechanically stable yet porous structure. Here, the influence of mentioned printing parameters on the porosity of in-situ alloyed Ni3Al is addressed. To investigate the inner pore structures as well as the elemental distribution and homogeneity of the samples, scanning electron microscopy was used. Within the larger pores, unmelted powder particles were found to have sintered to the walls. The porosity was quantified by means of light optical microscopy (LOM). Additional microcomputed tomography (µCT) measurements were conducted to verify the LOM results. Furthermore, µCT allowed the distinction between open and closed porosity by 3d reconstruction. With decreasing energy input, the lack of fusion porosity increases, while the size of the pores varies in dependence of the printing parameters. In summary, it is shown that it is possible to create bulk samples with a network of open pores suitable for future energy applications by means of LPBF.