Fabrication of porous metals layered by laser-assisted melting of sprayed Ti6Al4V powder and foaming agent mixture

This paper demonstrates the fabrication process of a porous metal using the direct energy deposition (DED) process, wherein Ti6Al4V powders mixed with a foaming agent (TiH2) were sprayed on the Ti6Al4V substrate, and subsequently, melted with the substrate using a high-power laser beam. Before the solidification of the molten metal, the hydrogen gas generated from TiH2 caused pores inside the deposited layer. The fabricated porous structures had porosities of 22% and 11% for laser powers of 900 and 1100 W, respectively, which indicated that the densities of the layered porous structures could be controlled by varying the process parameters. Finally, the compression testing of the samples proved that the porous structure fabricated by DED is significantly effective in absorbing mechanical energy.