Analysis of infiltration, solidification, and remelting of a pure metal in subcooled porous preform

The parts fabricated by selective laser sintering of metal powders are usually not fully densified and have porous structure. Fully densified parts can be obtained by infiltrating liquid metal into the porous structure and solidifying the liquid metal. When the liquid metal is infiltrated into the subcooled porous structure, the liquid metal can be partially solidified. Remelting of the partially solidified metal can also take place and a second moving interface can be present. Infiltration, solidification, and remelting of metal in a subcooled porous preform obtained by laser sintering of metal powders are analytically investigated in this article. The governing equations are nondimensionalized and the problem is described using six dimensionless parameters. The temperature distributions in the remelting and uninfiltrated regions were obtained by an exact solution and an integral approximate solution, respectively. The effects of porosity, Stefan number, subcooling parameter, and dimensionless infiltration pressure are investigated.