SpaceICE Satellite

Test freeze-casting technique in space.

Test freeze-casting technique in space. Freeze-casting is a novel materials fabrication technique that utilizes ice as a fugitive space-holder to create highly complex, three-dimensional pore structures and net-shape objects.

In this process, an aqueous suspension of particles is placed onto a cold plate. Ice nucleates at the cold surface and a planar ice front starts propagating. Due to the presence of inert particles, a constitutional undercooling region develops causing breakdown of planar ice and formation of dendrites. Under proper conditions, dendrites grow directionally with the thermal gradient, while pushing suspended particles away from the moving front. Rejected particles form an accumulation layer ahead of the solidification front and are forced to assemble within interdendritic space as solidification progresses. After solidification, ice is removed and the resulting, anisotropic structure is sintered to densify pore walls.