Open-cell Ag foams with tetragonal bipyramid pores in cellular struts

The foam manufacturing technique known as sintering and dissolution process (SDP) is applied to fabricate open-cell Ag foams with multi-level porous structure from Ag2SO4 substance. Initially, the tetragonal bipyramid Ag2SO4 is partially reduced, in the mixture of glycerol mixed with sodium hydroxide as reducing agent and reaction accelerator, respectively, to produce thin layer of fine aggregated Ag particles on the surface of Ag2SO4. The residual Ag2SO4 is then removed by ammonia dissolution after sintering of powder compacts, thereby leaving hollow tetragonal bipyramid shape of Ag in struts of foam structure. The resulting Ag foams exhibit unique microstructure and mechanical properties.