New process for making lighter metal foams Journal of the American Chemical Society
Metals that float on water? A relatively new group of materials -- metal foams -- do exactly that, defying the conventional notion of metals as heavy and solid. In comparison, metal foams are mere wisps, consisting of more than 80 percent air. Having very high surface areas and continuous open cell porosity, they are finding applications in catalysis, surface enhanced Raman scattering (SERS), heat transfer, insulation and other areas. Bryce C. Tappan and colleagues at the Los Alamos National Laboratory are reporting development of a new and simpler technique for making metal foams. Their report is scheduled for publication in the May 24 issue of the Journal of the American Chemical Society.
Technology for making metal foams has been limited mainly to aluminum and a handful of other metals. It produces either relatively heavy, dense foams or low-density foams with very large cell sizes. The new Los Alamos technique produces "unprecedented ultra-low density" foams with very small cell sizes from metals that could not be foamed in the past.
Some of the metal foams are lighter than StyrofoamTM. Researchers used the technology to make foams from iron, cobalt, copper and silver. "This new technique shows promise for being a flexible, general approach to the formation of a wide range of new nanoporous metals not currently accessible by state-of-the-art nanoscience," they stated. ARTICLE #2 "Ultralow-Density Nanostructured Metal Foams: Combustion Synthesis, Morphology, and Composition"