METAL FOAMS - JOHN BANHART AND DENIS WEAIRE

We have found this interesting article on the history of metals foams by John Banhart and Denis Weaire.

By the end of the eighties there was a resurgence in metal foam research throughout the world. Japanese engineers at Shinko Wire Co. developed what is now known as the Alporas process. Norsk Hydro in Norway and Alcan Corp. in Canada independently developed a foaming process for particle-stabilized melts. In 1990 an old powder-compact foaming route developed in the late 1950’s by Benjamin Allen at the United Aircraft Corporation in Delaware was rediscovered by German physicist Joachim Baumeister and brought to a considerable level of sophistication at the Fraunhofer Laboratory in Bremen, Germany. These and other variants have been continually refined up to the present day.

Two methods for foaming metals were used in those early days, and they are still current today. In the first of these, gas is injected continuously to create foam. In the second method, gas-releasing propellants are added to the melt, akin to the blowing agents of the plastic foam industry or indeed the yeast of the baker.(see the images mentioned above) aluminum was found to be particularly amenable to foam production.

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