Method to Produce High Porosity Metal Foam using Gelation of Water Base Binder

Abstract

Several methods have been developed for producing high-porosity open-cell metal foams, but no method is available for producing closed-cell type metal foams with a porosity of more than 95 %. We therefore developed a novel process for producing a high-porosity closed-cell metal foam using a hydro-gel binder. This process is gelled a slurry which contains a metal powder, an aqueous polymer solution and a foaming agent. When the gelled slurry is heated, the foaming agent causes it to foam; this develops the proper conditions for generating a closed-cell structure. We applied this method to making stainless steel foams and obtained metal foams with porosities of more than 98 %. This method is not only used for to producing metal foams, but could be applied in producing ceramics foams.