Abstract | A process based on a powder metallurgy approach was developed to produce open-cell metallic foams. A metallic powder, a solide polymeric binder and a chemical foaming agent are dry-mixed together. The molded mixture is then heat-treated in a three-step thermal treatment including foaming, debinding and sintering. This paper describes the microstructure and properties of iron-based foams (pure Fe and Fe-1.25%C) obtained with this process. The final material is highly porous (90% porosity) and has an interconnected porosity network. The structure of the resulting material is relatively complex and has 3 levels of porosity (i.e. main cells, windows and microporosity). The compressive mechanical properties are affected by the density and composition of the material. Compressive properties (i.e. compressive yield strength, modulus, energy absorbed at densification) increase with density. In addition, the compressive yield strength and energy absorbed at densification increase significantly while the modulus is little affected by the carbon content. The material structure and properties are interesting for light weight structures and energy absorption. The process is relatively simple and the materials produced provide a low cost alternative to aluminum foams. |
---|