Lead and lead alloy foams

Lead-based foams were produced by applying the powder route, i.e., by mixing metal powders and a powdered gas-releasing blowing agent and pressing the mixture to a foamable precursor material afterwards. This precursor was then foamed by heating it up to above its melting point, thus triggering gas release and foam formation. In a first step a set of process parameters was established, allowing us to foam lead alloys. This included finding suitable metal and blowing agent powders, mixing and compaction procedures, and determining appropriate foaming conditions. After this the foaming process of various alloys was studied as a function of time, temperature, alloy composition and blowing agent content.