Foaming pure, additive-free metallic melts with inert gases may be a means to avoid some of the unwanted side effects of stabilizing additives in metallic melts (e.g., brittleness).1 To keep viscosity low, the foaming process has to take place at temperatures very close to the melting point. This can be done by bubbling gas through a melt which is constantly cooled down (e.g., in a continuous casting process). The bubbles are then caught in the solidifying liquid and form a foam-like structure. In the liquid state such systems are very unstable compared to particle-stabilized metals, which can be kept liquid for some time.