Liquid metal foams feasible in situ experiments under low gravity

Metal foams are quite a challenge to materials scientists due to their difficult manufacturing. In all processes the foam develops in the liquid or semiliquid state. Liquid metal foams are complex fluids which contain liquid metals, solid particles and gas bubbles at the same time. An X ray transparent furnace was developed to monitor liquid metal foam evolution. Aluminium foams similar to the commercial Metcomb foams were produced by feeding argon or air gas bubbles into an aluminium composite melt. The foam evolution was observed in situ by X ray radioscopy under normal gravity. Drainage and rupture were evaluated during the 5 min foam decay and 2 min solidification. Argon blown foams showed significant drainage and cell wall rupture during the first 20 s of foam decay. Air blown foams were stable and neuther drainage nor rupture occurred. We demonstrated the feasibility of experiments during parabolic flight or drop tower campaigns. However, the development of a foam generator for low gravity is neede