A method was developed to produce Al- and Zn-based foams with a uniform distribution of small cells. Pre-alloyed AlMg50 powder containing hydrogen was used as a replacement for the usual blowing agent TiH2. AlMg50 powder released gas uniformly in the entire sample, caused the nucleation of a large number of cells and led to simultaneous growth that finally resulted in a uniform cell structure. The expansion behavior of these foams was studied by means of in situ X-ray radioscopy. The macrostructure of the solidified foams was then analyzed through optical microscopy and X-ray tomography and proved to be very uniform. The high strength of the foams was demonstrated by uni-axial compression tests.