matrix to form preforms heating the preforms to temperatures which are higher than the melting point of the metal which is to be foamed naturally applying the additives claimed in the present invention to a metal hydride system in accordance with the invention is not restricted to the powder metallurgy route but rather also covers systems which can be considered to form part of melt metallurgy 500 g of aluminum powder with a purity of 99 5 were mixed with stirring with 1 by weight of tego magnan u00ae magnesium hydride hydride content 95 based on the quantity of aluminum powder and 0 1 by weight of titanium powder based on the quantity of aluminum powder and 0 01 by weight of copper powder based on the amount of aluminum powder cylindrical pressed bodies were produced from this mixture by cold isostatic pressing the degree of compacting of the pressed bodies obtained in this way was 94 to 97 of the density which can theoretically be achieved in an induction furnace with a hf output power of 1 5 kw the pressed bodies were foamed freely in a graphite crucible at a heating rate of 300 u00b0 c min the foamed bodies were cooled rapidly 30 seconds after the foaming operation had commenced after the samples.