Process for the production of a fluid impermeable sintered body

Essentially metallic sintered bodies impermeable to fluids are produced by adding to a sinterable mixture consisting predominantly of metal powder, a powdered substance preferably a glass, which is inert with respect to the metallic components, melts at the sintering temperature and has a lower coefficient of thermal expansion than the metal. The mixture is shaped in the usual manner and sintered. The metal powder is preferably iron powder, bronze or aluminium. The powdered substance added may also be a mineral or rock powder.