Abstract: A highly efficient flame arrester adapted for use in preventing an external flame from backflashing upstream in a pipe, or a conduit, or a stream carrying a flammable substance. The flame arrester comprises a contained layer of nested spheroids formed from expanded metal sheets made from magnesium alloy foil. The arrester is useful in fuel tanks, combustion systems, sea-going tankers, hot water or space heaters, and the like.

Abstract: A highly effective barrier for protecting objects against focused beams of radiant energy. The invention has special applicability in a combat environment for protecting military equipment against destruction by laser weapons, or for thwarting detection of such equipment by reflected radar waves. The barrier comprises a layer of slitted and expanded metal foil, made from a non-ferrous metal having an absorptivity less than 3% and a thermal conductivity above 100 W/m/K, interposed between the radiant energy beam and the object to be protected. The barrier layer may be multiple sheets of the slitted and expanded metal foil, or a contained layer of nested ellipsoids formed from the expanded metal sheets.

Abstract: A highly efficient impact absorber for protecting articles against destructive mechanical impact. The invention has special applicability to containers for flammable materials, scientific instruments, or other fragile mechanisms or articles which may be damaged or become hazardous when ruptured. The impact absorber comprises a layer or layers of expanded metal net made from magnesium alloy foil having a thickness in the range from about 0.02 to 0.50 mm. A preferred embodiment comprises a contained layer or layers of nested spheroids formed from expanded metal sheets made from magnesium foil.