Method of manufacturing amorphous metallic foam

A method of manufacturing a metallic foam from a bulk-solidifying amorphous alloy comprising:

• providing a molten bulk-solidifying amorphous alloy;
• introducing a plurality of gas bubbles, to the molten alloy at a temperature about the liquidus temperature of the alloy to form a precursor at a first pressure such that the bubbles are formed with a specified internal bubble pressure;
• holding the conditions of the precursor after introduction of the plurality of gas bubbles steady for a specified period of time such that a proportion of the plurality of bubbles above a chosen size threshold are removed from the molten precursor via flotation such that the bubble size distribution within the precursor is at least partially homogenized;
• at least partially cooling the precursor to a processing temperature below the nose of the crystallization curve of the alloy and above the glass transition temperature of the alloy at a cooling rate such that the molten alloy substantially maintains its amorphous state;
• and
• expanding the bubbles in the precursor while the precursor is at the processing temperature by providing a pressure gradient to the precursor where the pressure during the expansion is lower than the internal bubble pressure of the introduced gas bubbles formed during the precursor forming step.