Method of producing a metal foam by oscillations and thus obtained metal foam product

A method for producing a block of metal foam having a monomodal pore size comprising:

• arranging a melt of a foamable material within a container so as to provide a free surface of the melt;
• bringing a bubble forming end of a nozzle capable of injecting gas from an external source of gas into mechanical interaction with the metal melt in an interaction region of the melt and creating bubbles at the bubble forming end to be released within the interaction region, wherein the interaction region is below the free surface, and wherein the bubble forming end faces towards the free surface;
• generating longitudinal waves of an energy less than a cavitation limit of the bubbles with a device that is separated from the nozzle and that is in contact with the metal melt, and introducing the longitudinal waves through the metal melt to the bubble forming end to induce oscillations within the interaction region when the bubbles are being created;
• and
• controlling the size of each of the bubbles to a controlled monomodal size value simultaneous to formation of the bubbles by detaching the bubbles from the bubble forming end only when the bubbles reach the desired monomodal size, the oscillations of the longitudinal waves acting to force bubbles to release from the bubble forming end only after reaching the desired monomodal size and without breaking the bubbles into smaller sizes, the desired monomodal size value defined by bubbles having the same size.