Metal foams, full of tiny air bubbles like a sponge cake, are gradually making inroads in industrial applications. Lightness and high energy absorption are two demanded material characteristics.
The most common technique for manufacturing metal foams involves mixing metal powders with blowing agents.
When mixture gets heated approaching melting point, the additive releases a gas which creates a mass of bubbles in the metal. However open-pored foam panels cannot be manufactured this way, because the pores extend through from one face to the other. An expanding gas would simply escape through the holes. Therefore M-pore employs a casting method; A mold cut in polyurethane foam is coated with wax. The cavity is filled with a heat-resistant ceramic paste. When liquid metal is poured into the mold – mostly aluminum at around 700 °C –, the plastic foam burns away, leaving behind a metal “sponge” filled with pores with diameters of between one and five millimeters. The final step is to blast off the ceramic mold with a water jet.
M-Pore produces open celled metal foams in a wide range of alloys (Sn, Al, Cu, Au, Ag or Fe).