Particle-stabilized metal foam and its production

Abstract

The invention relates to a process for producing a particle-stabilized metal foam from a composite capable of acting as a precursor composite for the metal foam. The precursor composite is formed by heating a matrix metal, e.g. aluminum or an aluminum alloy, above its liquidus temperature to form a liquid matrix metal, adding to the liquid matrix metal stabilizer particles capable of remaining dispersed within the matrix metal, e.g. MgO particles preferably in the form of agglomerates of particles and some fine particles, and mixing the liquid matrix metal and stabilizer particles under a covering gas, e.g. air, in such a way that bubbles of the gas, as well as the stabilizing particles, are dispersed throughout the matrix metal. The precursor composite can then be foamed by the introduction of a gas by a known technique to form a particle-stabilized metal foam. The entrainment of gas bubbles means that a microporosity may be introduced into some of the cell walls of the composite, which is retained when the composite is transformed into a metal foam. The foam product has improved crush and machining properties.

Dependencies are inferred from the claim text.