Forming metal foam structures

摘要

A method of fabricating a foamed metal structure using a powder supply of metal particles, comprising: (a) introducing the powder supply along with foaming agent particles into a propellant gas to form a gas/particle mixture stream; (b) projecting the mixture stream at a critical velocity of at least sonic velocity onto a metallic substrate to create a deposit of pressure-welded metal particles containing the admixed foaming agent; and (c) subjecting at least the coating of the substrate to a thermal excursion effective to activate expansion of the foaming agent while softening the metal particles for plastic deformation under the influence of the expanding gases.