Patent ID: 6516862
Filing Date: 2003-02-11
Classification: B22D

Abstract:
A method of fabricating a porous metal structure, the method comprising:(a) heating a casting chamber to a chamber temperature above a chamber ambient temperature and to a temperature sufficient to maintain a metal in a molten state; (b) providing a molten metal having a temperature above the chamber ambient temperature into the chamber; (c) introducing a gas soluable within the molten metal into the chamber at a chamber pressure sufficient to dissolve the gas into the molten metal; (d) regulating cooling rate of the chamber to decrease the chamber temperature at a rate below ambient cooling rate so as to form a solidification front within the metal capable of progressing throughout the molten metal at a rate slower than a rate achieveable through ambient cooling; and (e) controlling the chamber pressure for forming pores within the structure until the solidification front progresses throughout the structure.