Patent ID: 7597840
Filing Date: 2009-10-06
Classification: B22F,Y10T

Abstract:
1. A method of forming an amorphous metal foam formed of an amorphous metal powder comprising: mixing at least one amorphous metal powder and at least one gas-splitting propellant powder into a propellant filled amorphous metal powder mixture, such that upon decomposition of the gas-splitting propellant powder, gas-containing pores are created within the amorphous metal powder mixture; compacting the mixture such that the amorphous metal powder particles are bonded to one another to form a gas-tight seal around the gas-splitting propellant powder particles, the mixture being compacted at a compacting temperature and pressure sufficient to allow for bonding of the mixture, wherein the temperature is below any crystalline transition temperature of the amorphous metal powder, and for a duration not exceeding a time for any crystalline transformation of said amorphous metal powder at the compacting temperature and pressure; cooling the compacted mixture at a cooling rate sufficient that the amorphous metal powder mixture remains amorphous; expanding the compacted amorphous metal powder mixture to form a foam material, said expansion being conducted at an expansion temperature below any crystalline transition temperature of the amorphous metal powder, but sufficiently high to allow bubble expansion, at a surrounding pressure sufficient to promote expansion arising from a difference between a pressure in the gas-containing pores and the surrounding pressure, and for a duration not exceeding the time for any crystalline transformation to take place; and cooling the expanded foam material in order to allow the foam material to remain amorphous.