Patent ID: 6234243
Filing Date: 2001-05-22
Classification: B23K,F28F,Y10T

Abstract:
An improved heat exchanger assembly comprising:at least one aluminum based tube including magnesium adapted to be exposed to an ambient atmosphere and having an internal surface and an external surface;an aluminum based cladding disposed adjacent one of the internal and external surfaces;at least one aluminum based component disposed adjacent the cladding;a brazing flux applicable between the aluminum based cladding and the aluminum based component to facilitate brazing in the ambient atmosphere; andan aluminum based lithium enriched layer disposed between the one of the internal and external surfaces and the aluminum based cladding;whereby the aluminum based lithium enriched layer is adapted to scavenge sufficient oxygen from the ambient atmosphere during brazing to form a sufficient barrier against the diffusion of magnesium from the aluminum based tube that the formation of undesirable magnesium oxide is resisted.