Patent ID: 6656296
Filing Date: 2003-12-02
Classification: C22C,F28F

Abstract:
A method of making a heat exchange including the step of diametrically expanding heat exchanger tubing, the improvement comprising making the tubing to be diametrically expanded from the alloy composition comprising, between about 0.05 and 0.5% silicon; an amount of iron between about 0.1% and up to 1.0%; an amount of manganese up to about 2.0%; between about 0.06 and 1.0% zinc; between about 0.03 and 0.35% titanium; with the balance aluminum and inevitable impurities; wherein the manganese to iron ratio is maintained between greater than about 0.5 and less than or equal to about 6.0, and the iron and manganese amounts total greater than about 0.30% such that the article contains intermetallic compounds dispersed throughout an aluminum matrix in a volume fraction of the article of at least 0.5%, and wherein a difference in electrolytic potential between an aluminum matrix of the article and the intermetallic compounds is less than about 0.2 volts, the intermetallic compounds having an aspect ratio of less than about 5.0.