Rio Tinto Group
Aluminum alloy composition and method

Abstract:

An aluminum alloy composition includes, in weight percent: 0.7-1.10 manganese; 0.05-0.25 iron; 0.21-0.30 silicon; 0.005-0.020 nickel; 0.10-0.20 titanium; 0.014 max copper; and 0.05 max zinc, with the balance being aluminum and unavoidable impurities. The alloy may tolerate higher nickel contents than existing alloys, while providing increased corrosion resistance, as well as similar extrudability, strength, and performance. Billets of the alloy may be homogenized at 590-640.degree. C. and controlled cooled at less than 250.degree. C. per hour. The homogenized billet may be extruded into a product, such as an aluminum alloy heat exchanger tube.