Effects of Purity Level on the Mechanical Properties of 7000-Series Aluminums

摘要

The effect of purity level on the mechanical properties of high strength aluminum alloys was studied. Seven extrusions, representing three alloys, were tested for their mechanical properties. Three extrusions were 7049-T73511, one was 7050-T73511, and the remaining were 7075-T73511. The 7049 and 7075 extrusions were manufactured in three purity levels, indexed to iron and silicon. When going from high purity to low purity, the following observations were made; the tensile strength dropped slightly, the fracture toughness fell dramatically and fatigue and fatigue crack growth rate properties were not affected in a systematic manner. Stress corrosion cracking tests showed there does not appear to be a corrosion problem for any of the materials of purity levels. (Author)