Effect of iron and silicon impurities on the mechanical properties of an alloy in the system Al−Zn−Mg−Cu

1. A reduction in iron and silicon content in alloys of the system Al−Zn−Mg−Cu promotes a marked increase in ductility with retention of quite a high level of strength properties, and also an increase in alloy resistance to scaling corrosion. 2. The impact strength of alloy containing 0.08% Fe and 0.03% Si, is higher by a factor of two than alloy containing 0.2% Fe and 0.1% Si, and the fatigue crack growth rate with all ΔK is less.