VARIABILITY OF MECHANICAL AND CORROSION PROPERTIES OF STANDARDIZED ALUMINUM-BASED ALLOYS

Aluminum alloys show a high strength-to-weight ratio and a relatively good corrosion resistance making them prospective structural materials in many fields. In material standards of commercial Al alloys, chemical composition is always defined as concentration ranges of alloying elements and impurities. In some cases, concentration ranges allowed within one material grade are relatively wide. It can be expected that mechanical and corrosion properties of one material grade are also variable that can be problematic in some applications. Three commercial aluminum casting alloys (AlSi5Cu4Zn, AlSi9Cu3Fe, AlSi10MgMn) with chemical composition on the lowest and highest content of alloying elements prescribed by their material standards were studied. Microstructure, selected mechanical properties (hardness, tensile testing) and corrosion resistance (short-term exposure AUDI test) were determined. The properties of the alloys were tested in as-cast state and after their recommended heat treatment. The significant influence of chemical composition on the properties of aluminum alloys was found.