Investigation of mechanical properties of anodized aluminum using dilatometric measurements

Mechanical properties of anodized aluminum were studied using the results of dilatometric measurements of thermal expansion of anodized Al (the symmetric structure Al2O3–Al–Al2O3). The 100-μm-thick Al2O3 oxide layer was formed in 4% aqueous solution of oxalic acid in the galvanostatic regime at a current density of 20 mA cm−2. Measurements of thermal expansion of anodized Al (Al and Mg alloy of 2.7–3.2%, and 0.3–0.6% Mn, and 0.5–0.8% Si) with the thickness of initial Al from 0.6 to 3.7 mm and ceramic from Al2O3 in the temperature range of 20–500 °C were conducted using an automatic quartz dilatometer. Intrinsic stress in the Al layer, the values of the modulus of elasticity, and the porosity of Al oxide formed on Al of different thickness are calculated.