Effect Using Micro-Arc Oxidation method in coating with 𝒀𝟐𝑶𝟑on mechanical properties of AL (2024-T4)

Micro arc oxidation (MAO) is an electro chemical oxidation process usually applied to light metals: Al, Mg, Ti. This technique has a great improvement on properties of these alloys because coating has been troubled by inherent porosity since its conception. By this technique, oxide coating on metals can present high hardness and a continuous barrier which offer protection against wear, corrosion, heat and also electrical insulation. In this study micro-arc oxidation (MAO) technique was used as a process to enhance the mechanical properties of Al 2024-T4 using a ceramic layer of Y_2 O_3with an average size of 5.5 µm at different concentration (3, 5, and 10%) in 1 g of KOH solution for 10 min. at 80 °C. Several tests were carried out to evaluate the efficiency of the deposited layer, including x-ray diffractometry (XRD), atomic force microscopy (AFM), hardness, wear testing and scanning electron microscopy (SEM). All results confirmed that the deposited layer of (Y_2 O_3) resulted in a positive change in properties: an increase in hardness of 136, 125 and 116% with respect to the reference sample, also a decrease in weight loss of 8, 10 and 11 g cm-2 with increasing concentration of Y_2 O_3. XRD confirmed the presence of Y_2 O_3as a maximum peak. SEM photographs also confirmed the presence of Y_2 O_3, which was distributed and permeated through the surface layer of the sample.