EFFECT USING MICRO-ARC OXIDATION METHOD IN COATING WITH Y_2 O_3ON MECHANICAL PROPERTIES OF AL (2024-T4)
Author(s):
Baraa H. Al khaqani† & Ekbal Mohammed Saeed Salih‡
Affiliation(s):
†University of Babylon, College of Materials Engineering, Department of metallurgical engineering
‡College of Materials Engineering, University of Babylon, Hilla, Babil, Iraq
*Corresponding Author Email: [email protected]
This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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.