High-cycle fatigue and tensile strength of AZ91 Mg alloy with MAO-epoxy duplex coating

In this study, an epoxy layer was formed by the immersion process, on the oxide layer grown by the micro-arc oxidation (MAO) treatment of the AZ91 magnesium alloy, using the thin film sealing technology, and its effect on fatigue and tensile stress under high cycle conditions was investigated. The microstructures of the AZ91 base material, MAO/AZ91 and MAO-epoxy/AZ91 samples, which were subjected to high-cycle fatigue tests and uniaxial static tensile tests, were assessed through the scanning electron microscope (SEM), X-ray diffraction (XRD) mechanical tests, and fatigue and tensile tests. As a result, the MAO-epoxy duplex coating, which has a homogeneous and compact structure, was observed to improve the fatigue limit value/life, yield strength, ultimate tensile strength, and percentage elongation values of the base material significantly.