Fatigue Behavior Characterization of Magnesium and Aluminum Alloys in Military Trainer Aircraft

The increasing demand for lightweight and durable materials in aviation industry necessitates continuous improvements in research into fatigue-resistant alloys to improve operational efficiency, safety, and cost-effectiveness. The estimation of the operational life of aeronautical structures is directly related to the study of their mechanical properties, particularly concerning fatigue behavior due to the constant exposure to cyclic loads. For this reason, the aeronautical sector often invests significant capital in research for the development of new alloys that enable high structural performance, lightness, low cost, high durability, and tolerance to environmental damage. Despite the advancements in composite materials, aluminum and magnesium alloys remain the primary materials used in aeronautical structures. This study aims to comprehensively assess the fatigue behavior of key magnesium and aluminum alloys traditionally used in aircraft structures, specifically Mg AZ91C-T4, Mg AZ81A-T4, Al 6061-T6, Al 2024-T351, and Al 7075-T6, under varying cyclic loading conditions. The objective is to provide insight into their mechanical resilience and suitability for aeronautical applications. The results indicate notable differences between the materials in terms of both mechanical strength and fatigue effects. These findings have direct applications in optimizing aircraft material selection, improving component reliability, and refining maintenance and operational strategies in relation to, for example, fuel savings. By identifying fatigue-resistant alloys, the study supports safer and more efficient and cost-effective aircraft operations, contributing to advancements in aerostructural engineering and long-term fleet sustainability.