Issues and Requirements for Aluminum Alloys Used in Aircraft Components: State of the Art

Aluminum alloys have always been the material of choice for the aircraft industry owing to their versatile attributes, such as excellent strength to weight ratio, good corrosion resistance, thermal conductivity, and low production cost after wood. However, these days composite materials, carbon fiber reinforced plastic and fiber metal laminate are substituting aluminum alloys mainly because of their incapability to work at high temperatures. Nonetheless, continuous research in these aluminum alloys will effectively combat with those modern polymer composites and carbon fiber reinforced plastic. And so forth, mechanical and tribological properties of aluminum alloys can nowadays be enhanced by adding a suitable reinforcement in an appropriate volume fraction. Reinforcements like micro or nano sized SiC, Al2O3, TiC, B4C, SiO2 and iron powder when used, can alter the microstructural characteristics that develop excellent physical and mechanical properties in aluminum alloys, primarily for aerospace applications. These alloys are being used in different aircraft components that have a relative motion, like actuators and track roll units of a control surface. Stress and wear are generated due to the relative motion of these components during take-off and landing, causing a rise in temperature. And hence, a brief study on moving components used in aircrafts and tribological behaviour of aircraft components is presented in the literature. Also considering that the selection of an appropriate material for the proper functioning of an aircraft component is critical, three most important properties viz. strength, fatigue and corrosion resistance of an aircraft have been provided. Therefore this review article emphasizes on the following topics: (1) aluminum alloys in the aerospace industries, (2) aircraft components with relative motion, their working and material being used, (3) substantial properties of aircraft components viz. strength, fatigue resistance and corrosion resistance, (4) tribological aspect of an aircraft, (5) elevated-temperature behaviour of aluminum alloys, and (6) role of reinforcement for improving properties. This review article is beneficial for those researchers and academicians who want to seek the understanding, pertaining to the usefulness of the aluminum in the aircraft industry.