Recent advances in aircraft materials and their manufacturing technologies have enabled progressive growth in innovative materials such as composites. Al-based, Mg-based, Ti-based alloys, ceramic-based, and polymer-based composites have been developed for the aerospace industry with outstanding properties. However, these materials still have some limitations such as insufficient mechanical properties, stress corrosion cracking, fretting wear, and corrosion. Subsequently, extensive studies have been conducted to develop aerospace materials that possess superior mechanical performance and are corrosion-resistant. Such materials can improve the performance as well as the life cycle cost. This review introduces the recent advancements in the development of composites for aircraft applications. Then it focuses on the studies conducted on composite materials developed for aircraft structures, followed by various fabrication techniques and then their applications in the aircraft industry. Finally, it summarizes the efforts made by the researchers so far and the challenges faced by them, followed by the future trends in aircraft materials.

In the present investigation, the corrosion tendency of mild steel under acidic pH was studied by employing unused expired amiodarone (EAD) drug as a potential corrosion inhibitor by adopting the weight loss measurement method. The corrosion inhibition efficiency (IE) of the formed protective film (EAD) on the steel surface was analyzed using potentiodynamic polarization and AC-impedance spectroscopy studies. The surface morphology of the mild steel before and after corrosion (in 1.0 M HCl) was analyzed via scanning electron microscopy–energy dispersive X-ray spectroscopy (SEM–EDAX), atomic force microscopy (AFM), and thermodynamic studies. The weight loss measurement under different concentrations of EAD indicated that an excellent inhibition was displayed at a concentration of 0.001 M, and the IE was found to depend on both the concentration and molecular structure of EAD. A potentiodynamic polarization study revealed that EAD predominantly acted as a cathode inhibitor, and electrochemical impedance spectroscopy (EIS) confirmed the adsorption of EAD on the surface of mild steel, which obeyed Temkin’s adsorption isotherm model. The calculated thermodynamic parameters revealed that adsorption was spontaneous and exothermic.

The current work is motivated by the rising applications of value-regulated lead acid (VRLA) batteries. The performance of VRLA batteries depends on the type of electrolyte used. The gel electrolyte is an important factor that controls both the manufacturing process and the performance of VRLA batteries. We formulate polymer gel electrolytes composed of sodium alginate (NaAlg) with varying amounts of montmorillonite (MMT). The nature of gel electrolytes is analyzed by Fourier transform infrared (FTIR) spectroscopy, the ionic conductivity study and the water retention study. The gel electrolytes are subjected to electrochemical characterization methods like cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP). 2 wt% MMT@NaAlg shows better electrochemical performances. Galvanostatic charge–discharge (GCD) tests are performed on optimized gel electrolytes, and display a maximum discharge capacity of 138 μA h cm⁻² at a current density of 0.55 mA cm⁻². The prototype battery shows a maximum discharge capacity of 2.8 × 10⁻⁶ A h at a current density of 35 μA cm⁻². After 500 cycles, the battery accomplishes 89% discharge capacity. NaAlg-based gel electrolytes with additives can be used for the manufacturing of VRLA batteries.