Innovative Nanocomposite Coating for Aluminum Alloy in the Aircraft Manufacturing Industry with Increased Mechanical Strength, Flame Retardancy, and Corrosion Resistance

Abstract

AbstractNanocomposites containing impermeable two‐dimensional materials are of significant interest for protecting metals against corrosion. Incorporating 4‐aminobutyltriethoxysilane (ABES) functionalized tantalum nitride (TaN) into a coating matrix enhances the barrier effect due to TaN's notable chemical and thermal stability. When integrated with graphitic carbon nitride (GCN) in polyurethane (PU), functionalized TaN significantly improves corrosion resistance and fire‐retardant capabilities. Electrochemical evaluations of aluminum coated with varying amounts of functionalized TaN/GCN in PU demonstrated substantial enhancements in protective behavior in chloride environments. The PU nanocomposite exhibited superior flame retardancy, with significant reductions in peak heat release rate (PHRR), total heat release (THR), and total smoke production (TSP) compared to pure PU. Flame retardancy tests demonstrated increased thermal stability, attributed to the synergistic effects between GCN and silanized TaN. Electrochemical impedance spectroscopy (EIS) measurements showed a high coating resistance of 8.89×1011 Ω cm2 for PU/functionalized TaN/GCN, even after 40 days of electrolyte exposure. Additionally, the PU/functionalized TaN/GCN coating demonstrated exceptional water repellency, indicated by a water contact angle (WCA) of 164°. Mechanical tests revealed that PU/functionalized TaN/GCN exhibited favorable adhesion strength and hardness, maintaining integrity even under prolonged immersion. These findings suggest that this nanocomposite is a promising coating component for aerospace applications. The integration of functionalized TaN/GCN within the PU matrix presents a novel approach to developing multifunctional coatings with enhanced performance across various metrics essential for aerospace materials.