Optimizing mechanical and electrochemical behavior of aliphatic amine cured epoxy coatings via micaceous iron oxide and nanocrystalline aluminum

Purpose This study aims to develop and evaluate epoxy coatings enhanced with micaceous iron oxide (MIO) and nanocrystalline aluminum (Al) particles, focusing on improving mechanical and corrosion-resistance properties for extended durability. Design/methodology/approach Three epoxy coatings were fabricated by incorporating 1, 2 and 3 wt% MIO with a fixed 2 wt% of ball-milled Al particles. The coatings were thoroughly characterized using field emission scanning electron microscopy, thermogravimetric analysis, hardness and scratch resistance tests, nanoindentation and electrochemical impedance spectroscopy (EIS). The EIS measurements in 3.5 wt% NaCl solution were performed over various immersion periods (1 h, 7, 14, 21 and 30 days) to study the coatings’ corrosion behavior. Findings The coating with 2 wt% MIO exhibited superior corrosion resistance across all immersion periods, outperforming the other formulations. Although corrosion resistance initially declined after seven days of immersion, it improved significantly after extended exposure (14–30 days) due to the formation of protective oxide layers on the coating surface. The combination of MIO and nanocrystalline Al also enhanced the mechanical properties of the epoxy coatings, delivering improved hardness, scratch resistance and overall stability. Originality/value This study highlights the synergistic effect of MIO and nanocrystalline Al particles in epoxy coatings, demonstrating their potential to enhance both mechanical performance and long-term corrosion resistance. The research offers valuable insights into the formulation of advanced epoxy coatings for applications requiring durability under harsh conditions.