Preparation and properties of CNTs/2024 aluminum matrix composite micro-arc oxidation film

Aluminum alloys are prone to pitting and intergranular corrosion during use, which greatly limits their large-scale application. This study explores micro-arc oxidation (MAO) coatings on 1.5 wt.% CNTs/2024Al composites to improve corrosion resistance. Using a Na 2 SiO 3 -NaOH electrolyte at 430 V for 12 min, MAO coatings were prepared. SEM shows denser surfaces with smaller pores in CNTs-reinforced coatings due to CNTs optimizing discharge channels. XRD confirms α-Al 2 O 3 and γ-Al 2 O 3 phases, with higher crystallinity in CNTs/2024Al coatings. EDS detects C elements, indicating CNTs participation in film formation. Electrochemical tests in 0.5 wt.% NaCl show CNTs/2024Al-MAO has a lower corrosion current density (2.63 × 10 -7 A/cm 2 ) and higher charge transfer resistance, demonstrating superior corrosion resistance. MAO with CNTs offers a viable strategy for enhancing Aluminum Matrix Composites (AMCs) durability in harsh environments