Investigation into the effect of introducing functionalized hafnium carbide with GO in the epoxy coated aluminium alloy for aerospace components

Abstract

The inorganic nanofiller hafnium carbide (HfC) was modified with 4-amino-5-pyridin-3-yl-4H-triazole-3-thiol (APTT) and the resultant APTT/HfC was encapsulated with graphene oxide (GO) in the epoxy matrix (EP). The shielding behaviour of the epoxy coating on AA5086 aluminium alloy in the presence of various amount of GO enveloped with APTT/hafnium carbide was analyzed by EIS and SECM in seawater. The EIS measurements proved that the EP-GO/APTT-HfC had an increased coating resistance of 13,659.19 kΩ.cm2, even after 720 h subjected to the seawater. The surface protection of the EP-GO/APTT-HfC was also found to be 95.5 times higher than the pure EP after subjected to seawater for 1 h. SECM investigations showed that the lowest aluminium ion dissipation occurred at the EP-GO/APTT-HfC nanocomposite coated AA5086 aluminium alloy (1.0 I/nA). FE-SEM/EDX investigated that APTT/hafnium carbide was enhanced in the corrosion products that produced a strong passive coating layer. The new EP-GO/APTT-HfC coating had superior hydrophobic properties (WCA: 161º). The inclusion of APTT/HfC wrapped in graphene oxide in the epoxy bed showed excellent mechanical properties. For AA5086 aluminium alloy coated with EP-GO/APTT-HfC, an enhanced adhesive strength was obtained prior to seawater immersion (18.8 MPa). The GO/APTT-HfC develops a strong crystalline passive coating, which hinders the penetration of ions getting to the specimen. This causes the improved adhesion strength and the coating becomes intact even prolonged contact with the electrolytes. This newly created EP-GO/APTT-HfC coating has the potential to be employed as a coating material for aircraft components.