Insight into synergistic corrosion inhibition of 3-amino-1,2,4-triazole-5-thiol (ATT) and NaF on magnesium alloy: Experimental and theoretical approaches

A novel mixture, comprising sodium fluoride (NaF) and 3-amino-1,2,4-triazole-5-thiol (ATT), was reported as an effective hybrid corrosion inhibitor for magnesium alloy in pH neutral NaCl solution. The highest efficiency (95.8%) was achieved when 50 mM NaF and 5 mM ATT were mixed. Both experimental and theoretical approaches were employed for addressing the synergism. The synergism was proposed as the formation of a double-layered inhibitors film, in which the lower layer is a uniform fluoride-enriched precipitate layer and the upper one is a hydrophobic adsorption layer. These two layers were mutually strengthened to produce an excellent inhibition effect as a whole.