Corrosion effects of runway de-icing chemicals on aircraft alloys and coatings

▶ Corrosion effects of urea and four new runway de-icing chemicals on Al alloy 2024, Mg alloy RZ5 and cadmium-plated and subsequently chromate-treated steel 4340 were examined by three types of corrosion tests. ▶ Corrosion effects of urea on Al alloy 2024 were more pronounced than those of the new de-icing chemicals, with pitting corrosion being evident in urea in all tests. ▶ The rate of corrosion in Mg alloy RZ5 was often higher in new de-icing chemicals than in urea, although the form of corrosion was the same in most cases, i.e., general corrosion. ▶ Corrosion effects of the five runway de-icing chemicals on cadmium-plated and subsequently chromate-treated steel 4340 were slightly different in all three tests, but some loss of the coating layers was detected in all cases.