To protect the offshore and onshore infrastructure metalwork in the Arctic conditions, the NUST MISIS scientists have proposed a composite coating with the addition of organic polymer, which not only actively prevents the spread of corrosion but also possesses anti-icing features. Offshore and onshore infrastructure facilities covered with the new composite material will have a long service life, which will significantly save money on repair and replacement of equipment. The outcomes of experiments are to be found in the scientific Surface and Coatings Technology journal.
The offshore infrastructure makes use of a large number of metal mechanisms exposed to tribocorrosion, being the destruction of the material surface in an aggressive external environment under the concurrent influence of friction and corrosion. In the Arctic conditions, another negative factor reducing the durability of metalwork is icing, which significantly accelerates corrosion due to an increased mechanical load.
The MISIS University scientists have developed a wear-resistant and corrosion-resistant composite coating with enhanced hydrophobic and anti-icing properties for the marine industry metalwork. As noted in the study, water droplets rolling off rapidly from the hydrophobic surface render it possible to mitigate the risk of corrosion damage and the probability of icing.
The researchers proposed adding a top layer of graphite and polytetrafluoroethylene (a polymer remarkable for its hydrophobic properties, often also called fluoroplastic) to the structure of a titanium carbide-based hard coating. This combination of components enabled the coating to retain its high wear and corrosion resistance, while providing it with high hydrophobicity and a low friction factor.
“A study of the structure, tribocorrosion behavior, wettability and adhesion to ice of coatings obtained by vacuum electrospark deposition demonstrated that the PTFE addition increases hydrophobicity and considerably extends the freezing time of a water droplet to 65 seconds, giving it virtually no chance to freeze on the surface. And if ice does form, the adhesion strength of the treated surface with ice is reduced down to 0.38 MPa, which guarantees its complete removal when breaking off. At the same time, high tribocorrosion characteristics of the coating are preserved,” Konstantin Kuptsov, a co-author of the study, Senior Researcher at the NUST MISIS SHS Center, said.
The composite coating proposed by the researchers may be effectively used not only in the offshore infrastructure but also in other areas where anti-corrosion, wear-resistant coatings that do not freeze at low temperatures are required, for example, in the aviation or automotive industries.