Coating

TEHRAN, 31 August (MNA) — Researchers from the University of Science and Technology MISiS (NUST MISiS) have developed a unique technique for applying protective coatings to critical components and parts of modern technology.
Scientists from the Russian University MISIS (NUST MISIS) claim that the originality of their technology lies in combining the advantages of three deposition methods based on different physical principles in one technical vacuum cycle. By applying these methods, they obtained multi-layer coatings with high heat resistance, wear resistance and corrosion resistance, Sputnik reports.
According to the researchers, the original structure of the resulting coating resulted in a 1.5-fold improvement in corrosion resistance and high-temperature oxidation compared to existing solutions. Their results were published in the International Journal of Ceramics.
“For the first time, a protective coating of an electrode based on chromium carbide and a binder NiAl (Cr3C2–NiAl) was obtained by successive implementation of vacuum electrospark alloying (VES), pulsed cathode-arc evaporation (IPCAE) and magnetron sputtering (MS). ) is performed on one object. The coating has a compositional microstructure, which makes it possible to combine the beneficial effects of all three approaches,” said Philip, Head of the Laboratory “Innatural Diagnostics of Structural Transformations” at the MISiS-ISMAN Scientific Center. The education of Kiryukhantsev-Korneev is not indicated.
According to him, they first treated the surface with VESA to transfer the material from the Cr3C2-NiAl ceramic electrode to the substrate, ensuring high adhesion strength between the coating and the substrate.
At the next stage, during pulsed cathode-arc evaporation (PCIA), ions from the cathode fill defects in the first layer, latching cracks and forming a denser and more uniform layer with high corrosion resistance.
At the final stage, the flow of atoms is formed by magnetron sputtering (MS) to level the surface topography. As a result, a dense heat-resistant top layer is formed, which prevents the diffusion of oxygen from an aggressive environment.
“Using transmission electron microscopy to study the structure of each layer, we found two protective effects: an increase in load-bearing capacity due to the first layer of VESA and repair of defects with the application of the next two layers. Therefore, we have obtained a three-layer coating, the resistance of which to corrosion and high-temperature oxidation in liquid and gaseous media is one and a half times higher than that of the base coating. It would not be an exaggeration to say that this is an important result,” said Kiryukhantsev-Korneev.
The scientists estimate that the coating will increase the life and performance of critical engine components, fuel transfer pumps and other components subject to both wear and corrosion.
The Scientific and Educational Center for Self-Propagating High-Temperature Synthesis (SHS Center), headed by Professor Evgeny Levashov, unites scientists from NUST MISiS and the Institute of Structural Macrodynamics and Materials Science. A.M. Merzhanov Russian Academy of Sciences (ISMAN). In the near future, the research team plans to expand the use of the combined technique to improve heat-resistant alloys of titanium and nickel for the aircraft industry.