INVESTIGATION OF THE STRUCTURE AND PHYSICOCHEMICAL PROPERTIES OF COMBINED NANOCOMPOSITE COATINGS BASED ON Ti-N-Cr/Ni-Cr-B-Si-Fe

Tentative data are presented on a new type of nanocomposite protective coatings produced by a combination of two technologies: plasma-detonation coating deposition with plasma jets and thin coating vacuum-arc deposition. For coatings of thickness 80-90 mu m, the structure, physicomechanical properties,and morphology have been investigated and their hardness,elastic Young modulus,and corrosion resistance in various media have been determined. The grain size of a Ti-N-Cr-based nanocomposite coating varied from 2.8 to 4 nm. The following phases and compounds formed as a result of the plasma interaction with the surface of a thick coating have been detected: (Ti,Cr)N (200), (Ti,Cr)N (220), gamma-Ni3Fe, hexagonal Cr2Ti, Fe3Ni, (Fe, Ni)N, and Ti-Ni compounds such as Ti2Ni, Ni3Ti, Ni4Ti3, etc. It has been found that the nanocomposite coating microhardness increased to (32 +/- 1.1) GPa. The elastic modulus estimated from the loading-unloading curves was (320 +/- 20) GPa. The protective coatings demonstrated an increased corrosion resistance in acidic and alkaline media in comparison with that of the stainless-steel substrate.