Structure and Properties of Vacuum-arc Coatings of Chromium and Its Nitrides Obtained under the Action of Constant and Pulse High-voltage Bias Potential

Abstract

To reveal the regularities of structural engineering of vacuum-arc coatings based on chromium and its nitrides, the influence of the main physicotechnological factors (the pressure of the nitrogen atmosphere and the bias potential) in the formation of coatings was studied. It was discovered that during the deposition of chromium coatings the formation of the texture axis [100], as well as the macrodeformation of compression is happening. The supply of a high-voltage negative pulse potential to the substrate increases the mobility of the deposited atoms and leads to relaxation of the compression deformation. As the pressure increases from 210-5 Torr to 4.810-3 Torr, the phase composition of the coatings changes: Cr (JCPDS 06-0694) → Cr2N(JCPDS 35-0803) → CrN(JCPDS 11-0065). The supply of high-voltage pulses leads to the formation of a texture of crystallites with parallel growth surfaces planes having d ≈ 0.14 nm. The structure obtained by pulsed high-voltage action makes it possible to increase the hardness of the coating to 32 GPa and reduce the friction coefficient to 0.32 in the "chromium nitride-steel" system and to 0.11 in the "chromium nitride-diamond" system. The results obtained are explained from the viewpoint of increasing the mobility of atoms and the formation of cascades of displacements when using an additional high-voltage potential in the pulse form during the deposition of chromium-based coatings.

Modernization of Vacuum-Arc Deposition Technology of Multilayer Nanostructured Coatings

“…Метастабільність властивостей вакуумнодугових покриттів визначається нерівноважними умовами процесу формування їх структури (високі ступені переохолодження при конденсації, радіяційний вплив високоенергетичних часток конденсованого потоку плазми, складні багатокомпонентні види міжатомних зв'язків в синтезованих сполуках, вплив домішок і т.п.) [2][3][4][5].…”