The Influence of Layers Thickness on the Structure and Properties of Bilayer Multiperiod Coatings Based on Chromium Nitride and Nitrides of Transition Metals Ti and Mo

Authors O.V. Sobol1, A.A. Meylekhov1 , R.P. Mygushchenko1, А.А. Postelnyk1 , Taha A. Tabaza2, Safwan M. Al-Qawabah2, V.F. Gorban3 , V.A. Stolbovoy4

1 National Technical University «Kharkiv Polytechnic Institute», 21, Kyrpychov Str., 61002 Kharkiv, Ukraine

2 Al-Zaytoonah University Queen Alia, 594, Airport Str., 11733, Amman, Jordan

3 Frantsevich Institute for Problems of Materials Science, 3, Krzhizhanovsky Str., 03142 Kyiv-142, Ukraine

4 National Science Center Kharkiv Institute of Physics and Technology, 1, Akademicheskaya Str., 61108 Kharkiv, Ukraine

Issue Volume 10, Year 2018, Number 1
Dates Received 25 July 2017; published online 24 February 2018
Citation O.V. Sobol, A.A. Meylekhov, et al., J. Nano- Electron. Phys. 10 No 1, 01010 (2018)
DOI 10.21272/jnep.10(1).01010
PACS Number(s) 81.07.Bc, 61.05.cp, 61.82.Rx 61.50.Ks, 62.25. – g
Keywords Vacuum arc, Multi-period coatings, CrN (7) , MoN (47) , TiN (97) , Layer thicknessm, Bias potential (2) , Phase composition (3) , Structure (105) , Computer simulation (2) , Hardness (12) , Friction coefficient.

The influence of the layers thickness of bilayer multi-period coatings of the CrNx/MoNx and CrNx/TiNx systems on their phase-structural state, substructure, stress-strain state and mechanical properties was studied using methods of precision structural analysis in combination with computer simulation of implantation processes during particle deposition. It is established that a two-phase structure of CrN and g-Mo2N phases of the structural type NaCl is formed in the multi-period coatings of the CrNx/MoNx system with a nanometer thickness of the layers. Because of the small difference in periods (less than 0.5 %) for Λ < 20 nm, the layers form a coherent interlayer interface. The use of small Ub = – 20 V during deposition makes it possible to avoid significant mixing at interlayer (interphase) boundaries even at the smallest Λ = 10 nm. Nitride layers formed under conditions of vacuum arc deposition are under the action of compressive stresses.

In the СrNх/TiNх system, because of the relatively large discrepancy between periods (more than 2.5 %), during the formation of the same structural components in the layers (CrN and TiN phases of the structural type NaCl), the epitaxial growth with period adjusting does not occur, even for the smallest Λ = 10 nm. The action of the deformation factor at the interphase boundary allows achieving an ultrahard state (with a hardness of about 50 GPa), which causes a relatively low friction coefficient.

The obtained results on the formation of phase-structural states with the nanoscale thickness of layers of multi-period nitride coatings are explained from the position of minimization of surface energy and deformation energy.

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