Hydrogen Permeation, and Mechanical and Tribological Behavior, of CrNx Coatings Deposited at Various Bias Voltages on IN718 by Direct Current Reactive Sputtering

Abstract

In the current work, the microstructure, hydrogen permeability, and properties of chromium nitride (CrN x ) thin films deposited on the Inconel 718 superalloy using direct current reactive sputtering are investigated. The influence of the substrate bias voltage on the crystal structure, mechanical, and tribological properties before and after hydrogen exposure was studied. It was found that increasing the substrate bias voltage leads to densification of the coating. X-ray diffraction (XRD) results reveal a change from mixed fcc-CrN + hcp-Cr 2 N to the approximately stoichiometric hcp-Cr 2 N phase with increasing substrate bias confirmed by wavelength-dispersive X-ray spectroscopy (WDS). The texture coefficients of (113), (110), and (111) planes vary significantly with increasing substrate bias voltage. The hydrogen permeability was measured by gas-phase hydrogenation. The CrN coating deposited at 60 V with mixed c-CrN and (113) textured hcp-Cr 2 N phases exhibits the lowest hydrogen absorption at 873 K. It is suggested that the crystal orientation is only one parameter influencing the permeation resistance of the CrN x coating together with the film structure, the presence of mixing phases, and the packing density of the structure. After hydrogenation, the hardness increased for all coatings, which could be related to the formation of a Cr 2 O 3 oxide film on the surface, as well as the defect formation after hydrogen loading. Tribological tests reveal that hydrogenation leads to a decrease of the friction coefficient by up to 40%. The lowest value of 0.25 ± 0.02 was reached for the CrN x coating deposited at 60 V after hydrogenation.

Corrosion behaviour of multilayer CrN coatings deposited by hybrid HIPIMS after oxidation treatment

“…Thermal stress is mainly due to the difference in the linear thermal expansion coefficient (CTE) between the substrate and the coating after deposition, resulting in a mismatch between the substrate and the coating during the postdeposition cooling. The CTE for CrN is 2.3 × 10 −6 K −1 , while the CTE for the stainless steel is much larger (around 15 × 10 −6 K −1 ) [23,25].…”

Recent Advances and Prospects in Design of Hydrogen Permeation Barrier Materials for Energy Applications—A Review

“…In 2018, Kashkarov et al [ 39 ] studied CrN x coatings on Inconel 718 superalloy with respect to microstructure, hydrogen permeability and tribology. They found that a mixed cubic CrN and hexagonal Cr 2 N structure has the lowest hydrogen permeability at 873 K (500 °C) and 2 atm hydrogen pressure due to higher packing density of the cubic phase.…”

Microstructure, Mechanical and Corrosion Properties of Column-Free CrNx Coatings Deposited by Closed Field Unbalanced Magnetron Sputtering

“…Chromium nitride (CrN) coatings deposited by magnetron sputtering have been widely studied as a potential protective coating for cutting tools, dies, friction parts, etc. because of their high hardness, good wear properties and corrosion resistance [1][2][3][4][5][6][7][8][9][10][11]. The CrN x coatings deposited by conversational direct current magnetron sputtering (DCMS) generally exhibit a loose columnar structure with porosity between the columnar grains [6][7][8][9][10].…”