Chromium Nitride Layers Research Articles

Effect of PVD deposition method on indentation and friction wear characteristics with hydrogen embrittlement of CrN coated stainless steel for electric vehicle hydrogen valves

In this investigation, a chromium nitride layer was deposited on general austenite stainless steel (UNS S31603) by means of the physical vapor deposition coating method to improve the hardness, wear resistance, and hydrogen embrittlement resistance. Accordingly, the purpose of this investigation is to study the effect of different physical deposition methods on mechanical characteristics due to hydrogen embrittlement. Both the indentation and friction characteristics of the chromium nitride layer with in response to hydrogen embrittlement were examined. The ion beam-assisted deposition (IBAD) and arc ion plating (AIP) methods were used to densely deposit the coating layer with a thickness of approximately 2.0∼2.5 μm, and the hardness increased by around 1180.9 HV and 1638.6 HV, respectively, when compared with the base material (292.6 HV). In terms of the coating layer deposited using the IBAD method, all the base material was exposed after hydrogen embrittlement for 3 h, whereas in the case of the coating deposited using the AIP method, the base material began to be exposed locally following hydrogen embrittlement for 12 h. For the IBAD- and AIP-deposited coatings, the average friction coefficient was calculated as 0.52 and 0.34, respectively. In the case of the coating layer deposited using the IBAD method, the average friction coefficient increased by 0.29 after hydrogen embrittlement for 3 h, whereas the average friction coefficient of the coating layer deposited using the AIP method increased by 0.04 after hydrogen embrittlement for 48 h. Therefore, it can be seen that the AIP method is significantly better than IBAD in terms of mechanical characteristics with hydrogen embrittlement.

Properties of Multilayered CrN/VN Films Prepared Using a Hybrid System of High-Power Impulse Magnetron Sputtering and Pulsed Magnetron Sputtering

Nanomultilayered chromium nitride (CrN)/ vanadium nitride (VN) films with different layer thicknesses were synthesized on Si substrates using a hybrid system of reactive high-power impulse magnetron sputtering (HiPIMS) and pulsed magnetron sputtering. The microstructure and properties of the nanomultilayered CrN/VN films were investigated using X-ray diffraction (XRD), transmission electron microscopy (TEM), the nanoindentation method, and the friction wear test. The XRD results showed that the multilayered films exhibited nanocrystallite structure with a (200) preferred orientation, and the estimated crystallite size was not highly dependent on the CrN and VN layer thicknesses. Inserting the VN layers decreased the compressive stress slightly compared to that of the CrN monolayer film and increased the hardness by 4-5 GPa compared to that of the CrN and VN monolayer films. The friction coefficient of the multilayered films strongly depended on the CrN layer thickness rather than on the VN layer thickness.

Properties of CrN/TiN Multilayer Films With Nanoscale Layer Thickness

Chromium nitride (CrN)/titanium nitride (TiN) multilayer films at nanoscale layer thickness were prepared using a combination of reactive high-power impulse magnetron sputtering (HiPIMS) and pulsed magnetron sputtering. Each layer thickness was adjusted by controlling each deposition time. The hardness and Young’s modulus of the multilayer films, which were measured using nanoindentation technique, did not vary significantly with layer thickness. The film hardness ranged between 22 and 24.5 GPa, and the Young modulus was between 300 and 330 GPa. On the contrary, the compressive stress of the multilayer films gradually decreased with the increase in the TiN layer thickness. The friction coefficient of the multilayer film did not depend on the CrN layer thickness, but it reduced drastically to 0.2–0.3 with the increase in the TiN layer thickness in the range of the TiN layer thickness less than about 2 nm.

Surface roughness control in nanolaminate coatings of chromium and tungsten nitrides

Frictional forces arising during machining operations of cutting tools generate high temperatures at the tool-workpiece interface, promoting tool-wear phenomena. Surface roughness is acknowledged to contribute significantly to friction generation, and its control is therefore of paramount importance. Structural confinement of growth defects in multilayer coating architectures with individual layers thickness in the nanometric regime can help reduce surface roughness development. Here, a set of nanolaminate coatings consisting in an alternated repetition of cubic chromium nitride (CrN) and cubic tungsten nitride (c-WN) layers is fabricated via unbalanced DC magnetron Sputtering. The individual layers thickness range is between 100 and 10 nm. The reduction of surface roughness as a function of individual layers thickness is demonstrated by semi-contact Atomic Force Microscopy (AFM). Scherrer analysis performed on X-Ray Diffraction (XRD) crystallographic signals shows that the reduction in surface roughness is correlated to a reduction in crystallite size, modulated by the nanolaminate architecture. Conformity and uniformity of multilayer coatings is observed via FIB-SEM cross-section micrographs. The relative contribution of CrN and c-WN layers to the overall roughness development is investigated through a SEM cross-section micrograph-based analysis. The microstructural and topographical features of nanostructured CrN/c-WN multilayer coatings are correlated to the observations from the cross-section analysis and discussed in terms of the energy transfer to the growing surface during each deposition step. • Nanolaminate CrN/WN coatings are deposited via DC-magnetron sputtering. • Surface roughness decreases with the individual layers thickness. • The nanolaminate structure hinders the development of structural defects and asperities. • Roughness build-up is analyzed through a novel layer-by layer approach. • The contribution of the two materials is discussed in terms of sputtering yield differences.

Synthesis of plasma-nitrided Cr coatings on HT9 steel for advanced chemical barrier property in a nuclear cladding application

Chromium–chromium nitride multi-coating barriers were synthesized on HT9 steel disks using the electroplating and radiofrequency (RF) plasma nitriding techniques, respectively, to significantly mitigate fuel–cladding chemical interactions in sodium fast reactors. It was revealed that plasma nitriding not only synthesized an additional chromium nitride layer at the outer surface of the Cr coating but also had a significant crack-closure effect on hard Cr coatings. Further, Cr coatings nitrided for durations ranging from 0 to 72 h were investigated to observe crack-closure stages; notably, nitriding for 72 h at 600 °C and an RF power of 180 W resulted in the elimination of most visible interior and penetration cracks. Moreover, an additional 0.75–1 μm thick nitride layer at the outer surface of the Cr coating included columnar grains of CrN and Cr2N phases aligned with the growth direction. Diffusion couple tests of Ce–Nd alloys at 650 °C for 25 h revealed that the 72-h-nitrided Cr coating possessed an excellent barrier property without any visible inter-diffusion, in contrast with the untreated Cr coating, for which a substantial inter-diffusion area of up to 17,500 μm2 was observed.

Tribological characterization of hybrid chromium nitride thin layer synthesized on titanium

The chromium nitride thin film was synthesized on the pure titanium substrate by using hybrid coatings methods. The chromium electroplating and plasma nitriding was employed to obtained proper chromium nitride thin film. Chromium crack-free coating was obtained by an electroplating method using 30 A/dm2 within 15 min and plasma nitriding was applied at 600 °C for 8 h. Cr2N is the determined phase on the surface of the substrate and surface microhardness reaches 1109 HV0.25. Pin on disk test was conducted and the average friction coefficient decreased about 86% from 1.12 to 0.16. Due to the formation of a crack within the plasma nitriding process, the corrosion resistance of the chromium nitride layer decreased in comparison to chromium coating. Also, coupling phases cause galvanic corrosion in the surface of the coated samples.

Effect of zirconium addition on the phase evolution of chromium zirconium nitride prepared by magnetron sputtering

Abstract In the research reported in this contribution, chromium-zirconium nitride (CrZrN) layers were deposited on (100) silicon wafer by balance magnetron sputtering using argon and nitrogen as working and reactive gas, respectively. The coating layers were categorized into three groups according to zirconium content; low-zirconium (Low-Zr), medium-zirconium (Med-Zr) and high-zirconium (High-Zr). All layers had thicknesses in the range of 1.0-1.3 μm and the Med-Zr was the thickest sample. From the X-ray diffraction (XRD) results, zirconium could partially dissolve in chromium nitride (CrN) and formed complex nitride of chromium-zirconium [(Cr,Zr)N]. This phasic group was dominant for all samples, and the average crystallite sizes decreased with increasing zirconium fraction. In addition, the High-Zr sample had an extra broadened peak among (Cr,Zr)N peaks which could not clearly be identified by XRD. This ambiguity was eliminated by X-ray photoelectron spectroscopy (XPS). It was determined to be amorphous of zirconium oxynitride (Zr2ON2). Because of the high oxygen sensitivity of zirconium, it reacted with nitrogen and residual oxygen forming Zr2ON2. This study is among the first to examine the resulting nanoscale structure of the CrN layers incorporated with a high amount of zirconium.

Effect of zirconium addition on the phase evolution of chromium zirconium nitride prepared by magnetron sputtering

Abstract In the research reported in this contribution, chromium-zirconium nitride (CrZrN) layers were deposited on (100) silicon wafer by balance magnetron sputtering using argon and nitrogen as working and reactive gas, respectively. The coating layers were categorized into three groups according to zirconium content; low-zirconium (Low-Zr), medium-zirconium (Med-Zr) and high-zirconium (High-Zr). All layers had thicknesses in the range of 1.0-1.3 μm and the Med-Zr was the thickest sample. From the X-ray diffraction (XRD) results, zirconium could partially dissolve in chromium nitride (CrN) and formed complex nitride of chromium-zirconium [(Cr,Zr)N]. This phasic group was dominant for all samples, and the average crystallite sizes decreased with increasing zirconium fraction. In addition, the High-Zr sample had an extra broadened peak among (Cr,Zr)N peaks which could not clearly be identified by XRD. This ambiguity was eliminated by X-ray photoelectron spectroscopy (XPS). It was determined to be amorphous of zirconium oxynitride (Zr2ON2). Because of the high oxygen sensitivity of zirconium, it reacted with nitrogen and residual oxygen forming Zr2ON2. This study is among the first to examine the resulting nanoscale structure of the CrN layers incorporated with a high amount of zirconium.

Experimental Investigation of Single Bubble Nucleate Boiling in Microgravity

The multiscale boiling project, also known as RUBI, is an experimental project supported by the European Space Agency (ESA) focusing on the nucleate boiling within the framework of the utilization of the International Space Station (ISS). In order to investigate the operational behavior of the experimental components and determine a promising parameter range, an experimental setup with the same heater design is constructed and tested within the similar parameter range in the framework of the ESA 70th parabolic flight campaign. The present work introduces the experimental setup as well as the measurement methodologies. It concentrates on the results obtained for the nucleate boiling in the absence of external forces such as electric field or shear flow, which are also part of the multiscale boiling project. A barium fluoride glass sputtered with chromium on the top of a chromium nitride layer served as the heater. The manufacturing process of the heater substrate is presented in detail. In order to generate a vapor bubble in the subcooled liquid pool, a laser beam is used to provide the necessary heat at an artificial nucleation site situated at the center of the glass. The experimental setup allows for time adjustment between switch-on of the heater and shooting the laser which is defined as preheating time. The effect of the preheating time on the nucleation and behavior of the bubbles is investigated. Furthermore, by selecting a long laser pulse duration the influence of the laser thermal energy on the growth of the bubbles is studied. It is observed that the preheating time has a significant effect on the bubble growth. However, no influence of the laser shot is detected on the bubble growth, even for a long pulse duration.

Characteristics and properties of Cr[sbnd]N compound layer produced by plasma nitriding of Cr-electroplated of AISI 304 stainless steel

In this work, plasma nitriding of the Cr-electroplated coating on a 304 stainless steel (304 SS) was carried out at 700 °C in pure ammonia for different times (2 h, 3 h and 4 h). After plasma nitriding, a thin (1–2 μm) and compact chromium nitride layer mainly composed of Cr2N phase was formed on the surface region of Cr-electroplated coating. The corrosion resistance of CrN layers was examined in the proton exchange membrane fuel cell working environment to evaluate the possible application of the duplex-treated 304 stainless steel for bipolar plates. Before and after corrosion test the interfacial contact resistance was measured to determine the effect of nitriding on the electrical conductivity of all samples. The results show that the CrN compound layer has a very low passive current density 0.13 μA cm−2 and interfacial contact resistance 4.5 mΩ cm2.

Improved Mechanical Properties, Wear and Corrosion Resistance of 316L Steel by Homogeneous Chromium Nitride Layer Synthesis Using Plasma Nitriding

Here, pulsed plasma nitriding of AISI-316L austenite stainless steel is conducted in a narrow range of temperature 510-550 °C and simultaneous combination of expanded austenite phase, and homogenous, dense chromium nitride phase is attained in a single processing unit, with relative low-cost equipment and single-step processing. The results show a noteworthy enhancement in nanohardness at 530 °C, whereas best wear resistance is achieved by processing at 550 °C. A dual-layer structure is obtained constituted of expanded austenite phase covered by quite homogenous chromium nitride phase, which is probably responsible for the dramatic surface improvement. The wear mechanism is changed after plasma processing (abrasive to adhesive wear), and the friction coefficient is reduced and smoother, particularly for the sample treated at 530 °C. Interestingly, the corrosion resistance is also found to be enhanced, even in the presence of chromium nitride (which usually deteriorate the corrosion resistance), which is probably credited to the formation of fine-grained and homogeneous CrN layer over the expanded austenite phase. This study suggests that the development of homogenous CrN layer over the expanded austenite structure is highly valuable for mechanical and tribological features, and it enhances the corrosion resistance.

Residual stress measurement of {112}-oriented CrN layers in CrN/Cr multilayer films

In this work, the authors propose and verify a method of measuring the residual stress of {112}-oriented chromium nitride (CrN) layers in CrN/Cr multilayer thin films. The CrN layers of a CrN/Cr multilayer film deposited on a Ti6Al4V substrate by arc ion plating form both a randomly oriented mixed crystal structure and a {112}-oriented structure. Therefore, accurate stress measurement of the CrN layers cannot be performed by applying the sin2 ψ x-ray method assuming an isotropic homogeneous material. To overcome this obstacle, the proposed method to measure the residual stress uses four CrN-422 diffractions: at ψ = 0°, 33.56°, 48.19°, and 60.00°. Next, the authors vary the density of Cr droplets on the film surface to evaluate how it affects the residual stress in the CrN/Cr multilayer film. The results indicate that the Cr layer has a residual compressive stress of −350 to −530 MPa and that the two CrN layers have a very large residual compressive stress of −3.5 to −8.2 GPa. In addition, both residual compressive stresses decrease with increasing droplet density.

High performance of 3D silicon nanowires array@CrN for electrochemical capacitors

Silicon nanowire (SiNW) arrays were coated with chromium nitride (CrN) for use as supercapacitor electrodes. The CrN layer of different thicknesses was deposited onto SiNWs using bipolar magnetron sputtering method. The areal capacitance of the SiNWs-CrN, as measured in 0.5 M H2SO4 electrolyte, was as high as 180 mF cm−2 at a scan rate of 5 mV s−1 (equivalent to 31.8 mF cm−2 at 1.6 mA cm−2) with an excellent electrochemical retention of 92% over 15 000 cycles. This work paves the way toward using CrN modified 3D SiNWs arrays for micro-supercapacitor application.

Dependence of Wear and Mechanical Behavior of Nitrocarburized/CrN/DLC Layer on Film Thickness

Diamond-like carbon (DLC) films are amorphous metastable carbon form that provide interesting mechanical and tribological properties. The role of film thickness influence upon wear and mechanical properties is of interest and not yet fully reported. In this study, two samples of previously plasma nitrocarburized, quenched and tempered H13 steel were duplex treated. First, a physical vapor deposition (PVD) chromium nitride (CrN) layer was applied, followed by a top final diamond-like carbon layer applied by plasma-enhanced chemical vapor deposition (PECVD). To evaluate thicknesses influence on mechanical and wear properties of coatings, samples were treated using two different thicknesses of both layers. In this study, the thickest CrN and DLC case presented higher hardness and better tribological properties, however, its failure occurs in brittle fashion.

Effects of intermediate Ar plasma treatments on CrN coating microstructures and property evolutions

Chromium nitride (CrN) coatings with different steps of intermediate argon plasma treatments were deposited with primary (200) orientation by multi-arc ion plating technique. By virtue of scanning electron microscopy, X-ray diffraction and high-resolution transmission electron microscopy, the influence of intermediate argon plasma treatments on the coating microstructures, mechanical properties and corrosion properties as well as tribological behaviors in artificial seawater solutions were systematically investigated. It was assumed that the mechanical properties, adhesion strength, corrosion and tribological performances of coatings depended on argon plasma treatment steps. High-performance coatings could be obtained by proper plasma treatment steps. The superior anti-corrosion ability of coating with appropriate treatment steps may be ascribed to the increased charge transfer resistance due to alternative interface and CrN layer and the compact microstructure. On the other hand, the excellent tribological performances in seawater conditions may be attributed to the enhanced mechanical properties. Otherwise, further increase in treatment steps was assumed to distinctly increase defects and deteriorate the coating integrity thus weakening coating properties and behaviors. Copyright © 2016 John Wiley & Sons, Ltd.

Atomic Scale Interface Manipulation, Structural Engineering, and Their Impact on Ultrathin Carbon Films in Controlling Wear, Friction, and Corrosion.

Reducing friction, wear, and corrosion of diverse materials/devices using <2 nm thick protective carbon films remains challenging, which limits the developments of many technologies, such as magnetic data storage systems. Here, we present a novel approach based on atomic scale interface manipulation to engineer and control the friction, wear, corrosion, and structural characteristics of 0.7-1.7 nm carbon-based films on CoCrPt:oxide-based magnetic media. We demonstrate that when an atomically thin (∼0.5 nm) chromium nitride (CrNx) layer is sandwiched between the magnetic media and an ultrathin carbon overlayer (1.2 nm), it modifies the film-substrate interface, creates various types of interfacial bonding, increases the interfacial adhesion, and tunes the structure of carbon in terms of its sp(3) bonding. These contribute to its remarkable functional properties, such as stable and lowest coefficient of friction (∼0.15-0.2), highest wear resistance and better corrosion resistance despite being only ∼1.7 nm thick, surpassing those of ∼2.7 nm thick current commercial carbon overcoat (COC) and other overcoats in this work. While this approach has direct implications for advancing current magnetic storage technology with its ultralow thickness, it can also be applied to advance the protective and barrier capabilities of other ultrathin materials for associated technologies.

The Feasibility of Usage TiN and CrN Barrier Sublayers for Improving the Adhesion of Polycrystalline Diamond Films on WC-Co Hard Alloys

In the present study, the influence of Chromium nitride (CrN) and Titanium nitride (TiN) sublayers on the adhesion of polycrystalline diamond films applied to WC-Co substrates was investigated. CrN and TiN layers were deposited on WC-Co substrates by magnetron sputtering in Ar/N2 atmosphere. Synthesis of diamond films was conducted in an AC abnormal glow discharge CVD reactor. The phase composition of the films was characterized by small-angle X-ray diffraction (XRD). The adhesion of diamond films was compared by analysis of Rockwell indentation imprints. It was found that TiN does not react with the carbon of the diamond film while CrN almost completely converted into chromium carbide (Cr3C2). Adhesion tests showed that the efficiency of these sublayers usage is substantially lower than using a Murakami and HNO3/H2O pretreatment.

An investigation on corrosion protection of chromium nitride coated Fe–Cr alloy as a bipolar plate material for proton exchange membrane fuel cells

The corrosion properties of chromium nitride (CrN) coating are investigated to assess the potential use of this material as a bipolar plate for proton exchange membrane fuel cells (PEMFCs). Conductive metallic ceramic CrN layers are firstly deposited onto Fe–Cr alloy using a multi-arc ion plating technique to increase the corrosion resistance of the base alloy. Electrochemical measurements indicate that the corrosion resistance of the substrate alloy is greatly enhanced by the CrN coating. The free corrosion potential of the substrate is increased by more than 50 mV. Furthermore, a decrease in three orders of magnitude of corrosive current density for the CrN-coated alloy is observed compared to the as-received Fe–Cr alloy. Long-term immersion tests show that the CrN layer is highly stable and effectively acts as a barrier to inhibit permeation of corrosive species. On the contrary, corrosion of the Fe–Cr alloy is rather severe without the protection of CrN coating due to the active dissolution. Finally, the corresponding electrochemical impedance models are proposed to elucidate the corrosion process of the CrN/Fe–Cr alloy submerged in a simulated PEMFCs environment.

Antibacterial PVD coatings doped with silver by ion implantation

• Silver ion implantation of CrN PVD layers deposited on stainless steel substrates. • Mechanical and tribological properties remain stable or experience slight improvements. • Contact angle increases after implantation in wetability tests. • Implanted samples show clear antibacterial capability according to the JIS Z 2801:2010 Standard test. The antibacterial effect of certain metal ions, like silver, has been exploited since antiquity. Obviously, the ways to employ the biocide activity of this element have evolved throughout time and it is currently used in a wide range of clinical applications. The work presented here reports the results of an investigation focused on combining the protective properties of PVD coatings with the biocide property of silver, applied by ion implantation. For this purpose, chromium nitride layers were doped with silver implanted at two different doses (5 × 10 16 and 1 × 10 17 ion/cm 2 ) at 100 keV of energy and perpendicular incidence. Full characterization of the coatings was performed to determine its topographical and mechanical properties. The concentration profile of Ag was analyzed by GD-OES. The thickness of the layers, nano-hardness, roughness, wear resistance and coefficient of friction were measured. Finally, the anti-bacterial efficacy of the coatings was determined following the JIS Z-2801:2010 Standard. The results provide clear insights into the efficacy of silver for antibacterial purposes, as well as on its influence in the mechanical and tribological behaviour of the coatings matrix.

Comparisons of Wear Performance of Hardened Inconel 600 by Different Nitriding Processes

This paper describes the structure and properties of nitrided layers produced on the Inconel 600 alloy (16.5wt%Cr, 9wt%Fe, 2wt%Mn, 0.4wt%Co, balance-Ni). The characteristics of the nitrided layers at the surface were investigated by microscopic examinations, X-ray diffraction analyses, hardness measurements and wear tests. It was found that the diffusion-type chromium nitride layer produced on the alloy surface greatly decreased wear rates and slightly increased surface hardness.