CrN Films Research Articles

To assure the industrial scale deposited CrN films can be used on Ti bipolar plates by HiPIMS method

Benefited from the high-power impulse magnetron sputtering (HiPIMS) method with small targets (most of them in 2–4 in.) in labs, many published works reported that excellent anti-corrosion and interface conductivity CrN films were obtained in a wide processing window, which is favor in the coating industry. However, a paramount concern is whether this technology could achieve industrial mass production in large vacuum coating equipment with high loading capacity. To assure this, in the present work, a series of CrN films were prepared under different sputtering currents of Cr target by HiPIMS using Cr cylindrical targets with height and diameter of 675 mm and 100 mm, respectively. The effects of sputtering current on the electrical conductivity, corrosion resistance and mechanical properties were investigated. However, often stated as fact that the wide process window in labs turns narrow under industrial scale depending on HiPIMS. Only that the CrN film deposited at the Cr target current of 500 A showing best anti-corrosion and interface conductivity. Our results show that beautiful data obtained under lab scale cannot directly be generalized under industrial scale, which should be carried out in a more serious light.

Application of Cr-N and Fe-Pd Thin Films to Tactile Sensors for Simultaneous Strain and Temperature Measurement

Application of Cr-N and Fe-Pd Thin Films to Tactile Sensors for Simultaneous Strain and Temperature Measurement

Evaluation of Corrosion Resistance of TiN and CrN Films Coated on SS304 Stainless Steel Using Cathodic Arc Deposition

Monolayer (TiN/Ti) and multilayer films (TiN/Ti; CrN/Ti, TiN/CrN/Ti) with an average thickness of 2300 nm were deposited on SS304 steel using the cathodic arc deposition method. Analysis revealed the presence of numerous macroparticles (peaks) and pinholes (valleys) uniformly distributed across the surface. The monolayer film exhibited superior surface quality compared to the multilayer films but demonstrated poor adhesion to the substrate. X-ray diffraction spectroscopy detected a noticeable shift in the preferred orientation of the deposited film, transitioning from (111) to (200) when employing a multilayer structure. Applying ceramic coatings onto stainless steel induced significant alterations in the potentiodynamic polarization curves of monolayer and multilayer films, resulting in a shift towards more noble potentials and lower corrosion currents than the substrate. Furthermore, the potential passive range expanded when employing multilayer structures based on TiN and CrN.

High performance symmetric supercapacitors based on Au incorporated CrN thin films fabricated by reactive magnetron sputtering

Recently, transition metal nitrides are being investigated extensively as potential supercapacitor material. In the present study, Au incorporated CrN (Au_CrN) thin films have been synthesized using reactive magnetron co-sputtering technique for application as supercapacitor electrode material. Films have been prepared at different Ar to N2 flow rates keeping total deposition pressure constant to achieve the required structural phase in the sample. Electrochemical properties of the deposited materials have been investigated with a three-electrode system in 0.5 M H2SO4 aqueous electrolyte. The CrN thin film deposited under 3:1 Ar: N2 partial pressure or flow rate ratio shows the highest specific capacitance. Upon Au incorporation, the film shows an areal capacitance of 56.8 mFcm−2 at 1.0 mAcm−2discharge current density which is an almost nine-fold enhancement in specific capacitance value compared to pristine CrN sample. Symmetric supercapacitors have also been developed by sandwiching two identical Au_CrN thin film electrodes, which have found to deliver excellent specific capacitance of 86.03 mFcm−2at 1.0 mAcm−2 discharge current density with no decline in capacitance value till 20,000 cycles. Furthermore, it can deliver a high energy density of 52.02mWhcm−2and a power density of 0.12mWcm−2. The electrochemical properties of the supercapacitors fabricated with the Au_CrN thin film electrodes are found to be better than most of the results reported so far in the literature with CrN electrodes. Results of the present study clearly demonstrate that these Au enhanced CrN films prepared by easily scalable and highly reproducible magnetron sputtering technique have great potential as a high capacitance supercapacitor electrode material.

Effect of Stellite12 and NiCrBSi HVOF coatings on the tribological behavior of CrN PVD film

CrN film deposited on the stainless steel substrate is easy to crack and peel off due to the intrinsic brittleness and the low load carrying capability, which severely constricts its practical utilization under high load conditions. In this paper, CrN/Stellite12 and CrN/NiCrBSi duplex coatings were produced by PVD and HVOF technologies, then the microstructure, mechanical, and tribological properties was studied, and compared with single CrN film. The HVOF layers improved the hardness, binding strength and load carrying capability of duplex coatings, the wear resistance also be enhanced significantly, especially for CrN/NiCrBSi. We analyzed the wear mechanism and discussed the influence of different HVOF coatings on the tribological behavior.

Effect of different HVOF coatings on the tribological behavior of PVD/HVOF duplex coatings

CrN film shows obvious differences in hardness, elastic modulus, and thermal expansion coefficient between film and substrate, suffering from poor adhesion and wear resistance. Here we combined PVD and HVOF technologies to produce CrN/WC-12Co and CrN/WC-10Co-4Cr coatings, and then compare their mechanical and tribological behavior with that of CrN film. We show that the PVD/HVOF coatings exhibit higher hardness, load carrying capability, and adhesion; the wear resistance also be improved greatly, especially for CrN/WC-10Co-4Cr. We discuss the wear mechanism of such duplex coatings and analyze the influence of different HVOF coatings on the deposition characteristic of CrN film.

Comparative study of anti-corrosion properties in different CrN/WC-Co duplex coatings processed by PVD/HVOF

WC-Co coatings produced by high-velocity oxy-fuel (HVOF) show the high porosity which limits their application in seawater. Herein, we prepared CrN/WC-12Co and CrN/WC-10Co-4Cr duplex coatings combined with the physical vapor deposition (PVD) and HVOF technologies. The microstructure and the corrosion behavior were studied and compared with WC-Co coatings. The CrN film covers the pores on the surface of WC-Co coatings which enhances the corrosion resistance. In addition, the corrosion products of WC-10Co-4Cr coating seal the defects in the CrN film, and further improve the corrosion resistance of the duplex coatings. The CrN/WC-Co duplex coatings enhance the corrosion resistance of WC-Co coatings, especially for CrN/WC-10Co-4Cr, which greatly increases the corrosion potential and reduces the corrosion current density of WC-Co coatings.

Effect of magnetron sputtering C-doped CrN film on the conductivity and corrosion resistance of 304 stainless steel bipolar plates

Using a high-power impulse and direct current (DC) magnetron sputtering approach, C-doped CrN films with various C-target pulse frequencies are created on the surface of SS 304. The microstructure, corrosion resistance and conductivity of the films are examined. With the decreases of C-target pulse frequency, the roughness of the CrCN films decreases and the density increases. The results of XPS and TEM analyses demonstrate that C atoms are either present in CrN lattice as interstitial atoms or precipitate at grain boundaries to form amorphous carbon, which facilitates the increase of film density and conductivity. In the potentiodynamic tests, the CrCN-1000 Hz film exhibits the lowest corrosion current density 0.54 μA/cm2 at 0.6 V vs. Ag/AgCl potential. The values of icorr and Ecorr are 0.11 μA/cm2 and 0.427 V, respectively. Furthermore, the CrCN-1000 Hz film has the lowest interface contact resistance (ICR) under a compaction force of 140 N/cm2 after potentiostatic polarization test, indicating that C doping is beneficial to improve the corrosion resistance and conductivity of CrN film.

Enhanced Thermoelectric Properties by Embedding Fe Nanoparticles into CrN Films for Energy Harvesting Applications

Enhanced Thermoelectric Properties by Embedding Fe Nanoparticles into CrN Films for Energy Harvesting Applications

High-Power Impulse Magnetron Sputter-Deposited Chromium-Based Coatings for Corrosion Protection

The use of high-power impulse magnetron sputtering (HIPIMS) to deposit chromium-based thin films on brass substrates for the purpose of corrosion-protective coating was investigated. By varying the process parameters (pulse frequency, pulse width and N2 flow rate) and structure design, including single-layer and multilayer structures, the obtained results revealed that the Cr-N films deposited through the use of HIPIMS exhibited higher film density and corrosion resistance compared to traditional direct-current magnetron sputtering. Based on the results of a field test using copper-accelerated acetic acid solution, the Cr-N film with a multilayered structure can further extend the time to corrosion onset. This is because the bottom layer in the multilayer structure can block structural defects in the layer above it, effectively reducing the penetration of corrosive agents into the substrate. The high bias voltage, coupled with increased temperature during deposition, led to a dezincification effect, resulting in the reduced adhesion of the film to the substrate and decreased overall corrosion resistance.

Improving the tribological behavior of CrN film by PVD/HVOF design

Herein, CrN/WC–12Co duplex coatings were fabricated using physical vapor deposition (PVD) and high-velocity oxygen fuel (HVOF) technologies. The microstructure, mechanical properties, and tribological behavior of these coatings were studied and compared with those of a single CrN film. Although the WC–12Co interlayer did not change the phase structure of the top CrN film, it significantly improved the hardness, Young's modulus, load-bearing capability, and bonding strength. The wear resistance of the CrN/WC–12Co duplex system was twice that of a single CrN film. Moreover, the WC–12Co interlayer changed the wear mechanism from fatigue and polishing wear of single CrN film to the polishing wear of CrN/WC–12Co duplex coating.

Phase Composition and Thermoelectric Properties of Epitaxial CrMoVN Thin Films

Thin films of CrMoVN are deposited on c‐plane sapphire (Al2O3 (0001)) by direct current reactive magnetron sputtering, to investigate the effects of Mo and V addition to CrN‐based films. All films grow epitaxially, but Mo incorporation affects the crystal structure and nitrogen content. All films in the CrMoVN series are understoichiometric in nitrogen, but largely retain the NaCl B1 structure of stoichiometric CrN films. Addition of vanadium increases the phase‐stability range of the cubic phase, allowing for higher solubility of Mo than what has previously been reported for cubic CrN. The Seebeck coefficient and electrical resistivity are greatly affected by the alloying, showing a decrease of the Seebeck coefficient along with a decrease in resistivity. Cr0.83Mo0.11V0.06Nz shows a 70% increase in power factor (S2σ = 0.22 mW m−1 K−2) compared to the reference CrNz (S2σ = 0.13 mW m−1 K−2).

High corrosion resistance and conductivity of Al2O3/CrN coating for metal bipolar plates in PEMFCs: Al2O3 hinders CrN columnar crystals growth

An excellent corrosion-resistant and good conductivity coating is desired for metal bipolar plate (BP) in proton exchange membrane fuel cell (PEMFC). In this view, a novel strategy to achieve this aim by introducing Al2O3 into CrN film. Al2O3/CrN nanocomposite coatings are first prepared by co-sputtering. Subsequently, the microstructure, electrochemical corrosion resistance, interfacial contact resistances (ICR) and contact angle are systematically investigated. As a result, Al2O3/CrN nanocomposite coating shows a low corrosion current density of 0.084 μA/cm2 in room temperature and a low corrosion current density of 0.39 μA/cm2 at 70 °C, which highly meets the requirement of U.S. DOE 2025 targets. Besides, Al2O3/CrN nanocomposite coating displays a superior durability to pure Au film. It is revealed that Al2O3 can hinder the growth of CrN columnar crystals and result in coating amorphization, which is the mechanism of Al2O3-promoted the CrN corrosion resistance. Furthermore, Al2O3/CrN coating also exhibits an excellent electrical conductivity, featuring a smaller ICR of 3.09 mΩ cm2. Inspired by these results, introducing Al2O3 into CrN coatings can provide enlightening insights to design new non-noble-metal coatings for metal BP in future PEMFC manufacturing.

Study of the structure, structural transition, interface model, and magnetic moments of CrN grown on MgO(001) by molecular beam epitaxy

Structural phase transition is studied in high quality CrN thin films grown by molecular beam epitaxy on MgO(001) substrates. Cross-sectional transmission electron microscopy and x-ray diffraction reveal that the epitaxial relationship between CrN film and MgO substrate is [100]CrN/[100]MgO, [110]CrN/[110]MgO, and [001]CrN/[001]MgO. The films show tensile strain/compression at the CrN/MgO(001) interface, which relaxes gradually with the film growth. Temperature dependent x-ray diffraction measurements show a first-order structural phase transition. In addition to the experimental measurements, first-principles theoretical calculations have been carried out for finding a stable model for the CrN/MgO interface. These calculations determine two possible models for the interface, where a monolayer of chromium oxide is formed between the CrN and MgO layers.

Improvement of the Wear Resistance and Corrosion Properties of CrN Films on Oxynitriding-Treated Vanadis 23 High-Speed Steel by the DC Magnetron Sputtering Process

This study coated CrN films onto oxynitriding-treated Vanadis 23 high-speed steel using the DC magnetron sputtering process of the PVD technique. The experimental parameters include various deposition temperatures (275, 300, 325, and 350°C), a bias of -25 V, a power of 100 W, a gas flow rate of 45/30 (Ar/N2) sccm, and a deposition time of 2.5 h. The research results show that Vanadis 23 high-speed steel formed an effective oxynitriding layer with a depth of about 50 μm after the oxynitriding treatment, and the surface hardness increased to 1100 HV0.05. Furthermore, when the coatings were deposited at 325°C, the CrN coatings possessed an obvious columnar crystal structure, the highest hardness (13.4 GPa), and the highest elastic modulus (159.7 GPa). In addition, the CrN coating had the best wear properties (the lowest specific wear rates were 1.07×10-6 and 1.33×10-6 mm3·m-1·N-1 under the loads of 2 N and 4 N, respectively) and good corrosion resistance (corrosion current was 8.90×10-5 A·cm-2, and polarization resistance was 822.11 Ω·cm2 in a 3.5 wt% NaCl solution).

In-vitro corrosion and surface properties of PVD-coated β-type TNTZ alloys for potential usage as biomaterials: Investigating the hardness, adhesion, and antibacterial properties of TiN, ZrN, and CrN film

In this study, the corrosion and surface properties of non-toxic and non-allergenic β-type Ti–29Nb–13Ta–4.6Zr alloys (TNTZ) coated with TiN, ZrN, and CrN layers using the PVD technique were investigated under in-vitro conditions. The coatings' hardness, adhesion resistance, and antibacterial properties were also studied, with a focus on their potential usage as biomaterials. The corrosion tests were conducted using potentiodynamic polarization, the hardness tests were conducted using the Knoop method, and the adhesion tests were conducted using pull-off tests. The wetting properties of the coatings were examined through contact angle and 3D morphological analysis. The coatings were characterized using SEM-EDS and XRD. The results showed that the adhesion resistance of all coatings was significantly higher than the expected adhesion strength for biomaterial coatings, while their corrosion resistance was higher compared to the uncoated alloy. Besides, the study demonstrates the potential of TiN, ZrN, and CrN coatings on β-type TNTZ for use as a biomaterial with desirable surface and antibacterial properties.

Corrosion resistance of CrN film deposited by high-power impulse magnetron sputtering on SS304 in a simulated environment for proton exchange membrane fuel cells

Insufficient corrosion resistance and conductivity are two major problems hindering the wide application of stainless steel (SS) bipolar plates in proton exchange membrane fuel cells. This study explores the use of CrN monolayer and multilayer films to improve the performance of SS304 bipolar plates, which are realized by high-power impulse magnetron sputtering with single pulse width or alternating pulse width. The effect of pulse width on the film structure and composition was characterized by various characterization techniques. Furthermore, corrosion and interfacial contact resistance (ICR) test results show that monolayer CrN film using a single long pulse of 40 μs has the lowest corrosion current density of 0.08 μA/cm2 (0.6 V vs. Ag/AgCl) and ICR of 3.15 mΩ cm2 in all coated samples. As the pulse width increases, vacancy-like defects in film decrease and the density increases, which is attribute to high bombardment flux and high average power of long pulse during deposition.

Improvement of Corrosion and Wear Resistance of CoCrNiSi0.3 Medium-Entropy Alloy by Sputtering CrN Film

In this study, Co, Cr, and Ni were selected as the equal-atomic medium entropy alloy (MEA) systems, and Si was added to form CoCrNiSi0.3 MEA. In order to further improve its wear and corrosion properties, CrN film was sputtered on the surface. In addition, to enhance the adhesion between the soft CoCrNiSi0.3 substrate and the super-hard CrN film, a Cr buffer layer was pre-sputtered on the CoCrNiSi0.3 substrate. The experimental results show that the CrN film exhibits a columnar grain structure, and the film growth rate is about 2.022 μm/h. With the increase of sputtering time, the increase in CrN film thickness, and the refinement of columnar grains, the wear and corrosion resistance improves. Among all CoCrNiSi0.3 MEAs without and with CrN films prepared in this study, the CoCrNiSi0.3 MEA with 3 h-sputtered CrN film has the lowest wear rate of 2.249 × 10-5 mm3·m-1·N-1, and the best corrosion resistance of Icorr 19.37 μA·cm-2 and Rp 705.85 Ω·cm2.

Structural and Mechanical Properties of CrN Thin Films Deposited on Si Substrate by Using Magnetron Techniques

Chromium nitride thin films are known for their good mechanical properties. We present the characteristics of ultrathin chromium nitride films under 400 nm thickness deposited on silicon substrates by direct current and high-power impulse magnetron sputtering techniques. The methods of investigation of the CrN films were scanning electron microscopy, atomic force microscopy, and nanoindentation. Qualitative and quantitative analyses were performed using AFM and SEM images by fractal dimension, surface roughness and gray-level co-occurrence matrix methods. Our results show that using magnetron techniques, ultrathin CrN films with excellent mechanical properties were obtained, characterized by values of Young’s modulus between 140 GPa and 250 GPa for the samples obtained using high-power impulse magneton sputtering (HiPIMS) and between 240 GPa and 370 GPa for the samples obtained using direct current sputtering (DC). Stiffness measurements also reveal the excellent mechanical properties of the investigated samples, where the samples obtained using HiPIMS sputtering had stiffness values between 125 N/m and 132 N/m and the samples obtained using DC sputtering had stiffness values between 110 N/m and 119 N/m.

Nano-Cr2N dominated films with high conductivity and strong corrosion resistance for Ti bipolar plates

Films for bipolar plates deposited from PVD are always restricted by narrow parameters’ widow, which restrict the robust quality of high conductivity and anticorrosion due to the fluctuation of deposition plasma naturally. In this study, CrN films with high conductivity and strong corrosion resistance was deposited on Ti plates by high power impulse magnetron sputtering in wider Ar/N2 ratios. The results show that the CrN film prepared by this method effectively inhibits the columnar structure and forms a dense structure of amorphous wrapped nano Cr2N clusters, providing good protection for Ti plate. Meanwhile, First-principal calculations shown Cr2N has stronger metallicity than CrN, resulting in lower ICR. This work has opened up a new way for the large-scale preparation of metal bipolar plate films.