CrN Coatings Research Articles

A Tribological Study of CrN and TiBN Hard Coatings Deposited on Cobalt Alloys Employed in the Food Industry

In this work, a comparative study of the tribological performance of two hard coatings, CrN/TiBN, was conducted for research purposes and industrial applications in food products, particularly for food packaging into cans using the double hermetic sealing process. CrN and TiBN coatings were successfully deposited on a base-cobalt metal substrate of a CoCrW commercial alloy using physical vapor deposition by arc evaporation (AEPVD) technology to improve the tribological properties of the commercial alloy, including wear and corrosion resistance, lower coefficient of friction, and overall durability. This research focuses on conducting scratch and abrasion wear resistance tests in dry conditions; specifically, it pursues to evaluate the wear corrosion properties, known as tribocorrosion performance, on CrN/TiBN hard coatings. The experimental results show that the CrN coating (2.9 μm) is slightly thicker than the TiBN coating (2.7 μm), with a 47 N critical load. It also shows a lower coefficient of friction (CoF) in a dry environment, while the TiBN coating showed total detachment and a high coefficient of friction in a dry environment condition. Tribocorrosion testing in brine aqueous solution indicated that CrN coating shows a high friction coefficient with a higher open circuit potential value (Ecorr), and TiBN shows the lowest corrosion potential (Ecorr) and the lowest friction coefficient. This suggests that CrN could provide better corrosion protection for commercial cobalt alloys and improve tool performance during the food canning process in brine environments.

Current-carrying friction behavior of CrN coatings under the influence of DC electric current discharge

CrN coatings are renowned for their low friction coefficients, high chemical inertness, excellent corrosion resistance, and substantial hardness, making them ideal for the tribological demands of bearings and gears in electric vehicles. This study investigated the current-carrying friction behavior of CrN coatings when sliding against steel balls under both non-electrified and electrified conditions. The friction coefficient (CoF), wear volume, wear type, and mechanism of the coating were reported by adjusting the direct current (DC) intensity and lubrication status. The findings indicate that while the current significantly exacerbates substrate wear during dry friction, its impact on the CrN coating is minimal. Even at a maximum DC current of 1.5 A, the wear rate of CrN coating during dry friction is only 1.9 × 10−4 mm3·(N·m)−1, representing a reduction by 79.1 % compared to the steel substrate. This effect is further pronounced when lubricated with PAO oil. The wear of CrN coating shows minimal change even as the current increased, and surface wear remains very slight. At a current of 1.5 A, the wear rate of CrN coating decreases to as low as 9.7 × 10−6 mm3·(N·m)−1, indicating a reduction by 98.7 % compared to its substrate. It is observed that under electrified conditions, the oxidation and degradation of CrN coating are accelerated, thereby resulting in the formation of a loose and low-hardness Cr2O3 oxide layer on the surface. The oxide layer is primarily attributable to the deterioration in frictional properties of the CrN coating under electrified conditions. Finally, CrN coatings exhibit minimal changes in tribological behavior under electrified conditions, thereby offering effective protection for substrates against electrical damage. Therefore, CrN coatings are ideal for applications involving electrical contacts.

Evaluation of wear resistance of CrN, CrAlN, and TiAlN coatings deposited by multi-arc ion plating on spinning die of Cr12MoV

Abstract This study successfully deposited CrN, CrAlN, and TiAlN coatings on the surface of Cr12MoV substrate using multi-arc ion plating (MAIP). The influence of phase composition and surface morphology on the hardness, adhesion strength, friction performance, and wear mechanisms of these coatings was investigated, with a comparative analysis of their wear resistance. Nanoindentation results revealed that the hardness (H) of CrN, CrAlN, and TiAlN coatings increased by 70.37%, 74.97%, and 75.64%, respectively, compared to the substrate. The hardness (H) and elastic modulus (E) were found to be positively correlated. CrAlN demonstrated superior resistance to deformation, reflected in its higher H/E and H 3 /E 2 radios compared to the CrN and TiAlN. Adhesion tests showed that CrAlN had the strongest adhesion strength to the substrate, with an adhesion force of 81.55 N, representing a 14.78% and 8.46% improvement over CrN and TiAlN, respectively. Friction and wear tests identified CrAlN as having the lowest friction coefficient (0.389), attributed to its high hardness and strong adhesion. The wear mechanisms of CrAlN observed were primarily mild abrasive wear, oxidative wear, and adhesive wear. In comparison, CrN and TiAlN coatings exhibited higher friction coefficients of 0.424 and 0.391, respectively, due to their lower hardness and adhesion, which led to more severe oxidative and abrasive wear. Additionally, the TiAlN coating showed signs of brittle failure in wear scars, likely due to the formation of Al2O3 oxides during wear.

Energy-Efficient Application of CrN Coating on Low-Alloy Tool Steel: Comparative Analysis of Technological Processes

Abstract This research examines the technological processes of applying CrN coating on low-alloy tool steel, focusing on the comparison between hardening-tempering-coating (HTC) and hardening-coating (HC) processes, with an emphasis on energy savings. The study investigates the chemical composition, microstructure, mechanical properties, fractography, residual stress, and corrosion resistance of the coated tool steel. Notably, the results indicate no significant differences in the microstructural, mechanical, and corrosion properties between the HTC and HC processes, suggesting that tempering may be excluded without compromising the quality. This study introduces a novel approach to tool steel coating, which improves energy efficiency while maintaining high-quality outcomes. The findings highlight potential improvements in industrial applications, offering an energy-efficient alternative that does not sacrifice the performance or durability of the tool steel. This advancement could lead to significant improvements in manufacturing efficiency and sustainability.

Effect of Deposition Parameters on Micromechanical Properties and Machining Performance of CrN Coating for Wet Finish Turning of Ti6Al4V Alloy.

This study aims to optimize the performance of CrN coatings deposited on WC cutting tools for machining Ti6Al4V alloy, where the formation of built-up edge (BUE) is a prevalent and critical issue. In-house CrN coatings were developed using the PVD (Physical Vapor Deposition) process, with variations in deposition parameters including nitrogen gas pressure, bias voltage, and coating thickness. A comprehensive experimental approach encompassing deposition, characterization, and machining performance evaluation was employed to identify the optimal deposition conditions. The results indicated that CrN coatings deposited at a nitrogen gas pressure of 4 Pa, a bias voltage of -50 V, and a thickness of 1.81 µm exhibited superior performance, significantly reducing BUE formation and tool wear. These optimized coatings demonstrated enhanced properties, such as a higher elastic modulus and a lower coefficient of friction, which contributed to improved tool life and machining performance. Comparative studies with commercial CrN coatings revealed that the in-house developed coatings outperformed the commercial variants by approximately 65% in tool life, owing to their superior mechanical properties and reduced friction. This research highlights the potential of tailored CrN coatings for advanced machining applications and emphasizes the importance of optimizing deposition parameters to achieve high-performance tool coatings.

The Improvement of CrN Coatings Wear Resistance by Adjusting the Cycle Number of Electrochemical

The Improvement of CrN Coatings Wear Resistance by Adjusting the Cycle Number of Electrochemical

Tribological Properties of CrN/DLC and CrN Coatings under Different Testing Conditions

Tribological Properties of CrN/DLC and CrN Coatings under Different Testing Conditions

Microstructure, mechanical properties, and wettability of CrN and CrSiCN coatings with graded architectures

Protective CrN-based coatings are of interest for applications requiring a combination of corrosion resistance and toughness. Here, the processing-microstructure-properties relationships for metallic Cr, binary CrN, and quaternary CrSiCN coatings are reported. Hexamethyldisilazane (HMDS) was used as a single-source organosilicon precursor for Si and C during plasma-enhanced magnetron sputtering (PEMS). By varying the availability of reactive species during coating growth, graded coating architectures were produced. Scanning and transmission electron microscopy revealed that as Si and C content increased, the coating microstructure evolved from a coarse, columnar growth structure (0 at.% Si), to a nanocolumnar structure (3 at.% Si), and, finally, to a dense, nanoscale structure (6 at.% Si). Coating surface topography was characterized using optical microscopy and atomic force microscopy. While the CrSiCN coating deposited at the highest HMDS flow rate exhibited the lowest nanoscale surface roughness (Rq = 6.74 nm), it also had the greatest area fraction of microscopic surface defects. Evidence of the formation of secondary Cr2N phases within the graded interlayers of the coatings was acquired from selected area electron diffraction analysis. However, the practical adhesion of the coatings, as evaluated by the Rockwell C indentation test, was not adversely affected. Nanoindentation testing revealed that greater incorporation of Si and C into the CrN-based coatings increased coating hardness from 25.4 ± 1.6 GPa to 30.7 ± 1.8 GPa and decreased apparent elastic modulus from 295 ± 14 GPa to 284 ± 12 GPa. Contact angle goniometry was conducted to determine the wettability of the coatings. It was found that sessile water contact angles decreased from 86.5° ± 1.6° to 77.3° ± 2.1° as coating Si and C content increased.

The improved mechanical and tribological properties of CrN coatings sealed via electrochemical polarization treatment

In order to seal the void defects in CrN coatings so as to enhance its mechanical and tribological properties, the electrochemical polarization treatment at different over-potentials was employed. The results showed that the maximum content of oxygen was increased by 1.22 at% after electrochemical polarization treatment, but the crystal structure of CrN(111) and Cr2N(002) for CrN coatings remained stable. The formation of a little chromium oxides as expected sealed the CrN coatings pores, and therefore lowered its porosity from 16.79 % to 12.28 %. As a result, the maximum hardness was increased by 20.3 %. Moreover, the wear resistance of CrN coatings was enhanced by 29.9 % whilst the friction coefficient was reduced by 25.2 % at the over-potential of 70 mV.

Structural evolution, wear and corrosion failure mechanisms of CrN coating synthesized by applying gradient voltage and arc-enhanced glow discharge

A detailed characterization was conducted to investigate the mechanical, wear and corrosion properties of CrN coatings deposited using a duplex technique combining gradient voltage (GV) and arc-enhanced glow discharge (AEGD). The absence of GV+AEGD resulted in the formation of large particles embedded in CrN coating, which adversely affected its toughness, density, and resistance to wear and corrosion. Remarkably, the implementation of GV+AEGD effectively mitigated particle agglomeration and promoted a compact growth texture in CrN coating. Consequently, besides exhibiting exceptional toughness and wear resistance, the CrN coating demonstrated outstanding corrosion resistance. The structural evolution, wear and corrosion failure mechanisms of CrN coatings with or without GV+AEGD were comprehensively discussed.

Corrosion resistance and conductivity of CrN, CrAlN, and CrTiN coatings applied to bipolar plates for proton exchange membrane fuel cells

In order to improve the corrosion resistance and conductivity of 316L stainless steel bipolar plates used for proton exchange membrane fuel cells, three Cr-containing nitride coatings were deposited on 316L stainless steel by multiarc ion plating. First, the microstructure, composition, and contact angle of the three coatings were systematically investigated. Then, electrochemical impedance spectroscopy, potentiodynamic polarization, potentiostatic polarization (PSP), and interfacial contact resistance (ICR) of the three coatings were also fully examined. The results revealed that CrN coating has the highest contact angle of 98.26°, indicating its superior hydrophobicity. Additionally, CrN coating performed the best corrosion resistance with the highest corrosion potential of 0.31 V, the lowest corrosion current density of 2.28 × 10−7 A cm−2, and the largest resistance. Furthermore, CrN coating showed the lowest current density during PSP tests and the smallest ICR value after corrosion. The superior corrosion resistance of CrN coating is mainly attributed to its decreased pore density caused by vacancylike defects and its uniform structure. This article provided evidence for the potential application of CrN coating to bipolar plates.

Tailoring structure, morphology, and tribo-mechanical properties of HiPIMS-deposited CrxNy coatings for enhanced performance in wear and corrosion protection

During reactive sputtering of CrxNy, precise regulation of nitrogen gas is crucial to control the properties of the deposited coating. In the present work, we investigate the influence of nitrogen content on CrxNy characteristics, including morphology, crystalline structure, hardness, corrosion protection, and wear protection performances. Our findings reveal that the hexagonal Cr2N coatings, although slightly lower in hardness (19 GPa) compared to stoichiometric CrN, exhibit superior corrosion resistance with a protection efficiency of 82%, and a reduced sliding wear behavior at 1.35E-09 mm3/N/m. Conversely, stoichiometric CrN shows the highest hardness at 22.8 GPa. Using high-power impulsed magnetron sputtering as a deposition technique, we were able to design CrxNy protective coatings with desired microstructure and phase composition, enabling the production of performance-tailored CrxNy coatings suitable for a diverse range of applications.

Evaluating the corrosion and tribological performance of nanostructured CrN/TiN and TiN/CrN configurations applied on 410 stainless steel

ABSTRACT This study aims to compare the corrosion and tribological performance of TiN/CrN and CrN/TiN nanostructured multi-layer coatings deposited through cathodic arc evaporation PVD on 410-grade stainless steel. Both coating configurations were available in smooth (polished) and rough states. For the deposition of multi-layer coatings, a middle layer containing Cr and CrN was deposited to the substrate, followed by alternating nanolayers of TiN and CrN. finally, an upper layer of either CrN or TiN was applied. The nanoindentation test revealed that the hardness, Young’s modulus, H/E, and H3/E2 ratios of the coating with a TiN upper layer were 5.57, 1.42, 3.86, and 85.39 times of the substrate, respectively. At the coating with CrN upper layer, these values were 4.04, 1.13, 3.53, and 51.68 times of the substrate, respectively. Results showed that increasing the H/E and H3/E2 ratios increased wear resistance. Wear rates of smooth and rough TiN coatings and smooth and rough CrN coatings were reduced by 86%, 99%, 53%, and 26%, respectively, compared to the substrate. Results of the corrosion test showed that the rough CrN coating had greater corrosion resistance than the coating with a TiN upper layer and the substrate due to its higher hydrophobicity.

Investigation of the Corrosion and Tribological Properties of WC-Co Tools Hardened with PVD Coatings in Solid Oak Wood Processing

Corrosion and friction coefficient tests were performed on solid oak wood machined with hard-metal woodworking tools coated with PVD coatings (AlCrN, AlTiN, TiAlN, TiCN and CrN). The tannic acid attacks the carbide more intensively than the PVD coatings. During cutting, corrosion spreads on the cutting edge of the cutter due to mechanical action, which dissolves the cobalt binder of the hard-metal and causes the carbide grains to flake off. After 80 min of contact with the wood, the cobalt content decreases from 3.53 to 1.74%. Depending on the PVD coating material, cracks of 4 to 40 µm in width appear after 120 min (9000 m cutting path). After 120 min of machining, wear, corrosion effects and the influence of corrosion on the coefficients of friction were evaluated for tools with and without PVD coatings. TiCN is the most sensitive to corrosion, while AlCrN and CrN coatings are the least sensitive, with the AlTiN coating being the most affected under real cutting conditions (with mechanical + thermal + corrosion effects) and the tools with CrN and AlCrN coatings being the least affected. Corrosion affects the hard-metal and PVD coatings and reduces the coefficient of friction. The angle between the directions of sliding and sharpening of the cutting edge sharpening significantly influences this parameter. The coefficient of friction of hard-metal WC-Co and PVD coatings is higher in the parallel machining direction than in the perpendicular machining direction and ranges from 16.03% (WC-Co) to 44.8% (AlTiN). The coefficient of friction of hard-metal WC-Co decreases by 5.13% before and after exposure to tannic acid, while the corrosion of PVD coatings reduces it by 4.13% (CrN) to 26.7% (TiAlN).

Electrochemical corrosion and tribocorrosion behavior of CrN and CrAlN coatings in artificial seawater

AbstractThis study investigated the corrosion and tribocorrosion behavior of CrN and CrAlN coatings deposited on steel through direct current magnetron sputtering. Additionally, the effects of Al addition on the microstructure, corrosion inhibition, and tribocorrosion behavior of CrN coatings were evaluated. Compared with the CrN coating, the CrAlN coating exhibited a denser columnar crystal structure and a higher hardness of 23.8 GPa. The CrAlN coating reacted with water to form Al2O3 and Cr2O3 films, which enhanced its corrosion resistance. Moreover, the addition of Al enhanced the wear resistance of the CrN coating and reduced the material loss due to corrosion, wear, and their synergistic effects. The CrAlN coating exhibited a low corrosion current density of 1.14 × 10−8 A/cm2, indicating a 92% reduction compared with the CrN coating. Furthermore, under either open circuit potential or anodic accelerated tribocorrosion conditions, the CrAlN coating featured significantly lower total material loss and synergistic material loss than the CrN coating, demonstrating higher corrosion and tribocorrosion protection.

Tribocorrosion of CrN coatings on different steel substrates

In this paper, CrN coatings were deposited on AISI 1045 steel, AISI H13 steel, and AISI 2205 duplex stainless steel substrates using arc ion plating. The effects of substrate characteristics on the hardcoated sample properties, especially tribocorrosion performance were investigated systematically. The results show that there were little differences in the surface morphology, crystalline structure as well as nanohardness among the three hardcoated samples. Compared with the bare substrates, the electrochemical properties of 1045-CrN and H13-CrN in 3.5 wt% NaCl solution were significantly improved with the Icorr values of 2.10 × 10−6 A·cm−2 and 9.63 × 10−7 A·cm−2, respectively, but still worse than that of 2205-CrN specimen (1.84 × 10−8 A·cm−2). The Ecorr of 2205-CrN was over 200 mV higher than those of 1045-CrN and H13-CrN. In addition, 2205-CrN displayed the highest Rct value of 1.953 × 106 Ω·cm2, which was enhanced by two orders of magnitude compared to the other two specimens owing to the excellent corrosion resistance of AISI 2205 steel substrate. The tribocorrosion rates of the three hardcoated specimens in 3.5 wt% NaCl solution were significantly reduced compared with their underlying substrates (by 70 %, 36 %, and 85 % for 1045-CrN, H13-CrN, and 2205-CrN, respectively). The 2205-CrN specimen displayed the best tribocorrosion performance with the rate of 2.51 × 10−6 mm3·N−1·m−1. The tribocorrosion mechanisms of CrN coatings deposited on carbon and stainless steels were also discussed. Mutual promotion effect of corrosion and wear was confirmed for CrN-coated carbon steels, while a negative synergistic effect was observed from the CrN-coated stainless steel substrate.

Preparation of Cr-N coatings on 316H stainless steel via pack chromizing and gas nitriding, and their resistance to liquid metal corrosion in early stages

Liquid metal corrosion has become a critical issue in lead-cooled fast reactor when the steel encounters lead–bismuth eutectic (LBE). Although various coatings applied in LBE have garnered interest from many researchers, there are few reports on the compatibility of chrome carbide or chromium nitride coatings in LBE. Thus, Cr carbide and Cr-nitride coatings with thicknesses of 80 μm were prepared on 316H stainless steel (SS) to investigate the corrosion behavior in contact with static liquid LBE at 550 °C for 25, 76, and 207 h. These coatings were synthesized via pack chromizing and subsequent gas nitriding. The results showed that a distinct LBE penetration layer appeared on the surface of the as-received 316H SS after exposure to LBE. Pack-chromized coating and pack-chromized + gas nitride coating did not undergo obvious consumption in LBE in the early stages. Cracks in the pack-chromized coating promoted the preferential diffusion of oxygen and PbBi. The Cr in the pack-chromized + gas nitride coating slightly diffused outward to combine with oxygen to form Cr-oxide scale on the coating surface. These coatings act as a barrier to LBE corrosion, making the surface of the coating impermeable to LBE.

Tribological Properties at 20 and 500°C of TiN and CrN Cathodic ARC Coatings Deposited on Ti-6Al-4V Alloy

Tribological properties of TiN and CrN coatings deposited by cathodic arc method at three different bias potentials -50, -150 and -300V on Ti-6Al-4V alloy in pair with alumina have been investigated. X-ray diffraction analysis showed that single-phase textured cubic nitrides of TiN and CrN were formed in these coatings. It is shown that the friction coefficient of the coatings is practically equal to that established for the Ti6Al4V alloy, but the wear rate is more than an order of magnitude lower than for the titanium alloy substrate. Coatings deposited at a potential of -50 V show optimal tribological properties at temperatures 20 and 500°C. Friction coefficients for TiN coatings are 0.4-0.8 at 20°C and 0,75 at 500°C; for CrN coatings they are 0.5 at 20°C and 0,7 at 500°C. Wear rates for TiN coatings are 0.86·10-5 мм3/Нм at 20°C and 3.56·10-5 мм3/Нм at 500°C; for CrN coatings they are 1.43·10-5 мм3/Нм at 20°C and 7.13·10-5 мм3/Нм at 500°C.

Microstructure, Wear Resistance and Corrosion Resistance of CrN Coating with Platinum-Iridium Co-Doping

A novel Pt-Ir co-doping strategy was devised to enhance the corrosion resistance of CrN coating. The deposited CrN coating exhibits a coherent growth pattern, resulting in significant mechanical strength and large grain sizes. However, during the corrosion process, corrosive fluids infiltrate through growth defects, leading to inadequate corrosion resistance of the coating. By incorporating Pt-Ir atoms as dopants, coherent grain growth is effectively hindered, yielding a uniformly smooth surface. Simultaneously, localized non-coherent lattice growth occurs due to co-doping in the coatings, impacting the mechanical properties of CrN-PtIr coatings and causing multidirectional fracture. Nevertheless, this dense coating surface impedes the penetration of corrosive fluids and enhances the corrosion resistance of the coating to some extent.

In situ анализ кристаллической решетки нитридных однокомпонентных и многослойных покрытий ZrN/CrN в процессе термоциклирования

Introduction. Thermal expansion is an important thermal and physical characteristic of materials, showing its expansion when heated. Knowing this property is important both from a scientific point of view and for practical applications. Materials with low thermal expansion are widely used in electronics, thermal barrier coatings and other applications. Mismatch in thermal expansion between different materials can lead to thermal stress on contact surfaces. The in-situ synchrotron X-ray diffraction method can detect this mismatch. Thermal stress requires an analysis of the coefficient of thermal expansion. Bulk expansion behavior is observed in thermally sprayed coatings. The CTE is important for designing and predicting coating performance under thermal stresses. Changes in the KTE can cause cracking and degradation of the coating. In-situ X-ray diffraction analysis helps to understand thermal expansion, crystallite size and stress and strain variation with temperature change. The aim of this work is to interpret and use in-situ high temperature X-ray diffraction as an effective tool to study the thermal mismatch behavior of a W-Co alloy substrate (8 % w/w Co, WC — matrix) with CrN, ZrN and CrZrN multilayer coatings and the characteristic differences between single component coatings and its combination in a multilayer coating. Research Methodology. In this work, specimens of chromium and zirconium nitride coatings deposited on W-Co hard alloy substrates were investigated. The fundamental method in this work is in-situ analysis using synchrotron radiation. The lattice parameter as a function of cycling temperature, the coefficient of thermal expansion during heating and cooling, and the thermal expansion mismatch between the substrate-coating pair and the coating layers in the multilayer coating were evaluated. Results and discussion. The lattice parameters and thermal expansion of the coatings are investigated. The lattice parameter of all coatings decreased during thermal cycling, indicating nitrogen evaporation. The multilayer coating has the least change in the parameter, possibly due to diffusion barriers. Lattice distortions do not differ between single and multilayer coatings. All coatings exhibit thermal expansion similar to the substrate. The multilayer coating creates conditions for compressive stresses in one phase and tensile stresses in the other phase, so the lifetime of multilayer coatings is expected to be high.