CrSiN Coatings Research Articles

Enhancing wear and corrosion resistance of AISI410 stainless steel in simulated seawater environments through PVD sputtering of TiCrN and CrSiN coatings

Enhancing wear and corrosion resistance of AISI410 stainless steel in simulated seawater environments through PVD sputtering of TiCrN and CrSiN coatings

Mechanical Properties and Wear Resistance of CrSiN Coating Fabricated by Magnetron Sputtering on W18Cr4V Steel

To increase the service life of tool materials and further meet the demands of modern high-speed machining, a Si-doping CrN coating consisting of Si3N4 amorphous and CrN nanocrystalline was fabricated on top of W18Cr4V high-speed steel. The effect of coating thickness on its structure and properties was investigated by means of X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), scratch test, nano-indenter, and friction–abrasion tester. The thickness of the coating was modulated by the deposition time. The results show that the coating consists of a CrN phase distributed into an amorphous Si3N4 matrix. As the thickness increased, the surface defects decreased, and the residual compressive stress, hardness, and elastic modulus as well as the H/E and H3/E2 factors increased, improving the wear resistance significantly. The adhesion between coating and substrate increased first and then decreased, and it reached the maximum when the coating thickness was 1.9 μm (deposition 60 min). Moreover, the effect of toughness on wear resistance and the wear mechanisms is discussed.

Study of Structural, Mechanical, and Corrosion Resistance of a Nanocomposite CrSiN/CrN/Cr Coating Deposited on AZ31: Effects of Deposition Time

To improve the surface properties of Mg alloys and expand the applications of CrN-based materials, composite CrSiN coatings consisting of amorphous Si3N4 and nano CrN phases have been prepared on AZ31 based on the theory of fine grain strengthening and multigrain boundaries. The effect of the thickness of the coating on the structure and properties was investigated. The microstructure was studied by means of X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM). The mechanical properties, adhesion properties, and corrosion resistance were investigated using a nanoindentater, scratch testers, and electrochemical workstations. The results show that the coating consists of a face-centered cubic CrN phase, that Si3N4 is not found in the diffraction pattern, and that the HRTEM images show a composite structure of amorphous and nanocrystalline phases. With the increase in deposition time (thickness), the surface roughness decreases, the defects disappear, and the interface has no visible defects. Moreover, the hardness and elastic modulus of the coating increase, corrosion resistance improves, adhesion performance first increases and then decreases. The adhesion between coating and substrate reaches the maximum when sputtering time is 50 min, which corresponds to the CrSiN thickness of 0.79 μm.

Structural and mechanical properties of Si-doped CrN coatings deposited by magnetron sputtering technique

This study successfully deposited Si-doped CrN coatings onto Si (100) substrate by direct current magnetron sputtering. The concentration of Si in the CrSiN coatings was varied by changing the Si target current during deposition. The microstructural and mechanical properties were determined by employing X-ray diffraction, X-ray photoelectron spectroscopy, atomic force microscopy, and nanoindentation test. According to the results, the coating with 3.3 at.% Si contents (CrSiN-2) show an increase and decrease in the crystallite size and coating surface roughness, respectively, leading to solid solution hardening with an optimum hardness and elastic modulus of 21.37 GPa and 205.68 GPa, respectively. With continued Si addition, the coating roughness increased and the mechanical properties gradually decreased and attained 184.08 GPa and 18.95 GPa for the elastic modulus and hardness of the coating with a maximum Si concentration of 9.2 at.% (CrSiN-5).

The enhancement of individual friction and corrosion properties of CrSiN coatings by Mo doping in seawater

A series of CrSiN coating with various Mo contents were fabricated on Ti6Al4V alloys using a closed unbalanced magnetron sputtering system and their tribological and electrochemical behaviors were investigated. The results of friction tests suggested that oxidation behaviors of Mo element in the prepared coatings promoted the wear mechanism transforming to tribochemical wear, and the more Mo doping enhanced the tribological performance and presented the lowest wear rates of 2.27 × 10 −7 mm 3 /N.m and 8.12 × 10 −8 mm 3 /N.m for tribopairs of Cr( Mo )SiN/Al 2 O 3 and Cr( Mo )SiN/Si 3 N 4 , respectively. Besides, the corrosion product of MoO 3 reduced the corrosion rate of CrMoSiN coatings, CrMoSiN coating showed the low corrosion rate of 0.58 × 10 −3 mm/yr indicated that the passive behaviors of Mo element improved the corrosion resistance, and provided a good protection to Ti6Al4V alloys in seawater. • Cr( Mo )SiN coatings were successfully fabricated using the unbalance magnetron sputtering system. • The oxidization behaviors of Mo element decreased the friction coefficient. • The wear mechanism would be transformed to tribochemical wear with an increase in the Mo content. • The more Mo element doping enhanced tribological performance of CrMoSiN coating in seawater. • The corrosion rate and current density were slowed down due to the passive behaviors of Mo element on coating's surface.

Effect of Arc Currents on the Mechanical, High Temperature Oxidation and Corrosion Properties of CrSiN Nanocomposite Coatings

In methods for multi-arc ion plating technology, the behavior and characteristics of the arc spot determine the physical characteristics of arc plasma and the properties of the subsequent deposited coatings. In this paper, the effect of arc currents on the hardness, friction coefficient, high temperature oxidation, and corrosion properties of the CrSiN coatings was studied. According to the XRD and SEM results, with the increase of arc currents, the coatings grew preferentially to the CrN (111) crystal direction, and the CrN (220) crystal phase appeared at high currents of 90 A. In addition, the number of large particles increased when the current exceeded 70 A. The HR-TEM results confirmed the formation of nanocomposite structure of nanocrystalline of CrN embedded into the amorphous phase of Si3N4 as explored by XRD. The maximum hardness was achieved at 3120 Hv when the coatings were deposited under currents around 70 A. However, the hardness values decreased with further increase of arc currents. From the contact of ceramic balls with the wear of coatings, the surface of coatings gradually produced friction marks, and the friction force increased from a steady friction force to a dynamic friction force. The high temperature oxidation results showed that fewer oxides were formed on the surface of the coatings when oxidized at 800 °C. It was also found that CrSiN nanocomposite coatings prepared at an arc current of 70 A had a larger corrosion potential and polarization impedance, which could effectively protect the tool matrix.

Fatigue behaviour and mechanical properties of PVD CrSiN coating using cyclic nanoindentation

ABSTRACT In this study, chromium nitride-based CrSiN coatings were deposited by PVD (physical vapour deposition) magnetron sputtering on XC100 steel substrate. Mechanical properties of CrSiN were investigated using monotonic nanoindentation test. It was found that CrSiN coatings had excellent mechanical properties, hardness of 30.52 ± 1.85 GPa and elastic modulus of 338.32 ± 13.5 GPa. Fatigue behaviour of CrSiN thin film was studied using multi-cycles nanoindentation test. Under cyclic nanoindentation, the unloading–reloading paths produced the hysteresis loops which reflect a fatigue effect. In addition, the increase in the number of indentation cycle induced the degradation of the film mechanical proprieties and the evolution of damage mechanism. The similarity between the indentation fatigue depth propagation and the conventional fatigue crack growth was exploited based on Manson–Coffin law to extract the fatigue properties of CrSiN coating. The obtained fatigue ductility coefficient was and the fatigue ductility exponent was c = −0.96.

Electrochemical properties promotion of CrSiN coatings in seawater via Ni incorporation

Nickel was incorporated into CrSiN coatings to improve their electrochemical properties. The incorporated Ni existed as elementary substance (zero valence) regardless of concentration (5.2–13.9 at %). Ni–CrSiN coatings with a thickness around 2.5 μm all presented the nano-composite structure composing of CrN crystal, amorphous nickel and amorphous SiNx. With increasing Ni content, the morphology of Ni–CrSiN coatings became compact. The electrochemical impedance spectrum results showed that the charge transfer resistance (Rct) of Ni–CrSiN coatings increased from 1.62 × 106 to 3.51 × 106 Ω cm2 as Ni concentration increased from 0 to 8.3 at %. Meantime, the corrosion current density (icorr) decreased to 18.54 nA/cm2 owing to the extra formation of nickel oxides. In contrast, icorr increased to 31.83 nA/cm2 at Ni concentration of 13.9 at % due to the premature pitting of passive layer.

Friction and wear properties of CrSi-based coatings for nuclear fuel cladding

Friction and wear performance is a key issue in the development of accident tolerant fuel cladding coatings and worthy of attention. In this study, two types of CrSi and CrSiN coatings with two different Si content ratios were prepared via a multi-arc ion plating method, and their wear depth, wear volume, and coefficient of friction were compared in detail. The results show that the four CrSi-based coatings have better anti-friction and wear resistant properties than Zircaloy, and the CrSi-based coatings with high Si content have better friction and wear properties than the CrSi-based coatings with low Si content. In addition, the friction and wear properties of the CrSiN coatings are better than those of the CrSi coatings. This study also examined the friction and wear properties of the CrSi-based coatings in a water environment and after high temperature oxidation. The results show that water promotes the friction and wear of CrSi and Zr-4, but inhibits the friction and wear of the CrSiN coating. After high temperature oxidation, an appropriate increase in the Si content was found to improve the friction and wear resistance of the CrSi-based coatings.

Structural, mechanical and tribocorrosion performances of CrMoSiN coatings with various Mo contents in artificial seawater

CrMoSiN coatings containing various molybdenum (Mo) contents were prepared on Si wafers and titanium alloy substrates using unbalanced magnetron sputtering system via adjusting the Mo target current. The microstructures of CrMoSiN coatings were characterized by using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and transmission electron microscope (TEM), respectively. The mechanical properties of coatings were determined using scratch and nano-indentation tests, while the tribocorrosion behavior of coatings sliding against SiC balls in seawater was performed using a linear reciprocating motion of tribometer. The results showed that Cr(Mo)SiN coatings exhibited (2 0 0) preferred orientation. By adding the Mo element into CrSiN coating, an substitutional solid solution of (Cr, Mo)N was formed, and the columnar structure became significantly dense. Consequently, the coating surface changed from “fine-dome” like morphology to a relatively flat morphology with “groove-boundaries”. The hardness of CrMoSiN coatings accordingly increased to a maximum value of 35.5 GPa at the Mo content of 11.85 at.%. Due to the formation of MoO3, the tribocorrosion performances of coatings were enhanced.

Effect of Si Content on Structure and Friction and Wear Properties of CrSiN Coatings

CrN coatings with different Si contents were prepared on YG6 substrates by DC magnetron sputtering. The phase composition, morphology and element composition of the coatings were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). The hardness and adhesion of the coatings were measured by digital microhardness tester and scratch tester. The tribological properties were investigated by a friction and wear tester. The results show that all CrSiN coatings present (111), (200) oriented NaCl structure. With the increasing of Si content, the compactness of the coating increases. When Si content is low, the structure of CrSiN/YG6 coating is relatively loose and triangular granular growth. When Si content is high, the structure of CrSiN/YG6 coating is compact and circular growth. Doping Si element in CrN coating changes the crystalline structure of the coating, and four kinds of CrSiN coating are harder than CrN cating. The hardness of CrSiN/YG6 coatings increases first and then decreases with the increase of Si content. When Si atom fraction is 14.1%, the hardness of the coatings reaches the maximum value of 23.4 GPa. With the increase of Si content, the bonding force between the coatings and the matrix decreases at first. The friction coefficient of CrSiN coatings increases with the increase of Si atom fraction, but the wear rate decreases first and then it increase. When the atomic fraction of Si is 14.1%, the minimum wear rate is 0.602*10−8 mm3*(N.mm)−1. Adding appropriate amount of Si element can improve the hardness and wear resistance of CrSiN coating, and has a certain lubrication effect.

The influence of Ni concentration on the structure, mechanical and tribological properties of Ni–CrSiN coatings in seawater

The impact of Ni content on the microstructure, hardness, fracture toughness and tribological properties of Ni–CrSiN coatings in seawater was investigated by using X-ray diffraction, dynamic ultra micro hardness tester and ball-on-disk tribometer. The structural analyses indicated that the Ni existed in the form of amorphous phase regardless of concentrations. The hardness of Ni–CrSiN coating maintained around 28.1 GPa at low Ni incorporation but decreased to 20.1 GPa at 10.8 at% Ni concentration. Then, owing to grain refinement, the hardness increased to 24.5 GPa at 13.9 at% Ni concentration. All coatings presented compressive stress that led to the formation of circular cracks around indentation impression. The Ni incorporation especially at high concentration was able to improve coatings toughness against circular cracks. Although the Ni incorporation had no effect in reducing the friction coefficient of CrSiN coatings in seawater, but the moderate Ni incorporation (5.2 at%) could enhance the wear resistance of CrSiN coatings in seawater due to the favorable combination of hardness and toughness.

Isothermal Oxidation Behavior of CrSiN Coating Deposited by Magnetron Sputtering at 700°C

CrSiN coatings have been successfully deposited on the surface of GH169 alloy by closed filed unbalanced magnetron sputtering (CFUBMS). The microstructure, chemical and phase composition of the coatings were characterized by SEM, EDS and XRD, respectively. The mechanical properties of the coatings such as microhardness and adhesion strength were measured by indentation method and scratch method, respectively. The isothermal oxidation behavior of CrSiN coating at 700°C was investigated using thermogravimetric analysis. Results show that Cr, Cr2N and CrN coexisted in the dense as-deposited CrSiN coating without Si-containing phases; the coating surface was rough and a small amount of oxide (Cr2O3 and SiO2) was formed on the surface after oxidation at 700°C for 24 hours. The isothermal oxidation result suggested that CrSiN coating possesses excellent oxidation resistance at 700°C. It is considered that the good oxidation resistance of CrSiN coating itself and the formation of dense protectiveCr2O3 and SiO2 films are primarily responsible for the good service performance during the oxidation process at 700°C.

Tribological properties and corrosion resistance of CrSiN coatings prepared via hybrid HiPIMS and DCMS

CrSiN coatings have been prepared with hybrid high power impulse magnetron sputtering(HiPIMS) and direct current magnetron sputtering(DCMS). The microstructure and phase composition were analyzed by scanning electron microscopy (SEM) and glancing incidence x-ray diffraction (GIXRD). The tribological properties were determined by means of pin on disk wear test. Electrochemical workstation was used to characterize the corrosion resistance of CrSiN coatings. Results show that, the unit power deposition rate of CrSiN coating prepared by a Cr target in DC mode and a Si3N4 target in radio frequency(RF) mode (DCMS + RF) is 5.5 nm/(min · kW), however, that of using a Cr target in HiPIMS mode and a Si3N4 target in RF mode (HiPIMS + RF) reach only 3.0 nm/(min · kW). The friction coefficient of CrSiN coatings with different processes is within the range of 0.4–0.55, but the wear rate with HiPIMS + RF process is the lowest, 5.0 × 10−6 mm3 · N−1 · m−1. The CrSiN coating deposited with HiPIMS + RF have the highest elastic modulus and hardness of 241.7 GPa and 11.3 GPa, respectively. The CrSiN coating with HiPIMS + RF exhibits a denser columnar structure, and owns the best corrosion performance and the lowest corrosion current density of 3.21 × 10−7 A · cm−2 and the protection efficiency of 92.42%.

Doping silicon to enhance the anti-corrosion and anti-wear abilities of chromium nitride coating in seawater

To solve the friction and wear problem of mechanical part in seawater, we have contrastively researched the microstructure, mechanical, corrosion and tribological properties of CrN and CrSiN coatings, which were prepared by medium frequency magnetron sputtering technology using two Cr targets and one Si target. It confirmed that the grain size of CrSiN coating was reduced by 46.67% after Si was added into CrN matrix. In the meantime, the CrSiN coating owned a typical nanocrystallite/amorphous structure, which consisted of CrN crystal phase and Si3N4 amorphous phase. Furthermore, the hardness, toughness and anti-corrosion ability of CrN coating were obviously enhanced by the addition of proper silicon. Compared with CrN coating, the CrSiN coating exhibited a smaller friction coefficient (COF) and wear loss at different normal loads and sliding frequencies, which could be ascribed to its low surface roughness, high adhesion strength, good toughness, strong anti-corrosion ability and the lubrication of transfer film, indicating its excellent service potential as a protective coating.

Understanding the corrosion and tribological behaviors of CrSiN coatings with various Si contents in HCl solution

Abstract CrSiN coatings with various Si contents were prepared on 304L substrate through medium frequency magnetron sputtering. Toughness, corrosion resistance and tribology property of as-prepared coatings in 0.1 M HCl solution were studied. The result showed that the toughness of CrN coating was effectively enhanced by the incorporation of proper silicon. Compared with other coatings, the CrSiN coating with high silicon proportion presented lower icorr and higher |Z|0.01 Hz. When the silicon proportion exceeded 16.0 at.%, the inhibition efficiency was up to 99.10%. During tribology test, the COF and wear rate descended at the early stage and then ascended as the silicon proportion increased as a whole, which was ascribed to the combined action between toughness, anti-corrosion and lubrication behaviors.

Microstructural effect on the tribo-corrosion behaviors of magnetron sputtered CrSiN coatings

Minimization of corrosion loss or corrosion-related loss is highly desirable for enhancing the tribo-corrosion resistance of physical vapor deposition (PVD) hard coatings. Various tribo-corrosion tests against Al2O3 counterparts combined with microscopic examinations, were used to study the tribo-corrosion behaviors of three typical kinds of magnetron sputtered CrSiN coatings. The dense and columnar coating exhibited superior tribo-corrosion resistance, with a lowest specific tribo-corrosion rate of 6 × 10−16 m3/N m and a lowest friction coefficient of ~0.14, where the dominant mechanism was considered as a layer-by-layer mechanical removal and the chemical corrosion was inappreciable. The porous and columnar coating failed for its poor intrinsic corrosion resistance. For the almost column-free coating, brittle fracture leaded to an increase of the corrosion component in the material wear, despite that the coating had the best intrinsic corrosion resistance. The comparison studies demonstrated that the dominant factors of the tribo-corrosion resistance are more complicated than purely mechanical wear or purely chemical corrosion; high compactness, effectively crack-controlled wear, and the dynamic equilibrium of depassivation-repassivation surfaces on the worn are indispensable for the highly tribo-corrosion resistant PVD hard coatings.

Tribological Performances of CrSiN Coatings Deposited by High Power Pulse Magnetron Sputtering

The coatings deposited by physical vapor deposition (PVD) technique have found a wide industrial application as protective coatings for their attractive properties such as high hardness, good wear resistance and chemical stability. In order to explore the triboligical performances of CrSiN coatings, CrSiN coatings were prepared o the surface of 316 stainless steel by high power pulse magnetron sputtering (HPPMS) in this paper. Sliding wear tests of CrSiN coatings against Si3N4 ceramic balls and titanium balls have been carried out on a friction abrasion testing machine under reciprocating sliding conditions. nanoindentation and scratch tester, field emission scanning electron microscopy equipped with energy dispersive spectrometer (FESEM/EDS) and a X-ray diffractometer (XRD) was used to study the tribological behaviors of CrSiN coatings systematically. Results showed that CrSiN coatings exhibited good wear resistance, which can be attributed to the smoother and denser surface of CrSiN coatings resulted from much fewer macroparticles and pitting defects. The differences on wear debris removal behaviors and wear mechanism were caused by the different microstructure of CrSiN coatings.

Friction and Wear Properties of CrSiCN/SiC Tribopairs in Water Lubrication

CrSiCN coatings (3.4 at.% Si) were prepared on 316L stainless steels using unbalanced magnetron sputtering. According to the analysis results of x-ray diffractometer and x-ray photoelectrons spectroscopy, silicon in CrSiCN coatings mainly presented in the amorphous forms of a-SiN, a-SiCN and a-SiC. The hardness and Young’s modulus of CrSiN coatings were 19.4 ± 0.6 and 306.1 ± 5.9 GPa, respectively. In addition, the ball-on-disk sliding tests of CrSiCN/SiC tribopairs were performed in distilled water at varying velocities (0.1-0.5 m/s) and loads (2-12 N). The friction coefficient of tribopairs presented a decreasing trend with respect to velocity at low applied loads (≤ 4 N). To be specific, the low friction coefficient of 0.05-0.14 accompanied with polished wear scar was obtained at high velocities and low loads. Finally, the wear mechanism map of CrSiCN/SiC tribopairs was proposed based on a combination of friction coefficient, wear scar morphology and wear rates of tribopairs.

Structure, corrosion, and tribological properties of CrSiN coatings with various Si contents in 3.5% NaCl solution

The CrSiN coatings with different silicon contents were deposited on 304L stainless steel and single silicon substrates using medium frequency magnetron sputtering via adjusting the silicon target current. Microstructures, mechanical, corrosion, and tribological performances were systematically investigated by the corresponding equipment. The results showed that the CrSiN coatings were composed of 2 phases: the nanocrystalline CrN coordinated with adjacent Si3N4 to form a typical nanocrystalline amorphous structure. With the increase of silicon content, the hardness emerged a rising trend until 12.65 at.%, where the hardness reached its highest value at approximately 22 GPa. At the moment, the friction coefficient and wear rate were approximately 0.27 and 6.9 × 10−8 mm3/Nm, respectively, which were 18.75% and 61.67% lower than that of the CrN coating, respectively. This mainly attributed to the lubrication of tribochemical products of SiO2 and Si(OH)4. In addition, excellent toughness, high hardness, preferable adhesion, and good corrosion resistance also contributed to improve the tribological properties of CrSiN coating.