Corrosion Of Thin Films Research Articles

Corrosion and conductivity damage of AgNW transparent conductive thin films under a simulated sulfur-containing atmosphere and mechanical force

Silver nanowire (AgNW) transparent conductive thin films possess high flexibility, high conductivity, high light transmittance and etc., demonstrating significant advantages in flexible electronics applications. However, in the service occasions, the coupled effect of corrosion and mechanical force easily makes the electrical conductivity of AgNW films deteriorate or even fail, which seriously affects the service reliability of AgNW films. In this work, scanning vibrating electrode technique was firstly used to confirm the existence of electrochemical corrosion on AgNW films. Furthermore, electrochemical measurements (including OCP, PDP and EIS) were carried out for researching the electrochemical corrosion process on AgNW films under different environmental factors and mechanical forces. Their surface morphologies and electrical conductivity were characterized and evaluated by the Scanning Electron Microscopy and square resistance tester respectively. Experimental results indicate that the corrosion-mechanics interaction effect aggravates the damage process of electrical conductivity of AgNW films.

Monitoring Reinforced Concrete Structures Using Iron Thin Film Coated Optical Fibre Sensors

Structural health monitoring (SHM) of reinforced concrete structures (RCS) is crucial for mitigating the consequences of their deterioration. By identifying and addressing the issues early, SHM helps reduce environmental impact, safeguard lives, and enhance economic resilience. Rebar corrosion is a leading cause of early RCS decay and optical fibre sensors (OFS) have been employed for its monitoring. Reflection optrodes using optical fibres where the tip is coated with iron (Fe) thin films offer a robust, longlasting and straightforward solution. This study investigates the tracking of spectral changes during the Fe thin film corrosion, which has been neglected in the literature, in favour of tracking reflection changes from thin film spalling. A multimode fibre tip, coated with a thin Fe layer embedded in concrete, allows spectral changes to be observed during corrosion. A 100 nm thick Fe film was deposited using radio frequency magnetron sputtering on polished fibre tips. Corrosion was induced by applying salted water drops and allowing the fibre tip to dry. Corrosion monitoring was successful for both air-exposed and cementembedded tips, with results compared to reflection simulations of Fe, Fe2O3, and Fe3O4 thin films. This study supports monitoring at different wavelengths, enhancing robustness, cost-effectiveness and earlier detection.

In Situ Measurement of Hydrogen Absorption into Copper-Coated Titanium Using Neutron Reflectometry and Electrochemical Impedance Spectroscopy

We set out to investigate the possibility that a small amount of hydrogen, generated by sulfide-driven corrosion or radiolytic processes, might be absorbed into the copper coating proposed for use as corrosion protection for the used nuclear fuel containers (UFCs) to be stored in a deep geological repository (DGR) in Canada. Hydrogen absorption may have the potential to alter the mechanical properties of the copper coating. This contribution discusses our initial study, using in situ neutron reflectometry (NR) and electrochemical impedance spectroscopy (EIS), of hydrogen absorption into a 50-nm layer of copper coated onto 4 nm of Ti on a Si single-crystal substrate. In situ NR-EIS experiments detected no increase in the hydrogen content within the copper layer of the copper-titanium thin film following 55 h of polarization in deoxygenated 0.1 M NaCl solution at pH 9, at potentials ranging from −444 mV/SCE to −1300 mV/SCE (detection limit ~2 at.%). However, these NR results showed that hydrogen can be absorbed into copper when the latter is cathodically polarized below about ─900 mV/SCE, which is the experimentally measured potential threshold for the hydrogen evolution reaction (HER) under these conditions. Although hydrogen did not accumulate in the outer Cu layer, our experiments revealed that the absorbed hydrogen quickly traversed the Cu layer to concentrate in the underlying titanium layer, which favours absorbed hydrogen. This observation is consistent with hydrogen uptake measured using inert gas fusion analysis on oxygen-free, phosphorus-doped (OFP) copper, which showed that in the absence of hydrogen recombination inhibitors (e.g., As(III)), only a small increase of 22 wt. ppm hydrogen was absorbed into the copper after 24 h at E = −1300 mV/SCE, and no increase in absorbed hydrogen occurred at potentials of −1100 mV/SCE or more positive. The initial absorption efficiency for electrolytically produced hydrogen atoms at the copper surface was determined to be 3.2%, suggesting that there may be an upper limit for hydrogen uptake by the copper coating of the UFC, although studies on 3 mm copper-coated steel samples representative of UFC materials will be required to confirm that. This result supports the prediction that hydrogen absorption is unlikely to lead to any failure of the copper barrier within a proposed DGR, in which it will not be possible to achieve such negative electrochemical potentials. Intended future research using in situ NR-EIS to study hydrogen absorption during the corrosion of copper thin films by HS⁻ ions and further studies on hydrogen absorption into 3-mm-thick copper-coated steel samples will help to validate these conclusions.

Tailoring of Mg and MgLi thin-film corrosion rates with dielectric barrier discharge plasma treatment

Magnesium and magnesium alloys such as magnesium-lithium are of great interest for the application as biodegradable implants. To control the degradation, a tailoring of the corrosion rate is needed. In this study, the effect of a short (5–20 s) dielectric barrier discharge plasma treatment in ambient air on the corrosion rate of magnetron sputtered Mg and MgLi thin films is presented. The treatment with atmospheric plasma of as sputtered samples leads to a decrease of the corrosion rate of 45%−50% in Hanks’ balanced salt solution. The higher corrosion resistance is influenced by a change in surface structure and a formation of an MgCO3 containing film.

Characterization of Structural, Optical, Corrosion, and Mechanical Properties of HfO2 Thin Films Deposited Using Pulsed DC Magnetron Sputtering.

Various properties of HfO2, such as hardness, corrosion, or electrical resistance, depend on the method and the conditions of deposition. In this work, a thorough comparison of scarcely investigated mechanical properties of HfO2 thin films deposited with different conditions of reactive magnetron sputtering process is presented. Four thin films were sputtered in processes that varied in plasma ignition method (continuous or sequential) and target-substrate distance. The structural characteristics of the HfO2 thin films were examined using Raman spectroscopy and X-ray diffraction measurements. Furthermore, the optoelectronic properties were determined based on transmittance and current-voltage characteristics. The mechanical properties of the HfO2 thin films were determined using nanoindentation and scratch test. In turn, the corrosion properties were determined by analyzing the voltametric curves. The transparent HfO2 thin films deposited in the continuous process are characterized by better corrosion resistance than the same layer formed in the sequential process, regardless of the target-substrate distance (8 cm or 12 cm). Furthermore, these samples are also characterized by the highest value of Young's modulus and scratch resistance. The combination of good corrosion and scratch resistance could contribute to the new application of HfO2 as a corrosion protective material.

Temperature, Refractive Index, and Corrosion Simultaneous Monitoring Using Raman Anti-Stokes Reflectometric Optical Fiber Sensor

Optical sensors that can measure multiple parameters is a promising area of research. This can also be attributed to the fact that monitoring two or more measurands at the same time is crucial in embedded systems, especially when they are interconnected, as is the case of temperature and corrosion, or temperature and refractive index. In this work, an optical fiber sensor based on Raman scattering in single-mode optical fibers to simultaneously monitor temperature, refractive index and corrosion is proposed and experimentally demonstrated. This sensor consists of a distributed temperature detection system based on Raman scattering with additional sensor heads: for multipoint corrosion monitoring and multipoint refractive index variation measurement. The multiparameter sensor was evaluated for solutions with refractive indices in the range of 1.3370 – 1.3840 RIU (Refractive Index Unit), for temperatures between 30 °C and 100 °C, and for aluminum thin-film corrosion in acid solution. The experimental results show that the sensor presents sensitivities of 0.5 dB/10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> RIU to refractive index variations, of 0.43 dB/nm for corrosion, and of 0.243 dB/°C for temperature, with resolution of 2 °C. The sensor system can also provide the corrosion rate and operate in fiber links several kilometers long.

Corrosion selectivity and structural evolution in N doped Sb2Te thin films for lithography application

Te-based phase-change resist has lots of advantages such as high-resolution, broad spectral response, and simple preparation process, making it a promising candidate for lithography. Particularly, both positive and negative features can be simultaneously implemented in the resist. However, there are few reports on regulating atom concentration of the resist to realize both positive and negative features. This work has reported N doped Sb 2 Te thin films as both positive and negative resists by adjusting N concentration. The negative resist with the N concentration of lower than 21.7 at% possesses the corrosion selectivity of as high as 4.2 while the positive resist with the N concentration of higher than 24.7 at% has the maximum corrosion selectivity of 10.9. The mechanism of corrosion selectivity has been further investigated. Electrochemical analysis reveals that for the negative resist, the increased annealing temperature results in the gradual increment of charge-transfer resistance and thus the higher corrosion potential. For the positive resist, however, the increased annealing temperature leads to the gradual decreased charge-transfer resistance and thus the lower corrosion potential. Structural analysis indicates that the annealed state for the negative resist can form large amounts of Sb 2 Te or Sb phases containing Sb-Sb and Te-N bonds, which will restrain the corrosion of thin films whereas the formation of Te Te bond in the as-deposited state will promote the corrosion of thin film. However, the annealed state for the positive resist can generate large amounts of Te phase consisting of Te-Te bonds, which is readily oxidized into TeO 2 and further be dissolved whereas the as-deposited state comprising more Sb-N and Te-N bonds will retard the further corrosion of thin film. Results indicate that N doped Sb 2 Te thin film is a promising inorganic resist for lithography applications. • NSb2Te films act as both positive and negative resists by tuning N concentration. • The negative resist possesses the corrosion selectivity of as high as 4.2. • The positive resist has the maximum corrosion selectivity of 10.9. • The mechanism of corrosion selectivity has been investigated in detail.

Thermodynamic Descriptors to Predict Oxide Formation in Aqueous Solutions.

We formulate the maximum driving force (MDF) parameter as a descriptor to capture the thermodynamic stability of aqueous surface scale creation over a range of environmental conditions. We use free energies of formation, ΔfG's, sourced from high-throughput density functional theory (DFT) calculations and experimental databases to compute the maximum driving force for a range of materials, including oxides and hydroxides of varying compositions. We show how to use the MDF to describe trends in the aqueous corrosion of nickel thin films determined from experimental linear sweep voltammetry data. We also show how to account for subsurface oxidation behavior using depth-dependent effective chemical potentials. We anticipate this approach will increase the overall understanding of oxide formation on chemically complex multielement alloys, where competing oxide phases can form during transient aqueous corrosion.

Corrosion and mechanical behavior of 17G1S-U pipeline steel and its weld joint of in the terms simulating operational conditions

Corrosion and mechanical behavior of weld joint samples of the straight-weld pipe of 17G1S-U pipeline steel in the conditions simulating the operating conditions of internal and external corrosion has been studied. It is shown that the initiation of local corrosion of welded joints from the inner surface of the pipeline is due to thin-film corrosion in a two-phase medium (hydrocarbon-water) under deformation conditions. The depth of local damages of the base metal and weld metal can reach 0.337 mm and 0.381 mm. Stress corrosion cracking is a danger for the outer surface which is under cathodic protection. Maintaining the potential at the level of the maximum protective potential -1050 mV increases the stress corrosion cracking inclination of pipeline 17G1S-U steel and its weld joint, due to deterioration of the plastic properties of the metal during longtime exposure at cathodic polarization: decreasing in the relative elongation of the base metal is equal near 11 %, weld joint – by 20%. The KS susceptibility, estimated by the KS coefficient, under these conditions is equal to 1.8 for 17G1S-U steel, 1.5 for weld joint.

ОСОБЛИВОСТІ ЛОКАЛЬНОЇ КОРОЗІЇ ЗВАРНОГО З’ЄДНАННЯ ТРУБНОЇ СТАЛІ Х70, ОБУМОВЛЕНОЇ ЙОГО ЕЛЕКТРОХІМІЧНОЮ ГЕТЕРОГЕННІСТЮ

Establishing the influence of chemical composition and structure on local corrosion of the welded joint of X70 pipe steel in the conditions simulating operating conditions, and determining the main corrosion factors. Methodology. Standard methods were used: potentiometry, polarization curves method, research of corrosion resistance at constant deformation, profilometry, optical metallography. Results. The electrochemical heterogeneity of the welded joint (on the example of X70 steel) with the factory weld was studied. It was found that in the weld of this joint has a slightly lower content compared to the base metal of the following elements: Al (0.025% and 0.02%, respectively) and Nb (0.033% and 0.058%, respectively), but a higher content of Mo and Cr. The structure of base metal is ferritic-bainite, has small pearlite formations, the structure of the seam is heterogeneous, contains dispersed needle, grain boundary polygonal, pre-eutectoid ferrite and separate areas of lamellar ferrite. It is concluded that in the welded joint under studied, the greater electrochemical activity of any zone can be attributed to the lower content of alloying elements or features of the microstructure. According to the results of electrochemical and accelerated corrosion-mechanical tests in the simulated operating conditions, it was found that the determinative factor for initiating of local corrosion of welded joints is the corrosive environment and conditions of the corrosion process flying, in particular – thin-film corrosion in a two-phase medium (hydrocarbon water). Scientific originality. According to the results of complex research, new data on the influence of the chemical composition and structure of the welded joints of steel X70 with factory extensional weld on the susceptibility to local corrosion were obtained. It was found that in a welded joint, the greater electrochemical activity of any zone is due to the lower content of alloying additives (this applies to the weld metal) and/or the peculiarities of the microstructure (for weld metal and high affected zone). Practical value. The methodological approach to investigation of local corrosion of welded joints in the conditions which are simulating the condition of operation, on an example of welded joints of X70 steel is developed and substantiate. A laboratory stand for research has been developed. It is established that the determinative factor for initiating of local corrosion of welded joints is the corrosive-active medium and the conditions of the corrosion process flying, particularly – thin-film corrosion in a two-phase medium (hydrocarbon-water).

Fe Thin Film-Coated Optics for Corrosion Monitoring: Optical and Electrochemical Studies

Corrosion proxy materials integrated with an optical sensing platform enable a real-time optical corrosion sensor for natural gas pipelines to prevent methane leaks and catastrophic events. Effects of CO2, pH, and film thickness on corrosion of Fe thin films (25 nm, 50 nm, 100 nm) were studied using optical and electrochemical methods in 3.5 wt.% NaCl solutions at 30°C. An increase in light transmission (T%) corresponded to corrosion of Fe thin films. CO2 accelerated corrosion of Fe thin films because of the lower pH and the promoted corrosion reactions, resulting in a faster increase of T% than without CO2 or at higher pH. While the corrosion rate increased with increasing film thickness, electrochemical corrosion of Fe thin films was in good agreement with that of bulk carbon steel, verifying that Fe thin films can serve as a representative corrosion proxy when integrated with the optical sensing platform.

Examination of electrochemical corrosion properties of titanium carbide thin film grown by RF magnetron sputtering

This research study examines the significant contribution of Titanium carbide (TiC) thin film coatings on the electrochemical corrosion properties of Ti6Al4V substrate. TiC thin films coatings were deposited on Ti6Al4V substrates using RF magnetron sputtering. The surface morphology of the coatings was investigated using Field emission scanning electron microscope. Potentiodynamic polarization and Electrochemical impedance spectroscopic measurements were performed to determine the TiC thin film corrosion resistant effectiveness. The result revealed that the TiC thin film improves the corrosion resistance of the Ti6Al4V substrates, and the protective efficiency of the TiC thin film coatings depend on the surface morphology of the coating and the interaction between the sputtering process parameters.

Hydrolysis corrosion of alumina thin films produced by pulse DC reactive magnetron sputtering at various operating pressures

Alumina thin films were prepared by pulsed DC reactive magnetron sputtering using operating pressures that were varied from 3 to 20 mTorr. The films were immersed in DI water at temperatures of 55 °C and 65 °C for 30 min to study their hydrolysis corrosion behaviors. Unlike bulk crystalline Al2O3 materials, sputtered alumina films fabricated at operating pressures of 7 mTorr and higher were found to react with DI water within minutes, even under mild conditions. X-ray diffraction (XRD) and spectroscopic ellipsometry (SE) showed that the as-sputtered films had amorphous structures with various degrees of porosity within the films. The calculated porosity was found to increase from 17% to 25% as the operating pressure increased from 3 to 20 mTorr, respectively. Field-emission scanning electron microscopy (SEM) was employed to characterize the morphologies of the corroded films. Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy showed the presence of hydroxide-containing functional groups on surfaces of alumina films, suggesting that the corrosion was due to a hydrolysis reaction. X-ray photoelectron spectroscopy (XPS) revealed distinct features in the non-corroded and corroded sample groups. For the corroded group (7–20 mTorr), the Al 2p peak showed two transitions, at 74.2 and 75.5 eV, attributed to Al–O and Al–OH, respectively. The O 1s peak intensities associated with the hydroxide content of samples in this group were found to be stronger than those associated with the lattice oxygen. The O 1s signal from adsorbed water at 533.7 eV became much stronger in corroded samples. The results also show that films fabricated at higher operating pressures yielded higher levels of pre-adsorbed hydroxide. Corrosion may progress through collective processes, including the formation of soluble aluminum hydroxide complex species and Al–O bond breaking during the proton transfer reactions between adsorbed water and hydroxide.

Finite Element Method for Thin Film Corrosion Modelling: Where We Advanced and Where We would like to Advance?

Thin film corrosion is a serious issue in almost every sector. Thus, simulation of corrosion under thin electrolyte films has always been of high interest as experimental studies are often challenging. Thus far, progress has been made to model the effect of several important factors on thin film corrosion rates. Some of these parameters are electrolyte thickness, electrolyte composition, chemical reactions in the electrolyte, electrode size and change in electrode size, environmental parameters, and corrosion products deposition. However, these parameters are mainly drawn from different studies and have not been modelled concurrently in a single simulation study, making the thin film corrosion model far from being complete yet. Therefore, despite the many efforts so far, thin film corrosion modelers still strive to push the modelling edges further. This paper takes into account some of the highlighted recent advances in thin film corrosion modelling based on the mentioned parameters to provide a perspective on not only how far the field has come, but also how far it still is from a complete thin film corrosion model. Discussions have also been made on future needs and prospects to advance the thin film corrosion models further.

Tribological And Corrosion Characteristics Of Coatings Based On Chromium Nitride Deposited By The Mechanochemical Method

A study was conducted to evaluate the performances against wear and corrosion of Cr2N thin films. The thin film was synthesized onto steel substrates SHKH15, using mechanochemical method. The experimental work was achieved using ball-on-disc configuration in dry conditions against Al2O3 balls. The corrosion resistance was determined by potentiometric method. The main conclusions are: corrosion testing in 4 % solution of nitric acid (HNO3) solution indicated that Cr2N is improved anticorrosion performance when compared to the steel substrate SHKH15; the Cr2N coating presents the better tribological properties. Tribological tests against, that Cr2N coating presents the lowest coefficient of friction relatively to the steel substrate SHKH15.

Corrosion and tribocorrosion behaviour of titanium nitride thin films grown on titanium under different deposition times

Ti and its alloys exhibit combination of unique properties for biomedical applications, however their poor tribo-electrochemical behaviour is a major concern. Therefore, TiN coatings were deposited on cp-Ti (grade 4) by sputtering technique aiming the improvement of its tribocorrosion behaviour. The properties of the coated samples, using different TiN deposition times, were characterized by using grazing incidence X-ray diffraction, FIB-SEM, and nanoindentation. The corrosion behaviour was studied by electrochemical impedance spectroscopy and potentiodynamic polarization in 9 g/L NaCl solution at body temperature. Tribocorrosion tests were employed under open circuit potential by using a ball-on-plate tribometer with 1 N normal load, 3 mm total stroke length, 1 Hz frequency, and 1800 s sliding duration. The results suggested that the TiN coatings deposited during 80 min presented better corrosion and tribocorrosion behaviour as compared to the bare metal and TiN coatings deposited during 30 min.

Corrosion of Platinum Nanocoatings Thin Films Deposited by Sputtering Deposition Method for Medical Applications

Platinum (Pt.) thin films have been deposited by Magnetron Sputtering Deposition method with 25 nm and 50 nm thickness by used power RF for deposited 5 nm Titanium (Ti) firstly then used DC for deposited Platinum (Pt) on Ni-Cr alloy substrate. SEM/EDX and Ellipsometry Spectroscopy have been used to investigate the morphology, element analysis, nanothickness and roughness of the thin films respectively. Electrochemical corrosion tests have been used to analyze the localized corrosion resistance by used cyclic polarization, Tafel extrapolation and open circuit potential (o.c.p) methods on artificial saliva solution at 37 ±1 oC. The results show the ability to deposit 5 nm of Ti before deposited of Pt. film to improve the adhesive of the films, nanostructure morphology of the Pt. film without defect or microcracks, nanocoatings thickness of Pt. film, and high localized corrosion resistance in artificial saliva corrosive media.

Highly Sensitive Colorimetric Detection of Early Stage Aluminum Corrosion in Water Using Plasmonic Gold Nanoparticle Films

AbstractCorrosion remains the major reason for the failure of metallic parts. Therefore, spotting and evaluating the severity of corrosion at its early stages is of great importance. Herein, a novel optical corrosion probe based on plasmonic gold nanoparticles immobilized on aluminum surface is demonstrated. The measurements confirm that the corrosion rate and mechanism of bare aluminum is identical to that of the developed probe. During Al corrosion, the gold nanoparticles are located entirely at the interface between the inner dense and outer porous layers of the formed aluminum oxide. The growth of the inner oxide layer during corrosion prompts a change in the reflection spectra and the appearance of strong coloration that is easily observed by the naked eye. Numerical modeling reveals that these optical changes occur mainly due to light interference within the inner oxide layer, which is located between the plasmonic gold nanoparticles and the underlying reflective aluminum. The ability of the plasmonic probe is further demonstrated to monitor the aqueous corrosion of thin films, bulk and alloyed Al, as well as Al protected by a self‐assembled monolayer of hydrophobic surfactant, and, hence, the wide applicability of the method.

In situ EC-TEM Studies of Metal Thin Film Corrosion in Liquid Solutions at Elevated Temperatures

In situ EC-TEM Studies of Metal Thin Film Corrosion in Liquid Solutions at Elevated Temperatures

High-temperature Corrosion of CrAlSiN Thin Films in N2/0.1%H2S Gas

Cr25.2Al19.5Si4.7N50.5 thin films were deposited on steel substrates by cathodic arc plasma deposition. They consisted of alternating fcc-Cr(Al)N/hcp-Al(Cr,Si)N nanolayers. They were corroded at 900 and 1000 ℃ for 5-100 h in N2/0.1%H2S gas atmosphere. Their corrosion mechanism, the structure of the formed scales, and the role of film-constituting elements during corrosion were studied. Despite the presence of hydrogen and sulfur in the corrosion gas, the films displayed good corrosion resistance because Cr, Al, Fe preferentially reacted with impurity oxygen in the corrosion gas to form Cr2O3, Fe3O4, and amorphous Al2O3 owing to the thermodynamic stability of these oxides. The films were corroded by the outward diffusion of Cr, Al, Fe and nitrogen as well as the inward transport of sulfur and then oxygen. Silicon in the film was primarily oxidized by the inwardly transported oxygen. This study aimed to investigate the high-temperature corrosion behavior of nano-multilayered Cr25.2Al19.5Si4.7N50.5 thin films in a serious H2S-containing environment.