Currently,the demand for electromagnetic wave(EMW)absorbing materials with specific functions and capable of withstanding harsh environments is becoming increasingly urgent.Multi-component interface engineering is con...Currently,the demand for electromagnetic wave(EMW)absorbing materials with specific functions and capable of withstanding harsh environments is becoming increasingly urgent.Multi-component interface engineering is considered an effective means to achieve high-efficiency EMW absorption.However,interface modulation engineering has not been fully discussed and has great potential in the field of EMW absorption.In this study,multi-component tin compound fiber composites based on carbon fiber(CF)substrate were prepared by electrospinning,hydrothermal synthesis,and high-temperature thermal reduction.By utilizing the different properties of different substances,rich heterogeneous interfaces are constructed.This effectively promotes charge transfer and enhances interfacial polarization and conduction loss.The prepared SnS/SnS_(2)/SnO_(2)/CF composites with abundant heterogeneous interfaces have and exhibit excellent EMW absorption properties at a loading of 50 wt%in epoxy resin.The minimum reflection loss(RL)is−46.74 dB and the maximum effective absorption bandwidth is 5.28 GHz.Moreover,SnS/SnS_(2)/SnO_(2)/CF epoxy composite coatings exhibited long-term corrosion resistance on Q235 steel surfaces.Therefore,this study provides an effective strategy for the design of high-efficiency EMW absorbing materials in complex and harsh environments.展开更多
The atmospheric corrosion monitoring(ACM)technique has been widely employed to track the real-time corrosion behavior of metal materials.However,limited studies have applied ACM to the corrosion protection properties ...The atmospheric corrosion monitoring(ACM)technique has been widely employed to track the real-time corrosion behavior of metal materials.However,limited studies have applied ACM to the corrosion protection properties of organic coatings.This study compared a bare epoxy coating with one containing zinc phosphate corrosion inhibitors,both applied on ACM sensors,to observe their corrosion protection properties over time.Coatings with artificial damage via scratches were exposed to immersion and alternating dry and wet environments,which allowed for monitoring galvanic corrosion currents in real-time.Throughout the corrosion tests,the ACM currents of the zinc phosphate/epoxy coating were considerably lower than those of the blank epoxy coating.The trend in ACM current variations closely matched the results obtained from regular electrochemical tests and surface analysis.This alignment highlights the potential of the ACM technique in evaluating the corrosion protection capabilities of organic coatings.Compared with the blank epoxy coating,the zinc phosphate/epoxy coating showed much-decreased ACM current values that confirmed the effective inhibition of zinc phosphate against steel corrosion beneath the damaged coating.展开更多
A new method of corrosion-resistant coating of technical iron is presented. Processing by vibrationally excited hydrogen molecules of the iron surface covered with oxide film of α-Fe2 03 results in modification of su...A new method of corrosion-resistant coating of technical iron is presented. Processing by vibrationally excited hydrogen molecules of the iron surface covered with oxide film of α-Fe2 03 results in modification of surface by creating a film of amorphous iron on it. The presence of iron films with crystalline and amorphous phases, having the different Fermi levels, leads to formation of potential differences between them. This potential difference is opposite to the external electric field, resulting in decrease of anode current and increase of corrosion resistance.展开更多
The joining of different light metals through friction stir welding(FSW)is gaining interest as a method to decrease weight and improve fuel efficiency.However,to ensure durability,these welded metals may require surfa...The joining of different light metals through friction stir welding(FSW)is gaining interest as a method to decrease weight and improve fuel efficiency.However,to ensure durability,these welded metals may require surface treatments to protect against corrosion or wear.This study presents a novel approach for the simultaneous delivery of two distinct corrosion inhibitors to Ti-Mg dissimilar PEO treated joints on demand.The research focuses on the synthesis,characterization,and application of cerium@polystyrene(Ce@PS)nanocontainers,which are loaded with 8-hydroxyquinoline(8-HQ)to enhance corrosion protection.The synthesis involves several key steps,including the formation of a cerium-based outer layer around polystyrene nanospheres,the selective removal of the polystyrene core to create a porous structure,and the subsequent loading of the 8-HQ inhibitor.Structural and compositional analyses,conducted using scanning transmission electron microscopy(STEM)and energy-dispersive X-ray spectroscopy(EDS),confirmed the successful incorporation of 8-HQ within the nanocontainers.Additionally,Fourier-transform infrared spectroscopy(FTIR)provided detailed information about the chemical composition of the organic materials throughout the synthesis process.Thermal decomposition analysis verified the successful fabrication and stability of the dual-shell nanocontainers.Corrosion tests on Ti-Mg joints treated with plasma electrolytic oxidation(PEO)coatings and loaded nanocontainers demonstrated sig-nificantly improved corrosion resistance compared to untreated joints.This research highlights the potential of dual-shell nanocontainers,containing both organic and inorganic inhibitors,to offer prolonged corrosion protection,particularly against galvanic corrosion in dissimilar joints.The findings suggest that these synthesized nanocontainers hold promise for various industrial applications,particularly in the context of friction stir welded(FSW)Ti-Mg dissimilar joints,providing valuable insights for the development of advanced materials designed to mitigate corrosion.展开更多
Magnesium(Mg)alloys are lightweight materials with excellent mechanical properties,making them attractive for various applications,including aerospace,automotive,and biomedical industries.However,the practical applica...Magnesium(Mg)alloys are lightweight materials with excellent mechanical properties,making them attractive for various applications,including aerospace,automotive,and biomedical industries.However,the practical application of Mg alloys is limited due to their high susceptibility to corrosion.Plasma electrolytic oxidation(PEO),or micro-arc oxidation(MAO),is a coating method that boosts Mg alloys'corrosion resistance.However,despite the benefits of PEO coatings,they can still exhibit certain limitations,such as failing to maintain long-term protection as a result of their inherent porosity.To address these challenges,researchers have suggested the use of inhibitors in combination with PEO coatings on Mg alloys.Inhibitors are chemical compounds that can be incorporated into the coating or applied as a post-treatment to further boost the corrosion resistance of the PEO-coated Mg alloys.Corrosion inhibitors,whether organic or inorganic,can act by forming a protective barrier,hindering the corrosion process,or modifying the surface properties to reduce susceptibility to corrosion.Containers can be made of various materials,including polyelectrolyte shells,layered double hydroxides,polymer shells,and mesoporous inorganic materials.Encapsulating corrosion inhibitors in containers fully compatible with the coating matrix and substrate is a promising approach for their incorporation.Laboratory studies of the combination of inhibitors with PEO coatings on Mg alloys have shown promising results,demonstrating significant corrosion mitigation,extending the service life of Mg alloy components in aggressive environments,and providing self-healing properties.In general,this review presents available information on the incorporation of inhibitors with PEO coatings,which can lead to improved performance of Mg alloy components in demanding environments.展开更多
Understanding the interaction between cyclic stresses and corrosion of magnesium(Mg)and its alloys is increasingly in demand due to the continuous expansion of structural applications of these materials.This review is...Understanding the interaction between cyclic stresses and corrosion of magnesium(Mg)and its alloys is increasingly in demand due to the continuous expansion of structural applications of these materials.This review is dedicated to exploring the corrosion-fatigue mechanisms of these materials,with an emphasis on microscale processes,and the possibility of expanding current knowledge on this topic using scanning electrochemical techniques.The interaction between fatigue and corrosion of Mg alloys is analyzed by considering the microstructural aspects(grain size,precipitates,deformation twins),as well as the formation of pits.Furthermore,in the case of coated alloys,the role of coating defects in these phenomena is also described.In this context,the feasibility of using scanning electrochemical microscopy(SECM),scanning vibrating electrode technique(SVET),scanning ion-selective electrode technique(SIET),localized electrochemical impedance spectroscopy(LEIS)and scanning Kelvin probe(SKP)methods to study the corrosion-fatigue interaction of Mg alloys is examined.A comprehensive review of the current literature in this field is presented,and the opportunities and limitations of consolidating the use of these techniques to study the microscale processes involved in Mg corrosion-fatigue are discussed.展开更多
A series of electrochemical and long-term corrosion tests were carried out in a neutral saline (5%NaCl) vapor of 35 °C on thermal sprayed WC cermet coatings containing different kinds of metallic binders in ord...A series of electrochemical and long-term corrosion tests were carried out in a neutral saline (5%NaCl) vapor of 35 °C on thermal sprayed WC cermet coatings containing different kinds of metallic binders in order to examine the effect of composition of binder materials on the corrosion behavior. The experimental results revealed that the overall corrosion resistance of WC-Co coating was inferior to that of WC-Co-Cr coating. For the coatings without Cr, WC-Co, general corrosion occurred in binder materials in addition to galvanic corrosion between WC particles and metallic binders in the neutral environment. By contrast, the formation of passive film in the form of surface oxide in the coatings containing Cr, WC-Co-Cr, suppressed the binder and metallic binders to be eroded. It is found that the chemical composition of metallic binder materials is one of the important factors influencing the corrosion resistance of HVOF sprayed WC cermet coatings in the neutral vapor.展开更多
Magnesium phosphate conversion coating(MPCC)was fabricated on AZ31magnesium alloy for corrosion protection by immersion treatment in a simple MPCC solution containing Mg2+and3PO4?ions.The MPCC on AZ31Mg alloy showed m...Magnesium phosphate conversion coating(MPCC)was fabricated on AZ31magnesium alloy for corrosion protection by immersion treatment in a simple MPCC solution containing Mg2+and3PO4?ions.The MPCC on AZ31Mg alloy showed micro-cracks structure and a uniform thickness with the thickness of about2.5μm after20min of phosphating treatment.The composition analyzed by energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy revealed that the coating consisted of magnesium phosphate and magnesium hydroxide/oxide compounds.The MPCC showed a significant protective effect on AZ31Mg alloy.The corrosion current of MPCC was reduced to about3%of that of the uncoated surface and the time for the deterioration process during immersion in0.5mol/L NaCl solution improved from about10min to about24h.展开更多
The corrosion behavior of hot dip galvanized steel pretrvated with bis-[triethoxysilylpropyl] tetrasulfide (BTESPT) modified with alumina particles was studied. The corrosion resistance of the passiving films was ev...The corrosion behavior of hot dip galvanized steel pretrvated with bis-[triethoxysilylpropyl] tetrasulfide (BTESPT) modified with alumina particles was studied. The corrosion resistance of the passiving films was evaluated by Tafel polarization curve and electrochemical impedance spectroscopy. The films formed on the galvanized steel substrate were characterized by Fourier transform infrared spectroscopy and energy dispersive X-ray spectrometry. The surface morphology of the treated hot dip galvanized steel samples was observed by Field Emission Scanning Electron Microscope. The results show that the pretrvatments on the basis of silane films modified with nanoalumina particles have reduced both anodic and cathodic current densities, and increased total impedance in the measured frequency, consequently, improving corrosion protection for hot dip galvanized steel during immersion in NaCl solutions compared to chromate films and silane films.展开更多
This paper evaluated the protection effect of the cerium conversion coatings on the SiCp/5A06 Al composite and the 5A06 Al alloy.Electrochemical impedance spectroscopy(EIS) was employed to examine the variation of the...This paper evaluated the protection effect of the cerium conversion coatings on the SiCp/5A06 Al composite and the 5A06 Al alloy.Electrochemical impedance spectroscopy(EIS) was employed to examine the variation of the electrochemical variables of the samples treated and immersed in 3.5% NaCl solution at 35 °C for 1 h,which showed the enhancement of charge transfer resistance(Rt) and coating film resistance(Rc),i.e.,the corrosion resistance of the conversion coated samples was improved.The best protection ef...展开更多
Vanadium films were prepared on zinc surfaces by using a solution containing vanadate. Corrosion protection properties of vanadium-treated (V-treated), chromium-treated (Cr-treated), and untreated zinc surfaces in...Vanadium films were prepared on zinc surfaces by using a solution containing vanadate. Corrosion protection properties of vanadium-treated (V-treated), chromium-treated (Cr-treated), and untreated zinc surfaces in contact with a 3.5 wt.% NaC1 solution were studied using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and neutral salt spray (NSS) tests. According to these results, the V-treated layer significantly improved the corrosion resistance of zinc surfaces. In comparison with the Cr-treated layer, the V-treated layer exhibited a better corrosion resistance. The composition of the V-treated layer was studied using X-ray photoelectron spectroscopy (XPS). XPS measurements indicated that the vanadium layer formed on zinc surfaces and the vanadium-rich coating was a hydrated oxide with a composition of V2O5, VO2, and its hydrates such as V2O5.nH2O and VO(OH)2.展开更多
Corrosion protection afforded by a magnesium coating treated in cerium salt solution on steel substrate was investigated using open circuit potential, polarization curves, and electrochemical impedance spectroscopy (...Corrosion protection afforded by a magnesium coating treated in cerium salt solution on steel substrate was investigated using open circuit potential, polarization curves, and electrochemical impedance spectroscopy (EIS) in 0.005 M sodium chloride solution (NaCl). The morphology of the surface was characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). The cerium treated coating was obtained by immersion in CeCl3 solution. The results showed that the corrosion resistance of the treated magnesium coating was improved. The corrosion potential of the treated coating was found to be nobler than that of the untreated magnesium coating and the corrosion current decreased significantly. Impedance results showed that the cerium treatment increased corrosion protection. The improvement of anti-corrosion properties was attributed to the formation of cerium oxides and hydroxides that gave rise to a physical barrier effect.展开更多
Ultrathin conversion coatings, made from aligned graphene derivatives and ammonium zirconium carbonate(AZC), were fabricated on stainless steel by electrodeposition. Sulfonated graphene oxide (SGO) provided electronpa...Ultrathin conversion coatings, made from aligned graphene derivatives and ammonium zirconium carbonate(AZC), were fabricated on stainless steel by electrodeposition. Sulfonated graphene oxide (SGO) provided electronpathways and physical barriers to corrosive molecules. Electrodeposition ensured the alignment of SGO and thefacile fabrication of the coatings. AZC is an environmental-friendly crosslinking agent, water-repellent andcorrosion inhibitor. Upon dehydration reactions, AZC improved the cohesion between SGO layers and anchoredthe conversion coatings on metal substrates. When the mass ratio of SGO to AZC was 2:1, the corrosion currentdensity of the composite coatings reached 0.098 μA cm^(-2), while that of the bared stainless steel was1.04 μA cm ^(-2), given a coating thickness of only 500 nm. The electrical conductivity of SGO/AZC compositecoatings can be tailored from 3.84 × 10^(-5) to 2.28×10^(-3)S‧cm^(-1) by heat treatment and HI reduction, whichsatisfied the electrical conductivity requirement of wide applications in electronic industry, office appliances andpetroleum storage.展开更多
This work produced a Mg Al-layered double hydroxide by hydrothermal treatment of a plasma electrolytic oxidation(PEO) coating on magnesium alloy AZ31 in an phosphate electrolyte, followed by an ion-exchange reaction i...This work produced a Mg Al-layered double hydroxide by hydrothermal treatment of a plasma electrolytic oxidation(PEO) coating on magnesium alloy AZ31 in an phosphate electrolyte, followed by an ion-exchange reaction in 0.1 M phosphate solution. The coated specimens were scratched. Characterization, including utilization of the localized technique SIET, measured the pH and p Mg distributions and optical morphologies around the artificial defects during immersion in 0.05 M NaCl solution. In contrast with phosphate loaded PEO/LDHs, a stronger alkalinization area(with pH 11.4~12.3) appeared in the passive PEO specimens. Due to formation of insoluble Mg(OH)_(2) products, the p Mg map showed depletion of Mg^(2+) in this high p H area. Combined with optical morphologies and SEM images, the better self-healing ability toward defects for phosphate loaded PEO/LDHs was confirmed.展开更多
Superhydrophobic coating has been widely studied for its great applicational potential, such as for corrosion protection of magnesium alloys while it has been restrained by expensive materials, sophisticated preparati...Superhydrophobic coating has been widely studied for its great applicational potential, such as for corrosion protection of magnesium alloys while it has been restrained by expensive materials, sophisticated preparation process and infirm rough structures. In this study, the electrochemical method was adopted by using a two-electrode system for rapid hydrophobic modification to obtain superhydrophobic kaolin.By mixing the modified superhydrophobic kaolin with commercial epoxy resin and polydimethylsiloxane glue, a paint can be formed and easily used on various substrates for preparation of superhydrophobic coating via spraying method. The influence factors on wettability of the modified kaolin and the mixing ratio of each component of the coating were explored. Also, the wettability, durability and anticorrosion of the prepared coating were evaluated comprehensively. The coating was able to maintain superhydrophobic after immersed in HCl solution at pH 1, the NaOH solution at pH 14, and 3.5 wt.% NaCl solution for 16, 21, 30 days, respectively. In addition, the coating exhibited 4A grade adhesion, high hydrophobicity after abraded for 200 cycles on a 600-mesh sandpaper with 100 g weight, and 99.86% anticorrosion efficiency after soaked in 3.5 wt.% NaCl solution for 20 days, demonstrating a good robustness and anti-corrosion property. Furthermore, the coating showed good transparency, flexibility and was easy to make in a large scale by the spraying method, which is of great significance to promote the practical application of superhydrophobic coatings and the anticorrosion Mg alloys.展开更多
Colorful thin oxide films were synthesized by galvanostatic anodization on Ti−6Al−4V alloy.Three different aqueous solutions containing corrosion inorganic inhibitors(Na_(2)MoO_(4),NaH_(2)PO_(4) and NH4VO3)were employ...Colorful thin oxide films were synthesized by galvanostatic anodization on Ti−6Al−4V alloy.Three different aqueous solutions containing corrosion inorganic inhibitors(Na_(2)MoO_(4),NaH_(2)PO_(4) and NH4VO3)were employed for the anodization treatment.The effect of inhibitor anions on the corrosion behavior of the alloy in Ringer solution was studied.Open circuit potential(OCP),Tafel polarization,linear sweep voltammetry(LSV)and chronoamperometry(CA)were performed to evaluate the corrosion performance of the treated electrodes.The incorporation of the inhibitor ions was detected by the release of Mo,V and P through ICP-AES technique.The formed oxides were characterized by scanning electron microscopy(SEM),X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS).The results show that compact,amorphous oxides without pores or cracks were obtained independently of the solution used.The sample anodized in Na_(2)MoO_(4) solution registered the lowest corrosion current density(0.11μA/cm^(2)),and it was able to protect the alloy even after 168 h of immersion in Ringer solution.No cracks or corrosion products were detected.The XPS analysis reveals the incorporation of molybdenum to the oxide film in the form of Mo^(6+) and Mo^(4+).展开更多
The effectiveness of the corrosion protection of Nafion/Dimethysulfoxid (DMSO) organic coatings for AM50 magnesium alloy prepared by simple immersion and heat treatment was investigated. Its corrosion resistance and...The effectiveness of the corrosion protection of Nafion/Dimethysulfoxid (DMSO) organic coatings for AM50 magnesium alloy prepared by simple immersion and heat treatment was investigated. Its corrosion resistance and morphologies of the Nafion/DMSO organic coatings were studied by electrochemical corrosion testing and optical microscopy. The results show that Nafion/DMSO organic coatings can improve the corrosion resistance of AM50 magnesium alloy effectively. Also, the corrosion resistance increases with the surface density of the organic coatings.展开更多
Aluminum coatings on Mg alloy AZ31 were fabricated using the thermal spraying technique, and then sealed with silane.The surface morphology and chemical groups were discerned using scanning electron microscopy and exa...Aluminum coatings on Mg alloy AZ31 were fabricated using the thermal spraying technique, and then sealed with silane.The surface morphology and chemical groups were discerned using scanning electron microscopy and examined using Fourier transformation infrared spectroscopy, respectively.The salt fog tests and the potentiodynamic electrochemical technique were applied to evaluate the influence of silane on corrosion of the AZ31 alloy with aluminum coatings.The results showed that the corrosion resistance of the aluminum-coated AZ31 alloy was superior to that of the substrate.The aluminum coating sealed with various silane layers led to a further increase in the corrosion resistance of the alloy.Double silane layers were more corrosion-resistant than the single one.Also, it was no longer significant for more than two silane layers to improve the corrosion resistance.It implied that the optimum choice for silane treatment on the aluminum coatings was two layers.展开更多
Metal corrosion causes significant economic losses,safety issues,and environmental pollution.Hence,its prevention is of immense research interest.Carbon dots(CDs)are a new class of zero-dimensional carbon nanomaterial...Metal corrosion causes significant economic losses,safety issues,and environmental pollution.Hence,its prevention is of immense research interest.Carbon dots(CDs)are a new class of zero-dimensional carbon nanomaterials,which have been considered for corrosion protection applications in recent years due to their corrosion inhibition effect,fluorescence,low toxicity,facile chemical modification,and cost-effectiveness.This study provides a comprehensive overview of the synthesis,physical and chemical properties,and anticorrosion mechanisms of functionalized CDs.First,the corrosion inhibition performance of different types of CDs is introduced,followed by discussion on their application in the development of smart protective coatings with self-healing and/or self-reporting properties.The effective barrier formed by CDs in the coatings can inhibit the spread of local damage and achieve self-healing behavior.In addition,diverse functional groups on CDs can interact with Fe^(3+)and H^(+)ions generated during the corrosion process;this interaction changes their fluorescence,thereby demonstrating self-reporting behavior.Moreover,challenges and prospects for the development of CD-based corrosion protection systems are also presented.展开更多
To increase corrosion resistance of the sample,its electrical impedance must be increased.Due to the fact that electrical impedance depends on elements such as electrical resistance,capacitance,and inductance,by incre...To increase corrosion resistance of the sample,its electrical impedance must be increased.Due to the fact that electrical impedance depends on elements such as electrical resistance,capacitance,and inductance,by increasing the electrical resistance,reducing the capacitance and inductance,electrical impedance and corrosion resistance can be increased.Based on the fact that these elements depend on the type of material and the geometry of the material,multilayer structures with different geometries are proposed.For this purpose,conventional multilayer thin films,multilayer thin film including zigzag structure(zigzag 1)and multilayer thin film including double zigzag structure(zigzag 2)of manganese nitride are considered to protect AISI 304 stainless steel against corrosion in salt solution.These multilayer coatings including zigzag structures are prepared by alternately using the conventional deposition of thin film and glancing angle deposition method.After deposition,the samples are placed in a furnace under nitrogen flux for nitriding.The cross sections of the structures are observed by field emission scanning electron microscopy(FESEM).Atomic force microscope(AFM)is used to make surface analyses of the samples.The results show that the multilayer thin films including zigzag structures have smaller grains than conventional multilayer thin films,and the zigzag 2 structure has the smaller grain than the other two samples,which is attributed to the effect of shadowing and porosity on the oblique angle deposition method.Crystallography structures of the samples are studied by using x-ray diffraction(XRD)pattern and the results show that nitride phase formation in zigzag 2 structure is better than that in zigzag 1 structure and conventional multilayer thin film.To investigate the corrosion resistances of the structures,electrochemical impedance spectroscopy(EIS)and potentiodynamic polarization tests are performed.The results reveal that the multilayer thin films with zigzag structures have better corrosion protection than the conventional multilayer thin films,and the zigzag structure 2 has the smallest corrosion current and the highest corrosion resistance.The electrical impedances of the samples are investigated by simulating equivalent circuits.The high corrosion resistance of zigzag 2 structure as compared with conventional multilayer structure and zigzag 1 structure,is attributed to the high electrical impedance of the structure due to its small capacitance and high electrical resistance.Finally,the surfaces of corroded samples are observed by scanning electron microscope(SEM).展开更多
基金financially supported by the National Natural Science Foundation of China(No.52377026 and No.52301192)Taishan Scholars and Young Experts Program of Shandong Province(No.tsqn202103057)+4 种基金Postdoctoral Fellowship Program of CPSF under Grant Number(No.GZB20240327)Shandong Postdoctoral Science Foundation(No.SDCXZG-202400275)Qingdao Postdoctoral Application Research Project(No.QDBSH20240102023)China Postdoctoral Science Foundation(No.2024M751563)the Qingchuang Talents Induction Program of Shandong Higher Education Institution(Research and Innovation Team of Structural-Functional Polymer Composites).
文摘Currently,the demand for electromagnetic wave(EMW)absorbing materials with specific functions and capable of withstanding harsh environments is becoming increasingly urgent.Multi-component interface engineering is considered an effective means to achieve high-efficiency EMW absorption.However,interface modulation engineering has not been fully discussed and has great potential in the field of EMW absorption.In this study,multi-component tin compound fiber composites based on carbon fiber(CF)substrate were prepared by electrospinning,hydrothermal synthesis,and high-temperature thermal reduction.By utilizing the different properties of different substances,rich heterogeneous interfaces are constructed.This effectively promotes charge transfer and enhances interfacial polarization and conduction loss.The prepared SnS/SnS_(2)/SnO_(2)/CF composites with abundant heterogeneous interfaces have and exhibit excellent EMW absorption properties at a loading of 50 wt%in epoxy resin.The minimum reflection loss(RL)is−46.74 dB and the maximum effective absorption bandwidth is 5.28 GHz.Moreover,SnS/SnS_(2)/SnO_(2)/CF epoxy composite coatings exhibited long-term corrosion resistance on Q235 steel surfaces.Therefore,this study provides an effective strategy for the design of high-efficiency EMW absorbing materials in complex and harsh environments.
基金financially supported by the National Natural Science Foundation of China(No.52371049)the Young Elite Scientists Sponsorship Program by the China Association for Science and Technology(YESS,No.2020QNRC001)the National Science and Technology Resources Investigation Program of China(Nos.2021FY100603 and 2019FY101404)。
文摘The atmospheric corrosion monitoring(ACM)technique has been widely employed to track the real-time corrosion behavior of metal materials.However,limited studies have applied ACM to the corrosion protection properties of organic coatings.This study compared a bare epoxy coating with one containing zinc phosphate corrosion inhibitors,both applied on ACM sensors,to observe their corrosion protection properties over time.Coatings with artificial damage via scratches were exposed to immersion and alternating dry and wet environments,which allowed for monitoring galvanic corrosion currents in real-time.Throughout the corrosion tests,the ACM currents of the zinc phosphate/epoxy coating were considerably lower than those of the blank epoxy coating.The trend in ACM current variations closely matched the results obtained from regular electrochemical tests and surface analysis.This alignment highlights the potential of the ACM technique in evaluating the corrosion protection capabilities of organic coatings.Compared with the blank epoxy coating,the zinc phosphate/epoxy coating showed much-decreased ACM current values that confirmed the effective inhibition of zinc phosphate against steel corrosion beneath the damaged coating.
文摘A new method of corrosion-resistant coating of technical iron is presented. Processing by vibrationally excited hydrogen molecules of the iron surface covered with oxide film of α-Fe2 03 results in modification of surface by creating a film of amorphous iron on it. The presence of iron films with crystalline and amorphous phases, having the different Fermi levels, leads to formation of potential differences between them. This potential difference is opposite to the external electric field, resulting in decrease of anode current and increase of corrosion resistance.
文摘The joining of different light metals through friction stir welding(FSW)is gaining interest as a method to decrease weight and improve fuel efficiency.However,to ensure durability,these welded metals may require surface treatments to protect against corrosion or wear.This study presents a novel approach for the simultaneous delivery of two distinct corrosion inhibitors to Ti-Mg dissimilar PEO treated joints on demand.The research focuses on the synthesis,characterization,and application of cerium@polystyrene(Ce@PS)nanocontainers,which are loaded with 8-hydroxyquinoline(8-HQ)to enhance corrosion protection.The synthesis involves several key steps,including the formation of a cerium-based outer layer around polystyrene nanospheres,the selective removal of the polystyrene core to create a porous structure,and the subsequent loading of the 8-HQ inhibitor.Structural and compositional analyses,conducted using scanning transmission electron microscopy(STEM)and energy-dispersive X-ray spectroscopy(EDS),confirmed the successful incorporation of 8-HQ within the nanocontainers.Additionally,Fourier-transform infrared spectroscopy(FTIR)provided detailed information about the chemical composition of the organic materials throughout the synthesis process.Thermal decomposition analysis verified the successful fabrication and stability of the dual-shell nanocontainers.Corrosion tests on Ti-Mg joints treated with plasma electrolytic oxidation(PEO)coatings and loaded nanocontainers demonstrated sig-nificantly improved corrosion resistance compared to untreated joints.This research highlights the potential of dual-shell nanocontainers,containing both organic and inorganic inhibitors,to offer prolonged corrosion protection,particularly against galvanic corrosion in dissimilar joints.The findings suggest that these synthesized nanocontainers hold promise for various industrial applications,particularly in the context of friction stir welded(FSW)Ti-Mg dissimilar joints,providing valuable insights for the development of advanced materials designed to mitigate corrosion.
文摘Magnesium(Mg)alloys are lightweight materials with excellent mechanical properties,making them attractive for various applications,including aerospace,automotive,and biomedical industries.However,the practical application of Mg alloys is limited due to their high susceptibility to corrosion.Plasma electrolytic oxidation(PEO),or micro-arc oxidation(MAO),is a coating method that boosts Mg alloys'corrosion resistance.However,despite the benefits of PEO coatings,they can still exhibit certain limitations,such as failing to maintain long-term protection as a result of their inherent porosity.To address these challenges,researchers have suggested the use of inhibitors in combination with PEO coatings on Mg alloys.Inhibitors are chemical compounds that can be incorporated into the coating or applied as a post-treatment to further boost the corrosion resistance of the PEO-coated Mg alloys.Corrosion inhibitors,whether organic or inorganic,can act by forming a protective barrier,hindering the corrosion process,or modifying the surface properties to reduce susceptibility to corrosion.Containers can be made of various materials,including polyelectrolyte shells,layered double hydroxides,polymer shells,and mesoporous inorganic materials.Encapsulating corrosion inhibitors in containers fully compatible with the coating matrix and substrate is a promising approach for their incorporation.Laboratory studies of the combination of inhibitors with PEO coatings on Mg alloys have shown promising results,demonstrating significant corrosion mitigation,extending the service life of Mg alloy components in aggressive environments,and providing self-healing properties.In general,this review presents available information on the incorporation of inhibitors with PEO coatings,which can lead to improved performance of Mg alloy components in demanding environments.
基金support provided by the Spanish Ministry of Science and Innovation(MICINN,Madrid,Spain)the European Regional Development Fund(Brussels,Belgium)MCIN/AEI/10.13039/501100011033/FEDER,UE under grant PID2021-127445NB-I00.
文摘Understanding the interaction between cyclic stresses and corrosion of magnesium(Mg)and its alloys is increasingly in demand due to the continuous expansion of structural applications of these materials.This review is dedicated to exploring the corrosion-fatigue mechanisms of these materials,with an emphasis on microscale processes,and the possibility of expanding current knowledge on this topic using scanning electrochemical techniques.The interaction between fatigue and corrosion of Mg alloys is analyzed by considering the microstructural aspects(grain size,precipitates,deformation twins),as well as the formation of pits.Furthermore,in the case of coated alloys,the role of coating defects in these phenomena is also described.In this context,the feasibility of using scanning electrochemical microscopy(SECM),scanning vibrating electrode technique(SVET),scanning ion-selective electrode technique(SIET),localized electrochemical impedance spectroscopy(LEIS)and scanning Kelvin probe(SKP)methods to study the corrosion-fatigue interaction of Mg alloys is examined.A comprehensive review of the current literature in this field is presented,and the opportunities and limitations of consolidating the use of these techniques to study the microscale processes involved in Mg corrosion-fatigue are discussed.
文摘A series of electrochemical and long-term corrosion tests were carried out in a neutral saline (5%NaCl) vapor of 35 °C on thermal sprayed WC cermet coatings containing different kinds of metallic binders in order to examine the effect of composition of binder materials on the corrosion behavior. The experimental results revealed that the overall corrosion resistance of WC-Co coating was inferior to that of WC-Co-Cr coating. For the coatings without Cr, WC-Co, general corrosion occurred in binder materials in addition to galvanic corrosion between WC particles and metallic binders in the neutral environment. By contrast, the formation of passive film in the form of surface oxide in the coatings containing Cr, WC-Co-Cr, suppressed the binder and metallic binders to be eroded. It is found that the chemical composition of metallic binder materials is one of the important factors influencing the corrosion resistance of HVOF sprayed WC cermet coatings in the neutral vapor.
基金supported by a research grant from Korea Institute of Materials Science (PNK4652)
文摘Magnesium phosphate conversion coating(MPCC)was fabricated on AZ31magnesium alloy for corrosion protection by immersion treatment in a simple MPCC solution containing Mg2+and3PO4?ions.The MPCC on AZ31Mg alloy showed micro-cracks structure and a uniform thickness with the thickness of about2.5μm after20min of phosphating treatment.The composition analyzed by energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy revealed that the coating consisted of magnesium phosphate and magnesium hydroxide/oxide compounds.The MPCC showed a significant protective effect on AZ31Mg alloy.The corrosion current of MPCC was reduced to about3%of that of the uncoated surface and the time for the deterioration process during immersion in0.5mol/L NaCl solution improved from about10min to about24h.
基金the National Natural Science Foundation of China(No.50674022).
文摘The corrosion behavior of hot dip galvanized steel pretrvated with bis-[triethoxysilylpropyl] tetrasulfide (BTESPT) modified with alumina particles was studied. The corrosion resistance of the passiving films was evaluated by Tafel polarization curve and electrochemical impedance spectroscopy. The films formed on the galvanized steel substrate were characterized by Fourier transform infrared spectroscopy and energy dispersive X-ray spectrometry. The surface morphology of the treated hot dip galvanized steel samples was observed by Field Emission Scanning Electron Microscope. The results show that the pretrvatments on the basis of silane films modified with nanoalumina particles have reduced both anodic and cathodic current densities, and increased total impedance in the measured frequency, consequently, improving corrosion protection for hot dip galvanized steel during immersion in NaCl solutions compared to chromate films and silane films.
基金supported by Higher Education Commission of Pakistan
文摘This paper evaluated the protection effect of the cerium conversion coatings on the SiCp/5A06 Al composite and the 5A06 Al alloy.Electrochemical impedance spectroscopy(EIS) was employed to examine the variation of the electrochemical variables of the samples treated and immersed in 3.5% NaCl solution at 35 °C for 1 h,which showed the enhancement of charge transfer resistance(Rt) and coating film resistance(Rc),i.e.,the corrosion resistance of the conversion coated samples was improved.The best protection ef...
文摘Vanadium films were prepared on zinc surfaces by using a solution containing vanadate. Corrosion protection properties of vanadium-treated (V-treated), chromium-treated (Cr-treated), and untreated zinc surfaces in contact with a 3.5 wt.% NaC1 solution were studied using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and neutral salt spray (NSS) tests. According to these results, the V-treated layer significantly improved the corrosion resistance of zinc surfaces. In comparison with the Cr-treated layer, the V-treated layer exhibited a better corrosion resistance. The composition of the V-treated layer was studied using X-ray photoelectron spectroscopy (XPS). XPS measurements indicated that the vanadium layer formed on zinc surfaces and the vanadium-rich coating was a hydrated oxide with a composition of V2O5, VO2, and its hydrates such as V2O5.nH2O and VO(OH)2.
文摘Corrosion protection afforded by a magnesium coating treated in cerium salt solution on steel substrate was investigated using open circuit potential, polarization curves, and electrochemical impedance spectroscopy (EIS) in 0.005 M sodium chloride solution (NaCl). The morphology of the surface was characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). The cerium treated coating was obtained by immersion in CeCl3 solution. The results showed that the corrosion resistance of the treated magnesium coating was improved. The corrosion potential of the treated coating was found to be nobler than that of the untreated magnesium coating and the corrosion current decreased significantly. Impedance results showed that the cerium treatment increased corrosion protection. The improvement of anti-corrosion properties was attributed to the formation of cerium oxides and hydroxides that gave rise to a physical barrier effect.
基金the financial support from National Natural Science Foundation of China U1560108Science and Technology Commission of Shanghai Municipality (17511101603, 18ZR1426300, 19JC1410400)Shanghai Municipal Education Commission (2019-01-07-00-07-E00015)。
文摘Ultrathin conversion coatings, made from aligned graphene derivatives and ammonium zirconium carbonate(AZC), were fabricated on stainless steel by electrodeposition. Sulfonated graphene oxide (SGO) provided electronpathways and physical barriers to corrosive molecules. Electrodeposition ensured the alignment of SGO and thefacile fabrication of the coatings. AZC is an environmental-friendly crosslinking agent, water-repellent andcorrosion inhibitor. Upon dehydration reactions, AZC improved the cohesion between SGO layers and anchoredthe conversion coatings on metal substrates. When the mass ratio of SGO to AZC was 2:1, the corrosion currentdensity of the composite coatings reached 0.098 μA cm^(-2), while that of the bared stainless steel was1.04 μA cm ^(-2), given a coating thickness of only 500 nm. The electrical conductivity of SGO/AZC compositecoatings can be tailored from 3.84 × 10^(-5) to 2.28×10^(-3)S‧cm^(-1) by heat treatment and HI reduction, whichsatisfied the electrical conductivity requirement of wide applications in electronic industry, office appliances andpetroleum storage.
基金the International Cooperation in Science and Technology Innovation between Governments,National Key Research and Development Program of China(No.2018YFE0116200)the National Natural Science Foundation of China(51971040)the Fundamental Research Funds for the Central Universities(2020CDJQY-A007)。
文摘This work produced a Mg Al-layered double hydroxide by hydrothermal treatment of a plasma electrolytic oxidation(PEO) coating on magnesium alloy AZ31 in an phosphate electrolyte, followed by an ion-exchange reaction in 0.1 M phosphate solution. The coated specimens were scratched. Characterization, including utilization of the localized technique SIET, measured the pH and p Mg distributions and optical morphologies around the artificial defects during immersion in 0.05 M NaCl solution. In contrast with phosphate loaded PEO/LDHs, a stronger alkalinization area(with pH 11.4~12.3) appeared in the passive PEO specimens. Due to formation of insoluble Mg(OH)_(2) products, the p Mg map showed depletion of Mg^(2+) in this high p H area. Combined with optical morphologies and SEM images, the better self-healing ability toward defects for phosphate loaded PEO/LDHs was confirmed.
基金the financial support of the National Natural Science Foundation of China (Grant No. 21978182)。
文摘Superhydrophobic coating has been widely studied for its great applicational potential, such as for corrosion protection of magnesium alloys while it has been restrained by expensive materials, sophisticated preparation process and infirm rough structures. In this study, the electrochemical method was adopted by using a two-electrode system for rapid hydrophobic modification to obtain superhydrophobic kaolin.By mixing the modified superhydrophobic kaolin with commercial epoxy resin and polydimethylsiloxane glue, a paint can be formed and easily used on various substrates for preparation of superhydrophobic coating via spraying method. The influence factors on wettability of the modified kaolin and the mixing ratio of each component of the coating were explored. Also, the wettability, durability and anticorrosion of the prepared coating were evaluated comprehensively. The coating was able to maintain superhydrophobic after immersed in HCl solution at pH 1, the NaOH solution at pH 14, and 3.5 wt.% NaCl solution for 16, 21, 30 days, respectively. In addition, the coating exhibited 4A grade adhesion, high hydrophobicity after abraded for 200 cycles on a 600-mesh sandpaper with 100 g weight, and 99.86% anticorrosion efficiency after soaked in 3.5 wt.% NaCl solution for 20 days, demonstrating a good robustness and anti-corrosion property. Furthermore, the coating showed good transparency, flexibility and was easy to make in a large scale by the spraying method, which is of great significance to promote the practical application of superhydrophobic coatings and the anticorrosion Mg alloys.
基金The financial supports of the Secretaría de Ciencia y Técnica-UNS (PGI 24/M159)the Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET-PIP 112-20150-100147)the Agencia Nacional de Promoción Científica y Tecnológica (ANPCy T-PICT 2015-0726)。
文摘Colorful thin oxide films were synthesized by galvanostatic anodization on Ti−6Al−4V alloy.Three different aqueous solutions containing corrosion inorganic inhibitors(Na_(2)MoO_(4),NaH_(2)PO_(4) and NH4VO3)were employed for the anodization treatment.The effect of inhibitor anions on the corrosion behavior of the alloy in Ringer solution was studied.Open circuit potential(OCP),Tafel polarization,linear sweep voltammetry(LSV)and chronoamperometry(CA)were performed to evaluate the corrosion performance of the treated electrodes.The incorporation of the inhibitor ions was detected by the release of Mo,V and P through ICP-AES technique.The formed oxides were characterized by scanning electron microscopy(SEM),X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS).The results show that compact,amorphous oxides without pores or cracks were obtained independently of the solution used.The sample anodized in Na_(2)MoO_(4) solution registered the lowest corrosion current density(0.11μA/cm^(2)),and it was able to protect the alloy even after 168 h of immersion in Ringer solution.No cracks or corrosion products were detected.The XPS analysis reveals the incorporation of molybdenum to the oxide film in the form of Mo^(6+) and Mo^(4+).
文摘The effectiveness of the corrosion protection of Nafion/Dimethysulfoxid (DMSO) organic coatings for AM50 magnesium alloy prepared by simple immersion and heat treatment was investigated. Its corrosion resistance and morphologies of the Nafion/DMSO organic coatings were studied by electrochemical corrosion testing and optical microscopy. The results show that Nafion/DMSO organic coatings can improve the corrosion resistance of AM50 magnesium alloy effectively. Also, the corrosion resistance increases with the surface density of the organic coatings.
基金supported by the Key Technologies Research & Development Program of Chongqing Science and Technology Commission (CSTC) (Nos. 2007AC4073 and 2009AB4008)the Natural Science Foundation of CSTC, China (No. 2008BB0063)
文摘Aluminum coatings on Mg alloy AZ31 were fabricated using the thermal spraying technique, and then sealed with silane.The surface morphology and chemical groups were discerned using scanning electron microscopy and examined using Fourier transformation infrared spectroscopy, respectively.The salt fog tests and the potentiodynamic electrochemical technique were applied to evaluate the influence of silane on corrosion of the AZ31 alloy with aluminum coatings.The results showed that the corrosion resistance of the aluminum-coated AZ31 alloy was superior to that of the substrate.The aluminum coating sealed with various silane layers led to a further increase in the corrosion resistance of the alloy.Double silane layers were more corrosion-resistant than the single one.Also, it was no longer significant for more than two silane layers to improve the corrosion resistance.It implied that the optimum choice for silane treatment on the aluminum coatings was two layers.
基金financially supported by the Young Elite Scientists Sponsorship Program by the China Association for Science and Technology(YESS,No.2020QNRC001)the National Science and Technology Resources Investigation Program of China(No.2021FY100603)the Fundamental Research Funds for the Central Universities(No.FRF-BD-20-28A2)。
文摘Metal corrosion causes significant economic losses,safety issues,and environmental pollution.Hence,its prevention is of immense research interest.Carbon dots(CDs)are a new class of zero-dimensional carbon nanomaterials,which have been considered for corrosion protection applications in recent years due to their corrosion inhibition effect,fluorescence,low toxicity,facile chemical modification,and cost-effectiveness.This study provides a comprehensive overview of the synthesis,physical and chemical properties,and anticorrosion mechanisms of functionalized CDs.First,the corrosion inhibition performance of different types of CDs is introduced,followed by discussion on their application in the development of smart protective coatings with self-healing and/or self-reporting properties.The effective barrier formed by CDs in the coatings can inhibit the spread of local damage and achieve self-healing behavior.In addition,diverse functional groups on CDs can interact with Fe^(3+)and H^(+)ions generated during the corrosion process;this interaction changes their fluorescence,thereby demonstrating self-reporting behavior.Moreover,challenges and prospects for the development of CD-based corrosion protection systems are also presented.
基金Project supported by the Funds from the University of Mohaghegh Ardabili and University of Tehran and the Iran National Science Foundation(INSF)the Centre of Excellence for Physics of Structure and Microscopic Properties of Matter,Department of Physics,University of Tehran.
文摘To increase corrosion resistance of the sample,its electrical impedance must be increased.Due to the fact that electrical impedance depends on elements such as electrical resistance,capacitance,and inductance,by increasing the electrical resistance,reducing the capacitance and inductance,electrical impedance and corrosion resistance can be increased.Based on the fact that these elements depend on the type of material and the geometry of the material,multilayer structures with different geometries are proposed.For this purpose,conventional multilayer thin films,multilayer thin film including zigzag structure(zigzag 1)and multilayer thin film including double zigzag structure(zigzag 2)of manganese nitride are considered to protect AISI 304 stainless steel against corrosion in salt solution.These multilayer coatings including zigzag structures are prepared by alternately using the conventional deposition of thin film and glancing angle deposition method.After deposition,the samples are placed in a furnace under nitrogen flux for nitriding.The cross sections of the structures are observed by field emission scanning electron microscopy(FESEM).Atomic force microscope(AFM)is used to make surface analyses of the samples.The results show that the multilayer thin films including zigzag structures have smaller grains than conventional multilayer thin films,and the zigzag 2 structure has the smaller grain than the other two samples,which is attributed to the effect of shadowing and porosity on the oblique angle deposition method.Crystallography structures of the samples are studied by using x-ray diffraction(XRD)pattern and the results show that nitride phase formation in zigzag 2 structure is better than that in zigzag 1 structure and conventional multilayer thin film.To investigate the corrosion resistances of the structures,electrochemical impedance spectroscopy(EIS)and potentiodynamic polarization tests are performed.The results reveal that the multilayer thin films with zigzag structures have better corrosion protection than the conventional multilayer thin films,and the zigzag structure 2 has the smallest corrosion current and the highest corrosion resistance.The electrical impedances of the samples are investigated by simulating equivalent circuits.The high corrosion resistance of zigzag 2 structure as compared with conventional multilayer structure and zigzag 1 structure,is attributed to the high electrical impedance of the structure due to its small capacitance and high electrical resistance.Finally,the surfaces of corroded samples are observed by scanning electron microscope(SEM).