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Exploring the contribution of oxygen reduction reaction to Mg corrosion by modeling assisted local analysis

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Journal of Magnesium and Alloys 2023年第1期11卷 100-109页

作者： Cheng Wang Wen Xu Daniel Höche Mikhail L.Zheludkevich sviatlana v.lamaka Institute of Surface Science Helmholtz-Zentrum HereonGeesthacht 21502Germany Institute for Materials Science Faculty of EngineeringKiel UniversityKiel 24103Germany

Oxygen reduction reaction(ORR)has been disclosed in recent studies as a significant secondary cathodic process during magnesium *** work elaborates on the contribution of ORR to the total corrosion process of pure Mg at different impurity levels in NaCl electrolyte with the assistance of local techniques.A finite element based numerical model taking into account the contribution of ORR during the corrosion of the Mg test materials has been designed in this study considering the local oxygen *** computational simulations were calibrated based on the experimental data and evaluated ***,the simultaneous monitoring of local concentration of H_(2) and O_(2),and the combined modeling study reveal the relation between ORR and hydrogen evolution reaction.

关键词： Local oxygen concentration Oxygen reduction reaction Mg corrosion NaCl electrolyte Hydrogen evolution reaction Numerical model

A combined computational/experimental study of anode-concerned voltage drop in aqueous primary Mg-air batteries

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Journal of Magnesium and Alloys 2024年第5期12卷 1854-1866页

作者： Wen Xu Min Deng Darya Snihirova Linqian Wang Yulong Wu sviatlana v.lamaka Mikhail L.Zheludkevich Daniel Hoche Institute of Surface Science Helmholtz-Zentrum Hereon21502 GeesthachtGermany School of Materials Science and Engineering Hebei University of Technology300000TianjinChina Institute for Materials Science Faculty of EngineeringKiel University24143 KielGermany

The voltage drop appearing at Mg anode-electrolyte interface is a critical issue for the battery power and energy density of aqueous primary Mg-air *** respective voltage loss is typically assigned to the deposits layer forming on the anode surface during *** this work,we experimentally and computationally investigate the critical factors affecting the voltage drop at Mg anode towards a deeper understanding of the contribution of deposit and its growth.A two-dimensional(2D)mathematical model is proposed to compute the voltage drop of Mg-0.15Ca wt.%alloy(Mg-0.15Ca)by means of a semi-empirical formulas and experiments-based modification model,considering the effect of discharge current density,the negative difference effect(NDE)and surface deposits layer *** model is utilized to simulate the discharge potential of the anode at predefined experimental current *** computed voltage drop(half-cell voltage)is in good agreement with the experimental *** applicability of the mathematical model is successfully validated on the second material(namely high-purity Mg).

关键词： Aqueous Mg-air battery voltage drop NDE Charge transfer Deposits-related resistances

Biodegradation behaviour of Fe-based alloys in Hanks’Balanced Salt Solutions:Part *** evolution of local pH and dissolved oxygen concentration at metal interface

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Bioactive Materials 2022年第1期7卷 412-425页

作者： Cheng Wang Christabelle Tonna Di Mei Joseph Buhagiar Mikhail L.Zheludkevich sviatlana v.lamaka Institute of Surface Science Helmholtz-Zentrum HereonGeesthacht21502Germany Department of Metallurgy and Materials Engineering University of MaltaMsidaMalta School of Materials Science and Engineering&Henan Key Laboratory of Advanced Magnesium Alloy Zhengzhou UniversityZhengzhou450001PR China Institute for Materials Science Faculty of EngineeringKiel UniversityKiel24103Germany

Commercially pure Fe,Fe35Mn,and(Fe35Mn)5Ag alloys were prepared by uniaxial pressing of the mixture of individual powders,followed by *** influence of the alloying elements Mn and Ag on the corrosion behaviour of these Fe-based alloys was investigated in Hanks’Balanced Salt Solution(HBSS).Furthermore,the role of the components in HBSS,particularly Ca^(2+)ions during alloys degradation was *** of local pH and dissolved oxygen concentration was measured 50μm above the interface of the degrading *** results revealed that 5 wt%Ag addition to Fe35Mn alloy triggered micro-galvanic corrosion,while uniform corrosion dominated in pure Fe and *** precipitation of Ca-P-containing products on the surface of these Fe-based alloys buffered local pH at the metal interface,and blocked oxygen diffusion at the initial stages of *** the(Fe35Mn)5Ag,the detachment or structural changes of Ca-P-containing products gradually diminished their barrier *** findings provided valuable insights into the degradation mechanism of promising biodegradable Fe-based alloys.

关键词： Local pH Dissolved oxygen Fe alloys Biodegradable metals Powder metallurgy

Micro-alloyed Mg-Ca:Corrosion susceptibility to heating history and a plain problem-solving approach

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Journal of Magnesium and Alloys 2023年第4期11卷 1193-1205页

作者： Min Deng Linqian Wang Darya Snihirova Jan Bohlen Gerrit Kurz sviatlana v.lamaka Daniel Höche Mikhail L.Zheludkevich Institute of Surface Science Helmholtz-Zentrum HereonMax-Planck Str.1Geesthacht 21502Germany Institute of Material and Process Design Helmholtz-Zentrum HereonGeesthacht 21502Germany Institute of Materials Science Faculty of EngineeringKiel UniversityKiel 24143Germany

The exceptionally low corrosion rate(∼0.1 mm y^(–1)in concentrated NaCl solution for 7 days)enables lean Mg-Ca alloys great potential for diverse applications,particularly if relevant properties(*** strength,electrochemical performance,etc.)can be enhanced by thermomechanical ***,herein it is demonstrated that the corrosion performance of lean Mg-Ca is susceptible to the heating *** corrosion rate of Mg-0.15 wt%Ca alloy is remarkably accelerated after annealing even for a short time(4 h at 400℃)because Fe precipitation readily takes ***,it is found that micro-alloying with dedicated additional elements is able to solve this ***,the problem-solving capability is dependent on the element category,particularly the ability of the alloying element to constrain the Fe *** the three studied elements(***,Ge and In),only In shows good competence of restricting the formation of Fe-containing precipitates,thereby contributing to retention of the superior corrosion resistance after annealing even at a rigorous condition(24 h at 450℃).The finding creates good foundation for follow-up work of developing lean Mg-Ca-based alloys combining high corrosion resistance,superior electrochemical performance with excellent mechanical properties for applications as biodegradable implants and anode materials for aqueous batteries.

关键词： Magnesium Micro-alloying Thermomechanical processing Corrosion Impurity

Biodegradation behaviour of Fe-based alloys in Hanks’Balanced Salt Solutions:Part *** characterisation and corrosion testing

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Bioactive Materials 2022年第1期7卷 426-440页

作者： Christabelle Tonna Cheng Wang Di Mei sviatlana v.lamaka Mikhail L.Zheludkevich Joseph Buhagiar Department of Metallurgy and Materials Engineering University of MaltaMsidaMalta Institute of Surface Science Helmholtz-Zentrum HereonGeesthacht21502Germany School of Materials Science and Engineering&Henan Key Laboratory of Advanced Magnesium Alloy Zhengzhou UniversityZhengzhou450001PR China Institute for Materials Science Faculty of EngineeringKiel UniversityKiel24103Germany

Research on Fe-based biodegradable alloys for implant applications has increased considerably over the past ***,there is limited information on the influence of testing electrolytes on corrosion product formation and general corrosion *** this work,the effect of Hanks’Balanced Salt Solution(HBSS)with or without Ca^(2+)on the corrosion of Fe,Fe35Mn and(Fe35Mn)5Ag powder-processed coupons has been studied using potentiodynamic polarisation,Electrochemical Impedance Spectroscopy(EIS),and preliminary localised measurement of pH and dissolved oxygen concentration in close proximity to the metal *** Fe35Mn and(Fe35Mn)5Ag alloys showed accelerated corrosion when compared to pure Fe based on potentiodynamic testing results,with FeMnAg exhibiting the highest corrosion rate in Ca^(2+)-containing *** results indicate that in Ca^(2+)-containing HBSS,the formation of a partially protective Ca/P layer decelerates the corrosion progress,whereas the Fe-and Mn-phosphates formed in Ca^(2+)-free HBSS do not have the same *** Ca/P layer on(Fe35Mn)5Ag experienced a reduction in resistance following several hours of testing,indicating partial loss of its protective effect.

关键词： Fe alloys Biodegradable metals Powder metallurgy Electrochemical impedance spectroscopy Local pH Local DO

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Nanoporous magnesium

Nano Research 2018年第12期11卷 6428-6435页

作者： Ilya vladimirovich Okulov sviatlana v.lamaka Takeshi Wada Kunio Yubuta Mikhail L.Zheludkevich Jorg Weissmuller Jurgen Markmann Hidemi Kato Institute for Materials Research Tohoku UniversityKatahira 2-1-1Sendai980-8577Japan Institute of Materials Research Materials MechanicsHelmholtz-Zentrum Geesthacht21502GeesthachtGermany MagiC-Magnesium Innovation Centre Helmholtz-Zentrum Geesthacht21502GeesthachtGermany Faculty of Engineering University of Kiel24118KielGermany Institute of Materials Physics and Technology Hamburg University of Technology21073HamburgGermany

In this study, we present freestanding nanoporous magnesium as a novel lightweight material with high potential for structural and functional applications. Thus far, the high reactivity of Mg with oxygen and aqueous media prevented the fabrication of nanoporous Mg. First, in order to synthesize nanoporous Mg, we fabricated a bicontinuous nanocomposite consisting of interpenetrating Mg and non-Mg phases by liquid metal dealloying. The non-Mg phases in the nanocomposite protect Mg against corrosion. Second, we etched the non-Mg phases from the nanocomposite, leaving nanoporous Mg, using HF solution. This process is advantageous because the nanoporous Mg was passivated by a MgF2 layer during the etching. Our approach is very flexible, and we demonstrate that versatile microstructures of the nanoporous Mg—e.g., nanoscale bicontinuous network, hierarchical, or plate-like structures—can be designed for the given needs. More importantly, these nanoporous Mg samples can readily be exposed to air without being harmed by corrosion.

关键词： dealloying nanoporous magnesium

Understanding the corrosion of Mg alloys in in vitro urinary tract conditions: A step forward towards a biodegradable metallic ureteral stent

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Journal of Magnesium and Alloys 2023年第11期11卷 4301-4324页

作者： Margarida Pacheco Ivo M.Aroso Joana M.Silva sviatlana v.lamaka Jan Bohlen Maria Nienaber Dietmar Letzig Estêvão Lima Alexandre A.Barros Rui L.Reis 3B’s Research Group-Research Institute on Biomaterials Biodegradables and BiomimeticsUniversity of MinhoGuimarãesPortugal ICvS/3B’s-PT Government Associate Laboratory Braga/GuimarãesPortugal Institute of Surface Science Helmholtz-Zentrum hereon GmbHGermany Institute of Material and Process Design Helmholtz-Zentrum hereon GmbHGermany School of Health Sciences Life and Health Sciences Research Institute(ICVS)University of MinhoBragaPortugal

Ureteral stents play a fundamental role in modern time urology. However, following the deployment, stent-related symptoms are frequent and affect patient health and quality of life. Using biodegradable metals as ureteral stent materials have emerged as a promising strategy, mainly due to the improved radial force and slower degradation rate expected. Therefore, this study aimed to characterize different biodegradable metals in urinary tract environment to understand their propensity for future utilization as base materials for ureteral stents. The corrosion of 5 Mg alloys - AZ31, Mg-1Zn, Mg-1Y, pure Mg, and Mg-4Ag - under simulated urinary tract conditions was accessed. The corrosion layer of the different alloys presented common elements, such as Mg(OH)_(2), MgO, and phosphate-containing products, but slight variations in their chemical compositions were detected. The corrosion rate of the different metals varied, which was expected given the differences in the corrosion layers. On top of this, the findings of this study highlighted the significant differences in the samples' corrosion and corrosion layers when in stagnant and flowing conditions. With the results of this study, we concluded that Mg-1Zn and Mg-4Ag presented a higher propensity for localized corrosion, probably due to a less protective corrosion layer;Mg-4Ag corroded faster than all the other four alloys,and Mg-1Y stood out due to its distinct corrosion pattern, that showed to be more homogeneous than all the other four samples, making this one more attractive for the future studies on biodegradable metals.

关键词： Biodegradable metals Magnesium alloys Localized corrosion Biodegradable metallic ureteral stent

Predicting the inhibition efficiencies of magnesium dissolution modulators using sparse machine learning models

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npj Computational Materials 2021年第1期7卷 1783-1791页

作者： Elisabeth J.Schiessler Tim Würger sviatlana v.lamaka Robert H.Meißner Christian J.Cyron Mikhail L.Zheludkevich Christian Feiler Roland C.Aydin Institute of Material Systems Modeling Helmholtz-Zentrum HereonGeesthachtGermany Institute of Surface Science Helmholtz-Zentrum HereonGeesthachtGermany Institute of Polymers and Composites Hamburg University of TechnologyHamburgGermany Institute for Continuum and Material Mechanics Hamburg University of TechnologyHamburgGermany Institute for Materials Science Faculty of EngineeringKiel UniversityKielGermany

The degradation behaviour of magnesium and its alloys can be tuned by small organic ***,an automatic identification of effective organic additives within the vast chemical space of potential compounds needs sophisticated ***,we propose two systematic approaches of sparse feature selection for identifying molecular descriptors that are most relevant for the corrosion inhibition efficiency of chemical *** is based on the classical statistical tool of analysis of variance,the other one based on random *** demonstrate how both can—when combined with deep neural networks—help to predict the corrosion inhibition efficiencies of chemical compounds for the magnesium alloy *** particular,we demonstrate that this framework outperforms predictions relying on a random selection of molecular ***,we point out how autoencoders could be used in the future to enable even more accurate automated predictions of corrosion inhibition efficiencies.

关键词： corrosion alloy magnesium

输尿管支架用镁合金丝材在模拟尿液中的腐蚀行为

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输尿管支架用镁合金丝材在模拟尿液中的腐蚀行为