Mikhail L. Zheludkevich

Helmholtz-Zentrum Hereon | HZG · Institute of Surface Science

- The pretreatment methods (blast-cleaning, grinding, etc.) determine surface morphology and composition of the aluminium surface. - Grinding tools: cleaner surfaces, more regular surface morphologies. - Blasting processes: less clean surfaces, because of up-take of the blasting residue; irregular surface morphologies. - Surface roughness can be ad...

Ultra‐high strength steel (UHSS) structures are plated with Zn‐Ni coatings because of their excellent corrosion resistance properties, but the plating process is accompanied by the production of hydrogen. The presence of hydrogen in steel results in hydrogen embrittlement. Hence, during the production of UHSS parts, dedicated outgassing steps are e...

Small organic molecules can alter the degradation rates of the magnesium alloy ZE41. However, identifying suitable candidate compounds from the vast chemical space requires sophisticated tools. The information contained in only a few molecular descriptors derived from recursive feature elimination was previously shown to hold the potential for dete...

Corrosion is a major cause of material degradation and failure in various industries and applications. Damage caused by corrosion causes billions in damage each year and is a major cause of infrastructure degradation. Besides that, corrosion mechanisms, countermeasures and effects are generally not good understood. The platform CorWiz will provide...

Selecting effective corrosion inhibitors from the vast chemical space is not a trivial task, as it is essentially infinite. Fortunately, machine learning techniques have shown great potential in generating shortlists of inhibitor candidates prior to large-scale experimental testing. In this work, we used the corrosion responses of 58 small organic...

Coating technologies are a commonly used way to protect metals against corrosion. However, with more and more severe service environments of materials, many protective coating systems often are not environmentally friendly or toxic as in the case of chromates. Based on the world's abundant ideal magnesium (Mg) and its alloy, the smart self-healing...

The effect of different artificial ageing heat treatments on corrosion evolution kinetics as well as mechanical properties degradation of AA2024 was experimentally investigated. Isothermal artificial ageing heat treatment at 190 °C was performed for different times representing the different ageing tempers, e.g., under-aged (UA), peak-aged (PA), ov...

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 (e.g. mechanical strength, electrochemical performance, etc.) can be enhanced by thermomechanical processing. However, herein it is demonstrated that the...

In the present work, a hybrid hierarchical coating (HHC) system comprising a plasma electrolytic oxidation (PEO) coating and a homogeneously porous structured polycaprolactone (PCL) top-coat layer, loaded with ciprofloxacin (CIP), was developed on Mg3Zn0.4Ca alloy. According to the findings, the HHC system avoided burst release and ensured gradual...

This work first describes the intercalation of corrosion inhibitors into layered double hydroxides LDH-OH/CO3 nanocontainers (parental LDH) obtained in situ on the surface of magnesium alloy AZ91 in the presence of a chelating agent. Vanadate, as a typical broad inhibitor for active metals, and oxalate, as an inhibitor suitable for magnesium, were...

Carbon-fiber-reinforced polymers (CFRP), being conductive, are capable of supporting cathodic oxygen reduction reactions (ORR) and thus promote galvanic corrosion when coupled to many metallic materials. Hence, understanding cathodic processes at carbon surfaces is critical to developing new strategies for the corrosion protection of multi-material...

Stimuli-responsive nanocapsules, which can respond to various environmental stimuli and release their encapsulated payload on demand, have attracted wide interest in different fields in recent years. In this work, a novel kind of polypyrrole (PPy) nanocapsules is fabricated and loaded with zinc salt corrosion inhibitors. The synthesized PPy nanocap...

Selecting effective corrosion inhibitors from the vast chemical space is not a trivial task, as it is essentially infinite. Fortunately, machine learning techniques have shown great potential in generating shortlists of inhibitor candidates prior to large-scale experimental testing. In this work, we used the corrosion responses of 58 small organic...

Current implementation of Industry 4.0, the fourth stage of industrialisation, implies application of novel approaches for manufacturing oriented on strong personalisation and customisation of products. In this context, formation of active multifunctional surfaces with on demand tailored properties can be considered as a keystone in the area of mat...

Corrosion protection systems based on hexavalent chromium are traditionally perceived to be a panacea for many engineering metals including magnesium alloys. However, bans and strict application regulations attributed to environmental concerns and the carcinogenic nature of hexavalent chromium have driven a considerable amount of effort into develo...

Although hexavalent chromium-based protection systems are effective and their long-term performance is well understood, they can no longer be used due to their proven Cr(VI) toxicity and carcinogenic effect. The search for alternative protection technologies for Mg alloys has been going on for at least a couple of decades. However, surface treatmen...

Owing to the unique active corrosion protection characteristic of hexavalent chromium-based systems, they have been projected to be highly effective solutions against the corrosion of many engineering metals. However, hexavalent chromium, rendered a highly toxic and carcinogenic substance, is being phased out of industrial applications. Thus, over...

Open Model develops and provides to European Industry a comprehensive, integrated open modelling framework for accelerated innovation processes and development of novel materials and products. Validation in Open Model includes standardized workflows to quickly and reliably test materials models and solvers, benchmarks efficient comparison with meas...

The effect of various amounts of 5-sulfosalicylic acid (SSA) on the corrosion and discharge property of pure magnesium (Mg) is studied systematically. It was found that SSA plays a vital role in regulating the dissolution kinetics of the substrate and re-deposition rate of discharge product at the metal/electrolyte interface. Low concentration of S...

Recently the successful formation of PEO coatings on zinc in a phosphate aluminate electrolyte was shown. The produced composite coatings contain various mixtures of ZnO and ZnAl$_2$O$_4$. In frame of the current study, the properties of the formed coatings including adhesion/cohesion, wear, corrosion and photocatalytic activity were analysed to id...

The preparation and properties of zeolite-containing oxide coatings obtained by plasma electrolytic oxidation are investigated and discussed. Pure and Ce-exchanged natural (clinoptilolite) and synthetic (13X) zeolites are immobilized on aluminum support from silicate-based electrolyte. Obtained coatings are characterized with respect to their morph...

Diverse novel energy conversion and storage systems have developed rapidly in the last few decades to address the growing demand for sustainable and environmentally friendly energy sources. In this respect, aqueous Mg-air batteries have drawn much attention for their high energy density, cost-effectiveness, and environmental friendliness. A primary...

Nanometric layers of Al2O3 were applied by atomic layer deposition (ALD) on 2024-T3 aluminium alloy. The ALD layers suppressed the corrosion of the alloy as confirmed by Scanning Kelvin Probe Force Microscopy (SKPFM), polarization curves and Electrochemical Impedance Spectroscopy (EIS). The protection provided by the ALD layers weakened with the ti...

Oxygen reduction reaction (ORR) has been disclosed in recent studies as a significant secondary cathodic process during magnesium corrosion. This 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 numeri...

Ce³⁺ ions containing zeolite microparticles were in-situ incorporated into plasma electrolytic oxidation (PEO) coating to provide self-healing property for AM50 Mg alloy. It was found that the Ce³⁺ ions can be released from the inertly incorporated zeolite microparticles via ion-exchange as well as from dissolved coating material which contains hig...

In this work, the porosity of plasma electrolytic oxidation (PEO)-based coatings on Al- and Mg-based substrates was studied by two imaging techniques—namely, SEM and computer microtomography. Two approaches for porosity determination were chosen; relatively simple and fast SEM surface and cross-sectional imaging was compared with X-ray micro comput...

A numerical model is developed, aiming to understand and describe anode dissolution behavior and respective interface effects at an Mg-0.1Ca anode during discharge within an aqueous magnesium-air battery (MAB). In this model, the negative difference effect (NDE) that impairs the performance (e.g. utilization efficiency and capacity) of the anode is...

Reinforced concrete is one of the most important structural materials currently used for buildings and infrastructure, in which corrosion of the reinforcement is vital in the design, lifetime, and cost. Replacing steel with aluminium reinforcements is interesting from both a design and environmental standpoint. Conventional cement causes damage to...

Mechanical damage induced failure within protective coatings is one of the main reasons for loss of coating integrity. Thus, for applicability of any coating and sealing technology it is mandatory to know the stress/strain levels at which mechanical component failure will occur and it is important to understand which physical entities drive damage...

Metal corrosion causes huge economic losses, environmental pollution and industrial disasters. Application of smart self-healing coatings for the active corrosion protection of metal substrate has attracted substantial interest in recent years. The self-healing function can be achieved through either the intrinsic or extrinsic method. The intrinsic...

To meet the growing demand for sustainable and endurable energy sources, various novel energy conversion and storage systems have emerged and been developed rapidly over the last decades. Aqueous metal-air batteries have aroused much interest owing to their superior energy density, exceptional reliability, and environmental benignity. Nevertheless,...

The direct ZnAl layered double hydroxide growth on AA2024 is a fast-occurring reaction, yet is characterized by an inhomogeneous film thickness. It has been shown that at the periphery of Cu-rich intermetallic, the flakes tend to be larger and denser. A combination of in situ and ex situ measurements were used to monitor the changes in the layered...

In this study, the corrosion inhibition effect of 8-hydroxyquinoline (8HQ) on a PEO-coated AZ21 magnesium alloy is explored. The interaction of 8HQ molecules with both bare AZ21 and PEO layer was thoroughly scrutinized during the exposure to a corrosive NaCl electrolyte using different characterization methods, including EIS, SEM, Raman spectroscop...

Recently, plasma electrolytic oxidation (PEO) found broad application as a multi-purpose process to create effective corrosion and wear resistant coatings on various metallic substrates. The exceptional properties of metal organic frameworks (MOFs) put them also in focus as perspective materials for corrosion protection. In this work, the formation...

The large amount of corrosion inhibition efficiencies in literature, calls for a more efficient way to organize, access and compare this information. The CORDATA open data management application (https://datacor.shinyapps.io/cordata/) can help select appropriate corrosion inhibitors for application specific challenges.

In a quest for a better understanding of the mechanism and contribution(s) of fresh (“un-degraded”) and degraded CFRP surfaces to galvanic corrosion of coupled metals in multi-material assemblies the electrochemical behaviour of CFRP in quiescent 50 mM NaCl was studied using electrochemical techniques. Tests using ferricyanide/ferrocyanide redox co...

In this study, sodium salt of Ethylendiaminetetraacetic acid (EDTA), a strong and widely-used complexing agent, was utilized as an additive for a primary Mg-air battery electrolyte with a commercially pure magnesium anode. The electrolyte pH (ranged 7.0 to 11.0) was taken as the main parameter to explore the effect of EDTA on the discharge performa...

Effective protective coatings are an essential component of lightweight engineering materials in a large variety of applications as they ensure structural integrity of the base material throughout its whole service life. Layered double hydroxides (LDHs) loaded with corrosion inhibitors depict a promising approach to realize an active corrosion prot...

A strategy based on chelating agent addition was used to assist the in-situ growth of MgAl-layered double hydroxides (LDHs) films on magnesium alloy AZ31 in a relatively mild condition. The growth behavior of MgAl-LDH films was studied on the magnesium alloy AZ31 substrate as the sole source of Al³⁺ and/or adding aluminum compounds as a supplementa...

A comparison of PEO layers on Ti6Al4V alloy formed in phosphate, aluminate and silicate-based electrolytes respectively, has been made to reveal the influence of the electrolyte composition on the formation process. The phosphate-based electrolyte has been identified as the most promising one as it has the best coating formation efficiency and the...

Layered double hydroxides (LDHs), a class of two-dimensional (2D) brucite-like layers, have been effectively applied in diverse fields. However, the current synthesis methods restrict the in situ scaling-up and tunable production of LDH-based materials. Inspired by the growing characteristic of “Bryophyllum pinnatum”, a sacrificial co-sputtered Zn−...

A controllable degradable coating on Mg alloy based on plasma electrolytic oxidation (PEO) process is reported for the first time. The reported results show that introduction of silica nanoparticles into PEO electrolytes leads to their reactive incorporation in coatings and thus influencing the degradation behavior. Dissolution of amorphous phases...

Typically, steel is protected from corrosion by employing sacrificial anodes or coatings based on Zn, Mg, Al or Cd. However, stricter environmental regulations require new environmentally friendly alternatives to replace Cd. Traditionally, Al-based anodes have been employed to cathodically protect steel in marine applications or as ion vapour depos...

Magnesium-based engineering materials are increasingly considered for transport applications due to their exceptional strength to weight ratios. [1] However, effective corrosion protection strategies are required due to the high chemical reactivity of magnesium (Mg). A promising approach to achieve the desired active corrosion protection are layere...

Phosphate and silane containing organic self–assembled (SA) layers serve as pre–treatments on magnesium alloy sheet materials. A reliable protection was achieved in this work via application of alkyd–based coatings on the pretreated surface. The idea of adopting SA pre–treatments as functional layers at metal–polymer interface is to influence the a...

Magnesium (Mg) and its alloys present great potential to be extensively applied in different applications. However, the relatively poor resistance to corrosion and wear significantly restricts their applications in practice. As one of strategies of surface treatment, micro-arc oxidation (MAO) process attracts a lot of attention, since it does not u...

This paper proposes a practical implementation of robust ensemble learning models for accurate prediction of the internal corrosion rate in oil and gas pipelines. A correct assessment of the corrosion rate in fluid flowed oil and gas pipelines has a significant influence on the system's safety and the ability to control operation. The developed pre...

With the aim of improving the corrosion and wear resistance of pure magnesium, La2O3 nano-particles are added into the PEO electrolyte. The influence of the particles on coating formation, morphology and performance is investigated. Results indicate that the porosity and thickness decrease remarkably after the particle incorporation which influence...

Mechanisms of PEO coatings formation on AA2024 aluminum alloy in an aqueous solution, containing 3 g/L NaOH and 5 g/L Na2O∙2.9SiO2∙18H2O (base electrolyte) and with addition of 1.5 g/L CoOOH∙H2O, are studied. This addition results in a formation of black coatings. It is determined that structure, phase and elemental compositions of the coatings cor...

Although Tris-HCl and HEPES are typically used pH buffers for in vitro studies, they are recently proven to be unable to stabilize local pH at Mg interface in simulated body fluids. In this study, local pH close to physiological (7.1-7.5) was found at metal/fluid interface of pure Zn, Zn-0.8 wt.%Ca and Zn-0.8 wt.%Mg alloys in Tris-HCl or HEPES buff...

The preparation and properties of oxide coatings with immobilized ZSM-5 zeolite obtained by plasma electrolytic oxidation on aluminum support are investigated and discussed. Pure and Ce-exchanged ZSM-5 are immobilized on aluminum support from silicate-based electrolyte in ultra-low duty cycle pulsed direct current conditions. Obtained composite coa...

Aqueous primary Mg-air batteries have considerable potential as energy sources for sea applications and portable devices. However, some challenges at the anode-electrolyte interface related to self-corrosion, aging of the electrolyte...

A comparative analysis of the corrosion activity of bioresorbable MA8 magnesium alloy (Mg– Mn – Ce system) in a medium for cultivation of mammalian cells (minimum essential medium, MEM) and 0.83 wt. % aqueous NaCl solution was performed. The development of the corrosion process on the surface of a magnesium alloy in two media was established using...

Lean alloy (low alloyed) is beneficial for long-term sustainable development of metal materials. Creating a nanocrystalline microstructure is a desirable approach to improve biodegradability and mechanical properties of lean biomedical Mg alloy, but it is nearly impossible to realize. In the present study, the bulk nanocrystalline Mg alloy (average...

The novel hybrid phosphate pigment 6-amino hexanoic acid (6-AHA) intercalated in layered aluminum di-hydrogen tripolyphosphate (ATP-6-AHA) was successfully embedded in an alkyd coating at 5.0 wt% and applied on low carbon steel. Layered pigments used in coatings are becoming very attractive due to the improvement of the coatings barrier properties....

The degradation behaviour of magnesium and its alloys can be tuned by small organic molecules. However, an automatic identification of effective organic additives within the vast chemical space of potential compounds needs sophisticated tools.Herein, we propose two systematic approaches of sparse feature selection for identifying molecular descript...

This work reports the influence of alumina fiber reinforcement of an AZ91Nd MMC (metal matrix composite) on the PEO coating formation process in a sodium phosphate-based electrolyte. By comparison with the pure AZ91Nd, the evolution of alumina fiber during the processing and the characteristics of the resultant PEO coating were investigated. The vo...

In the presented work, the possibility of direct synthesis of LDH (layered double hydroxide) on the AZ91 surface in the presence of a chelating agent (diethylenetriaminepentaacetic acid - DTPA) is reported. Conversion layer of LDH nanocontainers were formed under ambient pressure conditions without carbonate addition in the electrolyte. The obtaine...

This study aims to examine the effect of clay micro particles addition on the microstructure, wear and corrosion behavior of PEO coatings on AM 50 magnesium alloy. PEO coatings were prepared using an aluminate-based electrolyte with and without the presence of 5 g/L clay particles. The structure and composition of the coatings were evaluated using...

Low interfacial pH (7.5-8.0) and corrosion rate were found for several Mg alloys (CP-Mg, UHP-Mg, Mg-0.15 wt.%Ca, Mg-4wt.%Ag) in Ca²⁺-containing Hanks’ Balanced Salt Solution (HBSS, pHinitialbulk=7.4) at 37 °C under hydrodynamic condition. Low interfacial pH and corrosion rate originated from the facilitated formation of the protective calcium-phosp...

A new corrosion inhibitor called ATP-6-AHA was elaborated, and its inhibition action on S235 low carbon steel in 3.5% sodium chloride (NaCl) was investigated using gravimetry, potentiodynamic polarization (PP), and electrochemical impedance spectroscopy (EIS). The release of ecofriendly 6-aminohexanoic acid (6-AHA) from its established aluminum tri...

In this work, the formation behavior of PEO coatings on polymorph Ti6Al4V alloy with two different lattice structures (hexagonal close packed α-Ti and cubic body centered β-Ti phases) was studied, using two galvanostatically controlled processes. The phase formation as a function of treatment time was studied ex-situ locally on the two Ti phases by...

Corrosion protection and surface properties of Magnesium (Mg) containing 51ppm Fe (HP-Mg) and 341 ppm Fe (CP-Mg) were assessed by EIS, AFM/SKPFM, and photoluminescence spectroscopy in NaCl solutions with/without fumarate (Fum), 2,5-pyridinedicarboxylate (PDCA) and salicylate (Sal) carboxylates. The PDCA was effective in corrosion inhibition of HP-M...

Adhesively-bonded titanium components enable new design concepts in lightweight engineering but often lack long-term joint durability and endurance. Major challenges are related to the fact that the titanium/adhesive interface is susceptible to environmental ageing which leads to interfacial deadhesion. In the present work, the issue is addressed f...

Tribo-electrochemical impedance spectroscopy (Tribo-EIS) measurements of pure Mg were performed to identify the origin of two time constants during standard EIS measurements in NaCl solution. The influence of abrasion introduced by tribometer on EIS spectra was investigated under different rotation speeds. Further quantitative analyses of abrasion...

In this work, plasma electrolytic oxidation (PEO) coatings were produced on magnesium alloy AZ31 in aluminate, silicate and phosphate- based electrolytes, and followed by hydrothermal treatments in order to synthesis layered double hydroxides (LDHs) based nanocontainers. LDHs synthesis was done in three different growth solutions (deionized water,...