Aluminum alloys readily corrode under aggressive conditions, necessitating advanced protective coatings with integrated passive and active functionalities. Herein, a ZIF-8/GO/Ag ternary composite filler synthesized via an in-situ strategy is developed, wherein Ag species are anchored onto graphene oxide (GO) to suppress ligand competition with Zn2+, while GO sheets serve as a growth platform to regulate the crystallization of ZIF-8. The composite is incorporated into an environmentally friendly sol-gel coating to provide dual anticorrosion and antibacterial protection for AA2024 aluminum protection. The resulting coating exhibits significantly enhanced corrosion resistance and excellent antibacterial activity. GO increases the diffusion resistance to corrosive species, Zn2+ and 2-methylimidazole provide active corrosion inhibition, and Ag contributes to antibacterial functionality. Density functional theory calculations support the preferential adsorption of Ag on GO, confirming the effectiveness of the anchoring strategy. This work provides a practical approach for designing MOFs-based multifunctional composite fillers and offers a promising route for advanced protective coatings with combined barrier, inhibition, and biocidal functions.

This study couples transient ISO 11997-1 cyclic salt-spray modelling with laboratory tests to assess galvanic corrosion of bolted A4 stainless-steel/EN AW-6082 assemblies. A time-dependent electrolyte-film thickness and conductivity model was coupled to a galvanic-corrosion solver to quantify how washer electrochemistry and geometry affect galvanic currents and corresponding mass loss. Washer open-circuit potential E-corr and exchange current density i(0) are primary controls: more noble washers or higher i(0) drive larger cathodic currents, especially in thin films. Design should keep the aluminium potential below the pitting potential E-pit via low-activity or insulating washers, geometric adjustments, or insulating/coating treatments. Simulations show nylon washers reduce predicted mass loss by approximate to 65 %, with a further approximate to 32 % reduction when washer diameter is increased by 8 mm. Geometry optimisation can reduce currents and mass loss up to threefold.

In this study, we reveal a direct structure–performance relationship in layered double hydroxide (LDH) intercalated with pyridine dicarboxylate (PDA) isomers. The spatial arrangement of PDA molecules within the interlayer, from near-vertical to tilted to disordered packing, governs structural stability, release kinetics, and chloride uptake, providing a molecular-level guide for designing LDHs with tailored properties. Three PDA isomers (2,3-, 2,5-, and 3,4-PDA) were incorporated into ZnAl LDH and characterized by XRD, FTIR, and UV–Vis spectroscopy. Multi-cycle ion exchange tests in NaCl solution provided mechanistic insight into ion-exchange kinetics. ZnAl-2,3PDA LDH showed superior stability and minimal release due to near-vertical alignment and strong electrostatic interactions. ZnAl-2,5PDA LDH achieved the highest chloride uptake while retaining moderate stability via tilted molecular orientation. ZnAl-3,4PDA LDH exhibited rapid release and structural degradation associated with disordered packing. Multi-cycle release confirmed pseudo-second-order kinetics consistent with chemisorption-driven exchange. Density functional theory calculations reproduced the isomer-dependent trends in binding strength and local charge distribution. These findings highlight the critical role of isomer configuration in guiding rational LDH design for controlled release and selective ion capture, enabling advanced functional materials for diverse applications.

The addition of Dy significantly enhanced the corrosion resistance of EK3-xDy alloys (x = 0, 0.5, 1.0, 1.5 wt%), with the EK3-1.5Dy alloy exhibiting the lowest corrosion rate of 0.132 mm y- 1, nearly an order of magnitude lower than that of the Dy-free alloy. Dy was found in solid solution in the Mg12Nd and Mg41Nd5 intermetallics forming Mg12(Nd, Dy) and Mg41(Nd, Dy), which acted as anodic sites and reduced the electrochemical potential difference with the magnesium matrix. The preferential dissolution of these anodic phases released Nd and Dy species that promoted the densification of the corrosion product film. As a result, a compact Dy2O3-Nd2O3containing protective layer formed, substantially improving corrosion resistance.

Efficient thermal management is essential for aluminum components operating in environments with fluctuating thermal loads, especially when protective surface treatments are required, like in heat exchangers working in phase change material (PCM) environments. Plasma electrolytic oxidation (PEO) provides excellent wear and corrosion resistance but typically produces ceramic layers with low intrinsic thermal conductivity, potentially limiting heat-transfer performance. This study systematically evaluates how PEO processing mode (unipolar vs. bipolar) and nanoparticle additives influence coating microstructure, phase composition, porosity, and the effective thermal conductivity of coated AlMg3 substrates. Coatings were produced using a standard alkaline silicate-phosphate electrolyte with and without ZnO, WS2, TiC, TiN, and BN particles. Microstructural and compositional analyses were performed via SEM/EDS and GIXRD measurements, while thermal conductivity of the full coated system was determined using laser flash analysis (LFA). Across all conditions, PEO coatings reduced thermal conductivity relative to bare alloy (129.78 W/(m.K)) but only moderately, with most 5-min treatments remaining within similar to 20% loss of the substrate conductivity (111.43 W/(m.K) for particle-free unipolar mode coatings). Particle additions resulted only in limited improvements; the best performing additive, 3 g/L ZnO in unipolar mode, yielded slight conductivity enhancement associated with more uniform particle incorporation (119. 03 W/(m.K)). Overall, results highlight that PEO coatings can deliver protective functionality while maintaining acceptable thermal performance.

The contribution is concerned with the influence of bristle-blasting on texture, chemical status, and corrosion of aluminum (AA6082) substrates in synthetic and real seawater. The performance of an offshore epoxy coating, applied onto the substrates, is also investigated. Bristle-blasting generated substrates with a low level of contamination and with a rather regular surface texture. It complied with requirements for offshore use in terms of substrate roughness and coating adhesion. The filiform corrosion tests delivered useful results. The cyclic corrosion test duration (3000 h), however, was too short, and the degradation was negligible. The coating performance was also evaluated during two years in real marine outdoor exposure in the splash zone and the tidal zone in a North Sea location (Helgoland); the results were compared with the laboratory test results. For the first time, acceleration factors were calculated for the filiform laboratory test. The test generated very high acceleration factors, which depended on the location of the specimens during outdoor site testing.

Titanium (Ti)-magnesium (Mg)-based composites have emerged as promising candidates for partially degradable implant materials in biomedical applications. The controlled degradation of bioactive Mg promotes bone ingrowth, while the porous Ti matrix provides mechanical support and helps mitigate stress shielding. Although the galvanic corrosion between Ti and Mg presents challenges for controlled degradation, the composite’s favorable mechanical properties and biocompatibility are driving significant research interest. Furthermore, the immiscibility of Ti and Mg, along with their large difference in melting points, limits the applicability of conventional melting and casting techniques for developing Ti-Mg alloys. As a result, research has focused on the development of composites using alternative processing techniques. This review highlights recent advancements in Ti-Mg composite development, aiming to provide both fundamental understanding and practical guidance for designing partially degradable implants with controlled local biodegradation. Firstly, we summarize various Ti-Mg composite fabrication techniques, which are broadly categorized into powder metallurgy and infiltration casting methods. Secondly, the mechanical properties, degradation behaviors, and in vitro and in vivo biocompatibility of the Ti-Mg composite are comprehensively analyzed. Finally, we address current limitations and possible future directions of Ti-Mg composite development to support further innovations in this field.

The integration of green hydrogen production with wastewater treatment is a promising strategy for addressing the dual challenges of clean energy generation and environmental remediation. Herein, we propose an innovative class of noble metal (Pt, Pd, Ru, etc.)-free cathodes based on tungsten trioxide (WO3), fabricated via plasma electrolytic oxidation (PEO) on affordable aluminum substrates. The PEO process produced porous, adherent, and compositionally complex coatings of mixed crystalline/amorphous WO3 with embedded W0, providing low-cost and scalable electrodes for the hydrogen evolution reaction (HER), which is also effective in water containing organic contaminants. The structural and surface analyses established a clear structure property relationship, correlating WO3 content and PEO-induced morphology with both hydrogen evolution and pollutant degradation efficiency, while the electrochemical characterization revealed that both increased WO3 loading and Zn-Al layered double hydroxide functionalization improved charge transfer and HER activity. A15W, selected as the best-performing cathode, achieved up to 1 mmol cm- 2 H2 generation in acidic water contaminated with model organic molecules (rhodamine B, gallic acid, and 3,4,5-trimethoxybenzoic acid), promoting at the same time pollutants electrooxidation (40-100% abatement depending on the reaction conditions). These findings highlight the potential WO3-based electrodes as promising, low-cost alternatives to Pt for integrated hydrogen production and wastewater treatment.

This study presents the development of immobilized photocatalytic coatings for the degradation of diclofenac (DCF), a persistent pharmaceutical pollutant, under solar light irradiation. Two-dimensional tungsten oxide (2D-WO3) nanoflakes were synthesized via hydrothermal treatment and incorporated into plasma electrolytic oxidation (PEO) coatings, together with Zn--Al layered double hydroxide intercalated with 2-mercaptobenzo-thiazole (Zn-Al LDH-MBT). This study demonstrates, for the first time, the synergistic effect of incorporating 2D-WO3 nanoflakes and Zn-Al LDH into PEO coatings on Al, enhancing photocatalytic performance compared to previous WO3-containing systems. To the best of our knowledge, this is the first report on the use of WO3 nanoparticles combined with Zn-Al LDH, an established PEO coating morphology modifier, within the PEO process for water remediation applications. Coatings were fabricated using silicate-, aluminate-, and tungstatebased electrolytes. Structural and morphological analyses confirmed the successful incorporation of WO3 particles and LDH-derived phases. Diffuse reflectance spectroscopy revealed a WO3 band gap of approximately 2.40 eV, suitable for solar light activation. Coatings with moderate WO3 loading (10 g/L) exhibited superior photo-catalytic performance compared to those with higher loading (15 g/L), attributed to the formation of inactive metallic tungsten (W0) at increased WO3 concentrations. Photocatalytic degradation of DCF under solar light reached up to 92 % for WO3 powder and 92 %, 66 %, and 87 % for WO3-doped coatings in silicate-, aluminate-, and tungstate-based electrolytes, respectively. Incorporation of Zn-Al LDH remained high activity and increased in the case of aluminum electrolyte from 66 to 87 %. The production of transformation products during the photocatalytic processes confirmed multi-step degradation. These results highlight the synergistic role of WO3 and LDH in PEO coatings, demonstrating their potential for scalable, solar-driven water treatment-

Recently, metal organic frameworks (MOFs), crystalline porous materials, demonstrated their effectiveness for the post-modification of coatings obtained by plasma electrolytic oxidation (PEO) treatment. The postmodification leads to the sealing of PEO porosity as well as endowing the coating with active corrosion protection ability. In the current work, ZnO-based PEO coatings on the surface of Z1 Zn alloy was partially converted into ZIF-8 by treatment with vapours of 2-methylimidazole (2-HmIm). It was found that the degree of PEO-toZIF-8 conversion and the size of the ZIF-8 particles increased with an increase in temperature from 120 to 150 degrees C, and with an extension of the treatment with 2-HmIm from 5 h to 60 h. Furthermore, the sealing of the PEO pores can be controlled by applying different treatment conditions. It was also found that such treatments resulted in the enhancement of the corrosion resistance of the materials. However, the key factor determining the performance of the final ZIF-8@PEO hybrid coatings was a balance between the level of ZnO-based PEO dissolution and crystallisation of ZIF-8 phase.

Inflammation is an inevitable problem associated with the use of bone-implant materials. In this study, naproxen sodium-loaded layered double hydroxides (LDH) capsules were incorporated in situ into a plasma electrolytic oxidation (PEO) coating on an AZ31 Mg alloy to alleviate the inflammatory response. The results indicated that the LDHs were embedded throughout the coating formation process which reinforced the barrier properties of the PEO layer. The coating showed good antibacterial properties and excellent cell adhesion, proliferation, and differentiation abilities. An in situ drug-loaded coating with considerable corrosion resistance and long-term antibacterial effects is suggested for use in biodegradable Mg alloys.

Plasma electrolytic oxidation (PEO) processing of light metals has been established for decades and is in increasing industrial use, even as an alternative surface treatment to produce multifunctional coatings with environmental-friendly processing concept. One of the benefits of PEO processing claimed already a couple of years ago was the ability to treat dissimilar metal joints, which can obviously improve the surface homogeneity and stability at the interface of the dissimilar components, especially impeding the galvanic corrosion due to the different electrochemical properties of each component. However, the progress and breakthrough develop slowly especially for the macro scales due to the much larger gap between each component. This literature review firstly demonstrates the still low number of studies reporting successful PEO treatment of material combination such as Mg/Al, Mg/Ti, Al/Ti and scarcely light metal combinations with steel. The main issues and challenges to performing PEO processing on the macro-scale dissimilar weldments were stated. On the other hand, dissimilar metal joints also widely exist in micrometer scale in alloys and metal matrix composites (MMCs). Moreover, there is a huge knowledge base on PEO treatment of such multiphase substrates. PEO processing of such complicated mixed microstructures is reviewed as well to reveal the basic problems. To some certain degree, these PEO-related studies on alloys and MMCs can be good examples to have an insight into the coating formation mechanism on macro-scaled dissimilar metal joints. Conclusions are drawn from the micro- to macroscale. Finally, critical access to the problems is given and possible solutions and reaming limitations are discussed.

The influence of minor concentrations of indium (In) on the microstructure, corrosion behavior, and mechanical properties of Mg-2.5Nd-0.5Zr-xIn alloys were studied. The mechanisms of corrosion protection were examined. Herein, Mg-2.5Nd-0.5Zr-1.0In exhibited the lowest corrosion rate (0.122 mm/y). The addition of an appropriate amount of indium not only reduced the grain size of Mg-2.5Nd-0.5Zr-xIn alloys but also decreased the size of the Mg12(Nd,In) and Mg41(Nd,In)5 phases, promoting uniform corrosion. The excellent anti-corrosion behavior of the Mg-2.5Nd-0.5Zr-1.0In alloys was ascribed to the growth of a unique three-layer corrosion product film, facilitated by the enriched In element near the Mg matrix.

Nowadays, interest in metal organic frameworks (MOFs) as potential materials for corrosion protection of aluminium alloys is increasing. However, application of MOFs in the form of conversion coatings remains limited due to challenging process of MOFs growth directly on Al based surfaces. This obstacle can be overcome by surface pretreatment that promotes further MOF formation. In the current investigation, Zn-Al LDH (layered double hydroxide) grown on the surface of AA2024 aluminium alloy was recrystallised into ZIF-8@Zn-Al LDH coating. In situ synchrotron and ex situ XRD analyses showed that recrystallisation of Zn-Al LDH into ZIF-8 was accompanied by intercalation of 2-methylimidazolate into the LDH gallery under the applied treatment conditions. Such a complex structure of the coating was beneficial for the corrosion protection of AA2024 alloy as the obtained coating contained an increased amount of 2-methylimidazole inhibitive species. Moreover, it was found that the variation of the treatment condition (95-140 degrees C, 3-24 h) affected the final performance of the ZIF-8@ZnAl-LDH coating and the coating obtained at 95 degrees C for 12 h demonstrated the best performance.

Hybrid implants composed of magnesium and titanium are a promising direction in orthopaedics, as these implants combine the stability of titanium with the biological activity of magnesium. These partly soluble implants require careful investigation, as the degradation of magnesium releases hydrogen, which can enter the Ti matrix and thus alter the mechanical properties. To investigate this scenario and quantify the hydrogen uptake along with its structural impacts, we employed inert gas fusion, scanning electron microscopy, X-ray diffraction, and a combination of synchrotron absorption and X-ray diffraction tomography. These techniques enabled us to investigate the concentration and distribution of hydrogen and the formation of hydrides in the samples. Titanium hydride formation was observed in a region approximately 120 µm away from the titanium surface and correlates with the amount of absorbed hydrogen. We speculate that the degradation of magnesium at the magnesium/titanium implant interface leads to the penetration of hydrogen due to a combination of electrochemical and gaseous charging.

Mg-Al LDH conversion films were synthesized by the hydrothermal treatment in deionized water on various ascast Mg-Al alloys. The micro-galvanic effect on the growth of the Mg-Al LDH films and their corrosion protection properties were investigated. It was found that a higher Al solute content in matrix phase reduced the microgalvanic effect between the matrix phase and secondary phase. However, both phases could be partially dissolved to provide the necessary Al source for the growth of LDH films. A higher Al solute in the matrix phase was helpful to the formation of more protective LDH films.

Corrosion protection of high-strength aluminum alloys remains a critical challenge, especially for applications in marine and aerospace environments. This work reports BIPT-6, a new cerium-based metal-organic framework designed for sustainable corrosion protection of AA2024 aluminum alloy. BIPT-6 contains both Ce(III) and Ce(IV) ions and is constructed with 2,5-furandicarboxylate (FDA2- ), a biomass-derived ligand, through a simple one-pot solvothermal method. The structure and composition were verified by a series of advanced characterization methods. BIPT-6 crystallizes in a monoclinic system with space group P21/n. The protective ability of novel BIPT6 was evaluated by electrochemical impedance spectroscopy (EIS). It demonstrated good corrosion inhibition efficiency for the AA2024 aluminum alloy samples immersed in 0.05 mol/L NaCl solution containing 5 x 10-4 mol/L BIPT-6. Finally, BIPT-6 was applied as an additive to epoxy resin to prepare anti-corrosive coatings. The EIS results show that BIPT-6@Epoxy coating system provides a superior corrosion protection and stability to aluminum alloy AA2024 compared to blank coating. The corrosion inhibition mechanism of BIPT-6 was also investigated, highlighting its synergistic effect from dual corrosion inhibitors. This work showcased BIPT-6 as a promising approach for sustainable, smart corrosion protection strategies in aluminum alloys.

This work presents PEO coatings' mechanical and spectroscopic properties on magnesium alloys (AZ31) using Y2O3 additions. To increase the functionality of the coating, Y2O3 doped with erbium and ytterbium was used, making it possible to measure the surface temperature contactless. Using Er0.02Yb0.4Y1.58O3 in the PEO process allows the preparation of a layer that protects the magnesium alloy against corrosion and improves its mechanical properties. The structure and morphology of the coatings were characterized using XRD and SEM (surface and cross-section), and the chemical composition of the layer was determined using GDOES and EDS on both the surface and cross-sections. The physical properties of all samples were characterized through microhardness, wettability, and anticorrosion measurements. The contactless temperature measurements of the coatings were performed over a wide range of temperatures to check the most useful range of its use. It was shown that using Er0.02Yb0.4Y1.58O3 additives in PEO electrolytes to produce a coating for light metal alloys improves the mechanical properties of the surface and adds additional functionalities.

The use of biometals is becoming more and more popular thanks to the development of new alloys that take advantage of their biodegradability. Due to this beneficial property, particularly Magnesium (Mg) and Zinc (Zn) have been studied frequently within the currently applicable group of bioabsorbable metals. This investigation studied the microstructure, and electrochemical behavior of WE43 and Zn1Mg alloys manufactured by extrusion and Laser Powder Bed Fusion (LPBF), with and without plasma electrolytic oxidation (PEO) surface treatment. The extruded WE43 showed a corrosion rate of 3.42 +/- 0.10 mm/year, while the LPBF counterpart has an increased corrosion rate of 11.85 +/- 0.14 mm/year. This increase was explained via yttrium oxide particles found in the LPBF material that decrease the protective effect of the corrosion layer, and hence reduce corrosion resistance. For the Zn1Mg, the extruded sample had a corrosion rate of 0.98 +/- 0.41 mm/year, whereas the LPBF sample also showed a higher corrosion rate of 2.70 +/- 0.09 mm/year. This result was explained by a higher volume fraction of second phase eutectic structure in the LPBF samples, which increased the microgalvanic corrosion between Zn grains and MgZn structures in the eutectic phase. The extruded samples showed thicker PEO oxide layer in both the WE43 and Zn1Mg materials than the LPBF-fabrication samples, and in all cases the corrosion resistance was improved when applying these surface treatments. These findings highlight the impact of evaluating the influence of different manufacturing methods and PEO surface treatments on the corrosion resistance and durability of these biomedical alloys.

Alternative chromium-free conversion coatings are still in focus of interest. In this work, the formation of mixed Zn/Li/Al LDH-CO32-/OH− (layered double hydroxide)-based multilayered CC (conversion coatings) was demonstrated for the first time. It was grown in-situ on the surface of AA7075-T6 aluminium alloy under mild conditions (30 ​°C) in a treatment bath containing 0.1 ​M Li2CO3 at pH ​= ​11.5 and in the presence of NH4OH. The Li ​+ ​ions required for the LDH structure formation came from the treatment bath, while the Zn2+ and Al3+ were provided by the alloy dissolution. The formed Zn/Li/Al LDH-CO32-/OH- CC significantly enhanced the corrosion resistance of the AA7075-T6 alloy. Based on the results of electrochemical impedance spectroscopy (EIS), the total impedance modulus |Z| at 0.01 ​Hz was increased by one order of magnitude compared to the bare substrate, while the salt spray test (SST) revealed no pitting after 816 ​h of exposure. These excellent protective properties were associated with the changes of the AA7075-T6 alloy surface during the LDH growth process, formation of a passive oxide layer with good barrier protection ability and LDH's smart nanocontainer function.