Surface Of Magnesium Alloy Research Articles

Construction of a Carbon Monoxide-Releasing Bioactive Hydrogel Coating on the Magnesium Alloy Surface for Better Corrosion Resistance, Anticoagulant Properties, and Endothelial Cell Growth

In this study, we first fabricated a crosslinked hydrogel coating by polymerizing methacryloyloxyethyl sulfonyl betaine and acrylamide (SBMA) on the magnesium (Mg) alloy surface employing ultraviolet (UV) polymerization. Bivalirudin and CO-releasing molecules (CORM-401) were further grafted onto the hydrogel coating surface to acquire a multifunctional biocompatible coating capable of releasing CO to augment corrosion-resisting properties and biocompatibility. The findings verified that the bioactive hydrogel coating significantly increased the corrosion potential and reduced the corrosion current, thereby improving the anticorrosion performance. Meanwhile, owing to the excellent hydrophilicity, the antifouling performance of the hydrogel coating, and the excellent anticoagulant performance of bivalirudin, the hydrogel coating significantly reduced the fibrinogen adsorption, platelet adhesion and activation, and hemolysis occurrence, displaying excellent ability to inhibit blood clotting. Moreover, endothelial cell (EC) experimental results demonstrated that the hydrogel coating could significantly promote EC growth, displaying great potential to induce re-endothelialization after implantation. Specifically, in the presence of cysteine capable of catalyzing CO release, the anticoagulant performance and ability to promote EC growth were further improved significantly. Therefore, the study offers an effective strategy to prepare a hydrogel coating capable of releasing CO to improve the corrosion-resisting performance and biocompatibility of Mg alloys, which is anticipated to be applied in the surface modification of Mg alloy intravascular stents.

Corrosion resistance and biocompatibility of silica coatings on AZ31 magnesium alloy via magnetron sputtering

Magnesium alloys have promising prospects in biodegradable implants, but premature degradation is the main factor limiting their application. We prepared silicon coatings of different thicknesses on the surface of AZ31 magnesium alloy using the RF magnetron sputtering method. The phase, microstructure, and elemental composition of the coatings were characterized by XRD, SEM, and EDS, respectively. The corrosion resistance of the coatings in simulated body fluids was tested using immersion corrosion and electrochemical corrosion tests. Results showed that the silicon coating sputtered for 3 hours had the best corrosion potential and current, with a corrosion current density of 6.5614E-6 (A/cm2), which is two orders of magnitude lower than that of the AZ31 substrate. The extract of the sample in RPMI-1640 medium was co-cultured with human umbilical vein endothelial cells (HUVEC), and its cytotoxicity was evaluated by the CCK-8 assay. It was found that the silicon coating sputtered for 3 hours had the least toxicity, and the endothelial cells had a high proliferation rate. Therefore, the magnetron sputtered Si coating on AZ31 magnesium alloy exhibits good corrosion resistance and biocompatibility.

Review of Surface Treatment Technology for Improving Wear Resistance of Magnesium Alloys

Background: As the lightest metal structural material in engineering, magnesium alloy has excellent mechanical properties, such as high specific strength, high specific stiffness, good damping performance, and good machinability. It is widely used in the fields of precision parts, automobiles, aerospace, and military. However, poor friction and wear performance are significant magnesium defects of the alloys, which make its use limited in some areas with high working conditions, so it is essential to improve the wear resistance of the magnesium alloy surface. Objective: The aim of this study was to summarize the technology of improving the wear resistance of magnesium alloy in recent year. The influence of different surface treatment technology for enhancing friction and wear properties was also analyzed, which could provide a reference for related scholars and researchers. Method: In this paper, the literature related to friction and wear properties of magnesium alloys in recent years were reviewed, the principles of various surface treatment technology of magnesium alloys were explained, and the advantages and disadvantages of each technology were analyzed. Results: Based on the literature analyses related to the wear resistance of magnesium alloys, the problems existing in the surface treatment technology for improving the wear resistance of magnesium alloys are summarized, and future development directions are put forward. Conclusion: Among the technologies to improve the wear resistance of magnesium alloys, the combination of various techniques can better meet the working demands. The environmentally friendly and efficient manner has a good prospect for development.

Relationship between high-level color features and temperature mapping of magnesium alloy surface images based on the K-nearest neighbor algorithm

Relationship between high-level color features and temperature mapping of magnesium alloy surface images based on the K-nearest neighbor algorithm

Microstructure and mechanical properties of Al2O3/AZ61 Mg alloy surface composite developed using friction stir processing and groove reinforcement filling processes

Abstract In this work, the alumina (Al2O3) particles-reinforced AZ61 magnesium (Mg) alloy surface composite was fabricated using friction stir processing (FSP) and groove reinforcement filling methods. The Mg alloy surface composites were developed with and without the addition of Al2O3 reinforcing particles, and their mechanical performance was compared with each other and with unprocessed base metal (BM). The Al2O3 powder was compressed into a groove of 4.5 mm depth that had been created in AZ61 Mg alloy plates. The volume fraction of Al2O3 powder was increased to 5, 10, and 15 vol.% depending on the width of the groove. Results disclosed that the problem of cluster formation of reinforcing Al2O3 particles was minimized by performing FSP in five number of passes. The ultimate tensile strength (UTS) and hardness of AZ61 Mg alloy were enhanced by 6.07 % and 22.23 % when it was subjected to FSP. This is primarily correlated to the significant refining of grains due to the severe plastic deformation associated with FSP. The 15 vol.%-FSPed Al2O3/AZ61 Mg alloy surface composite showed a higher UTS of 630 MPa and hardness of 300 HV. This is due to the integration of a greater quantity of Al2O3 particles with substantial grain refining.

Corrosion resistance and biocompatibility of carbon ion implanted AZ31B magnesium alloy

The poor corrosion resistance of magnesium limits its clinical applications. Accordingly, in the present study, carbon ions were incorporated into a AZ31b magnesium alloy surface via carbon plasma immersion ion-implantation to improve its corrosion resistance and biocompatibility. The surface morphology and properties of the modified alloy were evaluated by field-emission scanning electron microscopy, water contact angle measurement, Raman scattering, X-ray photoelectron spectroscopy, and energy dispersive X-ray spectroscopy. Furthermore, compositional depth profiles were obtained by glow discharge optical emission spectroscopy, revealing a Gaussian-like distribution of carbon concentration. Electrochemical and hydrogen-evolution analysis demonstrated the successfully improved corrosion resistance of the AZ31b Mg alloy, while its biocompatibility was demonstrated by MTT and cell-adherence assays.

Preparation of glass fiber-reinforced polyphenylene sulfide/magnesium hybrid based on micro-arc oxidation by hot pressing molding

ABSTRACT The construction of surface structures and joining technology has become a key technology for the preparation of polymer-metal hybrid(PMH) materials in recent years. The magnesium alloy surface was subjected to micro-arc oxidation(MAO) to create a micro-nanopore structure, and the Glass fiber-reinforced polyphenylene sulfide/magnesium alloy(GFRPPS/Mg) hybrid joints were prepared by hot pressing molding. The joining mechanism of the GFRPPS/Mg hybrid joints was explored, and the interfacial disruption forms, crystalline properties, embedding depths, and interfacial chemistry of the GFRPPS/Mg hybrids were investigated at different hot pressing temperatures. The results demonstrate that the mechanical strength of the GFRPPS/Mg hybrid joints is a consequence of the interplay between micromechanical interlocking and chemical bonding, and the optimal tensile shear strength is 18.51 MPa. The tensile shear failure of the hybrids can be attributed to a combination of cohesive and interfacial failure. The crystalline properties of the failed surface of GFRPPS were also analyzed by X-ray diffraction (XRD), which revealed that the crystallinity also affects the mechanical properties of the GFRPPS/Mg hybrid joints.

Rare earth oxides nanoparticles formed on the surface of WE43 magnesium alloy subjected to anodic oxidation plus heat treatment for anti-bone tumor

It was well known that rare earth elements (REE) oxides nanoparticles could inhibit tumor growth and promote osteogenesis. In this works, four WE43 magnesium alloys (AO-10, AO-30, AO-1h and AO-2h) containing different REE oxides nanoparticles were prepared by anodic oxidation plus heat treatment. The REE oxides nanoparticles on AO-10, AO-30, AO-1h and AO-2h surface were Gd2O3 and Nd2O3, (Gd0.745Y1.255)O3 and Nd2O3, (Gd0.18Y1.82)O3 and Gd2O3 as well as Y2O3 and Gd2O3, respectively. Subsequently, the bioactivity, antitumor property and osteogenic property of all materials in vitro and in vivo were studied, and their antitumor property, bioactivity and osteogenic property were all AO-2h > AO-1h > AO-30 > AO-10. The degradation behaviors of materials in vitro and vivo were further investigated, and the corrosion resistance of materials was AO-10 > AO-30 > AO-1h > AO-2h. AO-2h released the most H2 and produced the highest pH value in all materials during degradation. The results showed that the effects of different REE oxides nanoparticles on corrosion resistance, biactivity, osteogenic property and antitumor property of materials were different completely. In all materials, AO-30 had moderate inhibition of MG63 and 143B cells in vitro, and it could inhibit the growth of bone tumor in mice in vivo. Then, the osteogenic property of AO-30 was moderate. It could promote the adhesion and proliferation of MC3T3-E1 cells. Again, the corrosion resistance of AO-30 was relatively excellent. It release few H2, Mg2+ and REE. The REE levels in normal tissues were relatively low, whose effects was negligible. Hence, AO-30 was the most suitable material for anti-bone tumor in all materials.

Hydrothermal preparation of magnesium alloy surface composite coatings and its performance research

Magnesium alloys have great potential for industrial and aerospace applications due to their low density and high strength. Aiming at its defects of poor corrosion resistance and susceptibility to galvanic coupling corrosion in metal coatings, a composite coating was prepared on the surface of AZ91D magnesium alloy by the hydrothermal method. Scanning electron microscope, x-ray diffraction, and x-ray photoelectron spectroscopy were used to characterize the surface micromorphology, phase composition, and elemental valence and evaluate the adhesion of the coating to the substrate by the ASTM D3359-09 test standard. Electrochemical experiments were done in a 3.5% NaCl solution. The results show that there are nanoscale dense granular structures on the surface of the samples, and the main components of the coatings are Mg(OH)2, Al2O3, and MgSiO3. ASTM grade 4B is between coating and substrate. The corrosion rate of the best sample was reduced by a factor of 238.96 compared to the substrate, and the corrosion current density was reduced by two orders of magnitude. The corrosion rate and corrosion current of the samples after repeated friction did not change much compared with those before friction, which proved that the composite coating had better corrosion resistance and friction stability.

Superhydrophobic Corrosion-Resistant Coating of AZ91D Magnesium Alloy: Preparation and Performance

This research presents the development of a surface treatment for AZ91D magnesium alloy that exhibits both superhydrophobic and anticorrosive properties. Initially, a zinc-based phosphate film was deposited on the magnesium alloy surface. Subsequently, a composite coating with superhydrophobic properties was produced by surface modification using a fluorosilane-ethanol solution. The composite coating’s microstructure, chemical composition, wettability, self-cleaning, and anti-corrosion properties were evaluated using scanning electron microscopy, a contact angle measurement instrument, and an electrochemical workstation. The results demonstrated that the main components of the composite coating were P, O, Zn, F, and C. The static contact angle reached 158°, providing superior self-cleaning and acid and alkali corrosion resistance. Additionally, the charge transfer resistance and coating resistance of the composite coating were significantly higher than those of the magnesium alloy substrate, effectively preventing corrosion and preserving the surface from fouling.

THE PREPARATION AND CHARACTERIZATION OF A LANTHANUM-BASED RARE EARTH CONVERSION COATING ON MAGNESIUM ALLOY AZ91D AND ITS DEGRADATION IN 3.5% NaCl SOLUTION

Magnesium alloys have a huge market and broad prospects due to their high specific strength, good ductility, and strong thermal conductivity. However, the active chemical properties of elemental magnesium and the negative standard electrode potential result in magnesium alloys being highly susceptible to corrosion and failure. Chemical conversion treatment of magnesium alloy can improve its corrosion resistance by preparing a chemical conversion film on its surface. Rare earth conversion treatment has the advantages of effortless process, moderate price, no pollution, good corrosion resistance, and synergistic effect with inorganic or organic additives, which is in line with the pursuit of “green chemical” in industrial production. At present, there is little research and application on lanthanum-based rare earth conversion coatings (La-RECC). This paper selects rare earth element lanthanum (La) to prepare La-RECC on the surface of AZ91D magnesium alloy through chemical conversion treatment. The microstructure, chemical composition, and protective properties of La-RECC were discovered, as well as their interrelationships, revealing the degradation process of La-RECC in 3.5% NaCl solution. La-RECC is composed of La(OH)3 and Mg(OH)2, exhibiting a crystal cluster structure with cracks, and there are a large number of needle-like crystals on the crystal cluster of La-RECC, with a thickness of 2.14 [Formula: see text]m. The degradation process of La-RECC can be divided into three stages: Rapid degradation, slow degradation, and complete degradation. The complete degradation time of La-RECC in 3.5% NaCl solution is 82.5[Formula: see text]h.

Corrosion inhibition of AZ31 magnesium alloy in 3.5 % NaCl by green corrosion inhibitor: Maleic hydrazide derivative

A novel maleic hydrazide derivative containing multiple active groups (NOMAM) has been synthetized and characterized. Electrochemical tests revealed that it can provide effective protection for AZ31 magnesium alloys in 3.5 % NaCl. The best inhibition was achieved at 0.2 g·L−1. The observation results of the surface morphology also confirmed its excellent corrosion inhibition performance. Density functional theory (DFT) calculations and molecular dynamics simulations (MDS) revealed that maleic hydrazide derivative molecules adsorb onto magnesium alloy surfaces via a combination of physisorption and chemisorption with heteroatoms as active sites. The complexes formed by derivative molecules with Mg2+, together with the deposited Mg(OH)2, form protective barriers at the interface. The synthesized derivative has many advantages, such as low cost, simple processing and low toxicity. This study can contribute to the search for green corrosion inhibitors for magnesium alloys.

Biomimetic hydrogel coatings for improving the corrosion resistance, hemocompatibility, and endothelial cell growth of the magnesium alloy

The fast biodegradation and poor biocompatibility of Mg alloys in physiological environments are still the main problems restricting their application in cardiovascular stents. In this study, the hydrogel coatings (SBMA-AAM) with different proportions of methacryloyl ethyl sulfobetaine (SBMA) and acrylamide (AAM) were built on the surface of AZ31B magnesium alloy through ultraviolet (UV) polymerization. The corrosion degradation behavior, hemocompatibility, and endothelial cell (EC) growth performance of the samples were studied in detail. The findings revealed that the uniform and dense SBMA-AAM coatings could significantly enhance the corrosion resistance. In addition, the hydrogel coatings showed excellent hydrophilicity, which increased the albumin adsorption while inhibiting the fibrinogen adsorption, and thus reduced the platelet adhesion and activation and hemolysis rate, accordingly significantly enhancing their anticoagulant performance. Furthermore, SBMA-AAM hydrogel coating promoted the EC adhesion and proliferation and the vascular endothelial growth factor (VEGF) and nitric oxide (NO) secretion of ECs, which is conducive to promoting endothelialization. When the concentration ratio of SBMA and AAM was 1: 2, the modified magnesium alloy showed the best corrosion resistance and biocompatibility. Therefore, the SBMA-AAM hydrogel coating could effectively regulate the corrosion degradation performance and biocompatibility of Mg alloys, laying a foundation for the application of Mg alloys in cardiovascular stents.

Optimization of the two-step coating formation process for ZK21 magnesium alloy

Abstract The primary hindrance to the broader utilization of magnesium alloys lies in their insufficient corrosion resistance. This research initiative introduced an advanced two-phase methodology incorporating phosphating and alkali heating to produce a protective Ca-P coating on the surface of magnesium alloys. This innovative approach not only bolsters their corrosion resistance but also facilitates controlled degradation in bodily fluid environments. Following a 60-minute phosphating process in a solution with a pH level of 3, the resultant Ca-P coating achieved full coverage over the magnesium alloy surface, displaying commendable coating density and uniformity. Subsequent treatment with alkali heating for 30 minutes further enhanced the density and smoothness of the coating. Analysis utilizing EDS and XRD revealed that the primary constituents of the phosphate magnesium alloy and the phosphate + alkali heated magnesium alloy coating were DCPD and HA, respectively. Corrosion degradation assessments conducted in SBF solution validated that the two-step coating formation method significantly fortified the corrosion resistance of magnesium alloys.

Constructing sodium alginate/carboxymethyl chitosan coating capable of catalytically releasing NO or CO for improving the hemocompatibility and endothelialization of magnesium alloys

Although significant progress in developing biodegradable magnesium alloy materials in cardiovascular stents has been achieved recently, they still face challenges such as rapid in vivo corrosion degradation, inferior blood compatibility, and limited re-endothelialization after the implantation. Hydrogel coating that can catalyze the liberation of gas signal molecules offers a good solution to alleviate the corrosion rate and enhance the biocompatibility of magnesium and its alloys. In this study, based on alkaline heat treatment and construction of polydopamine coating on the surface of magnesium alloy, sodium alginate/carboxymethyl chitosan (SA/CMCS) gel was simultaneously covalently grafted onto the surface to build a natural polymer hydrogel coating, and selenocystamine (SeCA) and CO release molecules (CORM-401) were respectively immobilized on the surface of the hydrogel coating to ameliorate the anticoagulant performance and accelerate endothelial cells (ECs) growth by catalyzing the release of endogenous gas signal molecules (NO or CO). The findings verified that the as-prepared hydrogel coating can catalyze the liberation of CO or NO and significantly improve the corrosion resistance of magnesium alloy. At the same time, owing to the excellent hydrophilicity of the hydrogel coating, the good anticoagulant property of sodium alginate, and the ability of CMCS to promote the ECs growth, the modified magnesium alloy could significantly improve the albumin adsorption while preventing the adsorption of fibrinogen, hence significantly augmenting the anticoagulant properties and promoting the ECs growth. Under the catalytic release of NO or CO, the released gas molecules further enhanced hemocompatibility and promoted endothelial cell (EC) growth and the expression of vascular endothelial growth factor (VEGF) and NO of ECs. Therefore, the bioactive coatings that can catalyze the release of NO or CO have potential applications in constructing surface bioactive coatings for magnesium alloy materials used for intravascular stents.

Effect of CNTs concentration on the microstructure and properties of B, Ni, CNTs co-doped diamond like carbon films

B, Ni, and CNTs co-doped diamond-like carbon (B, Ni, CNTs co-doped DLC) films were synthesized on the surface of AZ91D magnesium alloy by electrodeposition with low cost. The effect of CNTs concentration on the microstructure, microhardness, tribological properties and corrosion behavior of B, Ni, CNTs co-doped DLC films were evaluated. Results revealed that the B, Ni, CNTs co-doped DLC films were hydrogenated amorphous carbon films. Raman spectra showed that the D and G peaks of DLC films appear near 1330 cm−1 near 1580 cm−1, respectively. When the concentration of CNTs was 0.25 g/L, the CNTs were evenly distributed, making the structure of co-doped DLC films uniform, dense and flat. At this time, since the combined synergistic effect of reticulation of CNTs and the network-like structure of DLC films, the microhardness of the co-doped DLC films reached the maximum of 248.3 HV. The tubular structure of CNT supports and lubricates the substrate, which weakens the frictional resistance between the friction partners and reduces the friction coefficient to the lowest value of 0.128. The wear loss was the minimum with 0.1 × 10−5 kg/m, which is the result of CNTs exerting their self-lubricating properties to improve the wear resistance of the DLC film so that less wear occurs during the repeated friction process. Meanwhile, the positive corrosion potentials of B, Ni, CNTs co-doped DLC films indicate that the three elements co-doped DLC films can improve the corrosion resistance of magnesium alloy substrates.

Micro-structure design of black ceramic composite surface towards photothermal superhydrophobic anti-icing

Conventional superhydrophobic surfaces have limitations in the melting and icing process in response to ambient temperature. In this study, we fabricated a composite coating using plasma-etched black ceramic as a low layer on the surface of AZ31 magnesium alloy, and loaded-polydimethylsiloxane nanoparticles (PDMS NPs) as a top layer to achieve a photothermal and superhydrophobic anti-icing. The absorbance and forbidden bandwidth of the ceramic layer exhibit the excellent photothermal properties of solid solution (Mg1-XCuXO). The ceramic phase exhibits a bandgap of 3.62 eV and achieves a temperature of up to 69.4 °C, demonstrating desirable light absorption and photothermal properties. The microstructure and polar bonds of Si-O-Si provide excellent superhydrophobic properties, allowing the surface contact angle to reach 156°. The wetting of water droplets on the composite coating’s surface is simulated using molecular dynamics, which is consistent with experimental findings and emphasizes the coating’s exceptional superhydrophobic. Additionally, the transition process between Cassie-Baxter and Wenzel was analyzed by researching the dynamic icing and ice-melting processes. This composite surface converts light energy into heat, melts snow/ice, and uses hydrophobicity to promptly desorb it from the surface, enabling a photothermal active and superhydrophobic passive anti-icing strategy.

Construction of superhydrophobic composite coating on AZ31B Mg alloy for improved corrosion resistance and anti-wear property

In this study, the EP (epoxy)/L(P) (layered double hydroxides powder)-DTMS (dodecyl-trimethoxy-silane) superhydrophobic composite coating was prepared on AZ31B Magnesium (Mg) alloy surface by spin-coating and self-assembly methods. Mg-Al layered double hydroxides (LDH) powder with ion exchange ability, prepared by hydrothermal coprecipitation, was mixed with EP to construct rough surface and provide good adhesion between the coating and Mg alloy substrate. The introduction of DTMS could reduce the surface energy of coating and improve the compactness of rough surface. Due to the shielding effect of superhydrophobic surface and the ion exchange ability of LDH, it was difficult for corrosive ions (Cl-) to reach the substrate surface in 3.5 wt% NaCl solution. And the corrosion current density was decreased by 4 orders of magnitude. Because of the lubrication of DTMS and the layered structure of L(P), the composite coating had a good wear-reducing effect under the reciprocating point contact mode against with an AISI5200 steel ball. It provided a feasible idea for the construction of multifunctional superhydrophobic coatings on metal surface with self-cleaning, corrosion resistance and wear resistance, which will expand the industrial application fields of superhydrophobic coatings.

A study on microstructural, mechanical properties, and optimization of wear behaviour of friction stir processed AZ31/TiC composites using response surface methodology

The primary objective of this study is to investigate the microstructural, mechanical, and wear behaviour of AZ31/TiC surface composites fabricated through friction stir processing (FSP). TiC particles are reinforced onto the surface of AZ31 magnesium alloy to enhance its mechanical properties for demanding industrial applications. The FSP technique is employed to achieve a uniform dispersion of TiC particles and grain refinement in the surface composite. Microstructural characterization, mechanical testing (hardness and tensile strength), and wear behaviour evaluation under different operating conditions are performed. Response surface methodology (RSM) is utilized to optimize the wear rate by considering the effects of process parameters. The results reveal a significant improvement in hardness (41.3%) and tensile strength (39.1%) of the FSP-TiC composite compared to the base alloy, attributed to the refined grain structure (6–10 μm) and uniform distribution of TiC particles. The proposed regression model accurately predicts the wear rate, with a confirmation test validating an error percentage within ± 4%. Worn surface analysis elucidates the wear mechanisms, such as shallow grooves, delamination, and oxide layer formation, influenced by the applied load, sliding distance, and sliding velocity. The enhanced mechanical properties and wear resistance are attributed to the synergistic effects of grain refinement, particle-accelerated nucleation, the barrier effect of TiC particles, and improved interfacial bonding achieved through FSP. The optimized FSP-TiC composites exhibit potential for applications in industries demanding high strength, hardness, and wear resistance.

Corrosion resistance of magnesium alloy surfaces substantially upgraded by gradient energy irradiation of femtosecond lasers

The poor corrosion resistance of magnesium (Mg) alloys is known to constitute a major obstacle to their practical applications. In this work, we proposed an approach of femtosecond laser multi-grid-scanning with the gradual decreasing energy fluence, to modulate the surface oxide properties for the anti-corrosion performance enhancement. This kind of laser processing can significantly increase the oxide passivation layer thickness by more than 100 times compared with the bare sample, and improve the oxygen content on the material surface to as high as 55.87 %. Simultaneously, the available size of MgO nanograins is further refined and has more spatially uniform distribution. Moreover, the massive production of micro/nano-structures by the femtosecond laser irradiation tends to promote the surface into the superhydrophobic with a contact angle of CA=162 ± 2 ° and a slide angle of SA=1.5 ± 0.5 °. As a result, the obtained optimal values for the corrosion current density and the annual corrosion rate are reduced to Icorr = 0.5 μA/cm2 and CR = 7×10−3 mm/y, respectively, more than 2 orders of magnitude lower than the bare sample. Such a method provides an efficient strategy to enhance the corrosion resistance of metal surfaces for future applications.