Corrosion Resistance Of Coatings Research Articles

Preparation and anticorrosion performance of graphene-reinforced epoxy powder coating

Existing studies have reported that graphene can enhance the corrosion resistance of solvent-based organic coatings. However, the role of graphene in organic powder coatings remains to be obscure. In the present study, the graphene powder was prepared through liquid-phase exfoliation of graphite followed by freeze drying and the effects of graphene on structures, anticorrosion performance and adhesion strength of epoxy powder coatings were investigated. Scanning electron microscopy (SEM) demonstrated that graphene reduced surface micropores and enhanced structural compactness of the epoxy powder coatings. Electrochemical impedance spectra, Tafel polarization measurement and salt spray test indicated that a small amount (0.0125, 0.025 and 0.05 wt%) of well-dispersed graphene powder would be sufficient to effectively reinforce the anticorrosion performance of the epoxy powder coatings, especially for the coating with 0.025 wt% graphene, of which the impedance modulus maintained the highest values of nearly 107 and 105.8 Ω cm2 after immersion in 3.5 % NaCl solution for 21 and 30 days. Pull-off test confirmed that graphene enhanced the adhesion strength of coatings after salt spray test for 240 h, while the coating with 0.025 wt% graphene exhibited the highest adhesion strength up to 3.88 MPa. In addition, differential scanning calorimetry (DSC) indicated that graphene sheets could improve the thermal conductivity and promote curing reactions of epoxy powder. The mechanism for the reinforcement of epoxy powder coating by graphene has also been proposed.

High corrosion and wear resistant electroless Ni-P gradient coatings on aviation aluminum alloy parts

High corrosion and wear resistant electroless Ni-P gradient coatings on aviation aluminum alloy parts

A ‘tortuous path’ and ‘protective oxide layer’ work in tandem in unique corrosion-resistant polyetherimide coatings

Schematic of corrosion mechanisms for reinforced polyetherimide composite coating via tortuous path and passive layer formation.

Evaluation of the corrosion protection effect of amorphous carbon coating through the corrosion behaviors on different substrates

One of the most straightforward and efficient approaches to enhance the corrosion resistance of the initial coatings is by applying an additional top-layer. In this work, a pure a-C:H coating (HDLC) and an a-C:H coating with a submicron-thickness a-C:H:SiOx top-layer (SiCOH) were fabricated on the substrates of 316 L stainless steel (SS 316), 304 stainless steel (SS 304), 45 steel and GCr15 bearing steel (GCr15). The electrochemical corrosion behaviors of the two coatings deposited on the mentioned substrates were studied in a 3.5 wt% NaCl solution. The findings revealed that SiCOH, compared to HDLC, exhibits higher polarization resistance and lower porosity across all tested substrates, indicating a beneficial protective effect of the a-C:H:SiOx top-layer on HDLC surfaces. The top-layer, characterized by higher sp3 carbon hybridization and the presence of insulating silicon oxide, significantly contributes to the corrosion resistance of the coating. Furthermore, the top-layer design enhances the coating's heterojunction, addressing inherent defects and pinholes in HDLC. This effectively obstructs the diffusion path (porosity) of the corrosive medium, substantially improving the corrosion resistance of the HDLC coating.

Insight into continuous growth mechanisms of ZrO2-Al2O3 composite PEO coatings with superior cavitation erosion resistance

The ZrO2-Al2O3 composite coatings were fabricated on TiB2/2024Al composite by the plasma electrolytic oxidation (PEO) treatment with either monoclinic (m-ZrO2) or tetragonal zirconia (t-ZrO2) nanoparticles (NPs) addition. Such PEO coatings showed a double layer morphology due to the limited physical motion ability of ZrO2 colloidal particles into coatings. t-ZrO2 remained as the main phase in ZrO2-Al2O3 PEO composite coatings whether t-ZrO2 or m-ZrO2 NPs were added. Based on the microstructure analyses by focus ion beam plus scanning electron microscopy and transmission electron microscopy, ZrO2 showed netlike morphology in the outer layer with NPs partially melted at the mesh boundary and lines-like morphology fully melted at the inner mesh in the coating. A prominent morphological transition of ZrO2 was clearly observed at the interface between outer layer and inner layer. Therefore, the continuous growth mechanisms of ZrO2-Al2O3 composite PEO coatings were proposed in terms of morphological evolution process. Furthermore, electrochemical measurements and cavitation erosion tests were conducted to study the comprehensive surface properties (corrosion and impact resistance) of ZrO2-Al2O3 composite coatings. As a result, the ZrO2-Al2O3 composite PEO coatings with m-ZrO2 addition exhibited the greatly reduced corrosion rate, and superior cavitation erosion resistance. Accordingly, the underlying mechanisms for these improved properties were intensively discussed.

Enhancing corrosion resistance in Mg[sbnd]Li alloy through plasma electrolytic oxidation coatings — Exploring the impact of ionic liquids (BmimBF4)

The wide application of MgLi alloys is limited by the poor corrosion resistance, which needs to be improved by surface treatment. Plasma electrolytic oxidation (PEO) method is one of the most promising methods for the formation of oxide coatings on MgLi alloys. However, the conventional PEO technique with high energy consumption causes poor coating compactness and hampers efforts to enhance corrosion resistance. In this study, various concentrations of ionic liquids (1-butyl-3-methylimidazolium tetrafluoroborate, BmimBF4) are introduced into the concentrated alkaline electrolyte to facilitate the formation of a PEO coating on the surface of LA91 magnesium‑lithium (MgLi) alloy. The influence of BmimBF4 on PEO coatings has been investigated. The results indicate that a concentrated electrolyte significantly lowers the working voltage of PEO, thereby enhancing energy efficiency. Uneven adsorption on the substrate surface, resulting from the low concentration of BmimBF4 (≤20 mL/L) in the electrolyte, induces partial discharge, leading to high surface roughness and the formation of large pores. However, when an excessive amount of BmimBF4 (>20 mL/L) is present, it uniformly adsorbed onto the substrate surface during the initial stage of PEO process, forming a corrosion inhibitor layer. This leads to a consistent discharge on the surface of substrate throughout the entire PEO process, resulting in a reduction in both surface roughness and micropore size. Among these coatings, the one prepared in an electrolyte containing 20 mL/L BmimBF4 exhibits the highest contact angle (66.8° ± 3.8°) and the best long-term corrosion resistance (hydrogen evolution rates <0.02 mL·cm−2·h−1). These properties can be attributed to the physical and chemical adsorption of BmimBF4, which contains hydrophobic long alkyl chains, as well as the maximum thickness with extended discharging channels. This study offers a guiding strategy for further reducing energy consumption and enhancing the corrosion resistance of PEO coatings.

Silicon oxide anticorrosion coating deposition on alloy steel surface by low temperature plasma

In this work, honeycomb-like SiOx coating was successfully prepared on steel surface by atmospheric pressure low temperature plasma jet. The surface morphology, corrosion resistance and stability of the coating were systematically analyzed. In addition, the growth mechanism of the coating was discussed. The analysis revealed that the coatings were primarily composed of Si-O-Si and Si-OH groups, with a minor presence of Si-CH3 moieties. The coating obtained after two deposition cycles exhibits the highest level of uniformity and density, with minimal porosity and superior corrosion resistance. The increase in deposition cycles led to particle aggregation, augmented particle dimensions and porosity, which adversely affected the coating's performance. The dense SiOx coating resulted in a significant reduction in the corrosion current density of the alloy steel, and showed no significant corrosion defects when exposed to the crude oil simulant in 25 °C. The coating simultaneously enhanced the hydrophilicity and oil transfer of the steel surface. Finally, the coating exhibited self-cleaning properties, stability and high potential for safeguarding steel pipes against low-viscosity crude oil contamination. This study provides a general surface modification method for the preparation of corrosion-resistant coatings on metal surfaces under mild conditions.

Effect of Si content on the 1200 - 1300°C steam oxidation and 360°C/18.6MPa autoclave water environmental resistance of Cr-Si coatings on Zry-4

In this study, we applied magnetron sputtering to deposit four Cr-Si coatings on Zry-4, with varying Si content ranging from 0.03 to 0.22 at.%. The main objective was to investigate the influence of Si content on the mechanical properties, steam oxidation resistance at 1200 - 1300 °C, and corrosion resistance in a 360 °C/18.6 MPa autoclave water environment. As the Si content increased, we observed a corresponding enhancement in both the mechanical properties and oxidation resistance of the coating. Notably, at 1300 °C, the oxidation resistance of Cr-Si coated Zry-4 demonstrated improvement when the Si content reached or exceeded 14 at.%, attributed to the formation of an in-situ Zr2Si layer at the coating/substrate interface. However, in the 360 °C/18.6 MPa autoclave water environment, we noted a decrease in the corrosion resistance of the Cr-Si coatings with increasing Si content. This phenomenon was ascribed to the selective dissolution of Si. Moreover, when the Si content surpassed 14 at.%, the surface Cr2O3 underwent a transformation, resulting in the formation of three non-protective sublayers: an amorphous layer, a nanocrystalline layer, and a coarse crystalline layer. These findings provide valuable insights into the overall performance, as well as the advantages and disadvantages, of Cr-Si coatings on Zry-4.

Enhancing epoxy coating corrosion resistance with a novel MoS2-modified polydopamine functionalized graphene oxide nanocomposite

Environmental-friendly epoxy (EP) composite coatings are regarded as distinguished candidates for preventing metal corrosion. In this paper, we synthesized a novel GO-PDA-MoS2/EP nanocomposite coating system by modifying dopamine (PDA) functionalized graphene oxide (GO) with MoS2. Here, the effect of different MoS2 additions on the corrosion resistant properties of coatings was investigated by altering the ratio of MoS2 to GO-PDA via electrochemical measurements, long-duration immersion experiments, and water contact angle tests. The results indicated that 0.3 wt.% MoS2 can substantially enhance the interfacial compatibility between EP and GO-PDA and the GO-PDA-MoS2-0.3 wt.%/EP coating presented optimum corrosion resistant properties. Specifically, the impedance modulus (|Z|) of the GO-PDA-MoS2-0.3 wt.%/EP coating still reached 2.36 × 107 Ω·cm2 after 30 days immersed, which was two orders of magnitude higher than pure EP coatings. This work demonstrates a novel economical and environmental scheme that MoS2 can be employed to enhance the corrosion resistant properties and improve the interfacial interactions of EP coatings.

Insight into effect of rust layer evolution on corrosion resistance of 55AlZnMg coating

The relationship between rust layer evolution and the corresponding corrosion resistance of 55AlZnMg coatings in NaCl solution were investigated by Scanning electron microscope, micro-Raman spectroscopy and electrochemical impedance spectroscopy. Alloy phases composing the coating were not corroded synchronically, and thus the coating would not transfer into a rust layer integrally along the depth direction. The rapid thickening of the rust layer was triggered with an outward migration of such cations as Zn2+ and Al3+, which were generated from the preferential corrosion of interdendritic MgZn2/Zn-rich phases. During this process, benefiting from the compact rust layer consisting of protective corrosion products (e.g., simonkolleite, hydrozincite and layered double hydroxide), the corrosion resistance of the coating was sharply enhanced until the immersion for 28 days. Later, because of transformations of simonkolleite and hydrozincite, the stratification of the rust layer and micro-cracks caused by the formation of Zn(OH)2 in large quantities, which led to a formation of fast diffusion tunnel and thus impaired the corrosion resistance of the coating. It could be concluded that the corrosion resistance of 55AlZnMg coatings in NaCl solution were not only determined by the properties of its corrosion products, but also, on the overall properties of rust layer.

Effect of Nb Addition on the Corrosion and Wear Resistance of Laser Clad AlCr2FeCoNi High-Entropy Alloy Coatings

Laser clad AlCr2FeCoNiNbx (x = 0, 0.5, 1.0, 1.5, 2.0, with x values in molar ratio) high-entropy alloy (HEA) coatings were fabricated on Q345 carbon steel. This study delves into the impact of Nb incorporation on the reciprocating sliding wear resistance of these laser clad coatings against a Φ6 mm silicon nitride ball. The microstructure of the as-clad AlCr2FeCoNiNbx coatings transformed from a single Face-Centered Cubic (FCC) solid solution (when x = 0) to the hypoeutectic state (when x = 0.5) and progressed to the hypereutectic state (when x ≥ 1.0). This evolution was marked by an increase in the Laves phase and a decrease in FCC. Consequently, the HEA coatings exhibited a gradually increasing Vickers hardness, reaching a peak at HV 820. Despite a decline in corrosion resistance, there was a notable enhancement in wear resistance, and the friction of the HEA coating could be reduced by Nb addition. The phase evolution induced by Nb addition led to a shift in the predominant wear mechanism from delamination wear to abrasive wear. The wear rate of Nb0.5 was impressively low, at 6.2 × 10−6 mm N−1 m−1 when reciprocating sliding under 20 N in air. In comparison to Nb0, Nb0.5 showcased 3.6, 7.2, and 6.5 times higher wear resistance at 5 N, 10 N, and 20 N, respectively. Under all applied loads, Nb1.5 has the lowest wear rate among all HEA coatings. This substantiates that the subtle introduction of Laves phase-forming elements to modulate hardness and oxidation ability proves to be an effective strategy for improving the wear resistance of HEA coatings.

Effect of hydrothermal treatment on the corrosion resistance of CO2 gas-assisted MAO coatings

1Micro-arc oxidation (MAO) is an effective method for preparing highly corrosion-resistant coatings on metal surfaces, but the presence of a porous structure on the surface tends to limit further improvements in corrosion resistance. In this paper, we report a CO2 gas-assisted MAO method to prepare a ceramic coating on the surface of magnesium alloys and seal the pores using a hydrothermal reaction. By comparing the corrosion resistance of the coatings of the specimens in different electrolytes, the study reveals the mechanism of the influence of CO2 gas and hydrothermal post-treatment method on the initial structure of the coating, as well as the influence law of the corrosion resistance of different coatings. The results show that the coating prepared in NaOH + Na2SiO3 solution has the largest thickness and exhibits the most excellent corrosion resistance, which is at least one order of magnitude higher than that of several other groups of specimens.

The Enigma of Titanium Electrodeposition on Various Substrates

Titanium is an oxiphilic reactive metal which readily forms passive oxide films onto substrates. The unique properties of the metal such as low density (d=4.5 g/cm3), high strength, and corrosion resistance in harsh environments offers practical advantages. The pure metal is used abundantly in aerospace, armors, submarines, missiles, biomedicals, golf clubs and special electronic applications. The electro-deposition of corrosion resistant coatings is imperative to protect base metals. A review of previous literature has indicated that methods such as roll-diffusion cladding, magnetron discharge sputtering, electron beam, vacuum evaporation, ion beam enhanced deposition (PVD), thermal spray, chemical conversion coatings etc. have been employed in special applications at a prohibitive cost. Plating of titanium films in molten salts at high temperature, and inert atmospheres is a challenge to follow stringent conditions. Electroplating in ionic liquids is extremely expensive and limited.It will be an important technological advancement if a feasible electrodeposition process for titanium is developed for light base metals and plastics in aqueous or semi-aqueous solutions. Titanium electrodeposition in aqueous systems is not a straight-forward process due to its far negative reduction potential than that of hydrogen. Its multivalence states, stability, limited potential range, gas evolution, and substrate passivation pose technical challenges. The present author has critically evaluated several recipes cited by Russian literature, and a few United States patents. Unfortunately, we could not substantiate their cited claims. We have developed an innovative and proprietary process for electro-deposition of Ti in aqueous and partially non-aqueous systems. Deposition of titanium and its alloy films is demonstrated on variety of substrates such as Steel, Pb, Zn, Al, and selected plastics. It is our hope that this endeavor will open new avenues in surface finishing applications.

Electrodeposition of Zn-Cr Alloys: A Comparison with Pure Zinc

The electrodeposition of zinc coatings is one of the most common surface treatments for providing corrosion resistance to metallic components. From the thermodynamic point of view, zinc is located in a sweet spot, with its reduction potential being lower than most other common metals, while at the same time being not too susceptible to atmospheric corrosion; overall these features make zinc the ideal candidate for the electroplating of sacrificial coatings for corrosion protection. Owing it to its low cost and scalability, zinc electroplating has cemented itself as a cornerstone process in a variety of industrial sectors in the last decades. [1]While zinc coatings corrosion resistance has proved to be satisfactory in most cases, it could still be improved to operate even in more aggressive environments. For this purpose, electrodeposition of zinc alloys with transition metals from the iron group (Ni, Co, Fe) has proven to be a successful method to enhance zinc coatings corrosion resistance. In particular, zinc-nickel alloys have found the greater success among them, due to improved corrosion resistance and mechanical properties. [2]Zinc-chromium alloys also present a good opportunity to improve coatings performance, thanks to the passivating effect of Cr. In fact, electrodeposited ZnCr alloys with a Cr content up to 10.4% were found to exhibit a corrosion potential shifted by up 150 mV in the anodic direction with respect to the pure zinc counterpart. [3] This shift led to a significant decrease in the coating dissolution rate but was sufficiently small that the layers could still preserve their sacrificial nature towards the underlying steel.In this work, ZnCr coatings are deposited on low carbon steel from an acidic sulfate formulation containing Cr(III) ions at various concentrations. The properties of ZnCr coatings are explored by varying the most common parameters such as current density, composition, and pH. Furthermore, the resulting coatings are characterized through conventional surface analysis techniques such as SEM, EDS, XRD and XRF. Finally, the corrosion resistance performance of the ZnCr coatings is compared to pure Zn coatings to highlight the benefits of the alloy.Bibliography[1] R. Winand, “Electrodeposition of Zinc and Zinc Alloys,” Mod. Electroplat. Fifth Ed., pp. 285–307, Feb. 2011.[2] N. Lotfi, M. Aliofkhazraei, H. Rahmani, and G. B. Darband, “Zinc–Nickel Alloy Electrodeposition: Characterization, Properties, Multilayers and Composites,” Prot. Met. Phys. Chem. Surfaces, vol. 54, no. 6, pp. 1102–1140, Nov. 2018.[3] V. Chakarova, T. Boiadjieva-Scherzer, D. Kovacheva, H. Kronberger, and M. Monev, “Corrosion behaviour of electrodeposited Zn-Cr alloy coatings,” Corros. Sci., vol. 140, pp. 73–78, Aug. 2018.

Corrosion resistance of cerium-doped Pb-Co alloy coatings in seawater

A luminum and its alloys, known for low density and high tensile strength, are widely used in marine equipment but prone to corrosion. This study aims to enhance their corrosion resistance by developing cerium-modified hydrophobic Pb-Co coatings through one-step electrodeposition. Adjusting the cerium to cobalt ion ratio optimized the coatings for superior resistance to wetting and corrosion. The research investigates physicochemical properties, wetting behavior, adhesion strength, and corrosion performance of these coatings on aluminum. Mechanisms of deposition and corrosion resistance are explained through experimental results, analytical insights, and DFT calculations, advancing our comprehension of corrosion protection in cerium-modified Pb-Co coatings.

Enhancing corrosion resistance and toughness of solvent-free epoxy coatings with low-viscosity fluorine-containing hyperbranched polyether

In this study, a low-viscosity epoxy-terminated fluorine-containing hyperbranched polyether (FHBPE) was synthesized and incorporated in a solvent-free epoxy coating formulation to enhance coating toughness and corrosion resistance while minimizing the impact on coating viscosity. FHBPE was synthesized by a solvent-free one-pot method with hexafluorobisphenol A (A2 monomer) and trimethylolpropane triglycidyl ether (B3 monomer). Subsequently, FHBPE, E51 epoxy resin, and an alicyclic amine curing agent were blended to create the solvent-free epoxy coating, which was applied onto a steel substrate by a scraping coating method. This research demonstrates that addition of FHBPE did not show adverse effect on coating viscosity; instead, it reduced the viscosity at around 6 wt% loading. The epoxy-terminated FHBPE increased the cross-linking density of neat E51 coating by up to 20.7 %. Furthermore, the introduction of flexible segments enhanced the toughness, leading to a one-grade increase in the coating flexibility from 1 to 0.5 mm. Furthermore, FHBPE significantly improved the corrosion resistance of the coatings, attributed to increased cross-linking density and hydrophobic properties of the coating. Among FHBPE-modified coatings, the coating with 6 wt% loading demonstrated superior overall performance. Over a 60-day immersion period, its electrochemical impedance value remained stable, while the neat E51 coating experienced a two-orders-of-magnitude decrease. Furthermore, the 6 wt% FHBPE-modified coating passed the 750-h salt spray test without obvious rust, outperforming the neat E51 coating (200 h). This study presents a feasible and promising strategy for the formulation design and mass production of solvent-free epoxy coatings.

Effect of methane and acetylene pre-gases on the corrosion resistance of DLC coatings

Diamond-like carbon (DLC) coatings were applied to 304 stainless steel specimens using two different pre-gases: methane and acetylene.Compared to DLC prepared with acetylene pre-gas(DLC-C2H2). DLC prepared with methane pre-gas(DLC-CH4) has a denser coating body and a smoother surface.The DLC-C2H2 film shows crack defects on the surface, and the DLC-CH4 film has a lower sp2/sp3 ratio than DLC-C2H2. DLC-CH4 has better electrochemical characteristics and salt spray corrosion testing results than DLC-C2H2 films in NaCl solution. DLC-CH4 has a high charge transfer resistance of 9.54 × 103 Ω/cm2. Compared to DLC-C2H2, DLC-CH4 coatings form a more complete, continuous, smooth surface and a minor porosity in the coating body, inhibiting localized corrosion processes. The DLC-CH4 coatings have less sp2 phase, which results in lower electrical conductivity and limited electron transport at the coating surface. DLC-CH4 shows more excellent corrosion resistance.

Effect of Minor Mo Addition on Microstructure and Corrosion Resistance of High-Velocity Air Fuel-Sprayed Fe-Based Amorphous Coatings

In this work, Fe64Nb3B17Si6Cr6Ni4 and Fe60Nb3B17Si6Cr6Ni4Mo4 (at. %) coatings were prepared with a high-velocity air fuel spraying method, and the effects of minor Mo addition on the microstructure, glass formation, and corrosion resistance of the coating were studied. It was found that the Mo addition improves the glass-forming ability of the alloy and a fully amorphous structure with a higher compactness was obtained in the Mo-containing coating. The thermal stability of the coating is enhanced by Mo addition and the onset crystallization temperature was increased by 20 K. In addition, the Mo-containing amorphous coating exhibited higher corrosion resistance than the Mo-free coating. The superior corrosion resistance can be attributed to the increased proportion of protective, stable Cr, Nb, and Mo oxides in the passive film and fewer defects of the Mo-containing coating.

Cellulose nanocrystals-reinforced waterborne epoxy coatings with enhanced corrosion resistance for steel

The practical applications of waterborne epoxy coatings are limited due to their poor barrier properties caused by the formation of numerous micropores and defects during the curing process. Herein, cellulose nanocrystals (CNCs)-reinforced waterborne epoxy coatings were fabricated by the direct addition of 0.2–1.0 wt% CNCs to waterborne epoxy emulsion followed by amine curing agent addition and spray coating. The incorporation of 0.2–0.5 wt% CNCs had no discernible impact on the stability of the waterborne epoxy emulsion. This led to the uniform dispersion of CNCs in the cured coating matrix, as evidenced by differential scanning calorimetry analysis. Because of the good compatibility, 0.2–0.5 wt% CNCs-reinforced epoxy coatings exhibited superior corrosion protection performance for steels. The impedance modulus of these coatings remained at 108 Ω cm2 after being immersed in a 3.5 wt% NaCl solution for 21 d. The hydroxyl groups present on the CNC surface undergo a reaction with the epoxy group, enhancing intermolecular interaction and leading to the formation of a defect-free dense structure that improves coating barrier properties. However, the incorporation of an excessive amount of CNCs (i.e., 0.8 and 1.0 wt%) significantly compromised the corrosion resistance of epoxy coatings due to aggregation-induced coating defects. Overall, this study provides a facile and green strategy for corrosion resistance improvement of waterborne epoxy coatings.

Antireflection Property and Corrosion Resistance of Black Ceramic Superhydrophobic Coatings on Aluminum Alloy

In this article, a black ceramic coating is produced on the surface of 7075 aluminum alloy by plasma electrolytic oxidation (PEO) in a silicate electrolyte containing ammonium metavanadate (NH4VO3). The PEO processed sample is further subjected to hydrothermal treatment (HT) and fluorination treatment (FT) to obtain a superhydrophobic PEO/HT/FT coating. The 21‐day air durability test and the tape stripping test show that the superhydrophobic surface shows excellent air durability and mechanical durability. The antireflection test study shows that the average antireflection of the PEO/HT/FT coating is as high as 96.6% in the wavelength range between 400 and 1000 nm. Furthermore, electrochemical test results show that the corrosion current density of the PEO/HT/FT coating decreases to 2.49 × 10−6 A cm−2, three orders of magnitude lower than the aluminum substrate, and the anticorrosion efficiency is as high as 99.87%. The preparation of PEO/HT/FT coating provides more methods for the wide application of Al alloy in aerospace field.