Corrosion Resistance Of Alloy Research Articles

Enhancing the mechanical properties and corrosion resistance of biomedical Ti15Mo alloy with ultra-finer {332} twins via cyclic deformation

Mechanical properties, passivation behaviors and corrosion resistance of biomedical Ti15Mo alloy with ultra-finer twins were investigated. Cyclic deformation was conducted to activating more {332} twin variants via periodic changes of tension and compression. Microstructural refinement via numerous twins with the stable boundaries is different from other mechanisms, resulting in a higher hardness and maintaining the low elastic modulus after deformation and annealing. The results of electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy tests, revealed that twin boundaries are beneficial to enhancing passivation behaviors via forming a thicker oxide film in PBS solution. The alloy with ultra-finer {332} twins exhibit a better corrosion resistance due to a lower passivation current. The expected biomedical performance was obtained in the alloy after ±3 % amplitude cyclic deformation and 730 °C/7 min annealing, in contrast to the initial alloy with coarse grains, increasing 8.8 % of the hardness, decreasing 46 % of the corrosion current and maintaining the low elastic modulus.

Role of Mn in improving the corrosion resistance and cytocompatibility of antibacterial Mg-Ag-Mn alloy

To improve corrosion resistance and cytocompatibility of biodegradable Mg-Ag alloy, the non-toxic Mn was added to produce Mg-Ag-xMn (x=0, 0.5, 1, 2 and 3 wt%) alloys. It was revealed that Mg-Ag-2Mn alloy exhibits an optimized comprehensive property after post-casting heat treatment (PCHT). Microstructural factors for the improved performances are then determined. It is revealed that the addition of Mn promotes the precipitation of the Fe-containing α-Mn phase and alters the configuration of the corrosion product after PCHT, which enhances the corrosion resistance of the alloy and thus optimises the ionic release kinetics for improved biological performance.

Investigation on corrosion behaviour of metal oxide nanoparticles reinforced magnesium composites by salt spray and immersion corrosion test methods

ABSTRACT This study explores the increasing utilisation of lightweight materials, particularly magnesium (Mg) alloy, in sectors such as automobile, aerospace, and marine due to its notable advantages such as high strength-to-weight ratio, good castability, and excellent damping capacity. Despite these merits, Mg alloy faces challenges, notably in wear and corrosion resistance. The research focuses on enhancing the corrosion resistance of Mg alloy by incorporating Zinc Oxide (ZnO), Manganese Oxide (MnO), and Titanium Oxide (TiO2) nanoparticles. The alloy AZ91D and three nanocomposites, namely AZ91D + 1% ZnO, AZ91D + 1% MnO, and AZ91D + 1% TiO2, were manufactured using a stir squeeze casting technique combined with an ultrasonication process. To confirm the even distribution of reinforcement particles, Optical Microscope (OM), Scanning Electron Microscope (SEM) and High-Resolution Scanning Electron Microscope (HR-SEM) were employed. X-ray Diffraction (XRD) analysis revealed the presence of matrix and reinforcement material with intermetallic precipitates around the grain boundaries. Corrosion properties were assessed following ASTM standards and utilising a 3.5% NaCl concentration. The study found that AZ91D + 1% TiO2 nanocomposites exhibited superior corrosion resistance compared to the AZ91D alloy, showing a remarkable 77.78% and 69.89% improvement in corrosion behaviour under salt spray and immersion environments, respectively, after 48 hours.

In situ evaluation of sensitization in the heat affected zone of supermartensitic stainless steel welded with superduplex filler metal

Supermartensitic stainless steels (SMSS) are high strength corrosion resistant alloys used in oil and gas production in deep water. Failures related to sensitization and excessive hardness in the heat affected zone (HAZ) are prone to happen in harsh environments, such as those found in oil production. To avoid dangerous types of failure, post weld heat treatments (PWHT) are necessary. Temperature and duration of PWHTs are fundamental parameters to be adjusted. In the present work, a minicell was developed to perform DL-EPR tests in different regions of a multipass welded joint of SMSS with superduplex stainless steel as filler metal. The welded joint was submitted to PWHT at 650 °C for 5 and 15 min. The effects of these short duration PWHT on the HAZ and base metal were analyzed using a minicell for double loop electrochemical tests (DL-EPR), atomic force microscopy (AFM), and scanning electron microscopy (SEM). The results indicate that both PWHTs (5 and 15 min) caused the increase in the degree of sensitization of HAZ without the reduction of hardness to acceptable values.

Corrosion behaviour of superaustenitic stainless steel N08029 in harsh acidizing environment

It is vital to examine the resistance to corrosion of corrosion resistant alloys (CRAs) in severe oilfield corrosive environments such as acidizing to validate their performance. Super austenitic stainless steel (SASS) UNS N08029 was recently developed to offer competitive and improved corrosion resistance in extreme and aggressive environments. However, no systematic studies have evaluated the N08029 performance in acidizing conditions. In this study, N08029 was investigated in harsh acidizing conditions of different HCl concentrations (up to 25 % HCl), long immersion duration (up to 48 h), and at elevated temperatures (up to 80 °C) using both weight loss and electrochemical measurement techniques. Interestingly, all the test methods show that the corrosion resistance of the SASS increases with increasing the concentration of HCl acid. This may be due to the formation of ferric chloride protective layer on the steel surface after the dissolution of the formed chromium oxide layer by the increasing acid concentration. The decrease in the corrosion rate observed at higher HCl concentrations is because the higher concentration of HCl causes the more ferric chloride layer to form on the metal's surface. This layer protects the metal from further acid attack. Also, after 24 h immersion duration, a decrease in corrosion rate with further increase immersion duration was observed which may is also due to the formation of more ferric chloride protective layer. However, the corrosion resistant of the SASS was observed to decrease with increase in temperature of the test solution. The decreased resistance of the SASS to corrosion with increase in temperature is associated with the instability or damage of the passive/protective film on the surface of the SASS at elevated temperatures.

Unveiling the novel anti-corrosion and anti-bacterial biofilm forming characteristics of eco-safe MWCNT-AZ91E alloy for food-processing surfaces

This study explores the eco-friendly modification of AZ91E alloy with MWCNT casting to enhance surfaces crucial for food processing, storage, and transportation, with a specific focus on reducing bacterial biofilm formation and preventing corrosion. Incorporating nanomaterials like MWCNT into magnesium alloys offers promising prospects for improving the surfaces of equipment and structures used in food-related industries. The advanced mechanical properties observed in MWCNT-doped alloys can lead to the development of lightweight yet durable surfaces essential for maintaining hygiene standards and ensuring food safety during processing, storage, and transportation. Employing sophisticated systematic practices such as XRD, FTIR, and Vickers hardness testing allows for comprehensive evaluation of surface modifications and mechanical enhancements. Furthermore, the demonstrated corrosion resistance of MWCNT-doped magnesium alloys is crucial for protecting surfaces from degradation caused by exposure to corrosive environments commonly encountered in food processing facilities and transportation systems. Additionally, the remarkable antibacterial properties exhibited by MWCNT-doped alloys hold promise for mitigating bacterial biofilm formation on surfaces, thereby contributing to enhanced sanitation and hygiene practices in food-related industries. KEY WORDS: Multiwalled carbon nanotube, Magnesium alloys, Anticorrosion, Squeeze casting, Antibacterial, Biofouling Bull. Chem. Soc. Ethiop. 2024, 38(6), 1897-1914. DOI: https://dx.doi.org/10.4314/bcse.v38i6.30

Study of the Synergistic Influence of Plasma Electrolytic Oxidation and Wet Post-Treatment on the Surface of AA7075.

In this study, we enhanced the corrosion and microbial resistance of aluminum 7075 alloys by applying a thin layer of alumina through plasma electrolytic oxidation (PEO) in an alkali-silicate electrolyte. In addition, the influence of film sealing on coated aluminum alloy 7075 was studied in detail, specifically in oil and water at 100 °C after treatment. The surface and cross-sectional morphology, element composition, and phase composition of the PEO coatings were characterized by using scanning electron microscopy (SEM) assisted with energy-dispersive X-ray spectrometry (EDS) and X-ray diffraction (XRD), respectively. The corrosion resistance of the coating on AA7075 PEO was evaluated before and after post-treatment using hot water and hump oil at 100 °C. This assessment was conducted by using various electrochemical techniques, including open-circuit potential (OCP), linear polarization resistance (LPR), potentiodynamic polarization scan (PD), electrochemical impedance spectroscopy (EIS), and cyclic potentiodynamic scan (CPS). The results showed that the corrosion resistance of the AA7075 alloy was significantly improved after the PEO coating. The AA7075 + SF, among all of the examined alloys, exhibited superior corrosion properties, due to its fat sealing. This is probably due to the formation of a mixed fatty acid layer from oil on the surface of the AA7075 PEO, which synthesizes a hydrophobic layer. Interestingly, the samples treated with PEO showed a great resistance to microbial growth.

Enhancing Corrosion Resistance and Antibacterial Properties of ZK60 Magnesium Alloy Using Micro-Arc Oxidation Coating Containing Nano-Zinc Oxide

Enhancing Corrosion Resistance and Antibacterial Properties of ZK60 Magnesium Alloy Using Micro-Arc Oxidation Coating Containing Nano-Zinc Oxide

Boosting corrosion resistance of Mg-Li alloy: Implanting bioinspired superhydrophobic surfaces into MAO matrix for enhanced protection

The corrosion problem has significantly impeded the practical application of Mg-Li alloys. In this report, a method that combines micro-arc oxidation (MAO) with electrochemical deposition is developed to create a superhydrophobic matrix on Mg-Li substrate. The combination approach harnesses the superiority of both coverages, including MAO as the dense, firmly bonded ceramic oxide layer on the metal substrate and the superhydrophobic surface (SHS) implanted into MAO matrix. The MAO-SHS coating exhibits high mechanical stability, maintaining the superhydrophobicity due to the “implanting effect” even after a long distance of friction effect. For corrosion inhibition, compared to the bare Mg-Li with icorr of 9.26 × 10−5 A/cm2, the icorr for MAO and MAO-SHS is 7.83 × 10−6 A/cm2 and 7.50 × 10−9 A/cm2, respectively, representing the reduction of approximately one and four orders of magnitude. Focusing the atmospheric corrosion inhibition, MAO-SHS proves to manipulate the dynamic evolution of saline solution evaporation and salt particle deliquation. The salt particle crystalized from saline solution on MAO-SHS is found to have significantly smaller contact area than that of the bare Mg-Li and MAO. By employing atomic force microscopy, the adhesion force of salt particle is revealed as ca. 45 nN, 13 nN, and 2 nN for salt particle on Mg-Li, MAO, and MAO-SHS, respectively. This suggests that the salt can be more easily removed from the MAO-SHS surface, thereby reducing the susceptibility to corrosion. The in situ deliquation is conducted to understand the formation of the droplet on different surfaces. The air in the SHS layer hinders chloride ingress and the SHS layer seals the pores in MAO layer, proving the synergistic effect afforded by MAO-SHS to achieve superior corrosion resistance.

Microstructure evolution and properties of semi-solid Al80Mg5Li5Zn5Cu5 light weight high entropy alloy prepared by SIMA

The semi-solid Al80Mg5Li5Zn5Cu5 light weight high entropy alloys were prepared by strain induced melting activation method (SIMA), and the microstructure evolution, mechanical properties and corrosion resistance of semi-solid Al80Mg5Li5Zn5Cu5 light weight high entropy alloys were investigated. The results indicate that the ideal globular or near-globular microstructures with an average grain size of 29.1 μm and a shape factor of 0.86 can be obtained when the Al80Mg5Li5Zn5Cu5 light weight high entropy alloys with 20% deformation held at 500 °C for 15 min. The coarsening coefficient is 35.8 μm3/s when the temperature is 500 °C, which is lower than the traditional single major element alloys due to the sluggish diffusion effect of high entropy alloys. The compression strength of semi-solid Al80Mg5Li5Zn5Cu5 light weight high entropy alloys is 558.4 MPa, which is 11% higher than that of as-cast state. The corrosion resistance of semi-solid Al80Mg5Li5Zn5Cu5 light weight high entropy alloys is also significantly improved.

Electrochemical stability of biodegradable Zn-Cu alloys through machine-learning accelerated high-throughput discovery.

Zn-Cu alloys have attracted great attention as biodegradable alloys owing to their excellent mechanical properties and biocompatibility, with corrosion characteristics being crucial for their suitability for biomedical applications. However, the unresolved identification of intermetallic compounds in Zn-Cu alloys affecting corrosion and the complexity of the application environment hamper the understanding of their electrochemical behavior. Utilizing high-throughput first-principles calculations and machine-learning accelerated evolutionary algorithms for screening the most stable compounds in Zn-Cu systems, a dataset encompassing the formation energy of 2033 compounds is generated. It reveals that most of the experimentally reported Zn-Cu compounds can be replicated, especially the structure of R32 CuZn5 is first discovered which possesses the lowest formation energy of -0.050 eV per atom. Furthermore, the simulated X-ray diffraction pattern matches perfectly with the experimental ones. By formulating 342 potential electrochemical reactions based on the binary compounds, the Pourbaix diagrams for Zn-Cu alloys are constructed to clarify the fundamental competition between different phases and ions. The calculated equilibrium potential of CuZn5 is higher than that of Zn through the forward reaction Zn + CuZn5 ⇌ CuZn5 + Zn2+ + 2e-, resulting in microcell formation owing to the stronger charge density localization in Zn compared to CuZn5. The presence of chlorine accelerates the corrosion of Zn through the reaction Zn + CuZn5 + 6Cl- + 6H2O ⇌ Cu + 6ZnOHCl + 6H+ + 12e-, where the formation of ZnOHCl disrupts the ZnO passive film and expands the corrosion pH range from 9.2 to 8.8. Our findings reveal an accurate quantitative corrosion mechanism for Zn-Cu alloys, providing an effective pathway to investigate the corrosion resistance of biodegradable alloys.

Investigation of sliding wear, electrochemical corrosion, and biocompatibility of Ti-Nb alloys for biomedical applications

This research emphasizes the development of biocompatible Ti-xNb (0, 5, 10, 15, 20, and 25 wt.%) alloys through powder metallurgy to attain a lower elastic modulus, high strength, low wear, and high corrosion resistance appropriate for biomedical implants. The developed alloys were comprehensively analyzed through microstructural, physical, mechanical, electrochemical, biological, and tribological investigations to assess their suitability by comparing their properties with commercially pure titanium (cpTi). The outcomes demonstrate, powder metallurgy is an effective route for developing Ti-Nb alloys with several desirable properties. Incorporating niobium (Nb) into titanium (Ti) introduces the β phase within the alloys, which increases with Nb concentration and contributes to decreasing the elastic modulus to as low as 43.47 ± 4.9 GPa. All Ti-Nb alloys exhibits higher hardness and compressive strength than cpTi, with values of 403.23 ± 21.38 HV and 1322.45 ± 25.64 MPa obtained for the Ti-10Nb alloy. A lower concentration of Nb shows comparable corrosion resistance of the Ti-Nb alloys to cpTi, whereas a higher Nb concentration is unfavorable. Furthermore, the tribological findings demonstrate superior antifriction and antiwear properties in all Ti-Nb alloys compared to cpTi. Notably, Ti-10Nb displays outstanding wear resistance with a 41.82% lower friction coefficient in dry conditions and 31.11% in simulated body fluid (SBF), along with 81.08% reduction in wear volume in dry conditions and 63.11% in SBF compared to cpTi. Among all developed alloys, Ti-10Nb exhibits various desired properties, suggesting its potential as an alternative to cpTi for biomedical implant applications.

Novel approach to corrosion resistance and radiative cooling with biomimetic amorphous coatings

To address the application challenges of high-power-density electronic devices in harsh conditions, it is crucial to develop electric insulation materials that possess both corrosion resistance and excellent radiative cooling performance. In this study, inspired by the wrinkle morphology of the Camponotus ant with thermoregulation, a biomimetic amorphous coating composed of a hemispherical array was fabricated on aluminum alloy using plasma electrolytic oxidation (PEO) technology. This biomimetic microstructure is obtained by controlling the content of hexagonal boron nitride (h-BN) nanoparticles in the electrolyte, where the increase in current density at a later stage allows the transition of the porous coating to the hemispherical array. The effects of functional group vibration and rotation in combination with the hemispherical structure afford the biomimetic coating a high emissivity of 0.91 within the range of 3–14 μm, which reduces the LED temperature by 17.1 °C and achieves a cooling efficiency of 10.6 %. Meanwhile, with a resistivity of 5.15 × 1014 Ω∙cm and a dielectric strength of 29.9 V/μm, the coating can prevent current leakage, consequently improving the stability and reliability of electronic packaging materials. In addition, h-BN flakes in the biomimetic coating with almost defects free act as a protective barrier to enhance the corrosion resistance of the aluminum alloy. This approach offers a time-efficient and cost-effective route for the manufacture of multifunctional coatings with potential applications in electronic packaging.

Corrosion behaviour of 110SS steel in hydrochloric acid and blended acid system at 200°C

The influence of organic acids (formic acid, acetic acid) on the corrosion behaviour of 110SS steel, a hydrogen sulphide corrosion resistant alloy steel, in hydrochloric (HCl) acid environments was studied. The corrosion rates of 110SS steels in HCl acid and blended acid were measured using the high-temperature and high-pressure corrosion tester. Scanning electron microscopy was utilised to observe the morphology of corrosion products on steel samples corroded by different acid systems, and the energy dispersive X-ray spectrometer was used to analyse the elemental composition of the corrosion products. The corrosion morphology was observed using a 3D laser scanner. The results indicated that the corrosion rate of 110SS steel in HCl acid at 200 °C was an exponential function of HCl concentration. Reducing the HCl concentration significantly decreased the corrosion rate of 110SS steel. Organic acids and corrosion inhibitors synergistically reduced the corrosion of 110SS steel in HCl acid. Adding 3 wt.% organic acid to the 15 wt.% HCl acid system further reduced the corrosion rate, with a more pronounced effect observed in the HCl–formic acid system compared to the HCl–acetic acid system. Organic acids chemically adsorbed onto the steel surface and decomposed to produce CO, which hindered the attack of hydrogen ions on the metal. The added corrosion inhibitor and intensifier Sb2O3 resulted in the formation of a compact adsorption film on the steel surface, further inhibiting corrosion. The optimal mass ratio of HCl acid to organic acid was found to be 15% to 3%.

Enhancement of Wear and Corrosion Resistance of Ti6Al4V Alloy through Hollow Cathode Discharge-Assisted Plasma Nitriding.

In order to improve the wear and corrosion resistance of Ti6Al4V alloy, a Ti-N compound layer was formed on the alloy by plasma nitriding at a relatively low temperature (750 °C) and within an economical processing duration (4 h), in a mixture of NH3 and N2 gases with varying ratios. The influence of the gas mixture on the microstructure, phase composition, and properties of the Ti-N layer was investigated. The results indicated that the thickness of the nitrided layer achieved in a mixed atmosphere with optimal proportions of NH3 and N2 (with a ratio of 1:2) was substantially greater than that obtained in an atmosphere of pure NH3. This suggests that appropriately increasing the proportion of N2 in the nitriding atmosphere is beneficial for the growth of the nitrided layer. The experiments demonstrated that the formation of the surface nitrided layer significantly enhances the corrosion and wear resistance of the titanium alloys.

Biocompatibility and corrosion resistance of drug coatings with different polymers for magnesium alloy cardiovascular stents

Recently, advances in enhancing corrosion properties through various techniques, and the clinical application of biodegradable cardiovascular stents made from magnesium (Mg) alloys face challenges to corrosion resistance, blood compatibility, and biocompatibility. Drug-eluting stents (DES) offer a solution to enhance the corrosion resistance of Mg alloys while simultaneously reducing the occurrence of restenosis. In this study, WE43 Mg alloy was pretreated using electropolishing technology, and different polymers (PEG and PLLA) were used as drug-polymer coatings for the Mg alloy. At the same time, PTX, an anticoagulant, was incorporated to achieve drug coating of different polymers on WE43 Mg alloy. The corrosion resistance of different polymer-drug coatings was assessed using a plasma solution. Furthermore, in vitro and in vivo tests were used to evaluate the blood biocompatibility of these coatings. The results indicated the PTX-PEG-coated WE43 Mg alloy exhibited the highest corrosion resistance and the most stable drug release profile among the tested coatings. Its hemolysis rate of 0.6 % was within the clinical requirements (<5 %). The incorporation of PEG prevents non-specific protein adsorption and nanoparticle aggregation, enhancing the surface hemocompatibility of WE43 Mg alloy. Therefore, the PTX-PEG coating shows promising potential for application in the development of drug-coated Mg alloy.

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.

Recent Progress on Atmospheric Corrosion of Field-Exposed Magnesium Alloys

It is well known that the poor corrosion resistance of magnesium alloys is a key factor limiting their application. Field exposure is the most reliable means to evaluate the atmospheric corrosion performance of magnesium alloys. This article reviews the field exposure corrosion behavior of magnesium alloys in typical atmospheric environments (including the marine atmosphere, industrial atmosphere, etc.) in recent years. According to the literature review, it was found that there are significant regional differences in the atmospheric corrosion behavior of magnesium alloys, which is the result of the coupling of multiple factors in the atmospheric environment. By investigating the corrosion rate and corrosion products of different types of magnesium alloys in different environments, the corrosion mechanism of magnesium alloys in different environments was summarized. Specifically, environmental parameters such as atmospheric temperature, relative humidity, CO2, and chloride ion deposition rates in the marine atmospheric environment can affect the corrosion behavior of magnesium alloys. The corrosion of magnesium alloys in different industrial atmospheric environments is mainly affected by atmospheric temperature and relative humidity, as well as atmospheric pollutants (such as SO2, CO2, NO2) and dust. This review provides assistance to the development of new corrosion-resistant magnesium alloys.

Engineering Corrosion Resistance in Magnesium Alloys for Biomedical Applications: A Synergy of Zn/Ca Atomic Ratio and Texture-Based Approach

Magnesium (Mg) and Magnesium-Zinc-Calcium alloys present a compelling option for biodegradable implant materials. Utilizing Vacuum Induction Casting, Mg–2.5Zn-xCa (with x = 0.3, 0.5, 0.9, 1.15 wt%) alloys were fabricated and subjected to hot-rolling for thermo-mechanical processing. The hot-rolled Mg–2.5Zn-0.3Ca alloy exhibits the lowest corrosion rate along with the highest basal texture. Increasing the Zn/Ca atomic ratio intensifies the basal texture and enhances corrosion resistance. Elevated Zn concentration improves corrosion resistance via Ca2Mg6Zn3 phase formation, while increased Ca content diminishes corrosion resistance due to the Mg2Ca phase. Advancement of this alloy is poised to extend Mg alloy use in innovative biomedical bone implants.

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.