Enhanced Corrosion Resistance Research Articles

Sonication assisted superior anti-corrosion properties of cathodically deposited novel nickel-graphene oxide-zinc oxide coating

This study details the sonication-assisted synthesis and characterization of a cathodically deposited novel nickel-graphene oxide -zinc oxide (Ni-GO-ZnO) composite coating achieved through electrodeposition and its comparison with anodically deposited GO. This coating was comprehensively characterized using Fourier-transform infrared (FTIR), X-ray diffraction (XRD), Raman spectroscopy, Field emission scanning electron microscopy (FE-SEM) coupled with Energy-dispersive X-ray spectroscopy (EDAX). Subsequently, its corrosion resistance for MS1010 mild steel in 3.5 wt % (NaCl) was evaluated via weight loss, contact angle, electrochemical impedance spectroscopy (EIS), Potentiodynamic polarization, and surface analysis techniques. These observations suggest that graphene oxide-zinc oxide (GO-ZnO) adsorbs nickel onto the MS surface effectively and reduces defects, which helps in blocking active corrosion sites. Tafel plots and EIS revealed that the Ni-GO-ZnO coating exhibited the lowest current density (39.95 µAcm²) and the highest charge transfer resistance (1211 Ωcm²). This was further validated by long-term immersion testing, where the Ni-GO-ZnO coating exhibited significantly less weight loss (1.33 mils/Y) compared to the deposited GO coating (2.2 mils/Y). The mechanism of formation of deposited GO and Ni-GO-ZnO coating on the metallic surface is proposed. The enhanced corrosion resistance of the Ni-GO-ZnO coating is attributed to its ability to 1) form a more compact metallic layer and 2) Minimize the active surface area vulnerable to corrosion attack. 3) Diminishes the presence of holes and cracks for corrosive ion ingress.4) Functionally impedes the ingress of chloride ions, primarily liable for steel degradation. The synergistic effect of the GO-ZnO constituents within the nickel matrix significantly enhances the long-term durability and integrity of the protective layer, a phenomenon hitherto unexplored. The empirical outcomes advocate for the advanced application of GO-ZnO-nickel coatings in safeguarding infrastructural materials against corrosive degradation.

Influence of Spatter on Porosity, Microstructure, and Corrosion of Additively Manufactured Stainless Steel Printed Using Different Island Size

Specimens of 316 L stainless steel were printed using laser powder bed fusion (LPBF), a popular metal additive manufacturing (AM) technique, with varying island sizes. Not many researchers have considered the impact of spatter while optimizing LPBF printing parameters. In this research, the influence of spatter was considered while also investigating the effect of varied island size on the microstructure, surface roughness, microhardness, and corrosion resistance of LPBF-316 L. No correlation was observed between surface roughness or microhardness and minor variations in island size. However, a correlation was drawn between varied island sizes and porosity in LPBF-316 L. The specimens associated with larger island sizes showed significantly enhanced corrosion resistance due to fewer manufacturing defects and reduced porosity, attributed to the minimal influence of the spatter. Based on analysis, the LPBF parameters were revised, which lead to superior corrosion resistance of LPBF-316 L, attributed to high density and reduced porosity.

Improvement of Mg alloy corrosion resistance and apatite formation ability via PEO/Alginate/Akermanite hybrid coatings for biomedical purposes

The rapid degradation of Mg alloys in biodegradable orthopedic applications is a significant concern to be investigated. In this study, a bilayer composite coating based on alginate/akermanite and plasma electrolytic oxidation (PEO/ALG-AK) on the AZ31 Mg alloy was intended to enhance its corrosion resistance. For this purpose, akermanite nanopowder was synthesized using the sol-gel method and characterized by TEM and XRD. The influence of the PEO/ALG-AK coating layer on the physicochemical properties, electrochemical, and immersion behaviors in simulated body fluid (SBF) was compared to that of uncoated and PEO-coated samples. The AFM images revealed that the bilayer coating exhibited the highest average roughness (Ra = 781 ± 49.3 nm) among the other samples. The EIS test was conducted after 2, 72, and 168 h of immersion in SBF. The bilayer coatings on Mg alloy consistently demonstrated the highest corrosion resistance due to the ALG/Ak layer covering the PEO coating pores. The results of the polarization test also confirmed the achieved results. Furthermore, the implementation of the coatings, particularly the PEO/ALG-AK coating, illustrated a significant reduction in the release of Mg2+ ions and hydrogen bubbles, resulting in corrosion resistance improvement. Finally, the ability of samples to induce apatite formation was also assessed. The results displayed that the deposits on the bare Mg alloy, PEO, and PEO/ALG-AK coatings exhibited Ca/P ratios of 0.83, 1.11, and 1.57, respectively, which closely resembled the natural bone in the PEO/ALG-AK sample. Hence, this developed bilayer coating can be a suitable candidate for enhanced corrosion resistance and bioactivity (apatite formation ability) in the field of Mg biodegradable implants.

Synergistic Enhancement of Strength, Ductility, and Corrosion Resistance of Ti6Al4V Alloy Through Low Cu Doping and Hot Extrusion

A Cu-containing Ti6Al4V alloy is considered an ideal biomedical material due to its excellent antibacterial properties. However, the addition of Cu leads to a mismatch in strength, ductility, and corrosion resistance, which hinders their further application. To address this issue, the study utilized low Cu doping and hot extrusion to optimize the material’s properties. The results showed that the primary lamellar structures were transformed into equiaxed grains, with an average grain size reduced from 10 μm to 300 nm. The nanoequiaxed grains had a homogeneous elemental composition and a stronger base texture, with orientations aligned with the extrusion direction. As a result, synergistic strengthening in terms of strength, ductility, and corrosion resistance was achieved. The film resistance increased from 127 kΩ·cm2 to 325 kΩ·cm2, the ultimate tensile strength (UTS) increased from 1,030 MPa to 1,330 MPa, and the elongation increased from 7% to 21%. These improvements were attributed to the nanostructure and basal texture, which facilitated the formation of a thicker passive film and reduced pitting corrosion, thereby enhancing corrosion resistance. Additionally, the nanoequiaxed grains could provide grain boundary strengthening and texture strengthening on UTS and ensure uniform deformation for elongation.

Albumin suppresses oxidation of TiNb alloy in the simulated inflammatory environment.

Literature data has shown that reactive oxygen species (ROS), generated by immune cells during post-operative inflammation, could induce corrosion of standard Ti-based biomaterials. For Ti6Al4V alloy, this process can be further accelerated by the presence of albumin. However, this phenomenon remains unexplored for Ti β-phase materials, such as TiNb alloys. These alloys are attractive due to their relatively low elastic modulus value. This study aims to address the question of how albumin influences the corrosion resistance of TiNb alloy under simulated inflammation. Electrochemical and ion release tests have revealed that albumin significantly enhances corrosion resistance over both short (2 and 24 h) and long (2 weeks) exposure periods. Furthermore, post-immersion XPS and cross-section TEM analysis have demonstrated that prolonged exposure to an albumin-rich inflammatory solution results in the complete coverage of the TiNb surface by a protein layer. Moreover, TEM studies revealed that H2O2-induced oxidation and further formation of a defective oxide film were suppressed in the solution enriched with albumin. Overall results indicate that contrary to Ti6Al4V, the addition of albumin to the PBS + H2O2 solution is not necessary to simulate the harsh inflammatory conditions as could possibly be found in the vicinity of a TiNb implant.

A simplified preparation of silica aerogel/epoxy composite coating based on rice husk ash for enhancing corrosion resistance

A simplified preparation of silica aerogel/epoxy composite coating based on rice husk ash for enhancing corrosion resistance

Influence of sample orientation on cytocompatibility of pure magnesium

This study aimed to investigate how sample orientation and texture distributions affect pure magnesium (Mg) cytocompatibility behavior and discuss the connection between metallurgical and microstructural factors with cytocompatibility. Three samples with varying orientations but the same grain size were used to investigate the influence of texture distribution on cell viability and adhesion. Results showed that an increase in the intensity of hexagonal closed-packed (hcp) basal planes or texture distribution with more basal planes improved cell viability and adhesion. Corrosion behavior and surface energy were identified as the link between microstructural factors and cytocompatibility properties. Different corrosion tests were performed to observe the enhancement of corrosion resistance whenever the texture distribution was dominated with basal planes. These findings suggest that the cytocompatibility of Mg alloys is fundamentally related to the orientation or texture distribution of the samples, with more hcp basal planes resulting in better cell viability and adhesion.

Investigating the effect of Cr content on the microstructure and electrochemical measurement of low alloy steel

In this study, the effect of Cr content on microstructure and electrochemical measurement of low alloy steel in 3.5 wt% NaCl solution was investigated using scanning electron microscope (SEM), X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS) and electrochemical workstation, and the CCT curves of the samples were calculated using JMatPro software. The results showed that the augmentation of Cr content inhibits the formation of ferrite and promotes the development of cementite in low alloy steels. And the reduction of Ar3 (the temperature at which austenite transforms to ferrite) and the increase in Ar1 (the temperature at which ferrite transforms to pearlite) also contribute to the expansion of the pearlite area. The XRD results show that the samples primarily consist of Fe-Cr solid solution with a body-centered cubic structure. As the Cr content increases, the peaks corresponding to the (110), (200), and (211) planes gradually enhance which means the improvement in the crystallinity of the samples. The improvement in the crystallinity can result in a decrease of grain size. Due to the suitable ratio of cementite to pearlite and the synergistic effect of grain size refinement, the Cr2 sample exhibits the best tensile property when the Cr content is 0.970 wt%. Cr(OH)3 and Cr2O3 with protective effects are generated in the corrosion film on the surface of Cr-containing low-alloy steels. And Cr also promotes the transformation of γ-FeOOH to α-FeOOH in the corrosion film because of the atomic radius of Cr3+ being smaller than that of Fe3+. These substances enhance the ability of the corrosion film to block corrosive media and protect the matrix. The results of the electrochemical measurement showed that the increasing Cr content from 0.970 to 4.657 wt% resulted in the enhancement of steel's corrosion resistance. The Cr4 sample exhibits the best corrosion resistance when the Cr content is 4.657 wt%.

Enhancement of corrosion resistance and superparamagnetic property by structural modulation in (Co-DLC)/DLC multilayered nanocomposite films

A structure of {[(Co-DLC)/DLC]X}n Multilayered Nanocomposite Films (MNF) is designed by inserting pure DLC high-resistance layers into Co-DLC nanocomposite film, which consists of alternating Co-DLC and DLC layers were prepared by magnetron sputtering. The electrochemical behavior and magnetic property of the films are modulated by varying the number of deposition cycles (n) and the thickness of one single-cycle (X). The electrochemical results show that this MNF structure significantly improves the corrosion resistance of the films owing to the clear interfaces, which block the micropores penetrating the films. Compared to the co-sputtering film, as the number of cycles n increases to 7, the corrosion resistance is enhanced by one order of magnitude from 2.3 × 104 to 2.2 × 105 Ω·cm2. However, the interfaces between the Co-DLC and DLC layer become blurred when the thickness of one single-cycle X is lower than 30 nm, and the corrosion resistance decreases to 3.7 × 104 Ω·cm2. In terms of magnetism, the multilayer structure helps to regulate the homogeneity of Co particle size. As X increases from 30 to 100 nm, the Co particle size increases from 2.7 to 4.7 nm, and the saturation magnetization intensity (Ms) of superparamagnetic property in the films increases from 2.8 to 8.2 mT. As X increases, the remanent magnetization ratio (Mr/Ms) decreases and reaches 0.011 at X = 100 nm, which is about one order of magnitude smaller than that of the co-sputtering film. This result indicates that the MNF have better superparamagnetic property. It is noteworthy that {[(Co-DLC)/DLC]X}n MNF with X ranging from 100 to 40 nm and n ranging from 3 to 7 can achieve high corrosion resistance and superparamagnetic property, simultaneously.

Effect of Ultrasonic Vibration on Microstructure and Antifouling Capability of Cu-Modified TiO2 Coating Produced by Micro-Arc Oxidation

Ti and its alloys have received wide attention in marine engineering. However, the limited anti-biofouling capability may hinder their wide application. In the present work, micro-arc oxidation (MAO) with and without the introduction of ultrasonic vibration (UV) has been conducted on metallic Ti substrate in an aqueous solution containing Na2Cu-EDTA to produce a Cu-modified TiO2 coating. Microstructural characterization reveals that the introduction of UV increased the thickness of the coating (ranging from ~13.5 μm to ~26.2 μm) compared to the coating (ranging from ~8.1 μm to ~12.8 μm) without UV. A relatively higher Cu content (~2.13 wt.%) of the coating with UV relative to the coating (~1.39 wt.%) without UV indicates that UV enhances the incorporation of Cu into TiO2. Further, both electrochemical properties and the response to sulfate-reducing bacteria (SRB) were evaluated, revealing that UV introduction endows Cu-modified TiO2 coating with enhanced corrosion resistance and antifouling capability. The present results suggest that ultrasound-auxiliary micro-arc oxidation (UMAO) obviously enhances the surface performance of Ti alloys for promising applications in marine engineering.

Structural and corrosion analysis of copper/chitosan coating on nanotubular TiO2/Ti6Al4V implant surface

In this research, we focused on the investigation of the structural, surface, and corrosion behavior properties of copper-loaded TiO2 nanotubular array surfaces that were further deposited with a chitosan biopolymer. This composite material was fabricated on Ti6Al4V alloy substrates using a combination of anodic oxidation (AO), electro-cathodic deposition (ECD), and electrophoretic deposition (EPD) techniques, primarily to apply it in medical implant contexts. Initially, the TiO2 nanotubes were prepared via anodization (AO). Subsequently, copper was introduced into the TiO2 nanotubes through electro-cathodic deposition (ECD), followed by the coating of chitosan over the copper-loaded TiO2 nanotubes using electrophoretic deposition (EPD). To comprehensively assess the characteristics of these surfaces, a series of analytical techniques were employed, including SEM, EDX mapping, XRD, and wettability measurements. Furthermore, the electrochemical properties of these surfaces, namely the OCP, PDP, and EIS, were extensively scrutinized.The outcomes of this investigation directed a notable development in the electrochemical corrosion resistance of the chitosan-deposited copper-loaded TiO2 nanotubular array surfaces in comparison to uncoated Ti6Al4V alloy, particularly under conditions simulating a physiological environment (simulated body fluid, SBF). Corrosion rates, assessed through PDP (Potentiodynamic Polarization) curves, were determined to be 0.3023 mm/y for polished Ti6Al4V, 0.1476 mm/y for TiO2 30 V 4 h, 0.1235 mm/y for TNT-Cu2/30/Ch, 0.0733 mm/y for TNT-Cu2/60/Ch, and 0.0611 mm/y for TNT-Cu2/90/Ch. Additionally, corrosion protection efficiencies were calculated as 51.16 % for TiO2 30 V 4 h, 59.15 % for TNT-Cu2/30/Ch, 75.76 % for TNT-Cu2/60/Ch, and 79.81 % for TNT-Cu2/90/Ch. Notably, the TNT-Cu2/90/Ch sample demonstrated a significantly low corrosion rate of 0.0611 mm/year and a high corrosion protection efficiency of 79.81 %. This enhancement can happen due to the chitosan coating, which acts as a protective layer, hindering the ingress of the physical solution into the original metal surfaces. Notably, TNT-Cu2/90/Ch coated sample exhibited a corrosion rate (icorr) approximately 5 times lower than that of the uncoated alloy. In conclusion, this study presents a novel chitosan-coated composite material consisting of copper-loaded TiO2 nanotubular surfaces that effectively enhances corrosion resistance compared to polished Ti6Al4V substrates.

Effects of grain refinement on the passivation and film composition of low alloy steels in NaHCO3 solution

In this study, the passivation of coarse-grained and ultrafine-grained steels was investigated through electrochemical measurements and potentiostatic polarization at 0 VSCE, 0.3 VSCE, 0.5 VSCE, and 0.8 VSCE in 0.1 M NaHCO3 solutions. Then Mott-Schottky, Raman spectra, X-ray photoelectron spectroscopy, and atomic force microscopy were adopted to characterize the compositions, topographic structure and semiconductor performance of the passive film. The findings indicate a positive correlation between grain refinement and enhanced corrosion resistance of the passive films. Specifically, grain refinement leads to an increase in the ratio of Fe3+/Fe2+ and average surface roughness, while the trends of donor concentration and the content of Fe0 demonstrate a decrease. These findings elucidate the impact of grain refinement on the enhanced corrosion resistance of the passive film. Moreover, it is observed that the corrosion resistance of the passive films initially increases and subsequently diminishes with rising passive potentials.

Investigation of Cr and rare earth (RE) on the corrosion resistance of HRB400 rebar in simulated concrete pore solutions containing chloride and sulfate ions

The effect of Cr and rare earth (RE) on the corrosion resistance of HRB400 in simulate concrete pore solution containing Cl− and SO42− was investigated. The results of electrochemical tests and corrosion morphology observations revealed that HRB400 corrosion rates increased with sulfate concentration, but Cr/RE addition notably reduced rates and passive current density, particularly in high sulfate conditions, suggesting a sulfate-Cr/RE interaction. The mechanism involves structural changes in the surface passivation film. Furthermore, the combination of Cr and RE effectively mitigated localized corrosion risk compared to Cr alone, highlighting their synergistic corrosion resistance enhancement.

Enhancement of ammonia corrosion resistance of coatings through improving dispersion and binding site of graphene oxide in silane coatings

Copper metal is essential to our production process, but it is highly corrosive in an ammonia environment and must be highly valued. Anti-corrosion coating is a simple and cost-effective method of preventing metal corrosion. In this study, a composite silane coating was prepared on copper using an impregnation method with mercaptopropyltriethoxysilane (TPTES) as the silane substrate and graphene oxide (GO) modified with isophorone diisocyanate (IPDI) or isocyanatopropyltriethoxysilane (IPTS) as filler to protect the copper from ammonia corrosion. The coating samples were hanging tested against ammonia corrosion by setting up two corrosive environments: ammonia gas and ammonia water. After 20 days of corrosion, the surfaces of the TPTES/IPDI-GO and TPTES/IPTS-GO coatings remained unchanged under both ammonia environments and the corrosion rate was consistently low at 2–3 μm/y. Additionally, the coating exhibited high protective qualities according to the electrochemical impedance spectroscopy (EIS) test in a 3.5% NaCl solution, which is attributed to the good dispersion that improves the densification and regularity of the coating. Meanwhile, IPTS-GO has a greater binding force with the coating matrix due to the increased number of reactive sites, resulting in further improved corrosion protection. This study provides an idea for research on ammonia-resistant coatings.

Waterborne epoxy composite coating containing N,S-doped carbon dots for enhancing corrosion resistance

In order to construct waterborne epoxy composite coating with enhanced anti-corrosive performance, the development of efficient additives with good compatibility with adhesive resin and good interaction with steel matrix is of significance. Herein, we adapted two heteroatom (N and S) doped carbon quantum dots, namely ACDs and LCDs, as eco-friendly anti-corrosion components to mix with water-based epoxy resin (WP) to prepare the CDs/WP composite coating. Compared with the ACDs/WP composite, the LCDs/WP composite exhibited a better performance because it contained more functional groups such as carboxyl and hydroxyl on the surface of LCDs, which not only made the system denser but also facilitated the multi-anchor coordination and adsorption on carbon steel. Following immersing in a 3.5 wt% NaCl solution for 28 d, the impedance modulus of LCDs/WP surpassed 109 Ω cm2, exhibiting approximately three orders of magnitude higher values compared to pure WP coatings. The inhibition efficiency was improved by 96.9%. The facile synthesis of LCDs coupled with excellent anti-corrosive properties of LCDs/WP composites, provides a new way for developing anti-corrosion coating materials.

Effect of Yttria-Stabilized Zirconia addition along with Cu in development of titanium based metal matrix composite via FSP technique for the application in biomedical devices

ABSTRACT The present study investigated the effect of incorporating Yttria-Stabilized Zirconia (YSZ) and copper (Cu) in the development of Titanium-Based Metal Matrix Composites (TMCs) using the Friction Stir Processing (FSP) technique. The macrostructure of the TMCs, after adding 5% YSZ and 2% Cu, displayed a defect-free, crack-free, and porosity-free surface, indicating the precision of the FSP method. Microstructure analysis revealed a uniform distribution of reinforcement particles and proper dispersion of grains, key for enhancing mechanical properties. The interfacial bonding between titanium and YSZ was exceptionally strong, devoid of cracks and porosity, attributed to the copper additive’s role. The increase in the number of grains per square inch for the Ti/5% YSZ/2% Cu composite (1176.26 grains per square inch at 500×) signified finer grain structure, contributing to a remarkable 48.04% improvement in tensile strength compared to pure titanium. The uniform distribution of reinforcement and strong bonding between titanium and YSZ are the driving forces behind the 46.34% increased in hardness. Additionally, the wear resistance of the composite improved by approximately 76.66%, a vital characteristic for applications facing abrasive conditions. The corrosion testing demonstrated an 8.33% enhancement in corrosion resistance with the Ti/5% YSZ/2% Cu composite.

Electrochemical analysis of the corrosion resistance of annealed steel with nickel coating in marine environment simulations: chronoamperometric and voltametric study

This study conducts a comprehensive investigation into the corrosion resistance of annealed steel wire, commonly used in marine construction, emphasizing its importance for the material's durability and functionality in such applications. An innovative approach was implemented by applying a Nickel (II) Chloride Hexahydrate coating through electrodeposition. This process was meticulously adjusted, varying critical parameters such as exposure time and electrical potential. To mimic marine corrosive conditions, a Sodium Chloride solution was used, allowing for a detailed comparative analysis between coated and uncoated samples. The evaluation was based on rigorous quantitative measurements of the wire's surface state and corrosion potential, using TAFEL curves for precise interpretation. The findings empirically demonstrated that the coating significantly enhances corrosion resistance, markedly outperforming untreated steel. These results reinforce the proposition of nickel electrodeposition as an effective and viable strategy for corrosion protection in marine industrial applications.

Corrosion performance and microstructure of a Q370qENH weathering steel welded joint treated by the laser surface remelting method

In this research, the laser surface remelting (LSR) method was utilized to treat the weld joint of Q370qENH weathering steel. A heterogeneous structure with superficial fine grains formed after LSR. The remelted joint demonstrated a 97.2 % increase in electrochemical impedance value, rising from 1424 Ω to 2808 Ω compared to the welded joint, indicating improved corrosion resistance. The enhanced corrosion resistance can be attributed to the reduction of grain size, which facilitates the diffusion of Fe on the surface and encourages the formation of passivated films. These findings are significant for extending the service life and expanding the application scope of weathering steel structural parts.

Influence of NaAlO2 Concentration on the Characteristics of Micro-Arc Oxidation Coating Fabricated on a ZK60 Magnesium Alloy

This study investigated the impact of NaAlO2 concentration in electrolytic solutions on micro-arc oxidation (MAO) coatings, focusing on their surface quality enhancement and corrosion resistance improvement. The surface morphology and microstructure of these coatings were assessed using scanning electron microscopy. Mechanical properties, such as hardness and wear resistance of MAO coatings, were tested. The hardness of the 6 g/L group was 411.2 HV. X-ray photoelectron spectroscopy examinations showed that MgAl2O4, CaMgP2O7, and MgSiO4 were the phases in the MAO coating. Antibacterial assessments were performed to evaluate the influence of NaAlO2 concentration, and the antibacterial rate of the 6 g/L group reached 97.08%. The hydrophilicity of the coatings was determined using water contact angle measurements, wherein the water contact angle of the 6 g/L was the lowest, at 58.25°. Corrosion resistance was evaluated with an electrochemical workstation. The findings revealed that the MAO coatings prepared with a NaAlO2 concentration of 6 g/L exhibited superior uniformity with fewer defects, enhanced corrosion resistance, and increased adhesive strength compared to other concentration groups. The 6 g/L NaAlO2 concentration MAO coating demonstrated the highest fitting coating resistance R3 (8.14 × 104 Ω∙cm2), signifying better corrosion resistance.

Plasma-sprayed GNP/CNT reinforced lanthanum-cerate coatings: Hot corrosion assessment in Na2SO4-V2O5 environment

This study investigates the hot-corrosion behavior of Carbon nanotube/Graphene-nanoplatelets (CNT/GNP)-reinforced lanthanum cerate (LC) coatings in a Na2SO4–V2O5 molten salt environment at 1350 °C for varying durations. Coatings were prepared using APS and characterized using XRD, FESEM, Raman, XPS, etc., techniques. The CNT/GNP-reinforced LCGC hybrid composite coating exhibited superior hot-corrosion resistance compared to LC and LCG coatings. The uniform dispersion of GNPs/CNTs within the coating matrix and the creation of protective LC oxides enhanced corrosion resistance. These findings highlight the potential of GNP/CNT-reinforced coatings in protecting high-temperature components like combustion chambers and gas turbine engines from hot corrosion.