Corrosion Resistance Of Coatings Research Articles

Carbon dot enhanced electrodeposited coatings for advanced early-stage corrosion sensing

This work explores a novel approach for metal corrosion by integrating carbon dots (CDs) into electrodeposited (ED) coatings. We detail the synthesis and properties of CDs, making them suitable for corrosion detection. Characterization techniques like Fourier Transform Infrared Spectroscopy (FTIR), Scanning electron microscope (SEM), Energy Dispersive X-ray Analysis (EDX), Fluorescent Microscopy and Photoluminescence Spectroscopy (PL).A Design of Experiment (DOE) optimized parameters like CD concentration, curing temperature, and voltage for improved coating performance. The optimized conditions (0.4 wt% M-CDots, 165 °C curing, and 36.2 V) resulted in enhanced adhesion and corrosion resistance.CD-infused coatings demonstrated superior adhesion and mechanical stability compared to controls. Electrochemical tests confirmed a 10 % improvement in corrosion resistance and PL study demonstrated an approximately 60 % enhancement in emission intensity. The adhesion was not affected by introducing carbon dots to the coating. Monitoring the onset of metal corrosion on samples in salt spray cabinets was achieved through the use of a UV source. The photoluminescence of M-CDs offered real-time, non-destructive monitoring of early-stage corrosion through quenching in the presence of exposed metal surfaces.This research presents a significant advancement by integrating CD-based sensing into corrosion-resistant coatings, holding promise for various industries and leading to improved safety, reduced maintenance costs, and extended equipment lifespans. Notably, the biocompatible and disposable nature of CD-based sensors further enhances their practical application.

Effects of ultrasonic impact treatment on the corrosion resistance of laser-cladded CrMnFeCoNi high-entropy alloy coatings

Ultrasonic impact treatment (UIT) was performed on the surface of the laser-clad CrMnFeCoNi high-entropy alloy coatings. The fluences of the UIT on the microstructure, microhardness, nanoindentation metrics and corrosion resistance of the coatings were explored. Furthermore, the enhancing mechanisms of the corrosion resistance of these coatings by the UIT were clarified. The results showed that the UIT markedly enhanced the corrosion resistance of the laser-clad CrMnFeCoNi high-entropy alloy coatings, and the enhancing effect continuously improved with the increasing of the UIT time. The most significant enhancement of corrosion resistance occurred under the action of UIT with a current of 1.6 A for 20 min. Compared to the untreated group, corrosion potential rose by 65.68 %, corrosion current density fell by 74.95 %, and equivalent resistance increased by 340.37 %. Corrosion morphology analysis showed that the primary forms of corrosion before the UIT were stress corrosion and pitting, which vanished after the UIT with a significant improvement in pitting. Analysis of corrosion products revealed an increased Cr content and a decreased FeOOH and O content on the coating surface after the UIT, leading to enhanced corrosion resistance. Additionally, microstructural analysis showed that large columnar crystals in the laser-clad CrMnFeCoNi high-entropy alloy coatings transformed into finer columns, drastically reducing the grain size of the surface. Concurrently, surface microhardness and nanoindentation mechanical properties markedly improved after the UIT, with the effects growing stronger over time. After the UIT with the current of 1.6 A for 20 min, the increasement of surface microhardness reached 109.01 %. A comprehensive analysis of the fluences on the corrosion resistance of laser-clad CrMnFeCoNi high-entropy alloy coatings by the UIT indicated that the refinement of grain size, improvement of the stress state of the coating, increasement of Cr element and its compounds, and decreasement of FeOOH content are the main reasons of enhanced corrosion resistance.

Electroactive additives into polyurethanes for high corrosion resistance coatings for mild steel

Electroactive additives into polyurethanes for high corrosion resistance coatings for mild steel

An effective utilization of raw fly ash obtained from thermal power plants using thermal spray technique to improve corrosion resistance for marine applications

Marine-grade steel structures in offshore environments often corrode due to the aggressive environmental conditions. Many ceramic materials can cater to this demand. However, as per economic and ecological concerns, fly ash (FA), an industrial waste, can be another strong contender to control corrosion. Therefore, the present study developed composite coatings of fly ash with additives ((50-48) wt.% Al2O3; 0-2 wt.% carbon nanotube (CNT)) onto marine-grade steel using a plasma spray technique to improve its corrosion resistance. The microstructure of 1 wt.% CNT-reinforced alumina-FA (1CAF) coating was denser than 2 wt.% CNT-reinforced alumina-FA (2CAF) coating due to the uniform dispersion of CNT and, thereby, uniform remelting of coating at localized sites. Consequently, the microhardness and adhesion strength of the 1CAF coating were improved by ∼14.66 % and ∼15.96 %, respectively. Further, Rietveld’s analysis of coatings showed that quartz, being the primary phase for corrosion control, was 19.23 ± 0.87%, 16.33 ± 1.04% and 14.60 ± 1.87% for alumina-FA (AF), 1CAF, and 2CAF, respectively. The electrochemical impedance spectroscopy and the salt spray corrosion tests showed that 1CAF coating corrosion resistance was improved by ∼11.2 % compared to AF coating, even with a lower quartz phase (∼15.08 %) due to the densification of coating. This densification was due to the remelting by CNT to seal pores in the coating. Furthermore, for the same reason, an increase in coating resistance and charge transfer resistance of 1CAF coating by ∼80.9 % and ∼19.93 %, respectively, were seen in the equivalent circuit analysis, showing great promise in controlling interfacial corrosion. Further post-treatments like plasma or laser treatments can seal the coatings further to improve corrosion resistance. Therefore, such coatings are expected to withstand harsh, corrosive environments and are well-suited for marine applications.

The Improvement in Corrosion Resistance of Electroless Ni-P Coating on Micro-arc Oxidized AZ31 Alloy Prepared with Sodium Dodecyl Sulfate Additive and Post-supercritical CO2 Mixed Electrolyte

The Improvement in Corrosion Resistance of Electroless Ni-P Coating on Micro-arc Oxidized AZ31 Alloy Prepared with Sodium Dodecyl Sulfate Additive and Post-supercritical CO2 Mixed Electrolyte

Enhanced mechanical properties and corrosion resistance of electro-deposited NiCoP composite coatings with ZrB2 particle addition

This work was initiated with the purpose of expanding the utilization of nickel-based composite coatings, especially in wear and corrosion-related industrial applications. NiCoP coatings have long attracted scientific and engineering interest due to their enhanced mechanical properties reinforced by incorporation with a reinforcement phase. In the present study, NiCoP composite coatings reinforced with ZrB2 ceramic particles were synthesized by direct current deposition using a modified Watt’s type bath. The microstructures of composite coatings were studied by x-ray diffraction analysis, energy dispersive x-ray spectroscopy, and scanning electron microscopy, respectively. The hardness and tribological properties of the composite coatings were evaluated and compared. The corrosion behaviors of the deposits were investigated using electrochemical spectroscopy and potentiodynamic polarization techniques in simulated seawater. The effect of ZrB2 content on the microstructures and mechanical properties of the composite coatings was explored and discussed. The present study indicates that there is a progressive enhancement in the hardness, corrosion resistance, and wear resistance of the composite coatings with the increase in ZrB2 loading. The NiCoP-12 g/l-ZrB2 coating possesses the highest microhardness and superior wear performance, while the NiCoP-6 g/l-ZrB2 coating exhibits the best anti-corrosion properties. The present study shows a cost-effective and feasible solution for the preparation of NiCoP protective coatings with enhanced properties, which holds great potential for industrial applications requiring wear and anti-corrosion protection.

Effect of Y2O3 on Microstructure and Corrosion Resistance of Ni45 Coating by Laser Cladding with Different Flow Rates of Carrier Gas

Effect of Y2O3 on Microstructure and Corrosion Resistance of Ni45 Coating by Laser Cladding with Different Flow Rates of Carrier Gas

Self-stabilized styrene-acrylic copolymer latex with heteroatom function for improved water and corrosion resistant coatings

This approach investigates the preparation of a set of styrene-acrylic copolymers incorporated with N-heteroatom in the form of N-vinyl pyrrolidone (NVP) as the functional co-monomer at different concentrations within the range of 17–33 mol%. In this case, self-stabilized copolymer latex was obtained without using any conventional surfactant in the system. The beneficial effect of NVP for the emulsion copolymerization of styrene and butyl acrylate was quantified by preparing and analyzing a control sample of the same copolymer latex that was stabilized by a conventional surfactant. The prepared self-stabilized copolymer latexes having particle sizes of 325–371 nm showed excellent colloidal stability with a zeta potential of >+44.5 mV. The air-dried films were found to be optically transparent and comparable to the control sample. The thermal, structural, microscopic, and water/alkali resistance properties of the films were characterized with respect to the NVP content in the copolymer. The coating characteristics of the copolymers on glass slides and mild steel panels were explored by analyzing the hydrophobicity (water contact angle up to 79°) and corrosion resistance (corrosion rate: 6.03 × 10−5 mm/year) that are significantly improved from the copolymer prepared by conventional emulsion polymerization. This study reveals the impact of N-heteroatom to obtain a self-stabilized polymer latex with improved properties and additional functionalities.

Bacterial and corrosion resistance of polytetrafluoroethylene-silver composite coatings by magnetron sputtering

Titanium alloy and stainless steel implants have been widely applied in orthopedics. However, harmful ions released from implant corrosion caused by human body fluids and bacterial infections may inhibit patients’ recovery. In this work, a polytetrafluoroethylene-silver composite coating was prepared by RF unbalanced magnetron sputtering to improve the bacterial and corrosion resistance of the SS316L. The removal rates of the composite coatings for Escherichia coli and Staphylococcus aureus reached 97.27% and 99.99%, respectively. The contact angle of 131.5° and fluorescence staining experiments show that the composite coating has an antiadhesive effect on bacteria and less cytotoxicity against osteoblasts. The corrosion voltage of the composite coating was much higher than that of the control SS316L substrate, and the corrosion current density was reduced to 1/3, implying the enhancement of the corrosion resistance of the SS316L substrate.

The Effect of Preheating Temperature on the Corrosion Resistance and Porosity Defects Development Behaviour of Ni60A Coating

The laser cladding of nickel-based fusion alloys makes them prone to cracks and defects that affect the overall performance of the coating. In this study, Ni60A coatings were prepared at different preheating temperatures (25 °C, 200 °C, 400 °C and 600 °C). The effect of the preheating temperature of the substrate on the corrosion resistance of the coating as well as on the development of defects were investigated by electrochemical tests and immersion experiments in a 65 wt% H2SO4 solution at 60 °C. The results indicate that preheating the substrate to 200 °C can completely eliminate cracks in the coating and reduce porosity. Preheating leads to a decrease in the corrosion resistance of the coating. The size of the porosity defects is related to the law of longitudinal development of the defects. Porosity defects with diameters smaller than 100 μm have a more pronounced tendency to expand vertically than those with diameters larger than 100 μm.

Investigating the CMAS corrosion resistance and thermal cycling failure behavior of porous thermal barrier coatings with different morphologies prepared by plasma spraying

This study investigates the influence of two-phase powder feeding spacing on the thermal cycling and CMAS corrosion resistance of the thermal barrier coatings (TBCs). Porous thermal barrier coatings with varying microstructures were prepared using the embedded micro agglomerated particle (EMAP) coating preparation method, which is based on conventional yttrium stabilized zirconia (YSZ) coatings. The method involved changing the powder feeding spacing. TBCs' failure mode and microstructure are investigated under complex service conditions. The corrosion resistance, thermal cycling life, hardness, and elastic modulus of TBCs are investigated by thermal cycling-CMAS experiments and isothermal corrosion tests. The EMAP coating has a good service life in the thermal cycling-CMAS tests, with a lower hardness, lower elasticit modulus and larger surface roughness than conventional coatings. This research aims to provide a strategy to optimize structure for TBCs with excellent comprehensive performance.

Effect of solution temperature on the microstructure and properties of ceramic coating on the surface of 2024 aluminum alloy

This study investigates the influence of the 2024 aluminum alloy was treated with solution before ceramic treatment on the microstructure and characteristics of ceramic coatings applied to 2024 aluminum alloy substrates. The microhardness, corrosion resistance, and microstructural properties of these ceramic coatings were assessed using a microhardness tester, an electrochemical workstation, and a scanning electron microscope. The findings indicate that pre-treatment involving solution treatment significantly enhances the hardness and corrosion resistance of 2024 aluminum alloy ceramic coatings. Notably, when the solution temperature was maintained at 460 °C, the most rapid decrease in current density was observed during the ceramization process, resulting in the attainment of the lowest final stable current density. This particular condition yielded ceramic coatings with optimal hardness and corrosion resistance, with hardness exhibiting a remarkable increase of 48.9 HV, self-corrosion potential rising by 0.207 V, and polarization resistance surging by 5310.7 Ω. Moreover, the surface of the ceramic coating displayed remarkable smoothness and was devoid of discernible defects such as cracks or looseness. In light of these findings, it can be concluded that the optimum solution temperature for achieving these desirable properties is 460 °C. This conclusion is derived from a comprehensive analysis encompassing both the morphology and corrosion resistance of ceramic coatings.

Corrosion Resistance of Magnesium Ammonium Phosphate Cement-Based Coatings Modified by Calcium Sulfoaluminate Cement on Carbon Steel in a Saline Medium

Corrosion Resistance of Magnesium Ammonium Phosphate Cement-Based Coatings Modified by Calcium Sulfoaluminate Cement on Carbon Steel in a Saline Medium

Microstructure Evolution and Molten Salt Corrosion Resistance Dependent on Pre-Oxidation Treatment of NiAl Coatings

The chloride-infused molten salt shows the most potential as the medium for the upcoming generation of concentrated solar power system. However, the molten salt put for ward higher corrosion resistance demand on the critical components of concentrated solar power system. The application of NiAl coating proves to be a highly efficient method for preventing corrosion. In this paper, the microstructure, adhesion, and corrosion resistance of NiAl coatings on 310S stainless steel with/without pre-oxidation treatment were studied. The coating predominantly consisted of β-NiAl phase nanocrystals with an Al content of 41.0 at.%. Continuous α-Al2O3 oxide film was formed and no obvious cracks were observed after pre-oxidation. The adhesion strength of NiAl coating was increased by about 70% to 40.0 N through pre-oxidation. Importantly, the corrosion results of NiAl coatings by pre-oxidation treatment in the mixed salt of NaCl/MgCl2/KCl at 1073.15 K for 10 h showed no obvious diffusion of molten salt elements into the coatings. Compared to 310S stainless steel, the pre-oxidized coating sample exhibited a significant reduction of 50.2% in corrosion mass loss. The pre-oxidation of the NiAl coating creates an Al2O3 oxidation layer that effectively blocks corrosion, offering a new method for protecting stainless steels in concentrated solar power system plants.

Corrosion Resistance of Zinc-Doped Hydroxyapatite Coating on Titanium Substrate using Plasma Electrolytic Oxidation for Biomedical Applications

Corrosion Resistance of Zinc-Doped Hydroxyapatite Coating on Titanium Substrate using Plasma Electrolytic Oxidation for Biomedical Applications

Influence of Additives on the Macroscopic Color and Corrosion Resistance of 6061 Aluminum Alloy Micro-Arc Oxidation Coatings.

In this study, we successfully employed the plasma electrolytic oxidation (PEO) technique to create a uniform white ceramic layer on the surface of the 6061 aluminum alloy using K2ZrF6 and Na2WO4 as colorants. A scanning electron microscope (SEM) equipped with an energy-dispersive X-ray spectrometer (EDS) and X-ray diffraction (XRD) were used to characterize the coatings, and we used an electrochemical workstation to test their corrosion protection properties. The corrosion resistance of the coatings was analyzed using potentiodynamic polarization curves. The results showed that K2ZrF6 addition whitened the coating with ZrO2 as the main phase composition, inhibiting Al substrate depletion and enhancing coating corrosion resistance. A small amount of Na2WO4 decreased the coating's L* value, successfully constructing ceramic coatings with L* (coating brightness) values ranging from 70 to 86, offering broad application prospects for decorative coatings.

Microstructure evolution, wear and corrosion behavior of WC reinforced CoCrFeNiMn high-entropy alloy composite coatings by induction cladding

In this study, CoCrFeNiMn high entropy alloy (HEA) composite coatings reinforced with different WC particle contents were prepared by induction cladding technology for the first time. The effects of WC particle contents (0–70 wt%) on the microstructure, hardness, wear resistance and corrosion resistance of the coatings were analyzed. The results showed that the coatings prepared by induction cladding exhibited good metallurgical bonding with the substrate. The addition of WC particles led to grain refinement in the CoCrFeNiMn HEA together with second-phase strengthening and solid solution strengthening, improving the microhardness of the coatings. Compared to the average hardness value of 183 HV0.5 for the CoCrFeNiMn HEA coating, the composite coating with 60 wt% WC particle content exhibited the highest average hardness value of 679 HV0.5. The addition of WC particles significantly enhanced the wear resistance of the composite coating, with wear mechanisms including adhesive wear, abrasive wear, fatigue wear and oxidation wear. The composite coating with 60 wt% WC particle content demonstrated outstanding wear resistance, with a specific wear rate value of 0.491 × 10−6 mm3N−1 m−1, representing a reduction of approximately 670 times compared to the CoCrFeNiMn HEA coating. However, the addition of WC particles caused uneven potential distribution within the composite coatings, leading to galvanic corrosion. The WC particles and precipitated carbides increased the defects in the passive film, thus reducing the corrosion resistance of the composite coatings.

Exploring the Impact of Potential, Ammonium Fluoride Concentration, and Anodization Time on the Structure, Surface Characteristics, and Corrosion Resistance of Nanotubular Titanium Oxide Coatings on Biomedical Alloy Ti-6Al-4V ELI

The current research delves into assessing the impact of applied potential, ammonium fluoride concentration, and anodization duration on the structural, phase compositional, microhardness, and surface roughness attributes of nanotubular titanium oxide coatings on anodized Ti-6Al-4V ELI. A meticulous experimental design was executed to systematically investigate the varied effects of these factors. Scanning electron microscopy (SEM) unveiled the presence of well-defined titania nanotubes on the surfaces of the anodized specimens. X-ray diffraction (XRD) analysis discerned the composition of the nanotubular oxide layer, revealing the presence of both anatase and a mixture of anatase and rutile phases contingent upon the anodization parameters. Notably, surface microhardness, surface roughness, and corrosion resistance manifested noticeable variations in response to alterations in applied voltage, NH4F concentration, and anodization duration within the designated experimental ranges.

Effect and mechanism of bias voltage on microstructure and corrosion resistance of CrxNy coatings in proton-exchange membrane fuel cells

The key factor limiting the long-term commercial application of CrxNy coatings in the PEMFC is that these coatings easily grow into coarse columnar crystals with subsequent microcracks and pinholes, leading to a sharp decrease in corrosion resistance performance. In this view, a series of different substrate bias voltages were applied to deal with this problem. The results demonstrated that with applying a −120 V bias voltage on the substrate, the adhesion strength is double that of the CrxNy coating without bias voltage. In addition, the −120V-CrxNy sample exhibits the lowest corrosion current density of 0.65 μA/cm2 and a minimum ICR value of 5.87 mΩ cm2, thus highly meeting the U.S. DOE 2025 targets. Moreover, the CrxNy coatings subjected to bias voltages ranging from −100 V to −140 V exhibit excellent durability and stability, with current densities that are 1-2 orders of magnitude lower compared to the 0V-CrxNy coatings. Therefore, this work provides a novel approach to control the growth of columnar crystals in CrxNy coatings for future PEMFC manufacturing processes, and has important reference value for the regulation of columnar crystals in other coatings such as TiN, NbN, AlN, etc.

Assessment of results of verification tests for corrosion-resistant coatings for use in pipeline transport of oil and oil products

Assessment of results of verification tests for corrosion-resistant coatings for use in pipeline transport of oil and oil products