Corrosion Resistance Of Coatings Research Articles

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.

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

Corrosion resistance and conductivity of CrN, CrAlN, and CrTiN coatings applied to bipolar plates for proton exchange membrane fuel cells

In order to improve the corrosion resistance and conductivity of 316L stainless steel bipolar plates used for proton exchange membrane fuel cells, three Cr-containing nitride coatings were deposited on 316L stainless steel by multiarc ion plating. First, the microstructure, composition, and contact angle of the three coatings were systematically investigated. Then, electrochemical impedance spectroscopy, potentiodynamic polarization, potentiostatic polarization (PSP), and interfacial contact resistance (ICR) of the three coatings were also fully examined. The results revealed that CrN coating has the highest contact angle of 98.26°, indicating its superior hydrophobicity. Additionally, CrN coating performed the best corrosion resistance with the highest corrosion potential of 0.31 V, the lowest corrosion current density of 2.28 × 10−7 A cm−2, and the largest resistance. Furthermore, CrN coating showed the lowest current density during PSP tests and the smallest ICR value after corrosion. The superior corrosion resistance of CrN coating is mainly attributed to its decreased pore density caused by vacancylike defects and its uniform structure. This article provided evidence for the potential application of CrN coating to bipolar plates.

Influence of TiB2 Incorporation on Microstructural Evolution in Laser-Clad FeCrV15 + TiB2 Deposits

AbstractVanadium carbide (VC)-reinforced Fe-based hard facings are pivotal in enhancing the wear resistance of tools prone to mechanical damage. This study investigates the impact of titanium diboride (TiB2) addition (at varying laser power and powder federate) on the microstructure, hardness, wear resistance, and corrosion resistance of high-carbon ferrochrome FeCrV15 clad coatings for agricultural and mining applications. Laser cladding techniques were employed to deposit coatings on steel substrates, and the samples were subjected to comprehensive material characterization, including microhardness testing, wear studies, and electrochemical polarization. Results reveal that TiB2 addition led to visible reactions during deposition, resulting in decreased hardness compared to pure FeCrV15 coatings. Moreover, TiB2 incorporation adversely affected the anti-corrosion properties of the coatings, although FeCrV15 coatings exhibited superior corrosion resistance compared to FeCrV15 + TiB2 coatings. Tribological evaluations showed that all coatings exhibited better anti-wear capabilities compared to the steel substrate, with varying degrees of improvement influenced by TiB2 concentration and laser beam power. Overall, FeCrV15 deposits demonstrated superior anti-wear and anti-corrosion properties compared to FeCrV15 + TiB2 coatings and attributed to increased convergence of carbide particles and higher grain-boundary density. This research contributes to understanding the intricate interplay between carbide reinforcement and matrix structure in Fe-based hard facings, providing insights for optimizing coating performance in demanding industrial applications.

Influence of Different Copper Feedstock Powders on the Microstructure and Corrosion Resistance of Coatings Prepared by Cold Gas Spray

Influence of Different Copper Feedstock Powders on the Microstructure and Corrosion Resistance of Coatings Prepared by Cold Gas Spray

Binary potential loop electrodeposition and corrosion resistance of Cr coatings

Binary potential loop electrodeposition and corrosion resistance of Cr coatings

Assessment of HVAF thermally sprayed coatings: Unraveling microstructural, electrochemical, and tribological performance using glass former Fe-Cr-Mo-Nb-B feedstock powder

In this paper the microstructural features of the glass former Fe68Cr8Mo4Nb4B16 coatings are unveiled and related to their electrochemical and tribological responses. The coating was mostly glassy with some embedded borides (M3B2, M2B-tetragonal; M being the metallic elements of the alloy) and ferrite. The tribological behavior of the HVAF coated sample, characterized by a thickness of about 200 µm, ∼6% porosity and a Vickers hardness of 357 HV0.5, was assessed in a sphere-on-plate configuration, revealing a specific wear rate of approximately 5 ×10−4 mm3∙N−1m−1. The wear mechanism was dominated by delamination caused by fragile intersplats. The corrosion resistance of HVAF coatings was evaluated in 0.6 M NaCl solution and compared with the results obtained for the crystalline Fe68Cr8Mo4Nb4B16 ingot, produced by melting in an induction furnace, and for the AISI 1020 steel substrate. The HVAF coating showed satisfactory corrosion resistance compared to the carbon steel substrate and the crystalline ingot, with the highest corrosion potential, Ecorr, values (−533 mVSCE) and the lowest corrosion current density, icorr, (10−6 A∙cm−2) followed by a clear passivation window upon anodic polarization in 0.6 M NaCl solution. Evaluations of HVAF coating showed a higher glassy content compared to the gas-atomized feedstock powders. This suggests that during spraying, certain particles were molten and experienced cooling rates adequate to inhibit crystallization, resulting in the freezing of the supercooled liquid. This phenomenon contributes to the good corrosion resistance observed in the present work and offers an opportunity to enhance the electrochemical behavior of HVAF coatings.

Effect of WC-10Co-4Cr Reinforcement Amount on Wear and Corrosion Resistance of Fe-Based Amorphous Coatings

Effect of WC-10Co-4Cr Reinforcement Amount on Wear and Corrosion Resistance of Fe-Based Amorphous Coatings

Study on the corrosion performance of supersonic atmospheric plasma sprayed Cr3C2-NiCr coatings

Purpose Due to the harsh underground environment in coal mining, the surface of hydraulic support columns corrodes severely, resulting in significant economic losses. Therefore, a highly corrosion-resistant coatings is needed to extend the service life of the columns. Design/methodology/approach This study aims to compare the corrosion resistance of ST-Cr3C2-NiCr (sealed treatment Cr3C2-NiCr) coatings with industrially applied chromium plating. The corrosion failure mechanism of the coatings was investigated. Findings The results demonstrated that the ST-Cr3C2-NiCr coatings exhibited excellent corrosion resistance. After sealing treatment, the corrosion potential of Cr3C2-NiCr coatings was −0.215 V, and the corrosion current density of Cr3C2-NiCr coatings was lower than that of the plated parts. Practical implications ST-Cr3C2-NiCr coatings prepared by supersonic atmospheric plasma spraying could provide excellent corrosion resistance in the coal industry. Originality/value The low porosity and the presence of the NiCr phase were crucial factors contributing to the preferable corrosion resistance exhibited by the ST-Cr3C2-NiCr coatings. The corrosive process of the coatings involved layer-by-layer delamination of surface oxide film, sub-surface pitting, formation and degradation of sub-surface passive film, as well as severe block-like delamination.