Corrosion Resistance Of Coatings Research Articles

Research progress on the high-temperature oxidation resistance and hot corrosion resistance of MCrAlY coatings

Research progress on the high-temperature oxidation resistance and hot corrosion resistance of MCrAlY coatings

Study on Synergistically Improving Corrosion Resistance of Microarc Oxidation Coating on Magnesium Alloy by Loading of Sodium Tungstate and Silane Treatment

Sodium tungstate (Na2WO4) was filled into the micropores and onto the surface of a magnesium alloy microarc oxidation (MAO) coating by means of vacuum impregnation. Subsequently, the coating was sealed through silane treatment to synergistically boost its corrosion resistance. The phase composition of the coating was inspected using XRD. FTIR was utilized to analyze the functional groups in the coating. XPS was employed to study the chemical composition and valence state of the coating. The surface and cross-sectional morphology of the coating, along with its elemental composition and distribution, were investigated by SEM and EDS. Meanwhile, the thickness of the coating was analyzed using Image J software. Electrochemical impedance spectroscopy (EIS) was employed to determine the corrosion resistance of the coating. The results show that compared with an MAO coating, M-0.125W composite coating (only filled with sodium tungstate on the surface of the MAO coating), and M-SG composite coating (only receiving silanization treatment applied to the surface of the MAO coating), the corrosion resistance of the M-nW-SG composite coating (loaded with sodium tungstate on the surface of the MAO coating and then treated with silane) is significantly improved. This is mainly attributed to the fact that sodium tungstate can be combined with Mg2+ to form insoluble magnesium tungstate protective film, which blocks corrosion media. At the same time, silanization treatment further seals the MAO coating and increases the compactness of the coating. In addition, with the increase in the impregnation concentration of sodium tungstate, the content of sodium tungstate in the M-nW-SG composite coating improves, and the sealing effect of silanization treatment is better. When the impregnation concentration of sodium tungstate is 0.1 mol/L or above, the MAO coating with sodium tungstate can be completely sealed. When the impregnation concentration of sodium tungstate is 0.125 mol/L, M-0.125W-SG composite coating has the best corrosion resistance, and its impedance modulus value can be maintained at 8.06 × 106 Ω·cm2 after soaking in 3.5 wt.% NaCl solution for 144 h, which is about three orders of magnitude higher than those of MAO coating and M-0.125W and M-SG composite coatings.

Wear and Corrosion Resistance of 304SS Coating Using High Speed Laser Cladding

Wear and Corrosion Resistance of 304SS Coating Using High Speed Laser Cladding

Improvement of the long-term corrosion resistance and adhesion property of waterborne polyurethane coatings by physical mixing with silane-grafted nano-SiO2/TiO2

Improvement of the long-term corrosion resistance and adhesion property of waterborne polyurethane coatings by physical mixing with silane-grafted nano-SiO2/TiO2

Enhanced wear resistance, hydrophobic properties and corrosion resistance of plasma electrolyte oxidation coatings on Ti6Al4V alloys via addition of ZrO2 nanoparticles

Enhanced wear resistance, hydrophobic properties and corrosion resistance of plasma electrolyte oxidation coatings on Ti6Al4V alloys via addition of ZrO2 nanoparticles

Effect of composite magnetic microspheres and curing time on the corrosion and wear properties of phosphate ceramic coatings

In order to enhance the corrosion and wear resistance of ceramic coatings in marine environment, different types of micro-nano structures were constructed on the surface of phosphate ceramic coatings by magnetic polystyrene (PS@Fe3O4) microspheres and curing time. Subsequently, the surface properties of the magnetic composite microspheres and coatings were characterized, and the corrosion and wear properties of the coatings were investigated. The results revealed that the microspheres were gradually decomposed with the increase of curing time, and the surface of the coating presented different micro-nano structure with convex, flat and concave. Compared to unstructured coating (NSC), the convex micro-nano structured coating (CXMNC) and concave micro-nano structured coating (CEMNC) possessed outstanding superhydrophobicity. Through three tests of the knife scraping, tape peeling and sandpaper abrasion, the coatings showed excellent bonding strength and mechanical durability. After a long immersion period (256h), the impedance modulus of CXMNC and CEMNC were 27 and 15 times that of NSC, respectively. Compared with the NSC, the wear rate of CXMNC and CEMNC was reduced by 31.09% and 5.42%, respectively. Compared with the uncorroded samples, the wear rate of NSC, CXMNC and CEMNC after the immersion corrosion (30 days) was increased by 127.23%, 59.18% and 65.48%, respectively. Therefore, the micro-nano structured coatings have superior corrosion resistance and wear resistance to NSC, and CXMNC so as to CEMNC, which will provide better insight into the development of new corrosion-wear resistant materials.

Effects of phase transformation on the corrosion resistance and conductivity of NbN coatings for metal bipolar plates

Effects of phase transformation on the corrosion resistance and conductivity of NbN coatings for metal bipolar plates

The effect of Ta alloyed state on the corrosion resistance of TC4 surface laser cladding high entropy alloy

Ti4Al0.5NiCr2NbTa0.5 non-equimolar high entropy alloy (HEA) coatings were successfully prepared by laser cladding technology, the Ta element alloyed state in the coatings was changed by adjusting the laser energy density during cladding. The effects of Ta alloyed state on the phase structure, microstructure evolution, microhardness, corrosion resistance and passivation film of coatings were investigated. The results showed that the Ti4Al0.5NiCr2NbTa0.5 coating was composed of BCC and Ti2Ni-laves phases. With the increase in energy density, the increased content of Ta in the BCC phase promotes the formation of the BCC phase while suppressing the precipitation of the Ti₂Ni-Laves phase. However, this also leads to the transformation of the BCC phase from a fine dendritic structure to coarse equiaxed crystals. Meanwhile, the Laves phase, which is initially distributed in a reticulated at the grain boundaries, gradually fragments into a dotted distribution within the BCC phase. As grain coarsening occurs and the Laves phase decreases, the effects of fine-grain strengthening and second-phase strengthening gradually weaken, and the microhardness of the coating decreases from 675.5 HV to 483.4 HV. Additionally, the coating exhibited excellent corrosion resistance. With the change in the alloyed state of Ta, the stability of the passive film on the coating gradually increased, and the oxides of the refractory elements Ta and Nb transitioned from a sub-oxidized state to a stable oxidized state. The minimum corrosion current density of the coatings was only 0.877×10-8 A/cm2, and secondary passivation were observed during the polarization treatment of all coatings.

Microstructure, mechanical properties, and corrosion resistance of L21 phase-strengthened laser cladding CrFeNiTixAl1-x high-entropy alloy coatings

In this study, CrFeNiTixAl1-x (x=0.3, 0.7 in mole ratio) high-entropy alloy coatings (referred to as Ti0.3Al0.7, Ti0.7Al0.3 alloy coating, respectively) were prepared on AlSI1045 steel using the laser cladding (LC) method by adjusting the Al and Ti element contents. The phase constitutions, microstructures, mechanical properties, and corrosion resistance of the prepared coatings were comprehensively investigated and compared. Both Ti0.3Al0.7 and Ti0.7Al0.3 coatings exhibited rich Fe-Cr disordered BCC phase (A2) and NiAl ordered BCC phase (B2). The L21 phase in the Ti0.7Al0.3 coating accounted for as much as 47.7% when the Ti content was 0.7. The elevated Ti content significantly refined the internal structure of the coating, reducing the average grain size from 7.495 μm to 2.281 μm. With the combined effect of grain refinement and obstruction of dislocation motion by large angle grain boundaries, the microhardness of the Ti0.7Al0.3 alloy coatings increased from 685.12 HV0.2 to 867.20 HV0.2 compared to Ti0.3Al0.7. The precipitation strengthening effect of the noncoherent hard L21 phase, along with the protective role of the TiO2 oxide film, resulted in the lowest friction coefficient of 0.171 for Ti0.7Al0.3. Ti0.7Al0.3 exhibits the dominant wear mechanisms of abrasive and oxidative wear. Meanwhile, these coatings also exhibited excellent resistance to Cl- corrosion, with corrosion potentials shifted to -0.52V and -0.46V for Ti0.3Al0.7 and Ti0.7Al0.3, and corrosion current densities decreased to 1.26 ×10-6A/cm2 and 4.35 ×10-7A/cm2, respectively. These findings suggest that the replacement of equimolar Al with equimolar Ti in the CrFeNiTiAl high-entropy alloy compositions is a meaningful phenomenon that offers new perspectives for the design of novel high-performance HEAs.

Corrosion and wear resistant Cr40Co40Ni20 coatings produced by plasma transferred arc

Corrosion and wear resistant Cr40Co40Ni20 coatings produced by plasma transferred arc

Electrochemical and Structural Properties of Ultrathin Atomic Layer Deposition Coatings for Corrosion Resistance on Aluminum alloy.

Electrochemical and Structural Properties of Ultrathin Atomic Layer Deposition Coatings for Corrosion Resistance on Aluminum alloy.

The role of MgO nanoparticles on the corrosion resistance of hot-dip Al-Zn coating.

This study investigates the impact of MgO nanoparticles (0, 0.1, 0.5, and 1wt%) on the corrosion behavior of hot-dipped galvalume (Zn-55Al-1.6Si) coating. The corrosion behavior of coatings was assessed using a salt spray, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization tests in air-saturated 3.5wt% NaCl solution. The surface of the coatings was examined using field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). The results revealed that MgO nanoparticles were mainly located in zinc-rich interdendritic areas and filled the micro-holes within the coating. By creating a protective shield and separating the coating from the corrosive agents, these nanoparticles enhanced the corrosion resistance of coatings. Notably, the galvalume coating with the highest MgO nanoparticle content (1wt%) exhibited the best corrosion resistance.

Improved Mechanical Performances of Hastelloy C276 Composite Coatings Reinforced with SiC by Laser Cladding.

Composite coatings reinforced with varying mass fractions of SiC particles were successfully fabricated on 316 stainless steel substrates via laser cladding. The phase compositions, elemental distribution, microstructural characteristics, hardness, wear resistance and corrosion resistance of the composite coatings were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Vickers hardness testing, friction-wear testing and electrochemical methods. The coatings have no obvious pores, cracks or other defects. The phase compositions of the Hastelloy C276 coating includes γ-(Ni, Fe), Ni2C, M6C, M2(C, N) and M23C6. SiC addition resulted in the formation of high-hardness phases, such as Cr3Si and S5C3, with their peak intensity increasing with SiC content. The dendrites extend from the bonding zone towards the top of the coatings, and the crystal direction diffuses from the bottom to each area. Compared with the dendritic crystals formed at the bottom, the microstructure at the top is mostly equiaxed crystals and cellular crystals with smaller volume. When SiC powder particles are present around the crystals, the microstructure of the cladding layer grows acicular crystals containing Si and C. These acicular crystals tend to extend away from the residual SiC powder particles, and the grain size in this region is smaller and more densely distributed. This indicates that both melted and unmelted SiC powder particles can contribute to refining the grain structure of the cladding layer. The optimal SiC addition was determined to be 9 wt%, yielding an average microhardness of 670.1 HV0.5, which is 3.05 times that of the substrate and 1.19 times that of the 0 wt% SiC coating. The wear resistance was significantly enhanced, reflected by a friction coefficient of 0.17 (43.59% of the substrate, 68% of 0 wt%) and a wear rate of 14.32 × 10-6 mm3N-1·m-1 (27.35% of the substrate, 40.74% of 0 wt%). The self-corrosion potential measured at 315 mV, with a self-corrosion current density of 6.884 × 10⁻6 A/cm2, and the electrochemical charge-transfer resistance was approximately 25 times that of the substrate and 1.26 times that of the 0 wt%. In this work, SiC-reinforced Hastelloy-SiC composite coating was studied, which provides a new solution to improve the hardness, wear resistance and corrosion resistance of 316L stainless steel.

Emerging boron nitride nanosheets: A review on synthesis, corrosion resistance coatings, and their impacts on the environment and health

Abstract The aim of this study is to assess the effectiveness of hexagonal boron nitride (hBN) coatings to enhance the corrosion resistance of metals as well as evaluate their crucial toxicological impacts on both the environment and human health. Organic coatings are extensively applied in the field of protecting metals against corrosion. They are preferred as corrosion inhibitors due to their carbonyl and hydroxyl group content, but they have drawbacks regarding brittleness, porosity, and oxidation susceptibility. In this review, we mainly focused on the synthesis, properties, and applications of hBN coatings and emphasized the way to improve corrosion resistance in metals and alloys. Furthermore, our discussion demonstrated that the boron nitride nanosheet (BNNS) coatings significantly improve corrosion resistance, hydrophobicity, and crack mitigation properties. The researchers achieved reduced coating porosity and enhanced protection against corrosive media by effectively dispersing BNNS in organic resin. This study also determines the protective mechanism of BNNS composite coatings against corrosion. Moreover, we addressed the impact of BBNS synthesis and its physicochemical properties on the environment and organisms. Finally, suggestions are made for future research and the sustainability of industrial use to broaden the scope of applications for BNNS composite coating.

Corrosion Resistance Analysis in Nickel Coatings by Electrodeposition with Different Layers and Waveform Combinations.

Nickel (Ni) single-layer coatings were electrodeposited under varying pulse periods (T), duty cycles (θ), and average current densities (iav) using four distinct pulse current waveforms: rectangular (Rec), triangular (Tri), ramp-up triangular (Rup), and ramp-down triangular (Rdn). This study demonstrated, through dynamic polarization curves and surface morphology analysis, that single-layer coatings showed relatively good corrosion resistance when deposited at shorter pulse periods, larger duty cycles, and higher average current densities. Moreover, compared with other pulse current waveforms, single-layer coatings electrodeposited at T = 10 ms, θ = 0.5, and iav = 10 mA/cm2, 20 mA/cm2, and 40 mA/cm2 with Rdn had similar dynamic polarization curves and relatively good corrosion resistance. Consequently, two pulse current combinations, the descending gradient and convex gradient, were introduced for electrodepositing Ni multilayer coatings. Analysis revealed that the corrosion resistance of coatings deposited with the convex gradient current was further enhanced.

Experimental and theoretical study of catalytic and radiative characteristics of anti-oxidation and anti-erosion coatings for high-speed aircraft

The catalytic activity coefficient and emissivity of the surface of thin-walled oxidation- and erosion-resistant coatings for high-speed aircraft were determined experimentally and theoretically. The coating was applied as an aerosol mixture to a carbon-carbon composite substrate, and the resulting sample was subjected to fully dissociated air to measure heat fluxes to the sample surface and its enthalpy. Using established relationships between total convective-diffusive heat fluxes, stagnation enthalpy, and the heterogeneous recombination coefficient of oxygen and nitrogen atoms into molecules, the catalytic activity coefficient and surface emissivity were calculated based on the Stefan–Boltzmann law utilizing the measured enthalpy (and temperature) of the wall. The experiments were performed on five coating types containing silicon, titanium, molybdenum, and boron. The findings were summarized in a table showing how the recombination coefficient and emissivity depend on heat fluxes and wall temperature.

Modelling and performance evaluation of cermet-based erosion-resistant coatings on gas turbine blades using CFD approach

Modelling and performance evaluation of cermet-based erosion-resistant coatings on gas turbine blades using CFD approach

Structure and properties of coatings obtained by gas-thermal spraying

The authors investigated the microstructure and mechanical properties of wear-resistant coatings applied by the method of gas-thermal spraying with heating of the metal to a liquid state and its subsequent spraying with a gas jet. Nowadays, thermal spraying is increasingly an alternative to various methods of surfacing due to the high costs of consumables, the complexity of maintenance and safety during repairs. By this method, it is possible to reliably solve a variety of technological tasks, which include spraying of wear-resistant, antifriction and corrosion-resistant coatings; alitizing by spraying (increasing heat resistance); increasing the size of products; surfacing and soldering; elimination of casting defects; manufacture of molds, etc. The tribotechnical properties of the vibration damper rod of a railway carriage with reinforcing surface layers applied to the working surface by methods of gas-thermal spraying with 40Kh13 steel and galvanic chromium plating were investigated. Structure and thickness of the coatings, microhardness distribution in the coating-substrate zone, as well as the features of the coatings destruction under the same test conditions were studied. The criterion for comparing the coatings’ wear resistance was the operating time of the samples before the beginning of the coating destruction. Wear of the rollers was determined by the change in diameter, and wear of the pads – by the depth and width of the grooves formed on their surface during the experiment. The coating applied to the vibration damper rod by spraying 40Kh13 steel wire has high wear resistance in conditions of boundary friction with grease and can be an alternative to electroplated chrome coating. The high wear resistance of the coating makes it possible to recommend it for restoring the dimensions of worn parts and increasing the durability of new ones, as well as for replacing special anti-friction bearing alloys.

Enhancing orthopaedic implant efficacy: the development of cerium-doped bioactive glass and polyvinylpyrrolidone composite coatings via MAPLE technique

This study investigates the potential of combining Cerium-doped bioactive glass (BBGi) with Polyvinylpyrrolidone (PVP) to enhance the properties of titanium (Ti) implant surfaces using the Matrix-Assisted Pulsed Laser Evaporation (MAPLE) technique. The primary focus is on improving osseointegration, corrosion resistance, and evaluating the cytotoxicity of the developed thin films towards host cells. The innovative approach involves synthesizing a composite thin film comprising BBGi and PVP, leveraging the distinct benefits of both materials: BBGi's biocompatibility and osteoinductive capabilities, and PVP's film-forming and biocompatible properties. Results demonstrate that the BBGi + PVP coatings significantly enhance hydrophilicity, indicating improved cell-material interaction potential. The electrochemical analysis reveals superior corrosion resistance of the BBGi + PVP films compared to BBGi alone, which is critical for long-term implant stability. The mechanical adherence tests confirm the robust attachment of the coatings to Ti substrates, surpassing the ISO standards for implant materials. Biocompatibility tests show promising cell viability and negligible cytotoxic effects, with a controlled inflammatory response, underscoring the potential of BBGi + PVP coatings for orthopedic applications. The study concludes that the synergistic combination of BBGi and PVP, applied through the MAPLE technique, offers a promising route to fabricate bioactive and corrosion-resistant coatings for Ti implants, potentially enhancing osseointegration and longevity in clinical settings.

The Impact of Nickel-Zinc Ferrite Nanoparticles on the Mechanical and Barrier Properties of Green-Synthesized Chitosan Films Produced Using Natural Juices.

A trend has been established concerning the research and development of various green and biodegradable plastics for multi-purpose applications, aiming to replace petroleum-based plastics. Herein, we report the synthesis of chitosan (CH) films using lemon juice; these were reinforced with NiZnFe2O4 nanoparticles (NiZnFe2O4 NPs) to obtain improved mechanical and barrier properties, facilitating their future application as sustainable, corrosion-resistant coatings for medical instruments. The synthesized NiZnFe2O4 NPs had a crystallite size of ~29 nm. Reinforcement with the nanoparticles in bio-sourced chitosan films was conducted at two concentrations: 1% and 2%. The mechanical strength of the CH film was found to be 1.52 MPa, while the 2% NiZnFe2O4 NP-containing films showed stress-bearing potential of 1.04 MPa with a larger strain value, confirming the elastic nature of the films. Furthermore, the % elongation was directly proportional to the NP concentration, with the highest value of 36.833% obtained for the 2% NP-containing films. The CH films presented improved barrier properties with the introduction of the NiZnFe2O4 NPs, making them promising candidates for coatings in medical instruments; this could protect such instruments from corrosion under controlled conditions. This approach not only broadens the application range of biopolymeric films but also aligns with global sustainability goals, serving to reduce the reliance on non-renewable corrosion-resistant coatings.