Corrosion Resistance Of Alloy Research Articles

First-Principles modeling of Corrosion current for Passive Magnesium alloys and its application in Mg-RE Alloy

Theoretical calculation could simulate Mg alloy corrosion behavior from electrochemical thermodynamic factors. By considering the kinetic factor as the passivation oxide layer, a comprehensive corrosion current model has been set up in this work. The corrosion current modeling should belgJtot′=lgJa+∆lgJc+km×∑fm×∆Em+ki×∑(fi×∆Ei)−koxCPBR×Winterface−∆Gs−∆GF(ln10)RT)). The formula as koxCPBR×Winterface−∆Gs−∆GF(ln10)RT) is just for passivation factor. Alloying element segregation energy ∆Gs, oxide formation energy ∆GF, oxide PBR value CPBR, interface cleavage work Winterface have all been considered. By this more considerate modeling, the corrosion current lgJtot′ (related to polarization icorr) could be obtained for passivate Mg alloys such as Mg-RE series (RE=Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu). Moreover, the prediction is quite coherent to experimental electrochemical polarization result. The work provides a more precisely prediction for Mg alloy with passivation. It also proposes a passivation criterion for seeking corrosion-resistant Mg alloy in another way.

ASSESSMENT OF THE CORROSION-MECHANICAL PROPERTIES OF THE LEFT MATERIALS AND FORECASTING THE SAFETY OF GAS TURBINE PARTS

Purpose. Determination of the possibility of using the temperature-time parametric dependences of Miller-Larson, Manson-Haferd, and Sherby-Dorn for long-term prediction of the strength characteristics of parts subjected to oxidation and high-temperature sulfide-oxidation effects. Research methods. Long-term strength studies were performed on samples of ВЖЛ-12У and ЗМІ-3У alloys in synthetic ash (66.2 % Na2SO4, 20.4 % Fe2O3, 8.3 % NiO, 3.3 % CaO, 1.8 % V2O5) and an oxidizing environment at temperatures of 800 °C and 850 °C. The Miller-Larson, Manson-Haferd, and Sherby-Dorn temperature-time parametric dependences were used to predict the tensile strength of materials in an oxidizing and corrosive environment. The microstructure of the samples was studied using an optical microscope MIM-8M. Results. The results obtained indicate a high level of corrosion resistance of ЗМІ-3У samples at 800 °C and 850 °C and the possibility of determining the tensile strength of the material for a period of 1000, 5000, and 10000 hours by the calculation method. Tests of ВЖЛ-12У alloy samples in synthetic ash showed a discrepancy between the experimental time to fracture and the calculated value, regardless of the parametric method, which indicates a direct dependence of long-term strength on the degree of corrosion damage to the surface of the samples. Scientific novelty. The possibility of using the Miller-Larson, Manson-Haferd, and Sherby-Dorn temperature-time parametric dependences for long-term prediction of the strength characteristics of parts in an oxidizing environment has been confirmed. In a sulfide-oxide environment, the use of parametric methods to determine strength characteristics for up to 10,000 hours is possible only for corrosion-resistant alloys. Intensive corrosion damage to ВЖЛ-12У alloy leads to accelerated deformation, which limits the use of temperature and time dependencies for effective prediction of the time of failure of parts made of this material. Practical value. Determining a reliable method for predicting the strength characteristics of heat-resistant alloys in an oxidizing and corrosive environment allows reducing the time and financial costs of conducting lengthy field studies.

Improvement in corrosion resistance of Mg97Zn1Y2 alloy by Zr addition

Improvement in corrosion resistance of Mg97Zn1Y2 alloy by Zr addition

Effect of applied magnetic field on ZnFe alloy electrodeposition

Corrosion-resistant materials for the protection of structures are of paramount importance to the industry. This research work reports on the effects of a magnetic field applied parallel to a working electrode on the electrodeposition process of the corrosion-resistant ZnFe alloy coating. The electrochemical study of ZnFe alloy coatings prepared using an acid sulfate bath was carried out in galvanostatic mode. The results indicated that the current density and magnetic field have remarkable effects on the formation kinetics of the ZnFe deposits. The diffusion rate of the Fe ferromagnetic species subjected to mass transport accelerated under the influence of the Lorentz force (applied magnetic field); moreover, these ions were deposited in large amounts under the effect of the magnetic field. The energy-dispersive X-ray (EDX) spectroscopy analysis confirmed the modification of the Fe ion atomic concentrations in the ZnFe coatings under the influence of the magneto-hydrodynamic (MHD) convection compared to those deposited without the imposition of the magnetic field. The morphological examinations revealed that the magnetic field acted positively on the deposited layers by endowing them with homogeneous surfaces. The X-ray diffraction (XRD) analysis of ZnFe deposits demonstrated the presence of delta (δ), zeta (ξ) and eta (η) phases when there was no applied magnetic field. Furthermore, depending on the magnitude of the applied magnetic field, XRD diagrams exhibited changes in crystallographic orientation, grain size, and the electro-crystallization. These changes favor the presence of certain crystallographic phases, such as (200) and (330).

Biocorrosion and Cytotoxicity Studies on Biodegradable Mg-Based Multicomponent Alloys.

Magnesium-based multicomponent alloys with different compositions, namely Mg60Al20Zn5Cu10Mn5 (Mg60 alloy), Mg70Al15Zn5Cu5Mn5 (Mg70 alloy), and Mg80Al5Cu5Mn5Zn5 (Mg 80) alloys, were prepared using the disintegrated melt deposition technique. The DMD technique is a distinctive method that merges the benefits from gravity die casting and spray forming. This approach facilitates high solidification rates, process yields, and reduced metal wastage, resulting in materials with a fine microstructure and minimal porosity. Their potential as biodegradable materials was assessed through corrosion in different simulated body fluids (SBFs), microstructure, and cytotoxicity tests. It was observed that the Mg60 alloy exhibited low corrosion rates (~× 10-5 mm/year) in all SBF solutions, with a minor amount of corrosive products, and cracks were observed. This can be attributed to the formation of the Mg32(AlZn)49 phase and to its stability due to Mg(OH)2 film, leading to excellent corrosion resistance when compared to the Mg70 and M80 alloys. Conversely, the Mg80 alloy exhibited high corrosion rates, along with more surface degradation and cracks, due to active intermetallic phases, such as Al6Mn, Al2CuMg, and Al2Cu phases. The order of corrosion resistance for the Mg alloy was found to be ASS > HBSS > ABP > PBS. Further, in vitro cytotoxicity studies were carried out using MDA-MB-231 tumor cells. By comparing all three alloys, in terms of proliferation and vitality, the Mg80 alloy emerged as a promising material for implants, with potential antitumor activity.

Corrosion characteristic of vitallium 2000 CoCrMo casting alloy in fluoride containing artificial saliva

In order to reveal the effect of fluoride ions (F−) on the passive film corrosion resistance and composition of CoCrMo dental prosthesis. The passivity of casting Vitallium 2000 CoCrMo series alloy was systematically studied by adopting electrochemical and surface techniques. The results show that F− have a certain effect on the passive film corrosion resistance of casting CoCrMo in oral environment, and the increase of F− concentration weakens the passive film corrosion resistance. With the increase of F− concentration, the open circuit potential moves negatively, the corrosion current density increases, the polarization resistance decreases, and the defect density in the passive film increases. With the extension of immersion time, the corrosion resistance of alloy will be enhanced and shows: AS > AS + 0.5 wt% NaF > AS + 1 wt% NaF. The addition of F− can decrease Co, Cr and Mo peaks sharply and promote the dissolution of the passive film. The result of present study could regulate and guide the application dose of oral fluorine-containing products.

Effect of Gadolinium Content on the Microstructures and Corrosion Properties of Mg-4Zn-3Gd Alloy

Lightweight metallic alloys in the transport sector are the essential choice to reduce carbon monoxide emissions. Magnesium (Mg) can serve this purpose appreciably because it has a low density compared to other metallic metals and a high strength in a small portion of metals. The reason behind this is having very low weight. Notwithstanding the alloys exhibit high susceptibility to corrosion especially galvanic corrosion, which impedes it from its various applications. The corrosion resistance of magnesium alloy depends largely on the surface film whether it can protect well and the corrosion due to galvanic effect between the second phase particles or microstructures and the magnesium matrix. Role of second phase particles eventually improves the corrosion property by enhancing its resistance to corrosion. Mg-4Zn being a promising alloy, 3 wt% Gd has been added further to investigate the corrosion resistant properties of Mg-4Zn-3Gd alloy. After preparing the alloys by casting method in induction furnace followed by homogenization at 410°C, the sample was hot rolled at 400°C. Preparation of the samples has been verified by EDS, XRF and XRD analysis. Corrosion study has been done for 1 hour, 24 hours and 72 hours. Microstructures have been taken for as cast, homogenized, and as rolled condition before corrosion test. The analysis shows a large difference in the grain size and phase distribution. Due to dynamic recrystallization during rolling hardness also shows differences compared to as cast and homogenized sample. The corrosion test is performed by weight loss test, electrochemical measurement, and immersion test. In the results, it has been seen an increase in corrosion rate at the initial stage, however it came to a constant rate after some time. After corrosion test, optical micrographs (OM) and scanning electron microstructures (SEM) images show typical morphology of corroded surface with some micro cracks. The presence of Gd in Mg-4Zn alloy enhanced the corrosion performance when it is done for longer time.

Ultrahigh corrosion resistance of Mg-Er alloys by two-layer barrier from oxide film and triangular prism-like Mg(OH)2

An ultrahigh corrosion resistance of Mg-Er alloys was achieved via a simple method by forming an Er2O3 oxide film using a high temperature treatment. The corrosion rate of Mg-8.1 wt% Er alloy with oxide film is only 0.12 mm/y in 3.5 wt% NaCl solution, even lower than that of high-purity magnesium. The triangular prism-like Mg(OH)2 was observed for the first time in corrosion field of Mg alloys, which was terrific compact and effectively hindered the further corrosion. A mechanism of two-layer barrier coming from the oxide film and triangular prism-like Mg(OH)2 was proposed to contribute the outstanding corrosion resistance.

Influence of rolling reduction on corrosion behavior of WE43 alloy

The corrosion behavior of WE43 alloy with different rolling reductions (0%, 25%, 45%, and 80%) at 500 °C was investigated in 3.5 wt.% NaCl solution. The microstructure evolution of the rolled WE43 alloy was characterized in detail by means of optical microscopy (OM), transmission electron microscopy (TEM) and electron back-scattered diffraction (EBSD). The results show that with increasing reductions, basal texture is gradually enhanced and grain size gradually decreases. Only the alloy with 45% reduction exhibits dispersed dynamic precipitates. Immersion and electrochemical measurements demonstrate the decreasing order of the corrosion resistance of the rolled WE43 alloy: 45% reduction > 80% reduction > 25% reduction > 0 reduction. The best corrosion resistance of the WE43 alloy with 45% reduction is mainly related to a large number of finely dispersed precipitates, which are capable of promoting the formation of a compact corrosion product layer. The increased corrosion rate of the sample with 80% reduction is induced by the re-solution of the majority of precipitates into the matrix. The grain size, basal texture and deformation twins have a limited effect on the corrosion resistance of rolled WE43 alloy compared with the precipitates.

Synergistic enhancement of hot corrosion resistance and mechanical properties of IN738LC alloy prepared by selective laser melting

The present study investigates the synergistic enhancement of hot corrosion resistance (900 °C, 75%Na2SO4+25%NaCl) and mechanical properties of IN738LC alloy prepared by selective laser melting after heat treatment. The results indicate that the M23C6 precipitation at the grain boundaries coupled with smaller-sized γ′ phase distribution in the inner grain is conducive to the formation of thicker Cr2O3 outer layer and Al2O3 inner layer for the samples, which effectively hinders the diffusion of S and Cl elements penetrate to the matrix, enhancing the hot corrosion resistance. Additionally, the presence of small-sized γ′ phase and re-crystallization-induced grain refinement contribute to an increase in yield strength (σYS = 1261 MPa) and ultimate tensile strength (σUTS = 1360 MPa) for the alloy.

Empowered corrosion-resistant products through HCP crystal network: a topological assistance

Human computer interaction (HCI) aims to enhance product effectiveness and efficiency by empowering users. This research examines corrosion resistance in alloys, a concern due to technological advancements. Metals and alloys are susceptible to degradation, leading to functionality loss, structural collapse, and environmental contamination. Improving corrosion resistance is crucial for product efficiency. In this paper, HCI identifies requirements that emphasize taking an existing hexagonal closely packed (HCP) network, investigating the network for requirements in the form of vertices and edges, mapping different vertices and edges of the network graph with topological invariants, solving the network graph by invariants, and providing results for modeling and design of advanced networks and architectures. The HCI also ensures and investigates the optimization of results produced under the specifications. The study examines network graph results for irregularities, providing guidelines for engineers and manufacturers to create advanced alloy architectures with characteristics through mathematical and graphical methods.

A review on manufacturing processes of cobalt-chromium alloy implants and its impact on corrosion resistance and biocompatibility.

Cobalt-Chromium (CoCr) alloys are currently used for various cardiovascular, orthopedic, fracture fixation, and dental implants. A variety of processes such as casting, forging, wrought processing, hot isostatic pressing, metal injection molding, milling, selective laser melting, and electron beam melting are used in the manufacture of CoCr alloy implants. The microstructure and precipitates (carbides, nitrides, carbonitrides, and intermetallic compounds) formed within the alloy are primarily determined by the type of manufacturing process employed. Although the effects of microstructure and precipitates on the physical and mechanical properties of CoCr alloys are well reviewed and documented in the literature, the effects on corrosion resistance and biocompatibility are not comprehensively reviewed. This article reviews the various processes used to manufacture CoCr alloy implants and discusses the effects of manufacturing processes on corrosion resistance and biocompatibility. This review concludes that the microstructure and precipitates formed in the alloy are unique to the manufacturing process employed and have a significant impact on the corrosion resistance and biocompatibility of CoCr alloys. Additionally, a historical and scientific overview of corrosion and biocompatibility for metallic implants is included in this review. Specifically, the failure of CoCr alloys when used in metal-on-metal bearing surfaces of total hip replacements is highlighted. It is recommended that the type of implant/application (orthopedic, dental, cardiovascular, etc.) should be the first and foremost factor to be considered when selecting biomaterials for medical device development.

Advancing sustainability in construction and environmental management about innovative materials, technologies, and policy frameworks

This comprehensive study explores the integration of advanced materials, innovative technologies, and policy frameworks to enhance sustainability in construction and environmental management. Through an in-depth analysis of self-healing concrete, energy-efficient insulation materials, recycled composites, membrane filtration advancements, photocatalytic water purification, bioremediation techniques, corrosion-resistant alloys, smart sensing technologies, earthquake-resistant designs, and green infrastructure, we demonstrate significant potential to reduce environmental impact, improve infrastructure durability, and promote water conservation. Additionally, the role of international standards, regulations, and incentives in fostering sustainable development practices is critically examined. Quantitative analyses and mathematical models provide a foundation for assessing the effectiveness and economic viability of these innovations, offering valuable insights for stakeholders across the construction and environmental sectors

Microstructure and corrosion behaviour of Mg-1Sc alloy with different processing conditions

The microstructure and corrosion resistance of Mg-1Sc alloys in different processing conditions were investigated. The composition was examined by Inductively Coupled Plasma Atomic Emission Spectrometer, the microstructure was analyzed by metallographic microscope. The corrosion behaviour of the alloy was investigated by hydrogen evolution tests and electrochemical tests. The results showed that as-cast and rolled Mg-1Sc possess better corrosion resistance compared with extruded Mg-1Sc alloys, which is due to the fact that the extrusion flow lines and residual stresses caused by machining in extruded Mg-1Sc alloys can lead to easier corrosion. In addition, rolled Mg-1Sc alloy shows better corrosion resistance than as-cast alloy, which is attributed to the finer grain sizes and a denser corrosion product film.

Improvement of Corrosion and Wear Resistance of Mg-Li Alloy by Binary- and Ternary-Layered Double Hydroxide/Steam Coating Composite Coatings

Improvement of Corrosion and Wear Resistance of Mg-Li Alloy by Binary- and Ternary-Layered Double Hydroxide/Steam Coating Composite Coatings

Effect of Polytetrafluoroethylene Coating on Corrosion Wear Properties of AZ31 Magnesium Alloy by Electrophoretic Deposition

In this study, we aim to enhance the corrosion and wear resistance of AZ31 magnesium alloy using electrophoretic deposition (EPD) technology to apply a hydrophobic polytetrafluoroethylene (PTFE) coating. Polyethyleneimine (PEI) serves as a charged dispersant, facilitating uniform deposition of PTFE particles on the alloy surface. Results demonstrate a significant reduction in corrosion current density (from 67.5 μA/cm2 to 5.2 μA/cm2) and improved wear resistance (wear volume decreased from 0.24167 mm3 to 0.00167 mm3) in a 3.5 wt% NaCl solution compared to uncoated alloy. Moreover, the friction coefficient of the coated sample decreases. These findings underscore the potential of nano-PTFE coatings prepared via EPD in enhancing AZ31 magnesium alloy’s corrosion and wear resistance, providing a foundation for future protective coating design and optimization.

Effect of Annealing Temperature on Microstructure and Properties of Solid Solution Extruded Mg–2.0Zn–1.0Y–0.5Zr Alloys

In this investigation, the effects of different annealing temperatures (180, 200, 220, 240, 260, and 280 °C) on the microstructure evolution and properties of an extruded Mg–2.0Zn–1.0Y–0.5Zr (wt%) magnesium alloys were determined. Optical microscopy (OM), scanning electron microscopy (SEM), immersion corrosion, electrochemical corrosion experiments, and tensile testing were performed. Research has found that combining hot extrusion with subsequent low-temperature annealing significantly improves the strength, plasticity, and corrosion resistance of alloys due to grain refinement and a reduced dislocation density. The alloy was completely recrystallized at an annealing temperature of 240 °C for 4 h after solid solution extrusion, and the grains were fine and uniform, demonstrating the best comprehensive properties. Its corrosion rate, ultimate tensile strength, yield strength, and elongation were 0.454 ± 0.023 mm/y, 346.7 ± 8.9 MPa, 292.4 ± 6.9 MPa, and 19.0 ± 0.4%, respectively. The corrosion mechanism of the specimens under extruded and annealed conditions was analyzed. After annealing at 240 °C for 4 h, the dislocation and bimodal grain structure of the samples were almost eliminated, resulting in uniform and fine grains, which were conducive to the formation of a more uniform and denser oxide film, thus improving the corrosion resistance of the alloy.

Corrosion resistance of a superhydrophobic polypropylene coating on magnesium alloy AZ31

PurposeTo improve the corrosion resistance of magnesium alloys, the construction of protective coatings is necessary to extend the service life of Mg-based materials.Design/methodology/approachSiO2 nanoparticles modified by dodecyltrimethoxysilane (DTMS) were added to the PP and a superhydrophobic Mg(OH)2/PP-60mSiO2 composite coating was fabricated on the surface of AZ31 magnesium alloy via the hydrothermal method and subsequently the immersion treatment.FindingsHydrophilic SiO2 nanoparticles become hydrophobic after modified by DTMS, showing a higher dispersibility in xylene. By incorporating modified SiO2 nanoparticles into the composite PP coating, the hydrophobicity of the layer was enhanced, resulting in a contact angle of 166.3° and a sliding angle of 3.4°. It also improved the water repellency and durability of the coating. Furthermore, the intermediate layer of Mg(OH)2 significantly strengthened the bond between the PP layer and the substrate. The Mg(OH)2/PP-60mSiO2 composite coating significantly enhances the corrosion resistance of the magnesium alloy by effectively blocking the infiltration of the corrosion anions during corrosion. The corrosion current density of the Mg(OH)2/PP-60mSiO2 composite coating is approximately 8.23 × 10–9 A·cm-2, which can achieve a magnitude three times lower than its substrate, making it a promising surface modification for the Mg alloy.Originality/valueThe composite coating effectively and durably enhances the corrosion resistance of magnesium alloys.

Evaluation of innovative fluroapatite /silicon dioxide modified zirconia nanocomposites coated on Ti–13Nb–13Zr alloy for dental implant application

Dental implants are intended to function as a durable method for replacing missing teeth. A biocompatible dental alloy is used to achieve integration with the jawbone through Osseointegration. This creates a strong base for the implant, allowing it to withstand the mechanical forces generated during biting and chewing. Dental alloys are commonly subjected to various mouth conditions known for their intricate corrosion potential. Corrosion can weaken the structural integrity of the implant, causing issues such as implant loosening, micro-motion at the implant-bone contact, implant fracture, allergic reactions, toxicity, and possible disruption of the Osseo integration process. To improve the alloy's corrosion resistance and biocompatibility, its surface can be altered using nanocomposite materials. The materials provide a protective coating to the alloy, creating a physical barrier that effectively prevents corrosive substances from reaching the underlying bulk material. This study involves modifying the surface of the dental alloy Ti–13Nb–13Zr with Fluroapatite (FAP)/Silicon dioxide (SiO2) modified zirconia (ZrO2) nano composites. The altered surfaces are then studied in simulated body fluid and artificial saliva solutions using in vitro methods. The FAP/SiO2 modified ZrO2 nanocomposites is applied onto a Ti–13Nb–13Zr alloy utilizing Electrophoretic deposition and Dip coating techniques. The coated samples were analysis utilizing FTIR, XRD, and SEM with EDS. Corrosion analysis was carried out on coated and uncoated samples using Electrochemical methods in simulated body fluid and artificial saliva solution. The biocompatibility is assessed using MTT assay, contact angle, and immersion testing in both SBF and Artificial saliva. EIS and corrosion study results show that FAP/SiO2 modified ZrO2 nanocomposites coated Ti13Nb13Zr alloy has high polarization resistance, low corrosion rate, and good charge transfer resistance, indicating excellent corrosion resistance. The contact angle study showed that the surface-modified Ti13Nb13Zr alloy is superhydrophilic, increasing implant surface osseointegration. Cell viability measurements reveal good cell growth, while immersion investigations show calcification, leading to enhanced osseointegration between the implant and its surrounding tissues. hence, it is an excellent material for dental implants application.

Improving Aging Behavior and Corrosion Resistance of Mg-5Ga Alloy by Ca Alloying

Improving Aging Behavior and Corrosion Resistance of Mg-5Ga Alloy by Ca Alloying