Corrosion Resistance Of Materials Research Articles

Self-Assembled MoS2 Cladding for Corrosion Resistant and Frequency-Modulated Electromagnetic Wave Absorption Materials from X-Band to Ku-Band.

Reasonable composition design and controllable structure are effective strategies for harmonic electromagnetic wave (EMW) adsorption of multi-component composites. On this basis, the hybrid MoS2 /CoS2 /VN multilayer structure with the triple heterogeneous interface is prepared by simple stirring hydrothermal, which can satisfy the synergistic interaction between different components and obtain excellent EMW absorption performance. Due to the presence of multiple heterogeneous interfaces, MoS2 /CoS2 /VN composites will produce strong interfacial polarization, while the defects in the sample will become the center of polarization, resulting in dipole polarization. Due to the excellent structural design of MoS2 /CoS2 /VN composite material, MoS2 /CoS2 /VN composite material not only has good conductive loss and polarization loss, but also can maintain excellent stability in simulated seawater, and enhance corrosion resistance. The MoS2 /CoS2 /VN composite with dual functions of corrosion resistant and microwave absorption achieves a minimum reflection loss (RL) of -50.48dB and an effective absorption bandwidth of up to 5.76GHz, covering both the X-band and Ku-band. Finally, this study provides a strong reference for the development of EMW absorption materials based on transition metal nitrides.

Investigation of rust layer on low alloy steel with 0.40 wt% Sn in a rural atmospheric environment

This study investigates the formation and properties of rust layers on low alloy steel containing 0.40 wt% tin (Sn) in rural atmospheric environments. The rust layer was analyzed using various techniques, including scanning electron microscopy, X-ray diffraction and Raman spectroscopy. Additionally, a new corrosion big data sensor was used to evaluate the corrosion resistance of Sn-containing low alloy steels. Results show that the presence of Sn in the low alloy steel positively affects corrosion resistance, resulting in the formation of a denser and more protective rust layer. The corrosion big data technology is a precise and intuitive approach for identifying the subtle impact of Sn on the corrosion resistance of low alloys. These findings offer insights into the mechanisms behind the corrosion resistance of low alloy steels in rural atmospheric environments and highlight the potential of Sn as an effective alloying element for improving the corrosion resistance of such structural materials.

Opto-electronic and electrochemical evaluations of particulate wo3 and sno2 in electrocodeposited Zn- tio2 nanocomposites coatings for sensor application

This study synthesized, characterized and determined the electronic and optical properties of Zn-TiO2, Zn-TiO2-WO3 and Zn-TiO2-SnO2 nano-composite coatings on low carbon steel. It has also determined the effect of these coatings on the corrosion of mild steel in saline environment. This was with a view to produce an active coating to providing alternative to hazardous chromium coating. Active multi functional nano crystalline coatings of the composites were electrolytically fabricated on low carbon steel from Zinc bath, with its Cation and nanoparticulates of TiO2, SnO2 and WO3 were uniformly codeposited in the Zn matrix. The nano-powders were characterized with Scanning Electron Microscope/Energy Dispersive Spectrometer (SEM/EDS) analyses for confirmation of the chemical compositions and purity. The electrocodeposition bath compositions were developed with 120 gram per litre of ZnCl2, 30 gram per litre of KCl along sides with the nanopowders. Other additives including cetylpridinum chloride, 2- Butyne 1,4diol were added as surfactants and Thiourea was added as stabilizer. The coated specimens were sectioned into parts, some of which were characterized with electrical meters and solar simulator to determine the electrical conductivity and solar response of the coated samples respectively. Samples were also subjected to corrosion experiment in 3.5% NaCl (saline) media to study their corrosion resistance properties in the test media through Potentiodynamic polarization method. The results, the electrical conductivity of the generated nano-composite coatings displayed a better electrical conductivity of 2.45E-01Ω-1m-1 which made it a better sensor material and outstanding corrosion resistance with corrosion rate at 0.10116 mm/year. The study concluded that both matrices with the Nano Particulate WO3 and SnO2 can be use as sensor materials but the WO3 matrix showed a better electrical conductivity both in the presence and absence of uv light and enhanced corrosion protection under light and dark conditions, thus a better sensor’s material.

Study on the effect of solution treatment on mechanical and corrosion properties of SAF 2507DSS produced by LPBF

In recent years, the application of Laser powder bed fusion (LPBF) technology in the manufacturing industry has become increasingly widespread. Compared to traditional casting processes, LPBF technology allows for the production of complex-shaped and structurally unique components made of 2507 duplex stainless steel (2507DSS), thus improving production efficiency and product quality. This article focuses on determining the LPBF parameters required for printing 2507DSS, successfully fabricating samples with a density of 98.71% and subjecting them to solution treatment followed by tensile testing. The results show that the LPBF-prepared samples exhibit a strength of 1173 MPa and an elongation of 18%. The presence of island-like structures enables excellent mechanical performance in the horizontal direction. The samples subjected to solution treatment at 1100 °C exhibit a strength of 860 MPa and an elongation of 45%. It is observed that when 2507DSS undergoes solution treatment from a single-phase state, the formation of large-angle grain boundaries and residual stresses within the austenite phase occurs, and a reasonable explanation is provided. Furthermore, the article conducts electrochemical tests on the samples. The results indicate that the LPBF-prepared samples possess the same electrochemical properties as the samples treated at 1100 °C, and both outperform the cast samples. Thus, this study reveals that the proportion of phases is not the sole determining factor for the corrosion resistance of DSS, providing valuable insights for the future development of more corrosion-resistant 2507DSS materials.

Porosity, roughness, and passive film morphology influence the corrosion behavior of 316L stainless steel manufactured by laser powder bed fusion

The development of additively-manufactured (AM) 316L stainless steel (SS) using laser powder bed fusion (LPBF) has enabled near net shape components from a corrosion-resistant structural material. In this article, we present a multiscale study on the effects of processing parameters on the corrosion behavior of as-printed surfaces of AM 316L SS formed via LPBF. Laser power and scan speed of the LPBF process were varied across the instrument range known to produce parts with >99 % density, and the macroscale corrosion trends were interpreted via microscale and nanoscale measurements of porosity, roughness, microstructure, and chemistry. Porosity and roughness data showed that porosity φ decreased as volumetric energy density Ev increased due to a shift in the pore formation mechanism and that roughness Sq was due to melt track morphology and partially fused powder features. Cross-sectional and plan-view maps of chemistry and work function ϕs revealed an amorphous Mn-silicate phase enriched with Cr and Al that varied in both thickness and density depending on Ev. Finally, the macroscale potentiodynamic polarization experiments under full immersion in quiescent 0.6 M NaCl showed significant differences in breakdown potential Eb and metastable pitting. In general, samples with smaller φ and Sq values and larger ϕs values and homogeneity in the Mn-silicate exhibited larger Eb. The porosity and roughness effects stemmed from an increase to the overall number of initiation sites for pitting, and the oxide phase contributed to passive film breakdown by acting as a crevice former or creating a galvanic couple with the SS.

Enhanced Durable Corrosion Resistance of Samarium-Doped ZnO Solid Solution Materials by 4f Electrons of Samarium Atoms

Enhanced Durable Corrosion Resistance of Samarium-Doped ZnO Solid Solution Materials by 4f Electrons of Samarium Atoms

Investigation of Helix-Pultruded CFRP Rebar Geometry Variants for Carbon-Reinforced Concrete Structures.

Carbon concrete is a new, promising class of materials in the construction industry. This corrosion-resistant reinforcement material leads to a reduction in the concrete cover required for medial shielding. This enables lean construction and the conservation of concrete and energy-intensive cement manufacturing. Bar-type reinforcement is essential for heavily loaded structures. The newly developed helix pultrusion is the first process capable of producing carbon fiber-reinforced polymer (CFRP) reinforcement bars with a topological surface in a single pultrusion process step, with fiber orientation tailored to the specific loads. The manufacturing feasibility and load-bearing capacity were thoroughly tested and compared with other design and process variants. Approaches to increase stiffness and strength while maintaining good concrete anchorage have been presented and fabricated. Tensile testing of the helical rebar variants with a 7.2 mm lead-bearing cross-section was conducted using adapted wedge grips with a 300 mm restraint length. The new helix geometry variants achieved, on average, 40% higher strengths and almost reached the values of the base material. Concrete pull-out tests were carried out to evaluate the bond properties. The helix contour design caused the bar to twist out of the concrete test specimen. Utilizing the Rilem beam test setup, the helical contour bars could also be tested. Compared with the original helix variant, the pull-out forces could be increased from 8.5 kN to up to 22.4 kN, i.e., by a factor of 2.5. It was thus possible to derive a preferred solution that is optimally suited for use in carbon concrete.

Shielding AZ91D-1%Ca from corrosion through ultrasound melt treatment: A study for stent design

Magnesium-based materials show great potential for producing biodegradable stents, but their high corrosion rates are a roadblock.This study investigates whether ultrasound melt treatment can change the corrosion response of an extruded AZ91D-1.0%Ca (wt.%) in Earle's Balanced Salt Solution by tailoring the intermetallics' morphology in the as-extruded state.The results showed that the wires from ultrasound-treated ingots corroded faster than non-treated ones in immersion for up to 6 hours. This trend shifted for longer periods, and ultrasound-treated material showed lower corrosion rates and uniform corrosion, while the non-treated material displayed localized corrosion signs. Tensile testing of the wires demonstrated that immersion in EBSS lowered the tensile strength and elongation at fracture due to material degradation, regardless of the processing route. Nonetheless, this decline was sharper in the non-treated material.These findings suggest that ultrasound melt processing can be a promising method for improving the corrosion resistance of magnesium-based materials, paving the way for their use in manufacturing biodegradable stents.

CDs Regulated Sulfur-Based Flexible Electrode with Range pH Values for Efficient and Durable Hydrogen Evolution Reaction.

How to mildly structure a high intrinsic activity and stable catalytic electrode to realize long-term catalytic water splitting to produce hydrogen at a wide range of pH values at industrial high current is a challenge. Herein, this work creatively proposes to prepare industrial-grade catalytic electrodes with high efficiency and stability at high current density through carbon quantum dots (CDs) modification nickel sulfide on hydrophilic flexible filter paper via one-step mild chemical plating (denoted as CDs-Ni3 S2 @HFP). The intrinsic activity and surface area, electron transfer ability, and corrosion resistance of Ni3 S2 material are increased due to the regulation, homogenous, and high concentration doping of CDs. The overpotential of the flexible catalytic electrode is only 30, 35, and 87mV in 1m KOH, simulated seawater (1m KOH + 0.5m NaCl), and neutral electrolyte (0.5m PBS) at a current density of 10mA cm-2 . More attractively, the CDs-Ni3 S2 @HFP electrode achieves over 500h of efficient and stable catalysis at industrial high current density (500mA cm-2 ). Due to the advantages of mild, universal, and large-area preparation of catalytic materials, this work provides technical support for flexible catalytic electrodes in efficient catalysis toward water splitting, energy storage, and device preparation.

Increased body fluid repellency and electrochemical corrosion resistance of intravascular stent materials by ICP-CVD-based DLC thin-film deposition

Intravascular stents face adhesion- and corrosion-based challenges causing In-stent Restenosis (ISR). This study analyzes the influences of thin-film Diamond-Like-Carbon (DLC) deposition on body fluid repellency and corrosion behavior in Simulated Body Fluid (SBF) at 37 °C for intravascular stent materials. The stent specimens of 316 L and 316 LVM stainless steel, Ti-Alloy, and CoCr-Alloy were coated with DLC thin-films by Inductively Coupled Plasma Chemical Vapor Deposition (ICP-CVD). The repellencies of bare and DLC-coated specimens to body fluids, including the blood, plasma, glycerol, and distilled water (DIW) were analyzed by their Contact Angles (CA). Electrochemical impedance spectroscopy (EIS) and corrosion analysis in simulated body fluid were conducted using a potentiostat system. Bare specimens exhibited hydrophilic behavior with 51° CA for distilled water and lower body fluid repellencies with 69°, 64°, and 57° CAs for total blood, blood plasma, and glycerol, respectively. DLC coating improved blood repellency to 88° CA and hydrophobic feature to 81° CA. The electrochemical corrosion analysis exhibited that ICP-CVD based DLC thin-film deposition increased the electrochemical polarization resistance of BMS specimens from 22.02 kΩ.cm2 to 386.6 kΩ.cm2 for 316 L SS, 408.8 kΩ.cm2 for 316 LVM SS, 1703.0 kΩ.cm2 for CoCr-Alloy, and 1748 kΩ.cm2 for Ti-Alloy. The obtained values reduced the corrosion rate from 447.1 μm/year to 0.241 μm/year and the mass loss rate from 357.1 mg/cm2year to 0.165 mg/cm2year. This study concludes that DLC thin-film structures can lower the risk of ISR by adhesion and corrosion inhibition in BMS specimens, and they have a potential application in fluid-repellent and anti-corrosive drug-free stents.

Review on the durability of eco-friendly engineering cementitious composite (ECC)

A comprehensive manual review of the use of slag and fly ash in engineered cement-based composites (ECBCs) was conducted. The extensive use of supplementary cementitious materials and integrated fibers in engineered cement-based composite (ECBCs) in seawater composite structures can help to enhance the durability of infrastructure in marine environments and minimize the extensive use of cement and CO2 emissions in the construction industry. This paper retrieved journal and review articles on slag/fly ash utilization in ECBCs from the Scopus database, mainly from 2015 to 2022, and performed an analysis using a suitable software tool. It also provided an up-to-date review of the literature on eco-friendly engineered cementitious composites’ (ECC) durability, with in-depth discussions on the effects of temperature fluctuation on ECCs, supplementary cementitious material, frost and salt corrosion resistance, pre-cracking, seawater resistance, and microstructural alteration. The durability of ECCs is closely related to the behaviors of the fiber distribution, matrix, and fiber-matrix interface under various environmental conditions. The main factors causing the deterioration of the engineering cement-based composites are fiber orientation and dispersion, frost resistance, corrosion, and alkaline environment. Fiber dispersion is mainly assumed to be highly homogeneous in theory, but in practice, due to the uneven dispersion of the fibers the property of each composite structure is not uniform. Further, among all issue associated with durability, sulfate salt attack considered as the most significant environmental deterioration process that affect the resilience of hydraulic structure. At last, it is necessary to conduct additional research on the durability of ECC under various environmental conditions to comprehend its behavior in the actual world. The experimental data currently available on the short-term durability of ECC fluctuate over time. Which indicates that the mechanisms for the long-term degradation of ECC under specific environmental conditions remain unknown.

Stray current induced chloride ion transport and corrosion characteristics of cracked ultra-high performance concrete

Ultra-high-performance concrete (UHPC) is a strong, durable, and corrosion-resistant material that is poised to revolutionize construction in complex environments, such as the deep sea and underground. However, the formation of cracks of UHPC during service and the occurrence of stray currents in underground stations and tunnels greatly accelerate the transport of chloride ions, posing a threat to the safety of underground construction. Here, we used the rapid chloride migration (RCM) method to study the effect of stray current in cracked UHPC. Essentially, electric field accelerates chloride ion transport in cracks by increasing ion transport in the uncracked zone. The wider the crack, the more severe the corrosion of steel fibers, which affects the pore structure of UHPC and leads to an increase in the diffusion coefficient in the uncracked area. In addition, area normalization was employed to precisely monitor the chloride ion concentration in the cracks, which was validated by numerical simulations. Finally, microscopy and atomic force microscopy (AFM) showed that larger crack widths led to deeper corrosion and more severe steel fiber corrosion in UHPC. These results have important implications for the durability design of UHPC structures in stray current environments.

Hydrogen production from seawater splitting enabled by on-line flow-electrode capacitive deionization

The conventional method of hydrogen production relies on non-renewable fossil fuels, which conflicts with the objective of future renewable and sustainable energy system. Seawater splitting for hydrogen production using offshore wind/solar power shows much promise as the solution for hydrogen-based energy systems coupling renewable energy. Direct seawater splitting is currently not feasible at a large scale due to its unsatisfactory durability caused by the anodic chloride corrosion which will make the catalyst deactivated and the substrate disintegrated. To tackle the anodic corrosion issue, here we present a novel seawater electrolysis system integrating an on-line flow-electrode capacitive deionization unit with a robust alkaline water electrolyzer. At an operating voltage of 1.6 V, the on-line deionization unit reaches a desalting ratio of 98.47%, so that the detrimental hypochlorite evolution could be greatly suppressed. Combined with a corrosion-resistant anode material—S-NiFeOOH@Ni foam, the connected electrolysis system achieves durable operation for 100 h at industrial-level current density (500 mA cm−2) with the anodic overpotential only at 296 mV. This novel system provides a practical solution for large-scale seawater splitting.

Understanding the generation and evolution of hydrophobicity of silane modified fly ash/slag based geopolymers

Silanes are widely used to enhance the corrosion resistance of cement-based materials by endowing the substrate with hydrophobicity. However, their applications in fly ash/slag based geopolymer (FSBG) are still rare. This study comprehensively investigates the hydrophobicity properties and reaction products of FSBG modified by isooctyltriethoxysilane admixture to reveal the mechanisms involved in the generation and evolution of hydrophobization effect. In spite of the verified compromise in compressive strength of modified FSBG for longer ages, the early strength at 1 day is amazingly found to slightly increase, ascribed to the heat release along with the hydrolysis of silane. The reduction of porosity is caused by the siloxane products of silane after condensation reactions and thus does not show consistencies to the decreasing compressive strength as well as the formation of hydration products. The amount of N-A-S-H gel is found to reduce more intensively compared to the C-A-S-H gel when silane is used. The evolution of contact angle on the surface of modified FSBG is dependent on the mutual effect of superficial density of silane and porosity, with the former controlled by the amount of coupling sites. The formula of contact angle evolution is proposed and can be potentially used to regulate and govern the hydrophobicity properties of FSBG, with the feasibility to be applied in other geopolymers and cement-based materials.

A Study on the Influence Regulation of Surface Integrity on the Corrosion Resistance of Hydrogen Production Reactor Material

A Study on the Influence Regulation of Surface Integrity on the Corrosion Resistance of Hydrogen Production Reactor Material

Exceptional combination of mechanical and corrosion properties in partially recrystallized CoCrFeNiMo medium-entropy alloys

Corrosion-resistant materials with good mechanical properties are an endless goal to develop reliable structural materials. Multiple strengthening mechanisms stemming from diverse microstructural factors have been developed, while the effect of microstructural factors on corrosion properties in high-entropy alloys has not been clearly defined yet. Herein, the corrosion behaviors of CoCrFeNiMo medium-entropy alloys with different annealing times are investigated. The influences of microstructures are summarized as follows: alloyed Mo accelerates repassivation, Mo-rich precipitates form micro-galvanic couples, and unrecrystallized microstructures induce pitting corrosion. Regarding mechanical properties, the alloyed Mo, Mo-rich precipitates, and unrecrystallized region with profuse dislocations lead significant solid solution strengthening, precipitation strengthening, and dislocation strengthening, respectively. Particularly, the sample annealed for 60 min possesses dissolved Mo in the matrix, fine precipitates, wide recrystallized regions, and low dislocation density, resulting in a wide passivation range of 1.512 V and high yield strength × fracture strain of 220.3 MPa simultaneously. The sample annealed for 60 min reveals a synergistic combination of diverse microstructural factors affecting corrosion and mechanical properties.

High-performance AlCoCrFeNi high entropy alloy with marine application perspective

2205 duplex stainless steel (DSS) and Incoloy 825 alloys are extensively utilized in the marine environment for decades but have some limitations of insufficient hardness and strength and poor wear resistance. Here, we developed AlCoCrFeNi high-entropy alloy (HEA), which showed a good combination of mechanical, wear-resistant and corrosion-resistant properties. Vickers hardness and compressive yield strength of AlCoCrFeNi HEA were ∼517.6 HV and ∼1306.4 MPa, respectively, which were much higher than those of 2205 DSS and Incoloy 825 alloys. Besides, there is a smaller wear rate and lower corrosion current density for AlCoCrFeNi HEA compared with those of 2205 DSS and Incoloy 825 alloys, suggesting good resistance to wear and corrosion damage. These merits are due to lattice distortion, high hardness and low grain boundary number per unit area. This work offers new insights for the development of wear- and corrosion-resistant HEA materials used in the marine environment.

Investigation on compaction pressure and sintering temperature suitable for Nimonic 90 superalloy

Fabrication of high strength, high temperature and corrosion resistant materials provide much assistance in aerospace, automotive, chemical and oil industries, as they have to withstand severe operating conditions. Traditionally, superalloys are widely used under these conditions that are prepared by casting method. Nowadays, powder metallurgy technique is gaining importance for preparing superalloys because of its capability of making homogeneous microstructure with near-net-shape. In this significant context, the processing of Nimonic 90 superalloy sample using conventional powder metallurgy route is discussed. Desired amount of metallic powders by weight percent are blended, uni-axially pressed and sintered in tubular vacuum furnace at different sintering temperatures. The influence of compaction pressure and sintering temperature on density, hardness, surface roughness and electrical resistivity is determined. Surface porosity and the effect of sintering temperature on the microstructural features are analyzed noticeably. It is found that the compaction pressure of 700 MPa and the sintering temperature of 1365℃ are the most desirable process parameters, essentially required for synthesizing the Nimonic 90 superalloy. Sample prepared under these conditions has achieved the desired density and hardness, as that of the standard Nimonic 90 alloy. Thus, the study paves the way for future researchers to appropriately identify the conditions suitable for preparing the superalloys as per the application needed.

Molecular dynamics simulation on the dissolution and diffusion characteristics of FeCrAl alloy in liquid LBE

Lead-bismuth eutectic (LBE) corrosion-resistant materials are crucial for the development of future fourth-generation nuclear reactors, and the dissolution and diffusion of material components are important processes in LBE corrosion-resistant materials. FeCrAl alloy is an important structural material for fourth-generation reactors, and it is essential to study its dissolution and diffusion processes in liquid LBE. Molecular dynamics simulations (MD) were used to investigate the mutual diffusion process between the FeCrAl alloy and liquid LBE. The dissolution and diffusion abilities of Fe, Cr, and Al atoms in liquid LBE were evaluated using mean-square displacement (MSD) and diffusion activation energy (DAE). Fe atoms exhibited the highest degree of diffusion, while Al atoms showed the lowest degree of diffusion, resulting in a distinct difference in the elemental distribution at the solid–liquid interface (SLI). There was a significant difference in the depth of penetration of Pb and Bi atoms into the FeCrAl alloy matrix, with Bi atoms penetrating deeper. Furthermore, there is a thermal vibration process during the invasion of Pb and Bi atoms into the FeCrAl alloy matrix, which promotes the invasion process of Pb and Bi atoms. In addition, an increase in temperature exacerbates the diffusion of Fe, Cr, and Al atoms in liquid LBE and the process of Pb and Bi atom invasion into the FeCrAl alloy matrix. Our research may contribute to the design of future nuclear-grade FeCrAl alloy and the development of next-generation reactors.

A Review on Controlling Grain Boundary Character Distribution during Twinning-Related Grain Boundary Engineering of Face-Centered Cubic Materials

Grain boundary engineering (GBE) is considered to be an attractive approach to microstructure control, which significantly enhances the grain-boundary-related properties of face-centered cubic (FCC) metals. During the twinning-related GBE, the microstructures are characterized as abundant special twin boundaries that sufficiently disrupt the connectivity of the random boundary network. However, controlling the grain boundary character distribution (GBCD) is an extremely difficult issue, as it strongly depends on diverse processing parameters. This article provides a comprehensive review of controlling GBCD during the twinning-related GBE of FCC materials. To commence, this review elaborates on the theory of twinning-related GBE, the microscopic mechanisms used in the optimization of GBCD, and the optimization objectives of GBCD. Aiming to achieve control over the GBCD, the influence of the initial microstructure, thermo-mechanical processing (TMP) routes, and thermal deformation parameters on the twinning-related microstructures and associated evolution mechanisms are discussed thoroughly. Especially, the development of twinning-related kinetics models for predicting the evolution of twin density is highlighted. Furthermore, this review addresses the applications of twinning-related GBE in enhancing the mechanical properties and corrosion resistance of FCC materials. Finally, future prospects in terms of controlling the GBCD during twinning-related GBE are proposed. This study will contribute to optimizing the GBCD and designing GBE routes for better grain-boundary-related properties in terms of FCC materials.