One of the solutions proposed by researchers to control the corrosion of reinforced concrete is the use of wrapping technology. Many researchers have investigated carbon-fiber polymer (CFP) for the ...aim of wrapping reinforced concrete. However, the effect of using CFP on the corrosion resistance of concretes has not been fully studied by researchers. This work focused on the mechanical performance and electrochemical corrosion behavior of carbon steel reinforced concrete wrapped with CFP. The samples were made with one, two, and three CFP layers and tested for corrosion resistance. The orientation of wrapped CFP has also been studied in this work. The results indicated that the compressive strength of the concrete cube samples increased by increasing the CFP layers. Electrochemical impedance spectroscopy tests indicated that the reinforced concrete wrapped with CFP had a higher value of passive film resistance compared to plain concrete, indicating more enhancement of corrosion resistance on the surface of carbon steel rebar.
A transformative concept of solid electrochemical corrosion has been put forward, in which solid-state electrolyte LiPON has been applied to replace the liquid one to prelithiate graphite with ...Li-metal. Thus, high prelithiation efficiency and low polarization of the treated anode can be obtained, with a unique mosaic structure left at the surface.
Prelithiation by solid electrochemical corrosion of lithium metal has been created with a graphite surface being modified by a mosaic structure.
To enhance the wear resistance and corrosion resistance of Ni-based coatings, carbon fibers reinforced nickel-based composite coatings (CFs/Ni) were fabricated on the surface of 1Cr13 stainless steel ...by laser cladding (LC). The microstructure characteristics, microhardness, wear and corrosion performances of the composite coatings were investigated. The results show that CFs can effectively improve the corrosion and wear resistances of Ni-based coatings. With increasing laser scanning speed, the morphology of CFs in composite coatings is more integral and the corrosion and wear resistances of the composite coatings are improved. Especially, when laser scanning speed is increased to 8mm/s, the average microhardness of the composite coating reaches up to 405HV0.2, which is about 1.3 times higher than that of Ni-based coating. Moreover, the corrosion current density and the wear rate of the composite coating are only 7% and 55% of those of the Ni-based coating, respectively, which is attributed to the good properties and homogeneous distribution of CFs and finer microstructure of composite coating.
•Carbon fibers reinforced Ni-based composite coatings are fabricated by laser cladding.•Laser scanning speed can affect the morphology and distribution of carbon fibers.•Carbon fibers can enhance the corrosion resistance and wear resistance of CFs/Ni-based coatings.•Properties of CFs/Ni-based coatings are improved with increasing laser scanning speed.
•Optimal pre-treatment of a molten salt applied anode is explored.•Chemical and electrochemical pre-treatment conducted for a Ni-11Fe-10Cu anode.•Electrochemical pre-treatment formed in-situ oxide ...layers specific to molten salt.•Chemical pre-treatment disrupted anode surface and led to enhanced corrosion.•Mild electrochemical pre-treatment resulted in anode protection.
Molten salt electrolysis offers an attractive pathway to net-zero emission manufacturing, including the electrolysis of carbon dioxide to generate high value carbon materials. This is only possible with the development of an anode material which is active towards oxygen evolution at elevated temperatures and stable within the melt. Here, it is shown that optimal pre-treatment of a Ni-11Fe-10Cu alloy includes formation of an active oxide layer which incorporates the molten salt. The molten ternary carbonate electrolyte (Li-Na-K CO3) is investigated at 600 °C and pre-oxidation conditions considered include chemical oxidation of the alloy surface under air, and electrochemical oxidation of the surface below that of oxygen evolution, at the onset of metal oxide formation. It was seen that chemical oxidation forms oxides more likely to destabilise the electrode surface when subsequently exposed to the carbonate salt. The unmodified electrode was also significantly corroded due to the fast rate of surface oxidation when stepped to oxygen evolution potentials. Extended (5 h) electrochemical metal oxide formation also causes a build-up of a reactive sub-surface nickel oxide rich layer during pre-treatment, however short-term pre-treatment (1 h) was seen to have the best outcome in terms of both stability and oxygen evolution activity. This is attributed to the formation of a stable LiFeO2 film at the Ni-11Fe-10Cu alloy surface which is highly active towards oxygen evolution. Understanding the interaction between the electrode surface and molten salt chemically and electrochemically under varied polarisation, as carried out here, is crucial to allow progression of this technology for application to carbon capture and other low emission manufacturing approaches.
•The effect of low dose heavy ion irradiation on the corrosion resistance of 321 SS is easily concealed by other factors, such as the content of delta phase, while the corrosion resistance of 321 SS ...is reduced by high dose heavy ion irradiation.•Unirradiated specimen and low dose irradiated specimen can easily form a complete passivation film in B-Li solution at room temperature, and the equivalent electrical circuitl (EEC) mode is the film impedance model.•It is difficult for irradiated specimens at higher doses to form a complete passivation film, which is mainly attributed to the defects such as nanoscale craters with protrusions in the surface of 321 SS and a large number of dislocation loops generated in the damaged layer.
Aiming to the environment for 321 stainless steel (SS) in primary circuit of pressurized water reactor (PWR), the effect of heavy ion irradiation to simulate neutron irradiation on the electrochemical behavior of alloy is unclear. The purpose of this work is to evaluate the corrosion resistance of 321 SS at different doses and the contribution of heavy ion irradiation in it. This work reveals that the corrosion resistance decreases in the order of 2 dpa > 0 dpa > 10 dpa > 60 dpa at room temperature, consistent with the sequence of δ-phase content near the surface. The effect of irradiation dose on the corrosion resistance of 321 SS is inversely proportional at higher dose and optimal performance of the SS irradiated to 2 dpa is attributed to the highest content of Cr-rich δ-phase. The pits occur in C enrichment zone, accompanied by increase of O content, while no pit occurs in Ti enrichment area. The results provide a reference for the irradiated SS with heavy ion to acquire optimal pitting resistence.
For this study, NiCrBSi–TiN composite coatings were fabricated on Q235 steel substrates by reactive plasma spraying and the coatings were heat treated at 600 °C, 700 °C, 750 °C and 800 °C for 1 h. ...The microstructure evolution of these coatings untreated and treated at different temperatures was analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) combined with energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM). The hardness of the coatings was characterised using the Weibull distribution while the wear and corrosion resistance were studied using a block-ring tribometer and an electrochemical workstation. The phase composition of coatings after heat treatment changed, the compactness of coatings was increased, and the interlayer bonding was significantly improved. Comprehensive experimental results illustrated that the performance of the NiCrBSi–TiN composite coatings was excellent at the heat treatment temperature of 700 °C.
The surface of TC18 titanium alloy was coated with a CoCrFeNiAl HEA coating using double-glow plasma surface metallurgy. The structure, phase, and growth mode of the coating were investigated, along ...with its electrochemical corrosion behavior. The prepared HEA coating, under the influence of the hollow cathode effect and non-equilibrium diffusion, exhibits a composite structure consisting of a deposited layer and an interdiffused layer. It demonstrates robust metallurgical bonding with the substrate, and it exhibits a hardness of 12.66 GPa and an elastic modulus of 158.52 GPa, along with exceptional hardness and high elastic modulus. The primary phase of the coating consists of an FCC solid solution, with a minor presence of Ni3Al and Al8Cr5 phases. TEM results demonstrate that hollow cathode enhanced sputtering effectively refines the grain structure on the substrate surface. The high entropy alloy coating, characterized by a significant abundance of nanocrystalline and amorphous structures, is obtained under the bombardment of high-energy particles. Gradually increasing from the interface to the deposited layer, there is an augmentation in the content of nanocrystals. The transition from the substrate to the sedimentary layer comprises three distinct regions: a surface fine crystal region, a nanocrystalline structure region, and a nanocrystalline and amorphous precipitated phase-rich region. In 3.5 wt% NaCl solution, the electrochemical corrosion rate of the coating is 1.36 × 10−1 μm·year−1, which is about ten times lower than that of the substrate. Moreover, pre-soaking forms a stable oxide film on the coating's surface, effectively preventing corrosion and demonstrating its remarkable corrosion resistance.
•CoCrFeNiAl HEA coating was successfully prepared by double glow technique based on hollow cathode effect.•The content of nanocrystals increases gradually from the interface to the deposited layer.•The electrochemical corrosion rate of the coating in 3.5wt % NaCl solution is very low, and it has good corrosion resistance.
Titanium and its alloys are employed as medical materials because of their low Young's modulus, excellent biocompatibility, and superior corrosion resistance. This work aimed to characterize the ...electrochemical behavior of titanium Ti-CP2 and alloys Ti-6Al-2Sn-4Zr-2Mo, and Ti-6Al-4V. Ti and Ti-alloys were exposed to Ringer´s solution at room temperature. The electrochemical characterization was made by cyclic potentiodynamic polarization (CPP) and electrochemical noise technique (EN). Two different methods filtered EN signal, the polynomial method and the potential spectral density (PSD). Also, the Wavelets method, where energy dispersion plots were obtained. Results indicated that Ti-6Al-2Sn-4Zr-2Mo presented less dissolution when exposed in Ringer analysis by ψ0. The wavelet method showed a diffusion process occurring on the surface.
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