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Influence of C2H2 Flows on Microstructure and Corrosion Resistance of TiCN Films Doped with Carbon Atoms
摘要: Nanosized TiCN/TiN films were deposited on AZ31 by reactive magnetron sputtering under different acetylene flows. The microstructures of obtained films were characterized, and their corrosion behaviors were also investigated. The films doped with carbon atoms under different acetylene flows own different structures and grain sizes. The grain size decreased to some extent, and the film structure changed from polycrystalline to nanocrystalline, with an increase of C2H2 flow. The surface morphology also changed from rough to smooth, with an increase of C2H2 flow. The Tafel curves and electrochemical impedance spectroscopy (EIS) demonstrated that the composite films could greatly improve the corrosion resistance of bare substrates in a 3.5% NaCl solution, and the films' corrosion resistance is different, owing to their different structures and grain sizes.
关键词: acetylene flows,ceramic coatings,microstructure,vacuum,corrosion behavior
更新于2025-09-23 15:22:29
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Light Metals 2014 (Grandfield/Light) || N-SiC Side Lining - Variations of Materials Structure
摘要: The key process in fabrication of Nitride bonded silicon carbide side lining of reduction pots is the reaction between Nitrogen and Silicon. Silicon may react with Nitrogen in solid, liquid and gaseous phase. The reaction is strongly exothermal. Almost all N-SiC refractory materials of more or less big shapes have the gradients of porosity from middle to the edges. The reason for these gradients may be the overheating of the middle part of shapes, compared to near surface layers, due to the exothermal effect and consequent increased concentration of volatile Silicon. Volatile Silicon tends to move to areas of lower temperature and the gradients of porosity are 1-2 %, but sometimes it may reach 5-7%. The problems with side lining of reduction pots may be because of the design of the pots, due to the overheating of the bath, yet the structure of N-SiC materials might be also critical.
关键词: corrosion resistance,side lining,N-SiC refractory
更新于2025-09-23 15:22:29
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Synergistic effect of Ag and ZnO nanoparticles on polyaniline incorporated epoxy/2pack coatings for splash zone applications
摘要: In this work, epoxy/2pack coatings containing polyaniline (PANI) in combination with Ag and ZnO nanoparticles have been synthesized. The nanoparticles were incorporated with bisphenol-A diglycidyl ether epoxy resin and polyamino-amide. The mechanical properties of the fabricated coatings, such as the pendulum hardness, scratch resistance, and impact strength, were studied. The composition of the fabricated coatings was confirmed by attenuated total reflectance infrared spectroscopy measurements. The thermal degradation and indentations were characterized through the use of differential scanning calorimetry and nano-indentation techniques, respectively. The surface morphology of the fabricated coatings was characterized using field-emission scanning electron microscopy. The synergistic effects of the Ag and ZnO nanoparticles on the corrosion resistance of the coatings after different exposure periods in 3.5% NaCl solutions were determined by electrochemical impedance spectroscopy. All the results were consistent with one another and confirmed that the addition of Ag and ZnO nanoparticles improved the mechanical properties of the coatings. This effect also led to a notable increase in the corrosion resistance of the PANI coatings.
关键词: Nanoparticles,Polyaniline,Nano-indentation,Corrosion resistance,Epoxy coatings,Surface morphology
更新于2025-09-23 15:22:29
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A micro-structural corrosion mechanism on the thermal degradation of BaMgAl10O17: Eu2+ phosphor
摘要: The thermal degradation is a vital issue that restricting luminous efficiency and service life of BaMgAl10O17: Eu2+phosphor for chromogenic and illuminating fields. The effects of heat-treatment temperature on the luminescence properties and micro-structure of BAM were researched to accurately elucidate the thermal degradation mechanism. Some pieces of evidence for micro-structural corrosion were detected according to the results of PL, TL, XPS and IR. With the heat-treatment temperature increasing, a decrease of blue-emitting intensity and new red-emitting peaks revealed thermal degradation and activator oxidation. The XPS results showed the surface chemical composition changes and the micro-structure adjustment. The defects elimination detected by TL could be responsible for this micro-structural corrosion. IR results further confirmed the changes on bond forms. These were direct evidence and specific forms for the micro-structural corrosion due to the thermal degradation. Based on the relationship between micro-structural corrosion and luminescence properties, a micro-structural corrosion mechanism was given for the thermal degradation of BAM phosphor. The thermal degradation was caused in parallel by the micro-structure corrosion and the activated ion (Eu2+) oxidation.
关键词: Micro-structural corrosion,Thermal degradation mechanism,BaMgAl10O17:Eu2+,Heat-treatment
更新于2025-09-23 15:22:29
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A highly efficient reduced graphene oxide/SnO2/TiO2 composite as photoanode for photocathodic protection of 304 stainless steel
摘要: A new photoanode RGO/SnO2/TiO2 nanocomposite material with a heterojunction structure was fabricated via hydrothermal method. The RGO/SnO2/TiO2 composite with different graphene content were prepared to explore optimal photoelectrochemical properties compared with pure TiO2. The morphology, structure and optical property of the obtained composite were characterized by TEM, FTIR, XRD and UV–vis. The photocathodic protection effect and anticorrosion properties of the nanocomposite for 304 stainless steel (304SS) were investigated by photocurrent density, open circuit potential, Tafel polarization curves and electrochemical impedance spectroscopy. The results show that compared with pure TiO2, the composite can provide an effective protection for 304SS not only under white light irradiation but also in the dark, and the optimal sample electrode potentials negatively shifted to ?590 mV under illumination. The possible photocathodic protection mechanism of the composite was also proposed.
关键词: Photocathodic protection,Corrosion resistance,Electrochemical properties,Graphene,Heterojunction
更新于2025-09-23 15:22:29
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Effect of temperature and bias voltage on electrical and electrochemical properties of diamond-like carbon films deposited with HiPIMS
摘要: The relatively high electrical resistivity of diamond-like carbon (DLC) film is one of the main drawbacks when applied in electronic device. In this study, DLC films were synthesized on 304 stainless steels by high power impulse magnetron sputtering (HiPIMS) process and the effect of deposition temperature and bias voltage on the microstructure, electrical and electrochemical properties, hardness and adhesion strength of the DLC films were investigated. The sp2/sp3 ratio of DLC films first decreased then increased and the surface became denser as bias voltage increasing from 0 to -400 V. While the film turned into graphite-like structure and became incompact when deposition temperature rose from 100 °C to 300 °C. The interfacial contact resistance (ICR) got reduced by increasing bias voltage and deposition temperature. However, as the deposition temperature increased to 300 °C the anticorrosion ability and hardness of DLC films deteriorated. The DLC films deposited at 300 °C presented soft and had better adhesion strength than hard DLC films deposited at 100 °C. DLC films deposited at -400 V bias and 300 °C had the lowest ICR while DLC films deposited at -400 V bias and 100 °C had the best performance when ICR, corrosion resistance and hardness were all taken into consideration.
关键词: Electrochemical corrosion,Substrate temperature,High power impulse magnetron sputtering,Interfacial conductivity,Diamond-like carbon,Bias voltages
更新于2025-09-23 15:22:29
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Hybrid Laser Ablation and Chemical Modification for Fast Fabrication of Bio-inspired Super-hydrophobic Surface with Excellent Self-cleaning, Stability and Corrosion Resistance
摘要: Although laser ablation is considered as a facile technique to fabricate bio-inspired super-hydrophobic surfaces, the issue is that the initial laser treated metallic surfaces show super-hydrophilic property. It will take a long period to reach super-hydrophobic state under ambient air. It is reported that these super-hydrophobic surfaces could be easily damaged by thermal heating effect or interaction with other liquids, causing uncontrolled loss of super-hydrophobicity. In this study, a stable super-hydrophobic aluminum surface was rapidly fabricated via the hybrid laser ablation and surface chemical modification of (heptadecafluoro-1, 1, 2, 2-tetradecyl) triethoxysilane (AC-FAS). Surface morphology and chemistry were systematically investigated to explore the generation mechanism of super-hydrophobicity. The water contact angle of the treated surfaces can reach up to 160.6? ± 1.5? with rolling angle of 3.0? ± 1.0?, exhibiting perfect self-cleaning capability, long-term stability, and excellent chemical stability in acidic as well as alkaline solutions. The potentiodynamic polarization tests implied that the super-hydrophobic surfaces showed better anti-corrosion performance. This hybrid laser ablation and surface chemical modification are very time-saving and low-cost, which offers a rapid way for quantity production of super-hydrophobic surface on aluminum material.
关键词: nanosecond laser,bioinspiration,corrosion resistance,chemical stability,self-cleaning,super-hydrophobic,long-term stability
更新于2025-09-23 15:22:29
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Research on Micro-Size Electrical Discharge Machining Polycrystalline Diamond
摘要: With the demand of modern cutting technology for ‘high efficiency, precise, flexibility and green manufacturing’, polycrystalline diamond materials as cutting tools have been widely used in automobile, aerospace and non-metal processing. Electro-spark erosion is one of the most effective ways to machine polycrystalline diamond materials. Single pulse discharge is one of the research foundations of micro-EDM. Using 2 micron granularity polycrystalline diamond as experiment material, the influence of single pulse discharge technology on the removal efficiency of materials was studied, such as pit radius, pit depth and radius-depth ratio, etc. The experimental results show that, with the extension of the pulse duration, the radius of the discharge pit begins to increase rapidly, then slowly increases, and finally to slow down; while the radius of thermal influence zone increases rapidly and then continues to increase slowly. With the extension of pulse duration, the ratio of pit depth to radius changes within the range of 0.05 ~ 0.25, which shows a downward trend basically.
关键词: Single pulse,Micro-size,Polycrystalline diamond (PCD),Electrical Discharge Machining (EDM),Corrosion pit size
更新于2025-09-23 15:22:29
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Zinc oxide array/polyurethane nanocomposite coating: Fabrication, characterization and corrosion resistance
摘要: Novel zinc oxide (ZnO) array/polyurethane (PU) nanocomposite coatings on the stainless steel substrates was fabricated via a simple process. ZnO arrays were prepared using zinc nitrate and hexamethylenetetramine by a seed growth method, followed by the spinning of PU. The morphologies, structure, wettability, mechanical performance and infrared radiation properties were characterized by transmission electron microscope, scanning electron microscope, X-ray diffraction, surface contact angle, nano indentation and infrared radiation tests. The corrosion properties of the ZnO array/PU nanocomposite coating were evaluated by the electrochemical tests. The results showed that the ZnO arrays were hexagonal wurtzite and well dispersed in the composite coatings, resulting in slight increase in hydrophilicity. The mechanical properties of the coatings were improved with increased content of the ZnO arrays. The as-prepared ZnO array/PU nanocomposite coatings exhibited excellent corrosion resistance. The infrared radiation performance was observed to be slightly improved as well. It is believed that the unique organic/inorganic nanocomposite coating offers the effective strategy and potential applications for designing the functional coatings of good corrosion resistance and mechanical properties in various polymer systems.
关键词: PU,Composite,Corrosion,ZnO array
更新于2025-09-23 15:21:21
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Electrochemical Polishing of Two-Dimensional Materials
摘要: Two-dimensional (2D) layered materials demonstrate their exquisite properties such as high temperature superconductivity, superlubricity, charge density wave, piezotronics, flextronics, straintronics, spintronics, valleytronics, and optoelectronics, mostly, at the monolayer limit. Following initial breakthroughs based on micromechanically exfoliated 2D monolayers, significant progress has been made in recent years towards the bottom-up synthesis of large-area monolayer 2D materials such as MoS2 and WS2 using physical vapor deposition (PVD) and chemical vapor deposition (CVD) techniques in order to facilitate their transition into commercial technologies. However, the nucleation and subsequent growth of the secondary, tertiary, and greater numbers of vertical layers poses a significant challenge not only towards the realization of uniform monolayers, but also to maintain their consistent electronic and optoelectronic properties which change abruptly when transitioning from the monolayer to multilayer form. Chemical or physical techniques which can remove the unwarranted top layers without compromising the material quality will have tremendous consequence towards the development of atomically flat, large-area, uniform monolayers of 2D materials. Here, we report a simple, elegant, and self-limiting electrochemical polishing technique which can thin down any arbitrary thickness of 2D material, irrespective of whether these are obtained using powder vapor transport (PVT) or mechanical exfoliation, into their corresponding monolayer form at room temperature within a few seconds without compromising their atomistic integrity. The effectiveness of this electrochemical polishing technique is inherent to 2D transition metal dichalcogenides (TMDCs) owing to the stability of their basal planes, enhanced edge reactivity, and stronger-than-van der Waals (vdW) interaction with the substrate. Our study also reveals that 2D monolayers are chemically more robust and corrosion resistant compared to their bulk counterparts in similar oxidative environments which enables electrochemical polishing of such materials down to a monolayer.
关键词: physical vapor transport,MoS2,WS2,monolayer,corrosion,two-dimensional (2D) materials,electrochemical polishing,electro-ablation
更新于2025-09-23 15:21:21