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Slow crack growth in silica aerogels: A review
摘要： The sub-critical crack growth in hydrophobic (as prepared) and hydrophilic (oxidized) silica aerogel was studied using the Dynamic fatigue experiment and the Double-Cleavage-Drilled-Compression test (DCDC). The effect of oxidation treatment is clearly evidenced. The temperature and water vapor content dependence on the crack growth rate is measured between 22 °C and 110 °C with relative air moisture ranging from 5 to 80% RH. Like dense silica, crack growth velocities were found to decrease when increasing the temperature at a constant water vapor concentration. Surprisingly, the crack velocity also decreases when increasing water vapor content at constant temperature. Such a behavior is contrary to expected results usually encountered in glasses. We assume that a capillary condensation phenomenon of water vapor inside the aerogel porosity takes place, inducing internal compressive stresses.
关键词： Silica aerogels,Slow crack growth,Stress corrosion effect
更新于2025-09-09 09:28:46
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Effects of inclination angle on surface roughness and corrosion properties of selective laser melted 316L stainless steel
摘要： Balling effect is an inevitable defect during Selective laser melting (SLM) process, and it deteriorates the mechanical and corrosion properties of the resulting parts. In this work, the SLM process is used with various inclination angles to fabricate samples. The deep relationship between the selective laser melting process and the corrosion properties of the as-SLM fabricated parts is established to understand the effect of the inclination angle on the surface roughness, microstructure evolution, and corrosion properties of 316L stainless steel components. Results show that the Ra value of fabricated parts increased with increasing inclination angles. Inclination angles play an important role in balling and defect formation. Fabricated parts exhibit a wide passive region in salty environments. The corrosion resistance of the SLM samples after polishing is decreased comparing to that of the unpolished which attribute to porosity and balling behavior. The typical corrosion characterization of polished surface is pitting and localized corrosion, and it mainly origin of pores and balling. Meanwhile, balling behavior accelerated corrosion rates of non-polished parts.
关键词： Selective laser melting,Inclination angles,Surface roughness,Corrosion resistant
更新于2025-09-09 09:28:46
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[Energy, Environment, and Sustainability] Sensors for Automotive and Aerospace Applications || Corrosion Monitoring and Control in Aircraft: A Review
摘要： There has been increasing trend for health monitoring of an aircraft to deal its life issues and to minimize the operational cost. The corrosion is one of the important factors which limits the life of an aircraft due to material loss and fatigue cracking. The development of corrosion monitoring systems and models can provide the solution for health monitoring and prediction for remaining life of an aircraft. This chapter provides a comprehensive review on different types of corrosion, corrosion monitoring, and corrosion control. The latest studies on aircraft corrosion have been discussed in chapter. The different techniques based on nondestructive testing methods such as ultrasonic, electromagnetic, radiographic, thermographic have been detailed out in the chapter. Further for corrosion control, different schemes of corrosion control and coating removal techniques have been discussed in detail.
关键词： Monitoring,Aircraft,Health,Corrosion control
更新于2025-09-09 09:28:46
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Effect of current density and ZnO nano particles influence on the microstructure and mechanical strengthening properties of Zn-TiO<sub align="right">2-ZnO alloys at constant deposition time
摘要： In this work, the effect of current density and particle loading on microstructure and mechanical properties of Zn-TiO2-ZnO nanocomposite produced via electrocodeposition are investigated. The morphological characteristics of the nano-composite coatings were characterised by scanning electron microscope (SEM) equipped with energy dispersive spectrometer (EDS). Mechanical examination was carried out using Dura scan micro-hardness tester and CERT UMT-2 multi-functional tribological tester. The corrosion properties were evaluated using linear polarisation technique in 3.5% NaCl. The result showed that the coatings exhibited good stability and the quantitative particle loading significantly improved the micro-structural properties of the coating. It is also noticed that the hardness performance and corrosion resistance of the coatings were significantly impacted with over 70% improvement as against the as-received samples.
关键词： Zn-TiO2-ZnO,electrocodeposition,coatings,corrosion resistance,nanocomposite
更新于2025-09-09 09:28:46
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Máscaras mecanicas de sombra por eletrocorros?o para dispositivos eletro-ópticos
摘要： Shadow masks are used in manufacturing processes for electro-optic devices to transfer patterns with different shapes and dimensions. For fabrication of organic based devices, shadow masks should be made of materials stable against organic solvents, high temperature, and robust, remaining unchanged after multiple cycles of use and fixation. Thus, stainless steel is suitable for shadow masks. A simple, cheap and quick method of obtaining shadow masks by electrochemical corrosion of stainless steel is reported. The shadow mask was used to evaporate cathode material to obtain an organic light emitting diode with active area of 9 mm2. This device exhibited a turn-on voltage of 5 V and luminance of 14 cd/m2.
关键词： electro-optic devices,electrochemical corrosion,shadow mask
更新于2025-09-09 09:28:46
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Characterization and Photocatalytic Performance of Potassium-Doped Titanium Oxide Nanostructures Prepared via Wet Corrosion of Titanium Microspheres
摘要： Potassium doped titanium oxide (KTiOx) nanowires were prepared by the wet corrosion process (WCP) and their photocatalytic effects were systematically characterized. For the synthesis of KTiOx, the potassium hydroxide concentration of the WCP was varied in order to obtain nanostructures with different surface area and surface charge. Structural and crystalline properties of KTiOx were studied by means of X-ray diffraction, scanning and transmission electron microscopy. Chemical composition was determined by X-ray fluorescence and energy-dispersive X-ray analysis. Photocatalytic performance was investigated as a function of the surface area, pH, and crystalline structures by studying the degradation of methylene blue, cardiogreen, and azorubine red dyes upon UV irradiation. The negatively charged crystalline KTiOx nanostructures with high surface area showed significantly higher photocatalytic degradation compared to their TiOx counterpart. They also showed high efficiency for recovery and re-use. Annealing KTiOx nanostructures improved structural properties leading to well-ordered layered structures and improved photocatalysis. However, annealing at temperatures higher than 600 °C yielded formation of rutile grains at the surface of nanowires, significantly affecting the photocatalytic performance. We believe that KTiOx nanostructures produced by WCP are very promising for photocatalysis, especially due to their high photocatalytic efficiency as well as their potential for re-use and durability.
关键词： Titanium Core Shell,KTiOx,Wet Corrosion Process,Photocatalysis,Nanostructures
更新于2025-09-09 09:28:46
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Anti-corrosion prevention of carbon steel by means of laser treatment
摘要： The article is devoted to the research of the opportunity for the increasing corrosion resistance of steel. The results of the experiments of laser processing of model samples made of carbon steel with CW ytterbium fiber laser at a wavelength of 1.06 micron. It is shown that laser processing can form resistant protective film with a thickness of 2–3 microns on the steel surface, which improve anti-corrosion properties of metal. One of the possible reasons for the increase in corrosion resistance of steel is the microstructuring of its surface to form a thin film of iron carbide (Fe3C), which is formed as a result of heating in the temperature range from 600 to 1000 °C. Besides, the exposure to laser radiation leads to reduction of surface roughness (from Ra = 0.53 μm to Ra = 0.48 μm). Optimal (from the point of view of the degree of resistance to corrosion) steel processing mode corresponds to the density level of laser radiation power density of 1.5 · 105 W cm?2, the conducted research allows to conclude that the use of CW fiber lasers is a promising method of improving the corrosion resistance of carbon steel.
关键词： fiber laser,steel treatment,anti-corrosion,laser micro structuring,metal treatment
更新于2025-09-04 15:30:14
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An overview of corrosion defect characterization using active infrared thermography
摘要： Corrosion is considered a destructive phenomenon that affects almost all metals. There is a variety of corrosion monitoring and measurement techniques being deployed across industries. However, very few techniques are ideally characterised with non-contact, non-intrusive, on-line and direct features for measuring the accurate corrosion rate or actual metal loss. Infrared Thermography (IRT) allows the recording of electromagnetic waves emitted from objects by using an infrared imaging system, such as an infrared camera. IRT is an online method of Non-Destructive Testing (NDT) meaning the delays in receiving results from a laboratory experienced in many NDT techniques can be eliminated. It is non-intrusive which means no process disruption and downtime will be imposed to the production line. It is also a non-contact method which mitigates the hazard occurrence and need for highly experienced personnel.
关键词： Infrared thermography,Non-destructive testing,Corrosion monitoring,Structural health monitoring,Image processing
更新于2025-09-04 15:30:14
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Atomic layer deposited TiO <sub/>2</sub> -IrO <sub/>x</sub> alloys enable corrosion resistant water oxidation on silicon at high photovoltage.
摘要： We synthesized by atomic layer deposition (ALD) TiO2-IrOx alloys that enable high photovoltages and catalyze water oxidation on silicon metal-insulator-semiconductor (MIS) photoanodes. The ratio of TiO2 to IrOx was precisely controlled by varying the number of ALD cycles for each precursor. Silicon with a 2 nm surface SiO2 layer was coated with TiO2-IrOx alloys ranging in composition from 18-35% iridium relative to the sum of titanium and iridium concentrations. IrOx catalyzed oxygen evolution and imparted a high work function to the TiO2-IrOx alloys, enabling photovoltages during water oxidation that exceeded 600 mV. TiO2 imparted stability and inhibited corrosion of the underlying silicon light absorber. After annealing in forming gas (5% H2 / 95% N2), TiO2-IrOx alloys were stable for 12 hours of continuous water oxidation in 1 M H2SO4. Key properties of the MIS junction affecting electrochemical operation were also extracted by electrochemical impedance spectroscopy. This work demonstrates that alloying by ALD is a promising approach for designing corrosion resistant Schottky contacts with optimized electronic and materials properties for catalyzed, solar driven water oxidation.
关键词： photovoltage,water oxidation,TiO2-IrOx alloys,Atomic layer deposition,corrosion resistance,silicon photoanodes
更新于2025-09-04 15:30:14
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[IEEE 2018 IEEE 7th World Conference on Photovoltaic Energy Conversion (WCPEC) (A Joint Conference of 45th IEEE PVSC, 28th PVSEC & 34th EU PVSEC) - Waikoloa Village, HI, USA (2018.6.10-2018.6.15)] 2018 IEEE 7th World Conference on Photovoltaic Energy Conversion (WCPEC) (A Joint Conference of 45th IEEE PVSC, 28th PVSEC & 34th EU PVSEC) - Reactive Silver Ink as a Novel Low-Temperature Metallization: Monitoring Corrosion
摘要： Reactive silver ink (RSI) forms low-resistivity (<5 μΩ?cm) metallization at temperatures below 100 °C –enabling lower resistive losses for thermally sensitive solar cells while drastically reducing Ag usage compared to other low-temperature Ag pastes. However, before adoption of the technology many reliability related questions must be addressed. Ag-based metallizations are susceptible to corrosion by acetic acid formed in encapsulated modules, resulting in increased resistive losses. Here we report on corrosion of three types of metallizations; high-firing-temperature Ag paste (HT Ag Paste), low-temperature Ag paste (LT Ag Paste), and RSI. We develop a method for exposing these metallizations to dilute acetic acid in concentrations comparable to those found in field- and damp heat-exposed modules. We find that HT Ag and RSI are quickly affected by acetic acid exposure after only 24 h. Interestingly, Raman spectroscopy suggests the formation of AgCl or AgCH3COO on HT Ag Paste, dissolution of AgCH3COO from RSI, and LT Ag Paste remains relatively unchanged throughout 2936 h of exposure to diluted acetic acid.
关键词： low temperature metallization,silver usage,metallization,silver,corrosion
更新于2025-09-04 15:30:14