scholarly journals Electrochemical and Oxidation Behavior of Yttria Stabilized Zirconia Coating on Zircaloy-4 Synthesized via Sol-Gel Process

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
S. Rezaee ◽  
Gh. R. Rashed ◽  
M. A. Golozar
Keyword(s):  
Heat Treatment ◽  
Electrochemical Impedance ◽  
Sol Gel ◽  
Dip Coating ◽  
Open Circuit ◽  
Treatment Temperature ◽  
Yttria Stabilized Zirconia ◽  
Coated Sample ◽  
Stabilized Zirconia ◽  
Temperature Oxidation

Sol-gel 8 wt.% Yttria Stabilized Zirconia (YSZ) thin films were prepared on zirconium (zircaloy-4 alloy) by dip-coating technique followed by heat treating at various temperatures (200°C, 400°C, and 700°C) in order to improve both electrochemical corrosion and high temperature oxidation properties of the substrate. Differential thermal analysis and thermogravimetric analysis (DTA-TG) revealed the coating formation process. X-ray diffraction (XRD) was used to determine the crystalline phase structure transformation. The morphological characterization of the coatings was carried out using scanning electron microscopy (SEM). The electrochemical behavior of the coated and uncoated samples was investigated by means of open circuit potential, Tafel, and electrochemical impedance spectroscopy (EIS) in a 3.5 wt.% NaCl solution. The homogeneity and surface appearance of coatings produced was affected by the heat treatment temperature. According to the corrosion parameters, the YSZ coatings showed a considerable increase in the corrosion resistance, especially at higher heat treatment temperatures. The coating with the best quality, from the surface and corrosion point of view, was subjected to oxidation test in air at 800°C. The coated sample presented a 25% reduction in oxidation rate in comparison with bare substrate.

scholarly journals Effect of Deposition Conditions on Phase Content and Mechanical Properties of Yttria-Stabilized Zirconia Thin Films Deposited by Sol-Gel/Dip-Coating

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Francisco J. Cano ◽  
Orlando Castilleja-Escobedo ◽  
L. J. Espinoza-Pérez ◽  
Cecilia Reynosa-Martínez ◽  
Eddie Lopez-Honorato
Keyword(s):  
Heat Treatment ◽  
Wear Rate ◽  
Adhesion Strength ◽  
Surface Defects ◽  
Sol Gel ◽  
Dip Coating ◽  
Yttria Stabilized Zirconia ◽  
Cubic Phase ◽  
Phase Content ◽  
Stabilized Zirconia

The effect of yttria concentration (0-33.4 mol%), extraction rates (0.17, 0.33, 0.50, and 0.67 mm s-1), and the number of layers (up to four) on the phase content, surface defects, thickness, hardness, adhesion strength, and wear rate of yttria-stabilized zirconia coatings produced by sol-gel/dip-coating were studied for its use on thermolabile substrates. At 700°C, a metastable tetragonal phase ( t ″ ) was obtained even with 33.4 mol% yttria when heat treated for 24 hours; however, a fully cubic structure was attained by extending the heat treatment up to 48 hours as confirmed by Raman spectroscopy. Furthermore, it was necessary to use withdrawal speeds of at least 0.67 mm s-1 to produce defect-free coatings. Although the coatings were produced at low temperature, they showed 41% lower wear rate than steel and an adhesion strength of 30 MPa. Our work stresses the importance of the heat treatment history on the stabilization of the cubic phase in sol-gel YSZ coatings.

Modification of Electroless Nickel-Plating Coatings with Sol-Gel Film

2005 ◽  
Vol 475-479 ◽  
pp. 3835-3838 ◽  
Author(s):  
Hui Cong Liu ◽  
Liqun Zhu ◽  
Yan Bin Du
Keyword(s):  
Heat Treatment ◽  
Oxidation Resistance ◽  
Sol Gel ◽  
Electroless Nickel ◽  
Dip Coating ◽  
Treatment Temperature ◽  
Gel Film ◽  
Sol Gel Films ◽  
Corrosion And Oxidation

Four Sol-Gel films were developed by dip-coating electroless nickel-plated samples in different Sols, followed by heat treatment. The effects of the coating times and heat treatment temperature on the corrosion, oxidation resistance and wearing quality of the modified coating were examined. Results show that, after six coating, Sol-Gel films obtained can provide good corrosion and oxidation resistance, and their anti-corrosion quality remains high even after being oxidized at 500 °C for 60 hours. Addition of inorganic molybdenum salt or chromate into the Ti Sol also makes the wearing quality of the Sol-Gel film better.

Preparation and Optical Absorption Properties of CuO/SiO2 Nanocomposite Films Fabricated by Sol-Gel Technique

2009 ◽  
Vol 60-61 ◽  
pp. 283-287
Author(s):  
Jia Qin Liu ◽  
Yu Cheng Wu ◽  
Guang Hai Li ◽  
Li De Zhan
Keyword(s):  
Heat Treatment ◽  
Heat Treatment Temperature ◽  
Sol Gel ◽  
Dip Coating ◽  
Treatment Temperature ◽  
Nanocomposite Films ◽  
Sio2 Matrix ◽  
Heat Treated ◽  
Mesoporous Sio2 ◽  
Dip Coating Technique

CuO/SiO2 nanocomposite films were prepared by sol-gel process combined with the dip-coating technique. The mean diameter of CuO nanoparticles formed during the heat treatment process and mainly lay in the pores of mesoporous SiO2 matrix increased by increasing the heat treatment temperature. Consequently, compared with mesoporous SiO2 matrix, the pore volume and specific surface area of prepared samples descend. The diffraction peaks of Cu and CuO and the crystalline diffraction ring of CuO with body centered cubic structure can be clearly observed after heat-treated in air and H2 at 800 oC for 1h. By increasing the heat treatment temperature and concentration of CuO, a slightly red-shift could be observed.

Fluorescence property and dissolution site of Er3+ in Ta2O5 film prepared by sol-gel method and dip-coating technique

2004 ◽  
Vol 19 (2) ◽  
pp. 667-675 ◽  
Author(s):  
Noriyuki Wada ◽  
Michiyo Kubo ◽  
Nobuko Maeda ◽  
Maegawa Akira ◽  
Kazuo Kojima
Keyword(s):  
Heat Treatment ◽  
Sol Gel ◽  
Dip Coating ◽  
Treatment Temperature ◽  
Fluorescence Property ◽  
Gel Method ◽  
Sol Gel Method ◽  
Coating Technique ◽  
Ta2o5 Film ◽  
Dip Coating Technique

Ta2O5–xEr2O3 (TE) films were produced by a sol-gel method and a dip-coating technique with heat treatment at 600–1000 °C. Their powders were also prepared from the same sol. The Er3+ fluorescence property of the TE films containing various contents of Er3+ was measured as a function of the heat-treatment temperature. In crystallized films, the Er3+ fluorescence was observed because water-related residues (Ta–OH and H2O) and carbon-related residues (–CH3, –CH2–, –(C ⁼ O)–, and C≡C–H) were removed from the films. It is shown from infrared absorption spectroscopy that Ta–O− and Ta ⁼ O structures dissolve the Er3+ ions selectively and play a role in dispersing the Er3+. The strongest Er3+ fluorescence is observed in the TE film with 2 mol% of Er2O3 because of its highest ability to disperse the Er3+ ions.

Characterizations of Synthetic 8mol% YSZ with Comparison to 3mol %YSZ for HT-SOFC

2020 ◽  
Vol 38 (4A) ◽  
pp. 491-500
Author(s):  
Abeer F. Al-Attar ◽  
Saad B. H. Farid ◽  
Fadhil A. Hashim
Keyword(s):  
Ionic Conductivity ◽  
Electrochemical Impedance ◽  
Structural Information ◽  
Impedance Analysis ◽  
High Energy ◽  
Yttria Stabilized Zirconia ◽  
X Ray Diffraction ◽  
Stabilized Zirconia ◽  
Powder Morphology ◽  
X Ray

In this work, Yttria (Y2O3) was successfully doped into tetragonal 3mol% yttria stabilized Zirconia (3YSZ) by high energy-mechanical milling to synthesize 8mol% yttria stabilized Zirconia (8YSZ) used as an electrolyte for high temperature solid oxide fuel cells (HT-SOFC). This work aims to evaluate the densification and ionic conductivity of the sintered electrolytes at 1650°C. The bulk density was measured according to ASTM C373-17. The powder morphology and the microstructure of the sintered electrolytes were analyzed via Field Emission Scanning Electron Microscopy (FESEM). The chemical analysis was obtained with Energy-dispersive X-ray spectroscopy (EDS). Also, X-ray diffraction (XRD) was used to obtain structural information of the starting materials and the sintered electrolytes. The ionic conductivity was obtained through electrochemical impedance spectroscopy (EIS) in the air as a function of temperatures at a frequency range of 100(mHz)-100(kHz). It is found that the 3YSZ has a higher density than the 8YSZ. The impedance analysis showed that the ionic conductivity of the prepared 8YSZ at 800°C is0.906 (S.cm) and it was 0.214(S.cm) of the 3YSZ. Besides, 8YSZ has a lower activation energy 0.774(eV) than that of the 3YSZ 0.901(eV). Thus, the prepared 8YSZ can be nominated as an electrolyte for the HT-SOFC.

Experimental study of the mechanical and corrosion properties of ethyl silicate resin applied on low carbon steel

2021 ◽  
Vol 2 (108) ◽  
pp. 68-74
Author(s):  
M. Ali ◽  
J.H. Mohmmed ◽  
A.A. Zainulabdeen
Keyword(s):  
Heat Treatment ◽  
Carbon Steel ◽  
Open Circuit Potential ◽  
Low Carbon Steel ◽  
Open Circuit ◽  
Treatment Temperature ◽  
Ethyl Silicate ◽  
Low Carbon ◽  
Corrosion Properties ◽  
Mixture Ratio

Purpose: This work aimed at evaluating the properties of the ethyl silicate-based coating that can be applied on low carbon steel. Design/methodology/approach: Two mixture ratio types (2:1, and 3:2) of resin and hardener respectively were used to prepared two specimen models (A and B). Findings: It found that some mechanical properties (tensile, hardness, and impact strength) of ethyl silicate resin were evaluated according to standard criteria. Research limitations/implications: The effect of heat treatments at various temperatures (100, 150, and 200°C) and holding at different times (10, 20 & 30) min on hardness was investigated. Practical implications: Moreover, an open circuit potential corrosion test with a solution of 3.5% Sodium Chloride at room temperature and 60°C was used to determine the corrosion resistance of low carbon steel specimens coated with the two mixture types. Originality/value: The effects of mixture ratios (for resin and hardener) and heat treatment conditions on properties of ethyl silicate-based coating were studied. From obtained results, acceptable values of tensile, hardness, and toughness were recorded. Increasing heat treatment temperature and holding time leads to enhance hardness for both model types. An open circuit potential (OCP) tests show that there is an enhancement of protective properties of ethyl silicate coatings with mixture type B in comparison with type A was achieved. Generally, the results indicate that specimen model B has higher properties as compared with specimen model A.

Characteristics of Lithium Polysilicate Electrolyte Synthesized by Sol-Gel Processing

2007 ◽  
Vol 124-126 ◽  
pp. 1031-1034
Author(s):  
Bong Soo Jin ◽  
Bok Ki Min ◽  
Chil Hoon Doh
Keyword(s):  
Heat Treatment ◽  
Acid Treatment ◽  
Treatment Time ◽  
Sol Gel ◽  
Silicate Solution ◽  
Treatment Temperature ◽  
Lithium Silicate ◽  
Treatment Conditions ◽  
Xrd Patterns ◽  
Si Wafer

To find out suitable Si surface treatment and heat treatment conditions, acid treatment of Si wafer was done for lithium polysilicate electrolyte coating on Si wafer. In case of HCl treatment, the wet angle of a sample is 30o, which is the smallest wet angle of other acid in this experiment. Acid treatment time is 10 min, which is no more change of wet angle. Lithium polysilicate electrolyte was synthesized by hydrolysis and condensation of lithium silicate solution using perchloric acid. Thermal analysis of lithium polysilicate electrolyte shows the weight loss of ~23 % between 400 and 500 , which is due to the decomposition of LiClO4. The XRD patterns of the obtained lithium polysilicate electrolyte also show the decrement of LiClO4 peak at 400 . The optimum heat treatment temperature is below 400 , which is the suitable answer for lithium polysilicate electrolyte.

Characterization and Electrochemical Performances of Vanadium Oxide Films Doped with Metal Ions

2013 ◽  
Vol 537 ◽  
pp. 174-178
Author(s):  
Ji Chao Wang ◽  
Guang Ming Wu ◽  
Guo Hua Gao ◽  
Xiao Wei Zhou
Keyword(s):  
Metal Ions ◽  
Vanadium Oxide ◽  
Volume Fraction ◽  
Electrochemical Impedance ◽  
Sol Gel ◽  
Electrochemical Techniques ◽  
Oxide Films ◽  
Dip Coating ◽  
Electrochemical Performances ◽  
Vanadium Oxide Films

Vanadium oxide films were prepared via the sol–gel process and dip coating method, using V2O5as raw materials and H2O2(volume fraction 30) as the solvent. Mn and Ni ions were added to vanadium oxide sol to prepare doping vanadium oxide films. The films were characterized by atomic force microscopy, FT-IR, X-ray diffraction and electrochemical techniques. The add-on of Metal ions will not affect the morphology of the vanadium oxide films, but change the valence of vanadium ion and vanadium oxide crystal phase. Furthermore, cyclic voltammetry curves show that metal ions doping vanadium oxide films exhibit reversible electrochemical reaction. But electrochemical impedance spectroscopy indicates pure vanadium oxide film has a better diffusion rate.

Preparation of La0.75Sr0.25Cr0.5Mn0.5O3-δ Nanometer Powders by Sol-Gel Method and Research about its Electrochemical Performance

2013 ◽  
Vol 712-715 ◽  
pp. 257-261
Author(s):  
Yin Lin Wu ◽  
Qing Hui Wang ◽  
Ling Wang ◽  
Hai Yan Zhao
Keyword(s):  
Heat Treatment ◽  
Particle Size ◽  
Electrochemical Performance ◽  
Heat Treatment Temperature ◽  
Sol Gel ◽  
Treatment Temperature ◽  
Preparation Process ◽  
Gel Method ◽  
Sol Gel Method ◽  
Ft Ir

The La0.75Sr0.25Cr0.5Mn0.5O3-δnanometer powders were prepared by citric acid sol-gel method.The samples were characterized by DTA, FT-IR, XRD, TEM techniques. The preparation process, morphology of synthesized powders, the best heat-treatment temperature and the electrochemical performance had been studied. The results show that the spherical nanometer powders can be obtained and the best heat-treatment temperature is 800°C. The particle size is about 30nm and Ea is 0.071 eV.

Medium-Low-Temperature NO2 Sensor Based on YSZ Solid Electrolyte and Mesoporous WO3 Sensing Electrode for Detection of Vehicle Emissions

NANO ◽  
2021 ◽  
pp. 2150083
Author(s):  
Cheng Zhang ◽  
Chuning Jiang ◽  
Xiaohong Zheng ◽  
Xin Hong
Keyword(s):  
Low Temperature ◽  
Electromotive Force ◽  
Electrochemical Impedance ◽  
Yttria Stabilized Zirconia ◽  
Mixed Potential ◽  
Stabilized Zirconia ◽  
Excellent Performance ◽  
Hard Template ◽  
No2 Sensor ◽  
Hard Template Method

A mixed potential-type NO2 sensor was fabricated using yttria-stabilized zirconia (YSZ) as the electrolyte and mesoporous WO3 as the sensing electrode for the detection of NO2 in vehicle exhausts. The mesoporous WO3 with a diameter of 7 nm was synthesized using the hard template method. The sensor showed excellent performance in the detection of 30–500[Formula: see text]ppm of NO2 at 300∘C and 500∘C. However, commercial WO3 only operate well at 500∘C. The response of the mesoporous WO3 was higher and the test temperature was lower compared to that of commercial WO3. XPS combined with NO2-TPD was used to explain the high activity of mesoporous WO3 at medium-low temperature, and the mechanism of mixed electromotive force was verified by electrochemical impedance spectroscopy. Furthermore, the sensor exhibited high NO2 selectivity in the presence of interfering gases, such as NO, CO, CO2 and NH3. Most importantly, the sensor had excellent repeatability and stability.

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