Optical and Corrosion Studies of Spray Pyrolysis Coated Titanium Dioxide Thin Films

2018 ◽  
Vol 24 (8) ◽  
pp. 5836-5842 ◽  
Author(s):  
V. P. Muhamed Shajudheen ◽  
K. Anitha Rani ◽  
V. Senthil Kumar ◽  
A. Uma Maheswari ◽  
M Sivakumar ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Titanium Dioxide ◽  
Spray Pyrolysis ◽  
Salt Spray ◽  
Salt Spray Test ◽  
Neutral Salt ◽  
X Rays

In the present work, nanostructured thin films of titanium dioxide (TiO2) have been coated on the stainless steel (SS 304L) substrate by spray pyrolysis coating technique. The surface morphology and chemical constituents of the thin film have recorded using Field Effect Scanning Electron Microscopy (FESEM) and Energy Dispersive Analysis of X-rays (EDAX) respectively. The structural and optical properties of the films of as deposited were examined by Micro Raman, Photoluminescence Spectroscopy (PL) and UV-Vis absorption method. The FESEM micrograph showed the microporous nature of the film. EDAX spectrum illustrated the presence of Ti and O on the coated surface of the steel substrate. The peaks in the micro Raman spectrum indicated that the TiO2 samples of present study are in rutile phase of titanium dioxide. A strong emission peak around 350 nm was observed in the Photoluminescence spectrum of the samples. The anti-corrosion properties of the TiO2 coated samples were investigated by neutral salt spray test for 390 h. Electrochemical Impedance Spectroscopy (EIS) analysis and Tafel analysis were performed before and after salt spray test and the results suggested an increase of corrosion resistance of the titanium dioxide thin film in a corrosive environment. The positive shift of equilibrium corrosion potential (Ecorr) of bare stainless steel to thin film coated stainless steel (from −0.96 V to −0.38 V) in the electrochemical Tafel analysis implied the significant increase of corrosion resistance.

scholarly journals Ultrasonic Sensors-Assisted Corrosion Studies on Surface Coated AlSi9Cu3 Alloy Die Castings

Coatings ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 85
Author(s):  
Yuh-Chung Hu ◽  
Senthil Kumaran Selvaraj ◽  
Manivannan Subramanian ◽  
Kathiravan Srinivasan ◽  
Srinivasan Narayanan
Keyword(s):  
Corrosion Resistance ◽  
Die Casting ◽  
Pure Aluminum ◽  
Salt Spray ◽  
Salt Spray Test ◽  
Al Alloy ◽  
Neutral Salt ◽  
Powder Coatings ◽  
Acrylic Paint ◽  
Epoxy Primer

A novel phenomenon known as Industry X.0 is becoming extremely popular for digitizing and reinventing business organizations through the adaption of rapid and dynamic technological, innovational, and organizational changes for attaining the profitable revenue. This work investigates the die-casted commercially pure aluminum alloyed with 9% silicon and 3% copper (AlSi9Cu3) that is produced through the gravity die casting process. Further, the degradation of surface coating on die-casted AlSi9Cu3 alloy was explored. The acrylic paint electrodeposition (ED) coat, 2-coat polyester without primer and 3-coat polyester with epoxy primer powder coatings were used in this study. Moreover, the 3.5 wt.% of sodium chloride (3.5 wt.% of NaCl) test solution was used for electrochemical and salt spray test and the tools used to assess electrochemical properties were electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, and neutral salt spray test (NSS). The microstructure of AlSi9Cu3 after corrosion exposure was investigated; also, the microstructure of coated and uncoated AlSi9Cu3 samples was analyzed by SEM microscopy after corrosion exposure. Besides, the electrochemical studies were also carried out on the Al alloy die casting. It was found that acrylic paint ED coatings exhibited higher corrosion resistance than 2-coat polyester without primer & 3-coat polyester with epoxy primer powder coatings. Acrylic paint ED coating showed higher corrosion resistance in AC and a lower value in DC and 3-coat polyester with epoxy primer powder coating displayed higher corrosion resistance in DC and a lower value in AC.

The Fabrication of Titanium Dioxide (TiO2) Thin Film via Deposited Spray Pyrolysis Using for Antibacterial Applications

2015 ◽  
Vol 804 ◽  
pp. 183-186
Author(s):  
Prapon Lertloypanyachai ◽  
Eakgapon Kaewnuam ◽  
Krittiya Sreebunpeng
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Titanium Dioxide ◽  
Spray Pyrolysis ◽  
Uv Light ◽  
Spray Pyrolysis Technique ◽  
Low Cost ◽  
Large Area ◽  
Bacteria Growth ◽  
Glass Substrates

Titanium dioxide (TiO2) is coated onto the materials (e.g.glass ceramic) to inhibit the bacteria growth. TiO2has become a popular photocatalyst for both air and water purification. It has also shown to be very active for bacterial destruction even under UV light. The photocatalytic of TiO2involves the light-induced catalysis of reducing and oxidizing reactions on the surface of materials. The spray pyrolysis technique for material synthesis in thin-film configuration is an interesting option due to the use of inexpensive precursor materials and low-cost equipment suitable for large-area coatings. In this research, TiO2thin films were deposited onto glass substrates using spray pyrolysis technique. Escherichia coli (E.coli) was used as testing bacteria. TiO2thin films showed some antibacterial effect in the halo test.

Particle-Doped Organic-Inorganic Hybrid Coatings as Corrosion Inhibiting Surface Treatments for Aluminum Alloys

2002 ◽  
Vol 726 ◽  
Author(s):  
Tammy L. Metroke ◽  
Olga Kachurina ◽  
Edward T. Knobbe
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Corrosion Resistance ◽  
Salt Spray ◽  
Electrochemical Analysis ◽  
Hybrid Coatings ◽  
Inorganic Hybrid ◽  
Good Corrosion Resistance ◽  
Potentiodynamic Polarization Curves ◽  
Organically Modified

AbstractOrganically-modified silicate (Ormosil) films have been found to provide good corrosion resistance for metal substrates and are potential replacement systems for hexavalent chromiumbased conversion coatings. Significant enhancement in corrosion resistance properties were observed upon addition of sub-micron to micron-sized particles (TiO2, Al2O3, SiN, TiN) to the Ormosil coating as determined using accelerated salt spray and electrochemical analysis. Rcorr values derived from potentiodynamic polarization curves were found to increase from 1520 to (3800 - 4680) kΩcm2 upon addition of various concentrations of TiO2, Al2O3, SiN or TiN particles to the Ormosil thin film. Similarly, Epit values were found to range from +0.2 V for the non-doped Ormosil to (0.6 – 1.9) V for particle-doped Ormosil thin films.

Research on the Performance of Shielded Wire Passivated by 823 Preservatives in Neutral Salt Spray Test

2014 ◽  
Vol 556-562 ◽  
pp. 3-5
Author(s):  
Ke Shun Dai ◽  
Wen Kai Xiao ◽  
Tan Yu
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Polarization Curve ◽  
Salt Spray ◽  
Corrosion Cracking ◽  
Salt Spray Test ◽  
Normal Operation ◽  
Neutral Salt

The corrosion cracking of Shielded wire could result in protection equipments and automatic devices failing to work, which seriously affects the normal operation of the grid [1]. Therefore, researching the corrosion of Shielded wire has an important meaning. This article, through measurements of the polarization curve of the shield, researched the corrosion rate of different spray time and treatments, and came to a conclusion that the corrosion resistance after passivated by 823 preservatives is higher than before it.

scholarly journals Study on the Corrosion Mechanism of Zn-5Al-0.5Mg-0.08Si Coating

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Shiwei Li ◽  
Bo Gao ◽  
Ganfeng Tu ◽  
Yi Hao ◽  
Liang Hu ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Salt Spray ◽  
Microstructural Characterization ◽  
Alloy Coating ◽  
Salt Spray Test ◽  
Corrosion Mechanism ◽  
Neutral Salt ◽  
Test Results ◽  
Coating Surface ◽  
New Type

A new type of hot-dip Zn-5Al-0.5Mg-0.08Si and Zn-5Al alloy coatings was performed on the cold rolled common steel. The hot-dip process was executed by self-made hot-dip galvanising simulator. SEM and EDS test results demonstrated that Mg was mainly distributed in crystal boundaries. XRD test results showed that the corrosion product of Zn-5Al-0.5Mg-0.08Si alloy coating was almost Zn5(OH)8C12⋅H2O. The features of Zn5(OH)8C12⋅H2O are low electric conductivity, insolubility and good adhesion.The corrosion resistance of alloy-coated steels was detected by neutral salt spray test. The microstructural characterization of the coating surface after neutral salt spray test and removing the corrosion products revealed that the corrosion process of Zn-5Al-0.5Mg-0.08Si coating was uniform and the coating surface was almost flat. As a result, the corrosion resistance of Zn-5Al-0.5Mg-0.08Si coating has a remarkable improvement with a factor of 9.2 compared with that of Zn-5Al coating.

The Significance of Buffer Solutions on Corrosion Processes of Cobalt Ferrite CoFe2O4 Thin Film on Different Substrates

2020 ◽  
Vol 23 (7) ◽  
pp. 599-610
Author(s):  
Elsayed M. Elsayed ◽  
Hazem F. Khalil ◽  
Ibrahim A. Ibrahim ◽  
Mostafa R. Hussein ◽  
Mohamed M.B. El-Sabbah
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Stainless Steel ◽  
Magnetic Properties ◽  
Corrosion Resistance ◽  
Alkaline Medium ◽  
Cobalt Ferrite ◽  
Spinel Ferrite ◽  
Open Circuit ◽  
Hard Material

Background: The spinel ferrite nanoparticles, such as zinc, nickel, and cobalt ferrites have exceptional electronic and magnetic properties. Cobalt ferrite nanomaterial (CoFe2O4) is a hard material that reveals high magnetic, mechanical, and chemical stability. Aim and Objective: The objective of this research is to predict the corrosion behavior of cobalt ferrite (CoFe2O4) thin films deposited on different substrates (platinum Pt, stainless steel S.S, and copper Cu) in acidic, neutral, and alkaline medium. Materials and Method: Cobalt ferrite thin films were deposited on platinum, stainless steel, and copper via electrodeposition-anodization process. After that, corrosion resistance of the prepared nanocrystalline cobalt ferrite on different substrates was investigated in acidic, neutral, and alkaline medium using open circuit potential and potentiodynamic polarization measurements. The crystal structure, crystallite size, microstructure, and magnetic properties of the ferrite films were investigated using a combination of XRD, SEM and VSM. Results: The results of XRD revealed a cubic spinel for the prepared cobalt ferrite CoFe2O4. The average size of crystallites was found to be about 43, 77, and 102 nm precipitated on platinum, stainless steel, and copper respectively. The magnetic properties of which were enhanced by rising the temperature. The sample annealed at 800oC is suitable for practical application as it showed high magnetization saturation and low coercivity. The corrosion resistance of these films depends on the pH of the medium as well as the presence of oxidizing agent. Conclusion: Depending on the obtained corrosion rate, we can recommend that, CoFe2O4 thin film can be used safely in aqueous media in neutral and alkaline atmospheres for Pt and Cu substrates, but it can be used in all pH values for S.S. substrate.

The Corrosion Resistance of Zn-Plated Samples with Blackish Green Passivation Film

2011 ◽  
Vol 383-390 ◽  
pp. 3081-3085
Author(s):  
Yu Bao Cao
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Sample Surface ◽  
Corrosion Current ◽  
Electrochemical Process ◽  
Salt Spray Test ◽  
Neutral Salt ◽  
Passivation Film ◽  
Passivated Sample

The corrosion resistance of blackishgreen passivation films on zinc-plated steel sheet was studied by polarization curve measurement, electrochemical impedance spectroscopy and neutral salt spray test. The passivated sample featured a more positive corrosion potential and much lower corrosion current density as compared to non-passivated sample in 5% (mass fraction) NaCl solution. The Nyquist plots of the samples with and without passivation were characterized as two complete capacitive arcs, indicating that the corrosion is controlled by electrochemical process. The radii of capacitive arcs of the passivated sample are larger than those of non-passivated sample, because the passivation film formed on the sample surface increases the reaction resistance in corrosion process, thus the corrosion resistance of the sample is improved. The anti-white rust time of the passivation film in neutral salt spray test is 400 h.

scholarly journals Design and Multidimensional Screening of Flash-PEO Coatings for Mg in Comparison to Commercial Chromium(VI) Conversion Coating

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 337
Author(s):  
Ewa Wierzbicka ◽  
Marta Mohedano ◽  
Endzhe Matykina ◽  
Raul Arrabal
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Protection ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Conversion Coating ◽  
Neutral Salt ◽  
Chromium Vi ◽  
Alkaline Electrolytes ◽  
Az31b Alloy ◽  
Plasma Electrolytic

REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) regulations demand for an expedient discovery of a Cr(VI)-free alternative corrosion protection for light alloys even though the green alternatives might never be as cheap as current harmful technologies. In the present work, flash- plasma electrolytic oxidation coatings (FPEO) with the process duration < 90 s are developed on AZ31B alloy in varied mixtures of silicate-, phosphate-, aluminate-, and fluoride-based alkaline electrolytes implementing current density and voltage limits. The overall evaluation of the coatings’ anticorrosion performance (electrochemical impedance spectroscopy (EIS), neutral salt spray test (NSST), paintability) shows that from nine optimized FPEO recipes, two (based on phosphate, fluoride, and aluminate or silicate mixtures) are found to be an adequate substitute for commercially used Cr(VI)-based conversion coating (CCC). The FPEO coatings with the best corrosion resistance consume a very low amount of energy (~1 kW h m−2 µm−1). It is also found that the lower the energy consumption of the FPEO process, the better the corrosion resistance of the resultant coating. The superb corrosion protection and a solid environmentally friendly outlook of PEO-based corrosion protection technology may facilitate the economic justification for industrial end-users of the current-consuming process as a replacement of the electroless CCC process.

scholarly journals Fabrication, micro-structure characteristics and transport properties of co-evaporated thin films of Bi2Te3 on AlN coated stainless steel foils

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aziz Ahmed ◽  
Seungwoo Han
Keyword(s):  
Thin Film ◽  
Crystal Structure ◽  
Thin Films ◽  
Stainless Steel ◽  
Substrate Temperature ◽  
Transport Properties ◽  
Structural Defects ◽  
Film Composition ◽  
High Substrate ◽  
Foil Substrate

AbstractN-type bismuth telluride (Bi2Te3) thin films were prepared on an aluminum nitride (AlN)-coated stainless steel foil substrate to obtain optimal thermoelectric performance. The thermal co-evaporation method was adopted so that we could vary the thin film composition, enabling us to investigate the relationship between the film composition, microstructure, crystal preferred orientation and thermoelectric properties. The influence of the substrate temperature was also investigated by synthesizing two sets of thin film samples; in one set the substrate was kept at room temperature (RT) while in the other set the substrate was maintained at a high temperature, of 300 °C, during deposition. The samples deposited at RT were amorphous in the as-deposited state and therefore were annealed at 280 °C to promote crystallization and phase development. The electrical resistivity and Seebeck coefficient were measured and the results were interpreted. Both the transport properties and crystal structure were observed to be strongly affected by non-stoichiometry and the choice of substrate temperature. We observed columnar microstructures with hexagonal grains and a multi-oriented crystal structure for the thin films deposited at high substrate temperatures, whereas highly (00 l) textured thin films with columns consisting of in-plane layers were fabricated from the stoichiometric annealed thin film samples originally synthesized at RT. Special emphasis was placed on examining the nature of tellurium (Te) atom based structural defects and their influence on thin film properties. We report maximum power factor (PF) of 1.35 mW/m K2 for near-stoichiometric film deposited at high substrate temperature, which was the highest among all studied cases.

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