Article
Electrochemistry
Sheila Silva-Fernandez, Belan Diaz, Iria Feijoo, Xose Ramon Novoa, Carmen Perez
Summary: The influence of temperature and pH variations on the Zn phosphate conversion treatment of high-strength steel was investigated. The results showed that higher temperature enhanced corrosion resistance for baths at pH 2.4, while pH 2.9 provided better surface coverage with smaller coating masses. Microstructural analysis revealed the formation of films composed of smaller crystals at pH 2.9. Impedance spectroscopy proved to be a powerful tool for characterizing phosphate layers, depending on the equivalent circuit used for simulation.
ELECTROCHIMICA ACTA
(2023)
Article
Materials Science, Coatings & Films
Ting Zhou, M. Ibrahim Coskun, Stephen Sanders, A. M. A. Mohamed, Teresa D. Golden
Summary: This study investigated the effects of Mo/Zn ratio on the structure and corrosion resistance of Zn-Mo coatings deposited on steel substrates in an alkaline solution. The coatings demonstrated decreasing crystallite size and the presence of zinc oxide and molybdenum oxide domains as the Mo/Zn ratio increased. The coatings exhibited excellent stability in a 3.5% NaCl solution due to protective oxide films in Mo-rich domains, with enhanced corrosion resistance observed in coatings with Mo/Zn ratios exceeding 10% after 30-day immersion in the NaCl solution.
SURFACE & COATINGS TECHNOLOGY
(2023)
Article
Chemistry, Applied
Diulia Quites, Anthony Somers, Maria Forsyth, Maria Paulis
Summary: Waterborne coatings are favored in industry for corrosion protection due to their low toxicity compared to traditional solvent-based coatings. However, the presence of surfactants in waterborne latex systems can negatively affect the barrier protection of the final films. This can be prevented by using polymerizable surfactants covalently bonded to the polymeric chains.
PROGRESS IN ORGANIC COATINGS
(2023)
Article
Chemistry, Multidisciplinary
Diana-Petronela Burduhos-Nergis, Gabriel Dragos Vasilescu, Dumitru-Doru Burduhos-Nergis, Ramona Cimpoesu, Costica Bejinariu
Summary: Phosphate coatings are crucial in preventing metal corrosion, offering advantages such as improved corrosion resistance, adhesion, and wear resistance. The study evaluates the potential of using phosphate coating in health and safety applications, specifically focusing on improving the corrosion resistance of carbon steel components for firefighter protective equipment. The research utilized electrochemical impedance spectroscopy and scanning electron microscope to analyze the electrochemical behavior of different coatings in fire extinguishing solution.
APPLIED SCIENCES-BASEL
(2021)
Article
Materials Science, Coatings & Films
Fan Yang, Debin Wang, Tianrun Li, Baijun Yang, Suode Zhang, Jianqiang Wang
Summary: The impact-corrosion behavior of monolayer and hierarchical Fe-based amorphous coatings fabricated by HVAF was investigated in 3.5 wt% NaCl solution. The monolayer coating exhibits corrosion failure with increased impact energy, while the hierarchical coating shows improved resistance. However, at high impact energies, both coatings experience corrosion degradation.
SURFACE & COATINGS TECHNOLOGY
(2024)
Article
Materials Science, Multidisciplinary
Carolina da Silva Lopes, Carlos Alberto Della Rovere, Isabel Cristina Rigoli, Claudia Lisiane Fanezi Da Rocha, Carlos Alberto Caldas De Souza
Summary: Zn-soybean nanocrystal composite coating was produced through electrodeposition, and the effect of nanocrystal addition on the coating characteristics was studied. The presence of soybean nanocrystal reduces the hardness, but increases the corrosion resistance of the coating.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Electrochemistry
Sheikh Idrees Ali, Sheikh Nazir Ahmad
Summary: In this study, Zn-Ni-Cu and Zn-Ni-Cu-TiB2 coatings were deposited on a mild steel substrate using HVOF thermal spray technique. Corrosion tests showed that both coatings exhibited corrosion resistance and developed less rust compared to the uncoated mild steel. Polarization and impedance tests confirmed the superior performance of the coatings in corrosive environments.
Article
Chemistry, Physical
Belen Diaz, X. Ramon Novoa, Carmen Perez, Sheila Silva-Fernandez
Summary: This research highlights the importance of acid cleaning before phosphate development on high-strength steel rods. It compares phosphate properties achieved under different acid-pickling conditions, revealing significant differences in coating morphology and chemical composition but minimal impact on weight or porosity. Hydrochloric and sulfuric acid are found to promote the growth of a Fe-enriched phosphate layer, while citric acid produces comparable results with slightly higher porosity. The temperature of the citric acid bath is an important factor affecting phosphate appearance, composition, and porosity.
Article
Chemistry, Physical
Chang Liu, Xiaopeng Lu, Yan Li, Qianqian Chen, Tao Zhang, Fuhui Wang
Summary: In this study, post-treatment process was utilized to enhance the corrosion and wear resistance of PEO coatings, with sol-gel and epoxy layers effectively sealing open pores to improve coating performance. The hybrid coatings with epoxy layer showed superior corrosion and wear resistance, especially with longer dipping time during post-treatment generating denser coatings with superior properties.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Electrochemistry
Yashwardhan Deo, Rishav Ghosh, Anushri Nag D. Vijay Kumar, Rajdeep Mondal, Atanu Banerjee
Summary: This study compared the properties of Zn-Mn coatings obtained by direct current and pulsed current electrodeposition, revealing that the coatings deposited by pulsed current had higher manganese content and better corrosion resistance. Zn-Mn coatings deposited by pulsed current at high frequency and low duty cycle exhibited a fine and compact morphology with the highest manganese content.
ELECTROCHIMICA ACTA
(2021)
Article
Chemistry, Physical
S. Velumani, G. Regmi, Minho Lee, H. Castaneda, Mathew Kuttolamadom, Xiaofeng Qian, A. Kassiba
Summary: The study demonstrates the improvements in properties of ultrathin coatings deposited using RF sputtering from optimized mechanically milled nanocomposites of zirconium dioxide (ZrO2), zinc oxide (ZnO), and titanium dioxide (TiO2), - Z(2)T, showcasing potential applications in antibacterial, anticorrosion, antireflection, and self-cleaning.
APPLIED SURFACE SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Marija Ridosic, Nebojsa D. Nikolic, Asier Salicio-Paz, Eva Garcia-Lecina, Ljiljana S. Zivkovic, Jelena B. Bajat
Summary: The main goal of this research was to electrodepose and characterize novel ceria-doped Zn-Co composite coatings. It was found that the use of ceria sol improved the corrosion resistance of the coatings, transforming them from a cauliflower-like morphology to a uniform and compact coral-like structure, and exhibited a good self-healing rate in a chloride-rich environment.
Article
Materials Science, Coatings & Films
Vanessa Husien Said, Florian Haakmann, Jessica Brinkbaeumer, Mathias Ulbricht
Summary: In this study, the cleaning behavior of a Ca-sulfonate film on zinc coatings with different alloy elements was investigated. The high polarity of the Mg-rich oxide layer in Zn-Al-Mg coatings led to less efficient cleaning of the Ca-sulfonate film. The strength of interaction between surface active corrosion inhibitors and the coating's oxide layer was found to be relevant for the cleaning and conversion coating process.
SURFACE & COATINGS TECHNOLOGY
(2022)
Article
Chemistry, Applied
Monica Penas-Caballero, Jesus Martin-Cordon, Violeta Barranco, Juan Carlos Galvan, Marianella Hernandez Santana, Miguel A. Lopez-Manchado, Raquel Verdejo
Summary: An autonomous self-healing polymer coating based on epoxy resin and superabsorbent polymer blend has been developed as an anticorrosion coating. It shows excellent performance in preventing coating delamination, protecting metal from corrosion, and enabling local repair of cracks.
PROGRESS IN ORGANIC COATINGS
(2023)
Article
Chemistry, Applied
Alfredo Rondinella, Ruben Offoiach, Francesco Andreatta, Giovanni Capurso, Luigi Calabrese, Edoardo Proverbio, Lorenzo Fedrizzi
Summary: In this study, a warning system using electrochemical impedance spectroscopy (EIS) measurements was developed to monitor the service status of organic coatings over large areas. The repeatability of measurements on surfaces with gradually increasing size was verified. A threshold value of normalized impedance modulus was set as a detectable warning signal for testing and maintenance of protective organic coatings. The monitoring lasted for nearly two years, validating the threshold value for long immersion times. The introduction of a defect could be easily detected through this system and the results were not significantly affected by disturbing factors. Additionally, a portable potentiostat was found to equally discern the state of protection of the organic coating, making the measurement system suitable for monitoring coated surfaces used in the naval industry.
PROGRESS IN ORGANIC COATINGS
(2023)
Article
Chemistry, Physical
Antonio Collazo, Raul Figueroa, Carmen Perez, Xose Ramon Novoa
Summary: This work focuses on the corrosion properties of 316L stainless steel obtained by selective laser melting (SLM), and compares the electrochemical results of samples manufactured with different parameters. The optimal manufacturing conditions were determined based on the analysis of microstructure and processing defects.
Article
Materials Science, Multidisciplinary
Belen Diaz, Xose Ramon Novoa, Carmen Perez, Miguel Rodriguez-Morgado
Summary: Graphene oxide (GO) is incorporated into waterborne resins due to its hydrophilic characteristic, improving corrosion resistance. This study focuses on the performance of a rust converter doped with different ratios of GO. X-ray diffraction and zeta-potential measurements are used to analyze the effect of GO additions. The optimal RC:GO ratio is found to be between 1:0.3 and 1:0.6, with the RC:0.3GO formulation showing the best corrosion resistance.
Article
Chemistry, Multidisciplinary
Ignacio Ezpeleta, Lorena Freire, C. Mateo-Mateo, X. Ramon Novoa, Aranzazu Pintos, Sara Valverde-Perez
Summary: Electrochemical impedance spectroscopy (EIS) was used to characterize the state and health of commercial cylindrical Li-ion cells under different conditions. By studying the redox reactions at the electrodes and considering the effects of temperature, a comprehensive electrical equivalent circuit was developed to assess the state-of-charge (SOC) and state-of-health (SOH) of the cell. The study demonstrated that the evolution of Li+ diffusion resistance through the solid electrolyte interface (SEI) layer could be used for early detection of cell degradation.
Article
Materials Science, Multidisciplinary
B. Diaz, X. R. Novoa, C. Perez, A. Pintos, V. Vivier
Summary: The need for a fast and reliable method for field monitoring reinforced concrete structures is addressed in this paper. A proof of concept is presented where a noncontact procedure provides quantitative information on the concrete resistivity and reinforcement corrosion rate. A Wenner-type probe is used to obtain the desired information by combining two- and four-electrode measurements in a relatively high-frequency domain.
Article
Chemistry, Applied
A. Collazo, B. Diaz, R. Figueroa, X. R. Novoa, C. Perez
Summary: This study investigates the effect of adding Graphene Oxide (GO) and reduced Graphene Oxide (rGO) on the corrosion protection provided by a water-borne resin applied on a galvanized steel substrate. The concentration and nature of the particles have significant influence on the results. Aggregation of GO and rGO affects the film morphology and the protective performance. Formulations with lower aggregation display better corrosion protection.
PROGRESS IN ORGANIC COATINGS
(2022)
Article
Electrochemistry
A. Collazo, R. Figueroa, C. Marino-Martinez, X. R. Novoa, C. Perez
Summary: A Fe-17Mn-6Si-19Cr-4Ni-1(V,C) shape memory steel was electrochemically characterized in both unstrained and pre-strained conditions. The study focused on studying the passive films formed in alkaline conditions and their behavior in different Cl / OH- ratios. The results showed that the passive film characteristics were similar in all samples, although the 304 L stainless steel exhibited higher corrosion resistance due to its higher Cr content. Additionally, the shape memory steels were found to be more sensitive to aggressive conditions, especially when pre-strained, and exhibited localized corrosion morphology at grain boundaries.
ELECTROCHIMICA ACTA
(2023)
Article
Electrochemistry
I. Bahtit, N. Gruet, B. Puga, X. R. Novoa, C. Thomas, V. Vivier
Summary: The corrosion of silicon-enriched stainless steel in nitric acid is highly dependent on the temperature of the electrolyte. In this study, the autocatalytic reduction mechanism of nitric acid on this material is highlighted using electrochemical measurements and chemical analyses. This research provides further insights into the nitric acid reduction on an oxidized material, despite slower kinetics, and shows the promotion of autocatalytic reactions in concentrated nitric acid.
ELECTROCHIMICA ACTA
(2023)
Review
Chemistry, Physical
X. R. Novoa, C. Perez
Summary: This article presents relevant developments in the characterisation of corrosion phenomena in the presence of two commonly used coating types: organic and inorganic (Portland cement) based coatings. Organic coatings act as physical barriers while cement-based coatings provide additional chemical protection due to high pH. Improving the performance of these coatings involves giving them self-healing characteristics, which can be analyzed using electrochemical techniques.
CURRENT OPINION IN ELECTROCHEMISTRY
(2023)
Article
Metallurgy & Metallurgical Engineering
I. Abidli, N. Souissi, K. Essalah, X. R. Novoa
Summary: The inhibition performance of aqueous Curcuma.L extract as a corrosion inhibitor for iron surface in 0.1 M HCl solution was investigated using ac impedance technique. The inhibitive effect of Curcuma.L extract was achieved through the adsorption of its molecules onto the iron surface and reached 81.1% at the optimal concentration. The main compounds in the extract, Curcumin (Inh A), demethoxycurcumin (Inh B), and bis-demethoxycurcumin (Inh C), showed varying inhibitive strengths, which could be attributed to their electron-donating abilities.
CANADIAN METALLURGICAL QUARTERLY
(2023)
Article
Electrochemistry
Sheila Silva-Fernandez, Belan Diaz, Iria Feijoo, Xose Ramon Novoa, Carmen Perez
Summary: The influence of temperature and pH variations on the Zn phosphate conversion treatment of high-strength steel was investigated. The results showed that higher temperature enhanced corrosion resistance for baths at pH 2.4, while pH 2.9 provided better surface coverage with smaller coating masses. Microstructural analysis revealed the formation of films composed of smaller crystals at pH 2.9. Impedance spectroscopy proved to be a powerful tool for characterizing phosphate layers, depending on the equivalent circuit used for simulation.
ELECTROCHIMICA ACTA
(2023)
Article
Construction & Building Technology
Zheng Dong, Chuanqing Fu, Chentao Lu, Xose Ramon Novoa, Hailong Ye
Summary: This study investigates the effect of stress state on the critical chloride content for depassivation of steel bars in a simulated concrete pore solution. Electrochemical techniques are used to study the passivation and depassivation behaviors of steel in chloride-free and chloride-containing solutions. The results show that stress enhances redox activity in highly alkaline solutions, with tension having a greater effect than compression. Stress also increases the donor density and dielectric properties of the passive film, significantly reducing the critical chloride content of steel by 80%.
JOURNAL OF MATERIALS IN CIVIL ENGINEERING
(2023)
