Effects of combined surface treatments of aluminium nanoparticle on its corrosion resistance before and after inclusion into an epoxy coating

We developed a sol–bath–gel method to prepare a hybrid coating for corrosion protection of aluminum alloy. The sol–bath–gel treatment included dipping the aluminum alloy into silane sol at 50 °C for 30 min, slowly withdrawing it, and then drying at room temperature. This procedure overcame the drawbacks of conventional sol–gel methods while retaining the advantages of sol–gel and chemical bath approaches. The morphology and compositions of the as-prepared hybrid coating were characterized by digital microscopy, atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectrometry (FTIR), and energy dispersive spectroscopy (EDS) mapping. The corrosion resistance and durable protection ability of the as-prepared hybrid coating were investigated and compared with the traditional chromate coating by the potentiodynamic polarization technique, and electrochemical impedance spectroscopy (EIS). The results showed that the aluminum alloy surface is coated with a continuous, homogeneous, and compact aluminum (hydr)oxide–silane hybrid film, which is composed of ca. 200 nm particle array that was tightly and regularly packed. The corrosion resistance of the as-prepared hybrid coating was 32,395 Ω cm 2 , which is higher than that for the chromate conversion coating (12,094 Ω cm 2 ). The as-prepared coating suppresses the anodic dissolution of the aluminum alloy substrate, resulting in a large decrease in corrosion current and long-term protection.

A sol–bath–gel approach to prepare hybrid coating for corrosion protection of aluminum alloy

Construction of a smart active/barrier anti-corrosion system based on epoxy-ester/zinc intercalated kaolin nanocontainer for steel substrate

Active protective Al–Ce alloy coating electrodeposited from ionic liquid

X-ray photoelectron spectroscopy (XPS) was used to analyze the composition of films at different deposition parameters of sputtered Al-Ce coatings on AA6061 aluminum alloys. By means of electrochemical impedance spectroscopy (EIS) measurements, the protective character of these coatings was studied for 21 days of exposure in a 3.5 wt% NaCl solution and an attempt was made to establish the relationship between film thickness and chemical composition (Al/Ce, Ce3/Ce4+ ratios) of the surface before and after the electrochemical characterization. XPS studies revealed the presence of the Alo, Al2O3, CeO2 and Ce2O3 compounds, confirming that the sputtered Al-Ce films were deposited in the metallic form and thereafter were superficially oxidized under ambient conditions. The Al–Ce bonds were overlapped with the signal of cerium oxides. The transport phenomena in the oxide film or controlled diffusion process are strongly dependent on the deposition parameters and exposure time in the aggressive medium. It was also found that in the deposited samples at p4P200t300, the film was still present after 21 days of exposure, although with visible cracks and erosion areas; however, the Ce3/Ce4+ ratio almost remained constant before and after the electrochemical characterization, which explained the barrier properties of these samples as compared with others at different deposition parameters.

XPS and EIS studies of sputtered Al–Ce films formed on AA6061 aluminum alloy in 3.5% NaCl solution

Effective corrosion protection of AA6061 aluminum alloy by sputtered Al–Ce coatings

In this work, sputtered Al–Ce films were studied in order to evaluate their possible application as coatings to delay pitting corrosion of aluminum alloy substrates. The morphology and structure of the coatings deposited on both silicon and AA6061 aluminum alloy substrates were studied by varying the magnetron sputtering conditions. The preliminary electrochemical performance was also discussed by means of Tafel plots and electrochemical impedance spectroscopy (EIS). The X-ray diffraction studies indicated that the microstructure varied from crystalline to amorphous, depending on the deposition parameters. The AFM images show that the films consist of equi-axial round domes distributed homogeneously. The mean grain size, roughness and thickness of the coatings were increased by augmenting the power and pressure. The EIS studies showed that there was a significant increase in the resistance to corrosion after depositing Al–Ce films on AA6061 aluminum alloy substrates. The electrochemical behavior of the films was related to the Ce/Al composition ratio as well as process parameters.

Structural and electrochemical performance of sputtered Al–Ce films on AA6061 aluminum alloy substrates

Although industry 4.0 has gained increased attention in the industry, academic, and governmental fields, there is a lack of information about the relationship between this digital transformation and sustainable development. This work explores the concept of sustainability applied in industry 4.0 and the main advantages that this revolution incorporates into society. To this end, a conscientiously documented investigation was conducted by reviewing actual case studies or scenarios where sustainability was applied in different manufacturing industries, enterprises, or research fields worldwide. A critical and descriptive analysis of the information was performed to identify the main tools and procedures that can be implemented in the industry to address the triple bottom line perspective of industry 4.0, and the results are presented in this document. From the analysis, it was observed that currently, I4.0 has been mainly adopted to improve efficiency and cost reduction in manufacturing companies. However, since only a few enterprises embrace the social paradigm of I4.0, a significant gap in understanding and unbalance is visualized. Therefore, we conclude that there is a lack of information on social benefits and the barriers that must be overcome from the social perspective. On the other hand, this work highlights the importance of adopting industry 4.0 as a positive way to improve the performance of emerging technologies, such as fuel cells, solar cells, and wind turbines, while producing products or services with high efficiency and profitability incomes. For practitioners, this work can provide insightful information about the real implications of I4.0 from a sustainability perspective in our daily life and the possible strategies to improve sustainable development.

/pdf/insight-into-the-expected-impact-of-sustainable-development-3k79b04q.pdf

Insight into the Expected Impact of Sustainable Development in the Context of Industry 4.0: A Documentary Analysis Approach Based on Multiple Case Studies across the World

Due to the importance of cutting-edge nanomaterials applications in energy generation and storage devices, electrochemical impedance spectroscopy (EIS) has been adopted to fully understand the electronic and chemical reactions occurring inside these emerging technologies. Electronic behavior can be correlated with electrochemical properties such as electron transfer resistance, rate of mass diffusion, and the number of electrons in the electrochemical reaction. Although there is a lot of information about the electronic diagrams and methods for parameter estimation, some readers have difficulty analyzing and interpreting EIS curves. Thus, this work proposed using a heuristic approach and genetic algorithms to successfully estimate the resistance and capacitance value of a previously defined circuit model. To assess the potential of the genetic algorithm in electrochemical parameters estimation, we carried out practical measurements with known elements, and then the experimental and theoretical values were compared. Furthermore, the versatility and effectiveness of the algorithm were validated by determining the parameters in an Li-ion battery. The results revealed that the heuristic genetic algorithm (HGA) is a powerful tool for EIS parameters estimation because it can handle large below and upper limits with more pragmatic results in a shorter computational time.

/pdf/performance-assessment-of-heuristic-genetic-algorithm-hga-3rzyekz9.pdf

G.G. Suárez-Velázquez

Papers

Effective corrosion protection of AA6061 aluminum alloy by sputtered Al–Ce coatings

Structural and electrochemical performance of sputtered Al–Ce films on AA6061 aluminum alloy substrates

Insight into the Expected Impact of Sustainable Development in the Context of Industry 4.0: A Documentary Analysis Approach Based on Multiple Case Studies across the World

Performance Assessment of Heuristic Genetic Algorithm (HGA) for Electrochemical Impedance Spectroscopy Parameter Estimation