Structural & Engineering Materials
Rajni Narang; Priya Vashishth; Himanshi Bairagi; Rashmi Sehrawat; Sudhish K. Shukla; Bindu Mangla
Abstract
This review highlights the overview of recent trends in the usage of drugs as corrosion inhibitor for metal/alloy surfaces, particularly mild steel, aluminum, and copper in acidic, basic, or saline medium. The drug molecules generally containing atom having lone pair of electrons such as nitrogen (N), ...
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This review highlights the overview of recent trends in the usage of drugs as corrosion inhibitor for metal/alloy surfaces, particularly mild steel, aluminum, and copper in acidic, basic, or saline medium. The drug molecules generally containing atom having lone pair of electrons such as nitrogen (N), oxygen (O), Sulphur (S) and phosphorus (P) as well as a hydrophobic moiety that will repel aqueous corrosive species away from the metal surface and a mediately with an aromatic ring, unsaturation that are observed to be a significant component of extremely efficient inhibitors. The efficacy of various drugs, including antipyretics, analgesics, antibiotics, anti-depressants, and anti-histamines, is studied using weight loss, electrochemical impedance spectroscopy, potentiodynamic polarization and surface analysis techniques. Drugs molecules work by producing a layer on the metal's surface and can serve as anodic, cathodic, or mixed inhibitors. This protective film formed results of strong interactions such as free- orbital adsorption, chemisorption, and electrostatic adsorption, which prevent corrosive species from attacking the metal surface. Recent concerns and future prospective for further research and development to achieve more efficient and environmentally friendly inhibitors are additionally highlighted.
H. C. Ananda Murthy; Somit Kumar Singh
Abstract
Aluminum matrix composites (AMCs), reinforced with ceramic particulates, have significant applications in the field of aerospace, marine, automobiles, sports and recreation. Al-TiC particulate composite has better potential for high-temperature applications. The corrosion behaviour of Al 6061-TiC particulate ...
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Aluminum matrix composites (AMCs), reinforced with ceramic particulates, have significant applications in the field of aerospace, marine, automobiles, sports and recreation. Al-TiC particulate composite has better potential for high-temperature applications. The corrosion behaviour of Al 6061-TiC particulate composites prepared by stir casting route, has been explored in chloride medium using electroanalytical techniques such as Tafel, Cyclic polarization and Impedance measurements (EIS). SEM and EDX analysis of the microstructures obtained in both matrix alloy and reinforced composites were performed in order to know the effect of titanium carbide on the corrosion resistance of composites. The polarization studies reveal an increase in the corrosion resistance in composites compared to the matrix alloy. The observed increase in corrosion resistance of TiC particulate reinforced composites is attributed to excellent bond integrity of TiC particulates with aluminium and possible electrochemical decoupling between TiC particles and Al 6061 matrix alloy. The EIS study reveals that the polarisation resistance (Rp) increase with increase in TiC content in composites and the corrosion process is mainly charge transfer controlled. Titanium carbide is proved to be a potential reinforcement for improved corrosion resistance in Al MMCs.
N. Khemasiri; N. Paleeya; D. Sae-tang Phromyothin; M. Horprathum; A. Sungthong; J. Nukeaw; S. Pratontep
Abstract
Silicon nitride is a promising alternative to carbon based materials for protective coatings, owing to its compatibility with existing silicon-based microfabrication. The complexity of the fabrication processes and contaminations hamper fine-tuning to obtain desirable coating properties. We have explored ...
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Silicon nitride is a promising alternative to carbon based materials for protective coatings, owing to its compatibility with existing silicon-based microfabrication. The complexity of the fabrication processes and contaminations hamper fine-tuning to obtain desirable coating properties. We have explored the reactive gas-timing rf plasma sputtering technique for silicon nitride thin film deposition as an alternative method to fine-tune the film properties. The gas-timing technique controls the on-off sequence of the sputtering gas (Ar) and the reactive gas (N2) during deposition. We focus this investigation to the effect of the Ar:N2 gas timing ratio (10:0, 10:1, 10:3, 10:5, 10:7 and 10:10) on the composition, the morphology, the corrosion resistance, and the hardness properties of the films, in comparison to the films deposited by conventional reactive sputtering with Ar-N2 gas mixture. These deposited silicon nitride films were characterized by Auger electron spectroscopy, Raman spectroscopy, and atomic force microscopy. The chemical resistance was measured by the electrochemical corrosion test in sulfuric acid, while the hardness properties were obtained by nanoindentation. The results reveal that although the nitrogen content in the films increases only slightly when the N2 timing is prolonged, the corrosive current of the films decreases abruptly. A thin passivating oxidized layer is found to play a major role in the corrosion resistance. In contrast, the hardness properties exhibit a uniform variation with the N2 timing. The gas-timing sequence may induce morphological changes the underlying silicon nitride films. The highest hardness obtained by the gas-timing technique almost doubles that produced by the conventional mixed gas sputtering. Thus the reactive gas-timing technique suggests a new route to selectively control the properties of silicon nitride films with minor modification to existing microfabrication processes.
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