Electrophoretic Deposition of Hydroxyapatite–Chitosan–Titania on Stainless Steel 316 L

In this research, hydroxyapatite (HA)–chitosan–titania nanocomposite coatings were formed on 316 L stainless steel using electrophoretic deposition (EPD) from alcoholic (methanol and ethanol) suspensions containing 0.5 g/L chitosan and 2 and 5 g/L HA and 2 and 5 g/L Titania. The effect of different parameters on the deposition rate, morphology, and corrosion resistance of the coatings in simulated body fluid (SBF) at 37 °C has been studied. The coatings’ properties were investigated using Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). Based on the results of this work, it was found that the deposition rate in ethanolic suspensions is lower than methanolic ones. Moreover, the coating surface was smoother when the ethanol was used as a solvent in suspensions in comparison to the ones where methanol was the solvent. The coating deposited from a suspension containing 0.5 g/L chitosan, 2 g/L HA, and 5 g/L titania with ethanol as solvent had the highest corrosion resistance in SBF at 37 °C

Rapid Ant based clustering-genetic algorithm (RAC-GA) with local search for clustering problem

Clustering is a critical data analysis and it is a popular data mining technique. This paper presents a rapid Ant based clustering-genetic algorithm (RAC-GA) with local search to solve clustering problem. GA and local search are used as a global and local search to obtain better results. The proposed algorithm is evaluated by testing on some of the well-known real-world datasets, and the results are compared with other popular heuristics in clustering, such as GA, SA, TS, ACO and RAC. The results show strong improvement both in quality solution and process time area, especially in process time which is much less than previous algorithm

Sustainable development of an effective anti-corrosion film over the St12-steel surface against seawater attacks using Ce(III) ions/tri-sodium phosphate anions

Abstract One application of organic compounds is to utilize them as corrosion inhibitors in acidic environments to diminish steel corrosion. These inhibitors do not show very good inhibition properties in saline (NaCl) environments. There have been many studies on boosting these inhibitors’ performance in such environments (especially Cl− containing media). One of the ways that have been proposed is the use of organic and inorganic inhibitors, simultaneously. The synergistic effect of these inhibitors has shown promising results in reducing steel corrosion. In this study, cerium(III) nitrate and tri-sodium phosphate (TSP) was used as organic and inorganic inhibitors to control the corrosion of steel in a 3.5 wt.% NaCl environment. The corrosion measurements were conducted in the 3.5 wt.% NaCl environment by EIS and polarization methods. Surface studies were done by SEM, Raman, GIXRD, and EDS methods. Corrosion studies (EIS and polarization) have revealed that when 500 ppm of Ce(NO3)3 and 500 ppm of TSP are added to the 3.5 wt.% NaCl medium, the highest synergism index (1.27) and inhibition efficiency (73.7%) are achieved. Also, by adding 500Ce-500TPS to the solution, i corr and R ct of steel decreased by about 80% and increased approximately 4-fold, respectively. This improvement in the steel performance against corrosion in the presence of an equal ratio of Ce(NO3)3 and TSP is the outcome of the formation of a hydrophobic dense film (consisting of Ce(OH)3, Ce/Fe-phosphate complexes) on the metal surface. This claim has been proven by SEM/EDS, contact angel, FT-IR, and XRD analysis

Electrochemical Corrosion of Oxidized Gamma TitaniumAluminide in Ringer's Solution: Electrochemical corrosion of oxidized gamma titanium aluminide

Ɣ-TiAl intermetallic alloy have a good potential for use as biomaterial, due to its good corrosion resistance. In this paper, two fundamental electrochemical techniques namely electrochemical impedance spectroscopy and potentiodynamic anodic polarization were used to evaluate the corrosion performance of Ɣ-TiAl in Ringer's solution. Surface modification treatments were employed with the purpose of improving corrosion resistance. The samples were oxidized at 550 °C in air for 1h. The results show that oxidized Ti-47Al-2Cr has much better corrosion resistant in Ringer’s solution. The presence of the oxide layer formed with the surface treatments increased their corrosion resistance. The low values of corrosion rate, and the high values for corrosion potential (Ecorr) and polarization resistance (Rp)obtained experimentally implies that Ɣ-TiAl can be competitively considered as analternative metallic biomaterial