Ranking the Cobalt Coating Nanostructures, Produced by Direct current Through the Analytic Hierarchy Process (AHP)

In recent years, cobalt coating has been known as an alternative material instead of chromium in corrosion and erosion resistant behavior. Extensive research has been carried out on a variety of electroplated cobalt coatings. In this study, for the first time, the relative priority of the cobalt coating has been calculated and ranked theoretically by the Analytic Hierarchy Process (AHP). For this purpose, through the AHP and the Expert Choice software, benefiting from expert opinions, the relative weights of the effective parameters on achieving nanostructure coating have been calculated. Then, by using the weights obtained, the relative priority of five available Co coatings was calculated and the quality of them was ranked. Among available Co coatings, the coating with 5 mA/ current density, pH 3, electrolyte saccharin of 0.25 grams per liter and a temperature of 45 °C during 30 minutes, in comparing with others had more favorable conditions for achieving nano-grain size. This shows that before experimental tests, the best alternatives to achieve the ultimate goal could be anticipated. This anticipation leads to reduce in trial and error and the multiplicity of the tests in investigations. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3488

Ranking the Cobalt Coating Nanostructures, Produced by Direct current Through the Analytic Hierarchy Process (AHP)

In recent years, cobalt coating has been known as an alternative material instead of chromium in corrosion and erosion resistant behavior. Extensive research has been carried out on a variety of electroplated cobalt coatings. In this study, for the first time, the relative priority of the cobalt coating has been calculated and ranked theoretically by the Analytic Hierarchy Process (AHP). For this purpose, through the AHP and the Expert Choice software, benefiting from expert opinions, the relative weights of the effective parameters on achieving nanostructure coating have been calculated. Then, by using the weights obtained, the relative priority of five available Co coatings was calculated and the quality of them was ranked. Among available Co coatings, the coating with 5 mA/ current density, pH 3, electrolyte saccharin of 0.25 grams per liter and a temperature of 45 °C during 30 minutes, in comparing with others had more favorable conditions for achieving nano-grain size. This shows that before experimental tests, the best alternatives to achieve the ultimate goal could be anticipated. This anticipation leads to reduce in trial and error and the multiplicity of the tests in investigations. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3488

Comparing the Ranking of Cobalt Coating Microstructures, Produced by Direct Current through Experimental Studies and the Analytic Hierarchy Process

In recent years, cobalt has been known as an alternative coating material to chromium in corrosion and erosion resistant applications. Extensive research has been carried out on a variety of electroplated cobalt coatings. In this study, for the first time, the relative priority of cobalt coatings has been evaluated by using the Analytic Hierarchy Process (AHP), in combination with empirical methods. In the first step, Cu substrates have been coated with Co under different experimental conditions. The SEM micrographs of Co coatings have been analyzed via image analysis (Clemex) software. In the second step, through the AHP and the Expert Choice software, benefiting from expert opinions, the relative weights of the effective parameters with an influence on microstructure have been calculated. Subsequently, by using the weights obtained, the relative priority of alternatives was calculated and the quality of coatings was ranked. The predicted ranking has been found to be in consistence with the experimental results. This result shows that before experimental tests, the best alternatives to achieve the ultimate goal could be anticipated. This anticipation leads to reduce in trial and error and the multiplicity of the tests in investigations. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3096

STUDY OF CHARACTERIZATION AND CORROSION RESISTANCE OF NIP/NANO-DIAMOND ELECTROLESS COMPOSITE DEPOSITION

Ni-P Electroless coatings provide appropriate resistance to wear and corrosion. Co-deposition of particles between layers can improve their properties, especially general corrosion and erosion-corrosion behavior by means of nano diamond as reinforcing particles. In this study Ni-P/nano diamond composite deposition were deposited on steel substrate. Structure of the coatings and corrosion resistance of theme were investigated by scanning electron microscopy and corrosion tests in salty media. The composite structure of the deposit was evaluated as nano size without using any surfactants. Also results for the composite coating show better corrosion protection and higher hardness comparing with as -deposited Ni-P. The optimum concentration of diamond nanometer particles were found by evaluation of scanning electron microscopy pictures, hardness measurement, linear polarization and electrochemical impedance spectroscopy result

Electrodeposition and Characterization of Sn-Zn Alloy Coatings from Sulfate Based Baths

Tin-Zinc alloy coatings have many applications because of their unique properties such as corrosion resistance, solderability and flexibility. In this study, the effect of current density, temperature and pH on chemical composition, cathodic current efficiency, morphology and structures of the coatings was investigated. The results illustrated that, at low current densities (<0.5 mA/cm2), the coatings were relatively pure tin, but Zn content increased with enhancing the current density. At higher currents a relatively pure Zn film was obtained. Temperature and pH also affected chemical composition of the alloy films. Zn content of the coatings was decreased by increasing the temperature, while its variation with pH had ascending-descending trend. Morphological investigation of the coatings revealed that increasing Zn content of deposits led to porous, rough and fine grained films

CHARACTERIZATION OF MICRO/NANO POROUS HOLLOW GLASS MICROSPHERES FABRICATED THROUGH VARIOUS CHEMICAL ETCHING PROCESSE FOR USE IN SMART COATINGS

Porous hollow glass microspheres have many uses, including encapsulation of active materials. In this paper a fast and facile method for fabricating porous hollow glass-microspheres was demonstrated by etching them using dilute hydrofluoric acid. Then, a highly reactive amine was infiltrated into the etched glass microspheres. Scanning electron microscopy was conducted for the hollow glass microspheres prior and post etching process. With regards to the porous hollow glass spherical sample, the spherical nature, morphology, pore diameter and the porosity were studied using scanning electron microscopy. Formation of the intact hollow glass microspheres with an open through wall porosities following phase separation and etching of the boron oxide rich phase was demonstrated using reciprocating shaker as the most suitable agitation method. The BET results indicated that the surface of the porous microspheres contained nano-pores. It is believed that the simplicity of the reported fabrication technique of micro/nano porous structure has the potential to scaling up for large scale productio

Optimization of plasma electrolyte oxidation process parameters for corrosion resistance of Mg alloy

Plasma electrolyte oxidation (PEO) is a surface treatment method with high dependency on the process parameters. This paper focuses on maximizing the corrosion resistance of PEO coatings applied on Mg–5Zn–0.4Ca (ZX504) alloy by optimizing the process parameters. For this purpose, the Taguchi method based on L18 orthogonal array with mixed level design was used for optimization and determining effective parameters. Main process factors including electrolyte concentration, current density, frequency and duty cycle were considered at different levels. The corrosion resistance, as the performance indicator, was obtained using electrochemical impedance spectroscopy technique. Surface characteristics were also evaluated using SEM (scanning electron microscopy), EDS (energy dispersive spectroscopy), profilometer and contact angle goniometer. The statistical analysis showed that the optimum condition could be obtained at a current density of 200 mA/cm2, frequency of 500 Hz and at a duty cycle of 30%, in an electrolyte containing 15 g/L Na3PO4•12H2O and 10 g/L KF