Browsing by Author "farid lekmine"

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    Deposition Rate and Electrochemical Corrosion Behavior of Nickel-Based Composite Coatings
    (2022-12-27) farid lekmine
    Metal corrosion control is technically, economically, environmentally and aesthetically important. The best option is to use coatings to protect metals and alloys from corrosion. Nickel plating is one of the most widely used methods for protecting less noble metal surfaces since the turn of the century. The need for improved coatings with better wear and corrosion resistance has led to the development and use of composite electrostatic deposits. In this paper, Ni-P-TiO2 composite coatings were fabricated by direct current electrodeposition on copper substrates. X-ray diffraction (XRD) analysis and energy dispersive spectroscopy (EDS) were employed to determine the average particle size of coatings elemental chemical composition. The electrochemical corrosion behavior of Ni-P-TiO2 composite coatings in 3.5 wt. % NaCl was characterized using a potentiodynamic polarization test and electrochemical impedance spectroscopy (EIS). The results indicate that TiO2 nanoparticles are included in the coatings. The deposition rate increased with increasing current density; the microhardness of the coatings noticeably increased with current density. Corrosion tests have shown that 3 A.dm – 2 is the optimal value of the applied current density in terms of the lowest value Ecorr  – 504 mV and the best charge transfer resistance Rp  114.7 Ω.cm2
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    Mechanical Characterization of Electrodeposition of Ni-P Alloy Coating
    (2020-02-25) farid lekmine
    The electrodeposition process plays a crucial role in the formation of thin films on materials, in particular, the electrodeposition of nickel-phosphorus because of its important properties. In this study, Ni-P coatings were deposited on X52 steel substrates by electrodeposition technique from a solution containing nickel sulfate, sodium hypophosphite (NaH2PO2). Composition, surface morphology, and mechanical properties of the Ni-P deposits were studied using SEM, EDAX, the Vickers method, weight loss and potentiodynamic polarization techniques. The effects of the current density were investigated on the surface morphology, phosphorus content, microhardness and corrosion of the coatings. It was observed that both the phosphorus content and microhardness are dependent on the current density. Results demonstrate that the morphology of the electrodeposited Ni-P alloys shows that the grains are spherical in nature for all the samples. It has been observed that the influence of current density on the P content of the deposit is an inverse relation with phosphorous content and also the as-plated coatings at current density of 5 Am − 4 exhibit the superior microhardness. Corrosion tests show that 5 Am − 4 is the best current density value which gives the best protection coating against corrosion.