Characterization Of Electrodeposited Ni–mos2 Composite Coatings Under The Influence Of Current Density

Résumé: In this paper, the influence of current density on electrodeposited Ni–MoS2 composite coatings has been studied for the first time. Low carbon steel alloy has been selected as a substrate. The Ni–MoS2 composite coatings are deposited at a temperature of 48 °C with applied current densities of (1, 2, 3 and 4 A/dm2). The x-ray diffraction (XRD) analysis of electrodeposited Ni– MoS2 coatings depicts a number of sharp peaks indicating a good crystallinity. Using ASTM database, the peaks at 14°, 32°, 33°, 39°, 49° and 58° correspond to (200), (100), (101), (103), (105) and (110) hkl planes respectively. The morphology was examined by scanning electron microscopy (SEM). Microhardness measurements show that all Ni–MoS2 samples are harder than low carbon steel substrate. EDX analysis of the Ni–MoS2 composite confirmed that the fraction of MoS2 increased with the increase of applied current density. The study of corrosion properties was carried out in a 0.6M NaCl solution. The potentiodynamic polarization curve of electrodeposited Ni–MoS2 confirmed that the corrosion resistance increases with the decrease of applied current density. In addition, Electrochemical tests show that the optimal value of applied current density is 3 A/dm2 in the sense of the least value of Ecorr = -314,1 mV and the best resistance was Rp = 9.52 K.cm2.

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