"Materials Reseach" Prof.Dr. Hüseyin SARIÇİMEN Corrosion Behavior of Coarse- and Fine-Grain Ni Coatings Incorporating NaH2PO4.H2O Inhibitor Treated Substrates adlı makalesi

Corrosion Behavior of Coarse- and Fine-Grain Ni Coatings

Incorporating NaH2PO4.H2O Inhibitor Treated Substrates

Anwar Ul-Hamid^a*, Abdul Quddus^a, Huseyin Saricimen^a, Hatim Dafalla^a

 ^aCenter for Engineering Research, Research Institute, King Fahd University of Petroleum & Minerals, P.O. Box 1524, Dhahran - 31261, Saudi Arabia

 Plain carbon steel substrates were treated with NaH2PO4.H2O inhibitor for 24 hours and coated with Ni using dc and pulse electrodeposition in standard Watt’s bath. The effect of dc and pulse electrodeposition, on the microstructure and corrosion properties of Ni coatings in 3.5 wt% NaCl solution was studied. The effect of inhibitor on the deposition process and corrosion behavior was also examined. Materials characterization was performed using field emission scanning electron microscopy, cross-sectional scanning transmission electron microscopy, atomic force microscopy, x-ray diffraction and nanoindentation. Experimental results indicated that pulse electrodeposition produced fine grained Ni coatings that showed lower corrosion rate compared to coarse grained dc electrodeposited Ni. Pre-treatment of substrates with inhibitor did not adversely affect the deposition process and adherent Ni coatings were readily developed. The results showed that pulse electrodeposition could be used to produce hard corrosion resistant Ni coatings while the inhibitor treatment yielded enhanced corrosion protection by providing a protective buffer layer between the Ni coating and the substrate.

 Keywords: corrosion, microstructure, Nickel (Ni), electrodeposition, inhibitor, NaH2PO4.H2O, sodium dihydrogen orthophosphate