Electroless Deposition of Ni-Cu-B Coatings and Investigation of Their Corrosion Behavior

Electroless plating has been used as a Suitable technique to protection of the metals. Electroless coatings have exclusive physicochemical and mechanical properties (Uniformity, Excellent corrosion resistance, High hardness and etc) that they are being used increasingly. Electroless Ni-B coating is a new technology for use in engineering industries due to its many Privileges. For improvement of this coating, addition of a third element is being developed. The copper as an effective element the coating characteristics have selected. In this study applying the electroless Ni-Cu-B alloy deposit on steel substrate was considered and Influence of the copper on coating properties was investigated. Alloy deposits were characterized for their structure, morphology, chemical composition, micro-hardness and corrosion resistance and compared with Ni-B deposits using X-ray diffraction (XRD), scanning electron microscopy (SEM) equipped with Energy dispersive analysis of X-ray, potentiodynamic polarization techniques. X-ray diffraction (XRD) pattern of Ni-Cu-B coatings was amorphous. Increasing CuCl2 in plating bath resulted in increasing of copper content in the coatings and coating with maximum copper content had the best corrosion resistance.