Improvement of adhesion, corrosion and wear resistance of Ni electrodeposited coating by applying Cu intermediate layer after zincate process

Abstract

Zincate treatment is extensively used for preparation of aluminium surface prior to deposition process. However, the zinc layer may be dissolved in acidic solutions such as Watts bath used for electrodeposition of Ni coating. Hence, the use of an intermediate layer between Zn film and top coating has been suggested. In this study, the effect of Cu intermediate layer on properties of Ni coating electrodeposited on 6061 Al alloys substrate is investigated. The properties of the coatings are studied by means of peel test, potentiodynamic polarization techniques and wear test. The results indicated that the use of Cu intermediate layer increased the adhesion strength of the coating from 0.85×10³ N/m to 4.01×10³ N/m. Furthermore, the corrosion and wear resistance of samples improved when Cu intermediate layer is applied after zincate process.