Corrosion behaviour of compositionally modulated nanocrystalline Ni–W coatings

ABSTRACT

The present study deals with corrosion behaviour of compositionally modulated nanocrystalline Ni–W alloy coatings and conventional hard chrome coatings. Compositionally modulated Ni–W alloy coatings of known composition were systematically deposited using pulse current deposition. The corrosion behaviour was analysed using potentiodynamic polarization and impedance spectroscopy in 2N H₂SO₄. Compositionally modulated Ni–W alloy coatings depicted substantial improvement in corrosion resistance over its single-layer counterpart and hard chrome coatings. The corrosion behaviour was rationalized based on porosity and surface residual stresses present in these coatings.

KEYWORDS:

• Multilayer
• electrodeposition
• corrosion
• nickel tungsten
• residual stress
• hard chrome
• EIS
• porosity

Acknowledgements

NPW wishes to thank Director, International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI) for granting permission to publish this paper. The financial support from Science and Engineering Board (SERB) India (SB/EMEQ-222/2013) is gratefully acknowledged. The author would also wish to thank Mr. G. V. R. Reddy for SEM analysis.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by Science and Engineering Research Board [grant number SB/EMEQ-222/2013].