How to create a Ni-free corrosion protecting deposit on basis of ZnFe-X

ABSTRACT

ZnNi-deposits are currently used for corrosion protection especially in the automotive industry. With current REACH¹ regulations there is a demand for Ni-free coatings. The objective of this research project was the design of a REACH-compliant ternary zinc alloy based on ZnFe-X (X= Cu, In, Mn, Sn, Mo, Cr) with superior coating properties compared to Ni-free alternatives such as binary Zn-alloys. Using a model-based electrolyte development approach both thermodynamic and kinetic phenomena were included in the simulations. The implementation of a robot assisted experimental set-up enabled an effective, resource-saving research on different electrolyte systems in parallel and on choosing optimum pulse plating parameters. Optimum results were obtained by incorporating Mo at up to 1.5% into the ZnFeMo alloy.

KEYWORDS:

• Electrolyte development
• ternary alloys
• nickel-free deposit
• pulse plating
• robot assisted experiments
• neural network
• corrosion protection

Acknowledgements

The financial support of the German Ministry of Research and Development (BMBF) in the programme InnoEMat via the VDI Technology is gratefully acknowledged. Partners within the project have been Chemnitz University of Technology, Coventya GmbH Gütersloh, Klero GmbH Berlin, Plating Electronic GmbH Sexau, B+T GmbH Wetzlar, Gazima GmbH Grünhain-Beierfeld.

Disclosure statement

No potential conflict of interest was reported by the author(s).