Friction, nanowear and corrosion properties of electroplated nickel surfaces after dual implantation of Cr ~+ and N _2 ~+ ions. Influence of the implantation energy of the N _2 ~+ ions

摘要

In this work, dual implantation of Cr ~+ and N _2 ~+ ions on electroplated Ni substrates have been investigated for N _2 ~+ implantation energies of 140keV, 100keV and 60keV. The implanted specimens have been analyzed by glow discharge optical emission spectroscopy, X-ray diffraction, nano-indentation, coefficient of friction, nano-wear and potentiodynamic corrosion curves. The properties of the dual implanted samples have been compared to Cr ~+ or N _2 ~+ implanted specimens.The microstructural and mechanical properties of the Ni plates depend on the penetration ranges of the Cr and N atomic profiles obtained after the implantation process. The increase of hardness reduced the coefficient of friction of the samples and the wear rates. Preferential formation of Cr-N over Ni-N compounds has been observed when the Cr and N atomic profiles coexist within the Ni matrix.The potentiodynamic corrosion curves in acidic solutions revealed that the presence of Me-N species is detrimental for the chemical stability of the plates. Both nano-wear and corrosion properties are optimized when a Ni-N sublayer is formed underneath a top Cr-Ni implanted film. This is achieved by tuning the implantation energies of Cr ~+ and N _2 ~+ ions at 140keV. This bilayer structure could be a suitable treatment for micro-embossing dies for plastic texturing processes.