Nano-wear, nano-hardness and corrosion-resistance of electroplated nickel surfaces after co-implantation of Cr+ and N2+ ions

In this work, a successful sequential co-implantation treatment of Cr+ and N-2(+) ions into electrodeposited nickel plates is presented. The goal of this treatment is the simultaneous enhancement of the wear resistance. mechanical stability and corrosion-protection properties of the Ni surfaces. The ion-implanted surfaces have been characterized by glow-discharge optical-emission spectroscopy, X-ray diffraction, nano-hardness. roughness, nano-wear and potentio-dynamic corrosion tests. It has been observed that the implantation of Cr+ or N-2(+) alone is not sufficient to achieve simultaneously the enhancement of both the wear-resistance and the corrosion-protection properties. Conversely, the sequential implantation of Cr+ and N-2(+) at 140 keV and fluencies of 3 x 10(17) and 1.5 x 10(17) ions/cm(2) respectively, permits the formation of a functional surface capable of reducing both the corrosion rate and the wear rates, with respect to those exhibited by the un-implanted Ni surfaces. This treatment can be used to protect the surfaces of micro-embossing/stamping dies based on electroformed Nickel, as an alternative to other coating strategies. Furthermore, the ion implantation assures the non-modification of the net-shape and surface finish of these types of dies, which is of crucial importance when they are used for high-precision micro-texturing/imprinting applications. (C) 2011 Elsevier B.V. All rights reserved.