Effects of nickel ion contents on electrodeposition, composition, structure and properties of palladium–nickel alloys

Abstract The effects of nickel ion contents on the electrodeposition, composition, structure and properties of palladium–nickel alloys were studied from a nearly neutral Pd(NH3)2Cl2–NiSO4.6H2O bath by adjusting the Ni2+/Pd2+ ion mole ratios. The results demonstrate that coatings with 17·1–44·0 wt-%Ni can be successfully electrodeposited by simply adjusting the Ni2+/Pd2+ ion mole ratios from 0·5∶1 to 2·5∶1. The coatings are bright, pore-free and crack-free with fine and compact grains. The structure of the coatings is a solid solution in a face-centred cubic structure; its lattice constant gradually decreases with a corresponding increase in the Ni content. The coatings exhibit a comparable corrosion resistance in a 3·5%NaCl solution, where the corrosion potentials Ecorr are between −0·010 and −0·064 V(saturated calomel electrode). Corrosion current densities jcorr slightly increased from 9·8 to 21·3 μA cm−2, with the Ni content increasing from 17·1 to 44·0 wt-%. The microhardness of the coatings increased with a corresponding increase in their Ni contents, and shows the highest value of 511 kg mm−2 with 44·0 wt-%Ni. The coatings exhibit comparable contact resistances of 0·2–0·4 mΩ.

[1]  W. Marsden.  I and J , 2012 .

[2]  G. Yin,et al.  Electrodeposited PdNi2 alloy with novelly enhanced catalytic activity for electrooxidation of formic acid , 2010 .

[3]  Ran Shang,et al.  Electrocatalytic activity of bimetallic Pd–Ni thin films towards the oxidation of methanol and ethanol , 2010 .

[4]  L. Piccolo,et al.  Alkene hydrogenation on metal surfaces: Why and when are Pd overlayers more efficient catalysts than bulk Pd? , 2009 .

[5]  P. Li,et al.  Electrocatalytic reduction of NO3- in a neutral solution on an electrodeposited film of amorphous Pd33Ni60P7 alloy , 2008 .

[6]  Y. Zuo,et al.  Study on corrosion resistance of palladium films on 316L stainless steel by electroplating and electroless plating , 2008 .

[7]  A. Lasia,et al.  Separation of hydrogen adsorption and absorption on Pd thin films , 2008 .

[8]  O. Hiramoto.  The Investigation of Au/Pd-Ni/Ni Plating for Electrical Contacts , 2008 .

[9]  S. Seshadri,et al.  Synthesis and characterization of electrodeposited Ni–Pd alloy electrodes for methanol oxidation , 2008 .

[10]  M. Grdeń,et al.  Study of hydrogen electrosorption in Pd-Ni alloys by the quartz crystal microbalance , 2002 .

[11]  F. Simon,et al.  Galvanische Palladiumschichten für technische Anwendungen in der Elektronik: Teil 1 , 2002 .

[12]  T. Perng,et al.  Stresses induced by hydrogen absorption and desorption in Pd nanofilms , 2001 .

[13]  J. Abys,et al.  The electrodeposition and material properties of palladium nickel alloys , 1996, Wescon/96.

[14]  J. Abys,et al.  Porosity of composite palladium, palladium-nickel and gold electrodeposits , 1992 .

[15]  S. Umemura,et al.  Contact resistance characteristics of noble metal alloys for connector contacts , 1991 .

[16]  William G. Moffatt,et al.  The handbook of binary phase diagrams , 1984 .

[17]  W. H. Safranek.  The properties of electrodeposited metals and alloys;: A handbook , 1974 .