Investigation the Effect of the Stabilizer for the Electroless Nickel – Boron Plating


Yıldız R. A. , Genel K., Gülmez T.

International Conference on Mining, Material and Metallurgical Engineering, Seoul, South Korea, 15 - 17 April 2016, pp.1

  • Publication Type: Conference Paper / Summary Text
  • City: Seoul
  • Country: South Korea
  • Page Numbers: pp.1

Abstract

The present work aims to study the effect of stabilizer added electroless plating baths for
Nickel – Boron coating. Electroless nickel plating which is an auto-catalytic chemical technique has a
wide range of usage area by virtue of high corrosion resistance and high wear resistance. Zn – Mg –
Cu alloyed 7075 aluminum alloy was used as a substrate as well as structural materials in aeronautical
industries. Three different electroless plating baths were prepared in order to deposit Ni – B coating
on 7075 Al alloy. Nickel chloride is used as the source of nickel ions and sodium borohydride as the
reducing agent for boron. The plating bath provides highest deposition rate was obtained and
appropriate electroless plating temperature was investigated. The effect of thallium nitrate, lead
nitrate and lead tungstate on the formation of electroless Ni-B and Ni-W-B deposits obtained from an
alkaline sodium borohydride reduced electroless bath is addressed in this paper. Plating rate is
determined as a function of stabilizers. On behalf of deposition of tungstate in electroless Ni-B
coating, sodium tungstate was added. The amount of added sodium tungstate to the electroless
alkaline bath had a siginificant influence on the deposition rate. Coating on the aluminum alloys
required zincating process. After zincating process, plating the Ni-B and Ni-W-B on 7075 Al alloy
have been executed. Moreover, the characteristics of the deposition of electroless Ni-B and Ni-W-B
were investigated by means of X-ray diffraction, SEM and EDS analyses. Addition of stabilizer to the
electroless Ni-B solution resulted in the formation of phases with the stabilizer which is revealed by
XRD analyses. It is observed that the stabilizer itself and amount of stabilizer is related the deposition
rate of plating.