Hindawi Publishing Corporation
Advances in Tribology
Volume 2013, Article ID 315965, 10 pages
http://dx.doi.org/10.1155/2013/315965
Research Article
Effect of Nanoadditives with Surfactant on the Surface
Characteristics of Electroless Nickel Coating on
Magnesium-Based Composites Reinforced with MWCNT
Ranganathan Dhinakaran, Rasu Elansezhian, and Arunachalam Arumugam Lalitha
Department of Mechanical Engineering, Pondicherry Engineering College, Pondicherry 605014, India
Correspondence should be addressed to Rasu Elansezhian; elansezhianr@pec.edu
Received 6 June 2013; Revised 23 October 2013; Accepted 20 November 2013
Academic Editor: S. Aravindan
Copyright © 2013 Ranganathan Dhinakaran et al. is is an open access article distributed under the Creative Commons
Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is
properly cited.
An experimental investigation has been carried out on optimizing process parameters of electroless nickel-phosphorous coatings
on magnesium composite reinforced with carbon nanotube. A comprehensive experimental study of electroless Ni–P coatings
on magnesium composite reinforced with multiwalled carbon nanotube under specific coating conditions was performed. e
electroless coating bath consists of nickel sulphate (26 g/L), sodium hypo-phosphite (30 g/L) as reducing agent, sodium acetate
(16g/L) as stabilizer, and ammonium hydrogen difluoride (8g/L) as the complexing agent. e surfactant SLS was added in the
solution for better wetting and spreading of coating on substrate. e stabilizer thiourea (1 ppm) was added in the bath to prevent
decomposition of bath. Different nanoadditives such as ZnO, Al
2
O
3
, SiO with various concentrations were used in the bath and their
influence on coating process characteristics were studied e nano additives such as ZnO, Al
2
O
3
, SiO were added at concentrations
of 0.1%, 0.5%, 1%, and 2% in the EN bath. e output parameters such as surface roughness, microhardness, specific wear rate, and
surface morphology were measured. Surface morphology was studied using scanning electron microscope. e results showed that
the proposed method resulted in significant improvement on the quality of the coatings produced.
1. Introduction
Electroless nickel coating has received widespread acceptance
as it provides a uniform deposit on irregular surfaces, direct
deposition on surface-activated nonconductors, formation
of less porous deposits, and high hardness and excellent
resistance to wear, abrasion, and corrosion [1, 2]. All smooth
surfaces possess some degree of roughness, even if only at the
atomic level. Correct function of the fabricated component
oſten is critically dependent on its degree of roughness. Every
machining operation bequeaths some characteristic on the
machined surface. is characteristic microirregularities leſt
by the cutting tool are termed as surface irregularity or sur-
face roughness [3]. Roughness is sometimes an undesirable
property, as it may cause friction, wear, drag, and fatigue, but
it is sometimes beneficial, as it allows surfaces to trap lubri-
cants and prevents them from welding together. Magnesium
composites have promising properties for several industrial
applications because of their low density [4]. Magnesium
composite with metallic (electroless/electroplating) deposits
are being used, in new light-weight engines which are less
in weight and hence consume less energy. However, metallic
coatings in magnesium are having multitudinous problems
caused by surface roughness. Example of mechanical mal-
function can be found in high-performance engine machine
parts which are required to move or rotate at high speed with-
out wear. Excess surface roughness can lead to unacceptably
high levels of frictional heating, causing damage and even
failure [5]. Surfactants are specifically added into the elec-
trolyte bath to reduce the vertical component of surface ten-
sion forces, which binds the nickel particles to the hydrogen
gas bubbles generated during the plating reaction. Due to this,
uniform and pit-free coating can be obtained. Smooth and
pit-free electroless Ni–P deposits were obtained by adding
150 ppm of sodium dodecyl sulfate (SDS) to the electroless
nickel bath [5]. Similarly, a very brief conclusion was derived
by Hagiwara et al. [6] as well, who studied the effect of three
different surfactants added in the Ni–P electroless bath on the