Title: Investigation of the tribological behaviour of electrocodeposited Ni-MoS₂ composite coatings

Authors: Ebru Saraloğlu Güler; Erkan Konca; İshak Karakaya

Addresses: Department of Mechanical Engineering, Baskent University, Bağlıca Kampüsü Fatih Sultan Mahallesi, Eskişehir Yolu 18. km 06790 Etimesgut Ankara, Turkey ' Department of Metallurgical and Materials Engineering, Atilim University, Kızılcaşar Köyü 06836 İncek Ankara, Turkey ' Department of Metallurgical and Materials Engineering, Middle East Technical University, Üniversiteler Mahallesi, Dumlupınar Bulvarı No. 1, 06800 Çankaya Ankara, Turkey

Abstract: Composite electroplating of solid lubricants in a metal matrix is an effective way to lower coefficient of friction (COF) and improve wear resistance of surfaces in sliding contact. In this work, Ni-MoS₂ composite coatings were deposited on AISI 304 stainless steel substrates by electroplating from Watts bath containing suspended MoS₂ particles and their tribological behaviour was studied. The effects of MoS₂ particle concentration (5, 10 and 30 g/l), MoS₂ particle size (1.440 and 5.156 m), pH (2, 3 and 4), current density (3.8, 4.8 and 5.8 A/dm²) and the surfactant (sodium lignosulfonate, SLS) concentration (0.3 and 1 g/l) on the tribological behaviour were investigated using a ball-on-disc tribometer at ambient conditions. Lower current density, smaller particle size and higher concentration of MoS₂ decreased COF. While increasing the surfactant concentration decreased the COF, its friction lowering effect was much more pronounced at relatively lower concentrations of MoS₂ in the electrolyte.

Keywords: electrocodeposition; MoS₂ particle; friction; wear; surfactant; sodium lignosulfonate; SLS.

DOI: 10.1504/IJSURFSE.2017.088120

International Journal of Surface Science and Engineering, 2017 Vol.11 No.5, pp.418 - 432

Received: 30 Jan 2017
Accepted: 19 Mar 2017
Published online: 24 Nov 2017 *

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