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.
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 *