Studies and Researches on Obtaining Electrochemical Composite Coatings in Nickel - Ni / Kaolin Matrix
Abstract
The paper presents the electrochemical obtaining of nickel matrix composite coatings using kaolin particles as dispersed phases. Watts electrolytes were used, with a pH = 4.5 current densities of 6, 9, 12 A/dm2 , a dispersed phase concentration of 20 g/L, shaking speeds of 500, 700 and 900 rpm, deposition time of 60 minutes. Their characterization has been achieved both from a microstructural point of view and from the point of view of layer thickness, microhardness and behaviour in salt mist corrosion. The presence of dispersed phase particles, which acted as nucleation centres, led to the reduction of the nickel crystallites, which further decreased the roughness of the coatings while increasing hardness. By correlating the current density with the rate of stirring, respectively the increase their, thicker layers were obtained.
Downloads
References
[2]. Raul Novac, Materiale compozite cu proprietăţi speciale, Teză doctorat, Galaţi, 2011.
[3]. Davies Nathan, Applications of Clay Sedimentation: Deposition of CIGS Photovoltaic Inks, December 2014, Institute of Mathematics and Physics Aberystwyth University.
[4]. Pavlov A. I., Influenţa tratamentelor electrochimice a suprafeţelor (straturi nanocompozite în matrice de nichel) asupra rezistenţei la coroziune şi uzură, Teză de doctorat, Galaţi, 2012.
[5]. Gül H., Kılıc F., Aslan S., Alp A., Akbulut H., Characteristics of electro-co-deposited Ni–Al2O3 nano-particle reinforced metal matrix composite (MMC) coatings, Wear, 267, p. 976-990, 2009.
[6]. Tushar Borkar, Electrodeposition of nickel composite coatings, Mumbai University India, 2007.
