%0 Journal Article
%T Studies on the Codeposition of SiC Nanopowder with Nickel, Cobalt, and Co-Ni Alloys
%A Ewa Rudnik
%A Sˋawomir Syrek
%J Journal of Coatings
%D 2014
%R 10.1155/2014/659697
%X Electrodeposition of SiC nanopowder (approximately 120ˋnm) with nickel, cobalt, and Co-Ni alloy matrix was studied. It was found that particles suspended in the bath affect slightly the reduction of metallic ions. Incorporation of the ceramic particles was governed mainly by the morphology of the matrix surface, while no strict correlation between the amount of cobalt ions adsorbed on the powder and the SiC content in the composites was found. Microhardness of nickel deposits was ˋHV, while for cobalt-rich coatings (84每95ˋwt.% Co) the values were in the range of 260每290ˋHV, independently of the SiC content in the coatings. Fine-grained nickel deposits were characterized by good corrosion resistance, while cobalt and Co-Ni alloys showed high corrosion current densities. 1. Introduction Electrodeposited composite coatings consist of intentionally joined together two or more components (i.e., matrix and reinforcement) with different properties receiving a new unique and macroscopically monolithic material exhibiting desirable, better, or different characteristics in comparison with each individual component or only mixed together. Properties of the composites are determined not only by a kind of matrix (metal or alloy), but also by the type and size of the incorporated particles. Various metal-particle combinations have been developed [1, 2]. Among them nickel matrix composites seem to be the most investigated systems [1每6], while composite coatings based on cobalt [1, 7每9] and Co-Ni alloys [10每13] were studied in a lesser extent. Coatings are reinforced usually with ceramic particles as carbides, oxides, nitrides, borides, and so forth. Such materials show high hardness and strength, but a decrease in the properties at elevated temperatures can occur in some cases [14]. A series of our previous studies on the codeposition of the composites was carried out using micron-sized SiC particles. The percentage of ceramic phase in the electrodeposited Ni, Co, and Co-Ni alloy matrix composites as well as some properties of the layers determined in the dependence on the powder concentration in the plating bath, current density, and the presence of some additives were reported [14每19]. The present paper is focused on understanding the influence of the electrolyte composition and the presence of SiC nanoparticles in the plating bath on the course of the cathodic reactions as well as composition, morphology, and some properties of the deposits. It is known that behavior of nanoparticles during electrodeposition differs seriously from that observed for the particles
%U http://www.hindawi.com/journals/jcoat/2014/659697/