Composite layers Ni/Cgraphite produced electrolchemically
Maria Trzaska, Marta Gostomska
Quarterly No. 1, 2009 pages 84-88
DOI:
keywords: composite coating, disperse phase, nikel coating, electrochemical method
abstract Electrochemical method as a one of the process in surface engineering allowed to obtain materials with high used properties to application in friction system and effective mechanical elements. Thanks to incorporation particles of different phase into nikel matrix, selection composition of the electrolyte and technological parameters of the electrochemical process as current, temperature, the kind of stirring, it’s possibile to modification hard and corrosion resistant nikel layers. Graphite as a dispersion phase has a good lubricating ability, low hardness and high thermal and electrical conductivity. Thanks to connection this materials it’s possibile to obtain a hard material with good used properties. Composite layers with nickel matrix and Cgraphite disperse phase have been the subject of the present authors’ investigations. Composite layers was deposited on steel substrate (St3S) by electrochemical metod. Results of the characteristics initial graphite powder are reported. The Ni-Cgraphite composite were electrodeposited in a sulfate Watt's bath of the following composition: nickel sulfate (NiSO4•6H2O), nickel chloride (NiCl2•6H2O), boric acid (H3BO3) and with organic substantion Z1. In this paper was presented the morphology, topography of Ni layers comparison with Ni/Cgraphite layers. The method computer analysis of images was applied to determine the content of the dispersed chase of graphite in the composite material. These investigations show that graphite powder in the whole volume of the composite layer is disposed uniformly and its introduction into the layer material causes considerable change of topography in comparison to Ni layer. The method of stirring while electrodeposition process caused change of morphology and structure of produced layers. In the present paper applied two kind of stirring: mechanical and ultrassound. The microhardness and tribology properties of nikel and composites layers were also examined used wear test. Incorporation of graphite powder into Ni matrix caused improvement abrasion resistance Ni/Cgraphite composites. The im of present research was to obtain composite materials with high tribology properties and compact, tight Ni-Cgraphite layer.