The properties of electrolytical nickel-titanium composite layers
Joanna Panek, Antoni Budniok, Edward Rówiński, Eugeniusz Łągiewka Uniwersytet Śląski, Instytut Nauki o Materiałach, ul. Bankowa 12, 40-007 Katowice
Annals 4 No. 9, 2004 pages 88-93
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abstract Ni+Ti composite layers were obtained by electrolytic deposition of nickel from an electrolyte containing Ti powder suspension. The layers were plated on steel substrate (St3S) under galvanostatic conditions. Their chemical composition, determined by X-ray fluorescence spectroscopy method, depends on amount of titanium powder dispersed in galvanic bath as well as on the galvanic conditions under which the layers were obtained (Tab. 1). Generally, the obtained Ni+Ti composite layers contained from 14 to 53% wt. of titanium. From the analysis of the Auger lines it was found that besides nickel and titanium the layers contain oxygen and carbon (Fig. 1). From the analysis of the Auger spectra line profile of Ti (LMV) the presence of NiTi and Ti4O3 was found (Fig. 2). Surface morphology of obtained layers as well as the cross-sectional images of obtained layers were tested by scanning microscope. It was stated, that incorporation of titanium powder into the electrolytic nickel matrix causes the obtaining of layers characterized by great, developed real surface area. The presence of electrolytical nickel nano-agglomerates plated on titanium particles confirms the adsorption mechanism of layers’ deposition (Figs. 3, 5a, b). The results of structural investigation of the obtained layers by the X-ray diffraction method show, that they consist in crystalline phases of nickel and titanium (Fig. 6a). Thermal treatment of Ni+Ti composite layers conducted in vacuum, at a temperature of 950°C for 3 hours changes the surface morphology and phase composition of the layers (Figs. 4, 5b, c). As a result of solid-state reaction Ni3Ti intermetallic compound is arising (Fig. 6b). Key words: nickel, titanium, electrolytic composite layers, intermetallic compounds