UDC 621.162 © Ewa Osuchowska, Jerzy Beliński CHARACTERISTICS OF Zn ALLOY COATINGS ELECTRODEPOSITED FROM ACIDIC-TYPE BATHS The paper describes the Zn-Mo and Zn-Cr alloy coatings. <...> The coatings were deposited from acidic-type baths (pH 3) with different buffering-complexing agents at current density 1-6 A/dm2 in non-agitated and agitated solution. <...> The bath temperature was 20C. The corrosion resistance of these coatings was studied in 0.5M NaCl solution using electrochemical method – potentiodynamic polarization. <...> The surface morphology was also evaluated by SEM. <...> Obtained Zn alloy coatings contained to 0,2 wt.% Cr and 30 wt.% Mo. The corrosion properties of Zn alloys mostly depend on the Mo/Cr content and the kind of buffering-complexing agent. <...> INTRODUCTION The zinc is widely used as corrosion protective sacrificial coatings for steel substrates, mainly for automotive, building and aerospace applications. <...> Zinc protects steel through a cathodic control mechanism and the coating acts as a barrier between the steel and the environment [1]. <...> Recently, zinc alloy coatings (Zn-Ni, ZnCo, Zn-Fe) have gained increasing importance in the industry because they have better properties, mainly corrosion protection, in comparison to pure zinc deposits and can be also a substitute for highly toxic cadmium coatings. <...> Actually, attention has been directed towards the electrodeposition of Zn-Cr, Zn-Mo and Zn-Mn al loy coatings [8-21]. <...> In this work Zn-Cr and Zn-Mo alloy coatings electrodeposited from acidic baths were investigated with respect to deposition process and its relation to corrosion behaviour and morphology. <...> The bath composition are illustrated in table 1. <...> The coatings were deposited at current densities 1-6 A/dm2 , at 20C in agitated or non-agitated solutions. <...> The cathode was platinum or low carbon steel and the anode was platinum. <...> Then the current efficiency and the composition of deposits were calculated. a) 100 Проблемы машиностроения и автоматизации, № 3 – 2011 b) Fig. 1. <...> SEM photograph of deposit obtained from succinate bath (a) and citrate bath (b) at current density 4 A/dm2 (zoom 500x) electrode cell system: the sample of the exposed area 0.33 cm2 The corrosion studies were carried out in a three was used as the working electrode <...>