Influencia da concentração de sulfato de cobalto e molibdato de sódio sobre a liga Co-Fe-Mo utilizando um planejamento fatorial 2².

Abstract

The amorphous alloys have attracted great interest in recent years and their magnetic properties, mechanical and corrosion resistance have been widely disseminated. The amorphous character and chemical homogeneity makes them free of defects associated with the crystalline state, giving them great potential in many technological applications. The electrodeposition has been one of the most prominent in obtaining these materials and operational parameters are well established and reported in the literature. This is due mainly to the ability of this technique offers to obtain deposits with high levels of purity, with very different compositions and thicknesses, allowing also take different kinds of substrates and with various geometric shapes. However, there is some difficulty in the production of amorphous alloys of molybdenum by traditional thermal methods. The electrodeposition becomes therefore an alternative method for producing such alloys. The term "induced codeposition" was presented by Brenner to describe a situation in which a metal cannot be electrodeposited from aqueous solution in its pure form and yes, codeposition in the presence of another metal, forming a league. According to Brenner's classification, the alloys containing molybdenum is regarded as a type of codeposition induced. This study aims to obtain coatings of Co-Fe-Mo and evaluate the corrosion resistance of the alloys obtained. In obtaining this alloy was used an electrolytic bath containing sodium citrate, sodium molybdate, cobalt sulphate and iron sulphate. In this process we evaluated the influence of the concentration of cobalt sulphate and the concentration of sodium molybdate on the corrosion resistance of the alloys obtained. Was successfully obtained by electrodeposition of a ternary alloy Co-Fe-Mo. It was observed that with increasing concentration of cobalt sulphate and the concentration of sodium molybdate were the best values of corrosion potential.