Estudo sobre as propriedades magnéticas e corrosivas da liga ni-co obtida pelo processo de eletrodeposição a partir de um banho com citrato de sódio

Abstract

Electrodeposition has been widely used in the development of metallic alloys, in order to promote corrosion-resistant coatings. Various electrolytic bath compositions are studied to obtain the Ni-Co alloy, therefore, the addition of sodium citrate (complexant) to the bath has gained prominence in studies. To optimize the process, a 2² Rotational Central Composite Design (DDCR) was used with axial points (-α, +α) and 2 central points, totaling 10 experiments. From the citrate bath it was possible to observe that there was the anomalous behavior characteristic of Ni-Co alloys, coatings obtained in acidic zones presented a more uniform morphology, greater saturation magnetization, however, low values for corrosion resistance due to the high content of cobalt in their composition, in addition, they presented a mixture of phases (fcc+hcp). The coatings obtained in alkaline zones presented a nodular morphology, similar to cauliflower, which is linked to the highest nickel content in the alloy according to chemical composition results. These coatings showed low saturation magnetization, however, good results for corrosion. Therefore, it is concluded that in the study it was possible to obtain alloys with high nickel contents, which allows applications such as protective coatings and alloys with high cobalt contents, enabling their use in the magnetic materials sector.