Eventos Anais de eventos
CONEM 2018
X Congresso Nacional de Engenharia Mecânica
Avaliação da resistência à corrosão e análise químico-morfológica da liga Cu-Zn-Ni revestida no aço A516
Submission Author:
Raíssa Queiroga , PB , Brazil
Co-Authors:
Raíssa Queiroga, Bianca Evaristo, Mikarla Sousa, Josiane Costa, Theophilo Maciel, Renato Santana
Presenter: Raíssa Queiroga
doi://10.26678/ABCM.CONEM2018.CON18-1192
Abstract
Cu-Zn-Ni electrodeposited alloy in three different electrolytic bath compositions was analyzed, as well as the microstructure of the electrodeposited metallic coating, by Scanning Electron Microscopy, as well as to analyze the chemical composition of the coatings through x-ray dispersive energy spectroscopy. Cu-Zn-Ni alloy coatings were electrodeposited on a substrate of A516 steel at room temperature, pH 6, adjusted with ammonium hydroxide. The baths were prepared by varying the concentration of nickel sulfate in each bath. In this way, 3 baths were carried out by varying the nickel sulphate concentration and keeping the concentration of copper sulphate and zinc sulphate 0.005 and 0.010 Mol / L, respectively, a concentration of nickel sulfate and sodium citrate 0.001 and 0.025 Mol / L in bath 1, 0.004 and 0.100 Mol / L in bath 2 and 0.016-0.400 Mol / L in bath 3, respectively. In the chemical analysis, it was found that the increase of nickel was followed in the samples according to the increase of the concentration of nickel sulfate in the electrolytic bath. From the analysis of the cathodic efficiency values, an increase in the cathodic efficiency of the coatings was observed, with the addition of nickel sulphate in the electrolytic bath. Morphological analysis revealed a change in the morphology of the coatings with the variation of the nickel concentration, as well as the presence of nodules and refined grains. In the electrochemical impedance spectroscopy tests, it was observed that increasing the concentration of nickel sulphate in the electrochemical bath caused an increase in corrosion resistance to a certain extent, since a large increase of nickel sulphate did not produce a coating with high nickel content and consequently decreased its corrosion resistance.
Keywords
electrodeposition, corrosion, coating, Metal alloys, CuZnNi
