Eletrodeposição de Ligas Co-B e avaliação da resistência à corrosão.

Abstract

Corrosion has caused several damages to the environment as well as in the industries because the process by which erode large buildings made of metal structures, can be seen everywhere in the world, causing the accumulation of junk parts unusable for human consumption. Given the serious problems caused by corrosion studies of metallic coatings have been developed, especially in the area of electrochemistry. The low cost and high durability in pieces obtained by electrodeposition have been gaining considerable space on the production lines. Various alloys obtained by the electrodeposition process, such as Co-B alloys exhibit high hardness, high gloss and high wear resistance. The amorphicity these alloys has attracted a new class of materials that have excellent mechanical properties in order that its alloys are light and have thin but high durability and corrosion resistance. The process of obtaining not pollute the environment, consume small amounts of dissolved metals and uses of electricity, for that reason has attracted the interest of big business and environmentalists. In this work were developed Co-B alloys obtained by electrodeposition at different current densities in galvanostatic mode with pH = 5.0. lts chemical evaluation as the process of corrosion resistance, was carried out by the techniques of potentiodynamic linear polarization (PLP) and Electrochemical Impedance Spectroscopy (EIS). It was observed that the agitation affects the visual appearance of the samples showed more brilliant and uniform electrodeposits. The eletrodepósito obtained at current density of 9,375mA/cm2 presents the potential for corrosion resistance more positive than -0.155V according to PLP. The formation of two arcs of impedance and 215311049 and 3.02xlOaQ confirms the result in polarization. Analysis by dissolving couiume'trica This film presents two potential levels suggesting the presence of boron in the alloy.