Corrosion Resistance of Zn and Zn-Ni Electrodeposits: Morphological Characterization and Phases Identification

Abstract

Zinc alloys coatings formed with elements of group VIIIB are promising because they display similar properties and protect steel by galvanic action. The Zn-Ni alloy is remarkable by showing improved mechanical properties and better corrosion resistance when compared to zinc coatings of similar thickness, also can be applied at higher temperatures. In this work, electrodeposits of Zn, Zn-12%Ni, obtained upon SAE 1010 steel from commercial alkali baths, were treated by blue chromatization and characterized according to mechanical properties and morphology. Studies were carried out by using measures of hardness, roughness, SEM, EDS and XRD. Among the studied electrodeposits, alloys treated by chromatization showed higher corrosion resistance and Zn-Ni electrodeposits showed higher value of roughness and hardness, while zinc coating had results similar to the steel substrate By means of XRD, it was found that electrodeposits are crystalline, being identified in Zn-Ni alloy the presence of the phases (Ni 5 Zn 21) and (Ni 3 Zn 22), which are responsible for its higher corrosion resistance.

The effect of a trimetallic nanocomposite in the solar absorber layer of organic solar cells

“…27 The enhanced absorption in the near infrared region might also be caused by the inelastic scattering of the electromagnetic radiation (EM) inside the photoactive medium that assisted the increased optical path length in the polymer matrix. [20][21][22][23][24][28][29][30][31] According to the Doppler shi effect, the red shied absorption peak of the doped device conrms the scattering effect of the synthesized silver-based nanoparticles incorporated in the photoactive medium.…”

Morphology and Corrosion Behavior of Zn-Ni Layers Electrodeposited on Low Alloy Carbon Steel Substrate

“…Generally, Due to the intrinsic property of nickel, the microhardness of Zn-Ni alloy with a greater nickel content is high [14]. For zinc coatings, the estimated microhardness value should be between 100 and 140 Hv [32]. There was an improvement in hardness with a Zn-Ni alloy with a higher Ni content, due to the higher Ni hardness than that of Zn-Ni.…”

Role of the newly synthesized brightener in modification of surface properties of Zn-Ni alloy electrodeposited on steel substrate

“…The following equations describe instantaneous eqn. (6) Non-dimensional plots obtained using experimental and theoretical data for Zn-Ni alloy deposition in absence and presence of SC are shown in Figure 3 at different potentials. The following mechanism explains the anomalous behaviour of Fe group metal ions on the electrode surface:…”

“…According to Lin's conclusion, anomalous electrodeposition of zinc-nickel alloy is caused by the slow kinetics and hydrogen evolution at the nickel deposit. Zinc-nickel alloy provides a sacrificial protection to steel [6].…”