Textural and morphological studies on zinc–iron alloy electrodeposits

Abstract

Zinc-iron alloy electrodeposits have industrial significance, since they provide better corrosion resistance and with improved mechanical properties when compared to pure zinc coatings. This is due to the unique phase structure of the alloy formed. But this deposition belongs to anomalous deposition, where the electrochemically less noble zinc deposits more preferentially, than the more noble iron. So the industrial process control over the deposition becomes difficult. So, this study correlates the effect of various deposition parameters over the deposition kinetics and deposited alloy characteristics. Transition and partial current densities were computed. Effect of hydrogen overpotential and surface coverage due to the adsorbed intermediates over anomalous deposition were explored. Plausible deposition mechanism and mathematical model was proposed to predict the anomalous electrodeposition characteristics. Textural, morphological and phase structural characteristics of the alloy was investigated. By the substitution of iron in the hcp lattice, c/a ratio was lowered and the lattice geometry was distorted. Intermetallic compounds of variable composition such as FeZn 14 , Fe 5 Zn 33 , Fe 3 Zn 13 and FeZn 3 with 'η' and ' ' phase structures were noted. Electrodeposition parameters were optimized and smooth, adherent, strain-free deposits with required iron content and hardness were obtained.

Effect of additives on nanocrystalline bright Zn–Ni–Fe alloy electrodeposit properties

“…The nanocrystalline bright Zn-Ni-Fe coating with (100) texture shows almost similar microhardness as coarse-grained ZNF dull coating. The observed results are in contrast with literature reports where deposit with smaller grain size and (100) texture exhibited higher hardness [19][20][21]. Thus microhardness value of ZNF bright deposit was not only influenced by grain size and texture but also depends on the chemical composition of the coating.…”

Methyl salicylate detection via electrochemical transients using nano spinel Co3O4 films

“…Based on the Volmer, Tafel and Heyrovsky models of HER and subsequent surface coverage of hydroxide intermediates [14] Based on atomic percent data from EDS analysis (Fig. 6) it can be noted that, the film contains the mixed spinel Co 3 O 4 composition with stoichiometric atomic weight ratio, O:Co as 1:~2.7.…”

Corrosion characteristics of ZnNiCo ternary alloy electrochemically deposited by using different anodes

“…Dosadašnja istraživanja su pokazala da trojne legure ZnNiCo u odnosu na dvojne legure cinka i elemenata trijade gvožđa [1][2][3][4][5][6][7] imaju veću otpornost prema korozionim procesima [8,9]. Antikorozione karakteristike zaštitnih prevlaka zavise od različitih faktora.…”