Interplay of Surface Diffusion and Surface Tension in the Evolution of Solid/Liquid Interfaces. Dealloying of β-Brass in Aqueous Sodium Chloride

Mártin, H. O.; Carro, Pilar; Creus, Alberto Hernández; Morales, J.; Fernandez, G. T.; Esparza, P.; González, S.; Salvarezza, Roberto Carlos; Arvía, Alejandro Jorge

doi:10.1021/jp001077c

Cited by 28 publications

(23 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The relaxation of species in the oxide layer due to adsorption and incorporation of Clions in the oxide film is also frequently considered 36,37 . The inductive arc might be associated with the beginning of pits formation 38,39 . In this study, the presence of Zn 2 Mg and Zn 11 Mg 2 , determined by the X-Ray diffractograms of Figure 4, is responsible for the pitting corrosion, since they have anodic behavior as compared to that of the Zn matrix.…”

Section: Electrochemical Impedance Spectroscopy (Eis) and Equivalent mentioning

confidence: 99%

Effects of Macrosegregation and Microstructure on the Corrosion Resistance and Hardness of a Directionally Solidified Zn-5.0wt.%Mg Alloy

et al. 2019

View full text Add to dashboard Cite

This study aims to analyze the influence of macrosegregation on microstructure evolution, and of microstructure length scale on the corrosion resistance of a Zn-5.0wt.%Mg alloy casting. The analyzed samples were taken along the length of castings unidirectionally solidified in unsteady state conditions of heat extraction. Microstructure characterization, microhardness, linear polarization and electrochemical impedance spectroscopy (EIS) tests were performed. A unique type of microstructure was observed, characterized essentially by a morphology typified by idiomorphic MgZn 2 crystals in a "complex eutectic mixture" [coexistence of stable (Zn+Mg 2 Zn 11 ) and metastable (Zn+MgZn 2 ) eutectics]. The correlation between thermal and microstructural parameters, permitted experimental growth laws, correlating the evolution of the lamellar eutectic spacing with the cooling rate to be established. Vickers microhardness and electrochemical corrosion tests showed that more refined microstructures associated with higher experimental cooling rates, are related to a better set of higher hardness and corrosion resistance.

show abstract

Section: Electrochemical Impedance Spectroscopy (Eis) and Equivalent mentioning

confidence: 99%

Effects of Macrosegregation and Microstructure on the Corrosion Resistance and Hardness of a Directionally Solidified Zn-5.0wt.%Mg Alloy

et al. 2019

View full text Add to dashboard Cite

show abstract

“…Especially, metal electrodes with nanoporous surface structure possess great advantages in analysis and chemical reactions [59][60][61].…”

Section: Au-based Electrocatalystsmentioning

confidence: 99%

Electrocatalysts for Glucose Electrooxidation Reaction: A Review

2015

View full text Add to dashboard Cite

The up-to-date research as far as it concerns the abiotic direct glucose fuel cells (DGFCs) is summarized and discussed in the present review. Platinum and goldbased as well as Raney-type electrocatalysts are among the most studied ones. In abiotically (non-implantable) DGFCs, unsupported Pt and PtRuO 2 , exhibited good activity (power density *20 mW cm -2 ), at room temperature and at atmospheric pressure. On the other hand, Au-based electrocatalysts adopted in a DGFC resulted in power densities up to ca. 5 mW cm -2 , exhibiting however high poisoning tolerance. Recently, after the introduction of alkaline membranes into the market, Pd-based electrocatalysts have attracted the attention of the research community because of their enhanced activity in alkaline media. However, there are still very few investigations where membrane electrode assemblies with palladium electrocatalysts have been applied. Moreover, Raney-type electrocatalysts, not yet examined for other fuels in direct polymer electrolyte fuel cells, are considered to be the most appropriate for implantable abiotic DGFCs. A novel implantable fuel cell in a human brain performed with 3.4 9 10 -3 lW power for 10 h adopting Raney-type electrocatalysts.

show abstract

“…The zinc atoms dissolve away from the alloy surface into the electrolyte, leaving vacancies 14,22,[26][27][28] and less coordinated copper atoms, i.e. Cu 3 Zn ͑s͒ → Cu 3 * ᮀ ͑S͒ + Zn ͑aq͒…”

Section: Resultsmentioning

confidence: 99%

Selective Dissolution of Alpha Brass in Acid Noncomplexing Media

Awadh¹,

Kharafi²,

Ateya³

2009

J. Electrochem. Soc.

View full text Add to dashboard Cite

The electrochemical behavior of alfa brass ͑Cu3Zn͒ was studied using electrochemical and surface characterization techniques in an acidic noncomplexing medium. The alloy was prepared from pure Zn and Cu to eliminate the dezincification inhibitors and was properly heat-treated. Below a transition potential ͓E t Ϸ 0.25 V standard hydrogen electrode ͑SHE͔͒ only zinc dissolves selectively while copper remains virtually immune. Beyond E t copper dissolves rapidly along with zinc, reaching equal rates at ϳ0.3 V, beyond which copper dissolves faster than zinc. The significance of the transition potential E t is different from the critical potential, E c , which is observed with noble metal alloys. Large values of the dezincification factor ͑Z͒ were measured at potentials below E t . As the potential increases above E t , Z decreases asymptotically toward a value of Z Ϸ 1, which indicates simultaneous dissolution of zinc and copper at rates that are proportional to their mole fractions in the alloy. Electrochemical impedance spectra were modeled using a constant phase element. As the potential increases, the polarization resistance decreases while the doublelayer capacity increases. Atomic force microscopy images show roughening of the alloy surface as a result of selective dissolution of zinc. Enrichment of copper on the alloy surface was documented using X-ray photoelectron spectroscopy.The selective corrosion of alloys involves preferential dissolution of the active component of the alloy, leaving behind a fragile surface that is enriched in the more noble component. The process is actually the reverse of alloy formation and hence is often described as dealloying. It leads to serious deterioration of the surface and mechanical properties of the remaining alloy and hence increases the risk of corrosion failures, which may be costly or fatal. It is of considerable industrial importance in view of the fact that alloys ͑e.g., brasses, bronzes, cupronickels, steels, superalloys, etc.͒ form the backbone of modern industries. Under some conditions, the process leads to the formation of noble metal nanoporous structures and Raney-type catalysts. The mechanism of this process is inherently different from and more complex than the mechanism of dissolution of a single metal. [1][2][3] Copper zinc alloys ͑brasses͒ provide a favorable combination of cost, thermal, mechanical, and electrical properties. They are extensively used in Kuwait and the Gulf region in various industries, such as desalination, power generation, refineries, etc. 4 The dezincification of brass is one of the more recognized forms of the selective dissolution of alloys. 5-7 Premature failure of brass condenser tubes was recently attributed to dezincification in a power plant in Turkey. 8 Dezincification has also been documented in another power plant in Spain. 9 The corrosion behavior of brass has been the subject of active research for some decades and is still attracting increasing attention. The measurements in many of the above works were performed on com...

show abstract

Interplay of Surface Diffusion and Surface Tension in the Evolution of Solid/Liquid Interfaces. Dealloying of β-Brass in Aqueous Sodium Chloride

Cited by 28 publications

References 19 publications

Effects of Macrosegregation and Microstructure on the Corrosion Resistance and Hardness of a Directionally Solidified Zn-5.0wt.%Mg Alloy

Effects of Macrosegregation and Microstructure on the Corrosion Resistance and Hardness of a Directionally Solidified Zn-5.0wt.%Mg Alloy

Electrocatalysts for Glucose Electrooxidation Reaction: A Review

Selective Dissolution of Alpha Brass in Acid Noncomplexing Media

Contact Info

Product

Resources

About