Effect of Alloying Elements on Electrochemical Properties of Magnesium-Based Sacrificial Anodes

Kim, J.-G.; Koo, Se-Jin

doi:10.5006/1.3280541

Cited by 30 publications

(11 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The electrochemical behaviour of magnesium is relevant for a variety of applications including lightweight structures, where it determines the corrosion resistance [1][2][3], batteries and sacrificial anodes where it determines efficiency [4][5][6][7], and surgical implants, where it determines the rate at which the implant disappears within the human body [8,9]. The electrochemical behaviour of magnesium in aqueous environment, however, is relatively complex compared to other light metals such as aluminium or titanium.…”

Section: Introductionmentioning

confidence: 99%

Correlation between electrochemical impedance measurements and corrosion rate of magnesium investigated by real-time hydrogen measurement and optical imaging

Curioni

Scenini

Monetta

et al. 2015

Electrochimica Acta

196

130

View full text Add to dashboard Cite

Please cite this article as: M.Curioni, F.Scenini, T.Monetta, F.Bellucci, Correlation between electrochemical impedance measurements and corrosion rate of magnesium investigated by real-time hydrogen measurement and optical imaging, Electrochimica Acta http://dx. AbstractThe corrosion behaviour of magnesium in chloride-containing aqueous environment was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) performed simultaneously with real-time hydrogen evolution measurements and optical imaging of the corroding surface. The potentiodynamic investigation revealed substantial deviations from linearity in close proximity of the corrosion potential. In particular, differences in the slope of the current/potential curves were observed for small polarizations above or below the corrosion potential. These observations, suggest that the usual method based on the use of the Stern-Geary equation to convert a value of resistance into a value of corrosion current is inadequate.Nonetheless, a very good correlation between values of resistances estimated by EIS and corrosion currents obtained from real-time hydrogen measurement was found. Real-time hydrogen measurement also enabled, for the first time, direct measurement of an 'apparent' Stern-Geary coefficient for magnesium. In order to rationalize the complex behaviours experimentally observed, an electrical model for the corroding magnesium surface is presented.

show abstract

Section: Introductionmentioning

confidence: 99%

Correlation between electrochemical impedance measurements and corrosion rate of magnesium investigated by real-time hydrogen measurement and optical imaging

Curioni

Scenini

Monetta

et al. 2015

Electrochimica Acta

196

130

View full text Add to dashboard Cite

show abstract

“…[6,7] Although pure Mg has a high electromotive force (about 150 mV more that Mg alloys have), some Mg alloys, especially AZ63, show higher efficiency. [8] In general, the addition of alloying elements with low hydrogen overvoltage to Mg significantly reduces the efficiency while noble elements with high hydrogen overvoltage, such as lead (Pb), tin (Sn), cadmium (Cd), and Zn, have little effect on the efficiency of Mg anodes. [9] On the other hand, some alloying elements are effective in grain refining and could be added to Mg to induce uniform corrosion in the anode.…”

Section: Introductionmentioning

confidence: 99%

“…[3] Different studies indicate that anode efficiency could be managed by controlling the grain size as well as the distribution of second phases. [8,12] Andrei et al [7] suggested solution heat treatment to improve the microstructure leading to anode efficiency improvement. It has also been shown that the addition of a very small quantity of beryllium (Be) improves the corrosion properties of Mg alloys while zirconium (Zr) addition, below 0.5%, not only results in extreme grain refinement but also improves corrosion properties of AZ63 alloy.…”

Section: Introductionmentioning

confidence: 99%

“…Several investigations have been done to improve the current capacity of Mg anode . Although pure Mg has a high electromotive force (about 150 mV more that Mg alloys have), some Mg alloys, especially AZ63, show higher efficiency . In general, the addition of alloying elements with low hydrogen overvoltage to Mg significantly reduces the efficiency while noble elements with high hydrogen overvoltage, such as lead (Pb), tin (Sn), cadmium (Cd), and Zn, have little effect on the efficiency of Mg anodes .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Influence of Zr and Be on microstructure and electrochemical behavior of AZ63 anode

Jafari

Hassanizadeh

2018

Materials & Corrosion

View full text Add to dashboard Cite

In this study, the effect of Zr and Be on the microstructure and electrochemical properties of a common magnesium alloy anode, AZ63, used in cathodic protection, was investigated. The AZ63, as well as Zr (0.25, 0.50, 0.70, and 0.90 wt%) and Be (0.0001, 0.001, 0.01, and 0.1 wt%) bearing AZ63 anodes, were prepared. The microstructure and electrochemical characteristics of the cast anodes were characterized. The results showed that the addition of Zr refines the grain size of the AZ63 anode; and above 0.5 wt% Zr, forms Al2Zr and β‐Mg17Al12. In contrast, grain coarsening was observed with increasing Be content. Moreover, the addition of 0.1 wt% Be to the anode resulted in the spheroidization of the β‐phase. Also, it was shown that AZ63‐0.5 wt% Zr provides the lowest corrosion rate among the experimented anodes, and the higher the Be content, the lower the corrosion rate of the anode. Higher content of both Be and Zr alloying elements resulted in improved efficiency of the anode for 20% and 13%, respectively. The results of this study indicate higher impact of Be on the efficiency increment of the AZ63 anode.

show abstract

“…It can be a side reaction during metal electrodeposition, 1-3 a parasitic reaction for batteries [4][5][6] and sacrificial anodes, [7][8][9][10] or the cathodic reaction for corrosion of metals with low electrochemical potential, such as for example magnesium [11][12][13][14][15][16][17][18][19][20][21][22][23] or aluminum. [24][25][26][27][28][29][30][31][32][33][34] The accurate measurement of the amount of hydrogen gas generated during an electrochemical process is important both to aid fundamental understanding and to optimize technological processes.…”

mentioning

confidence: 99%

Development of an Electrochemical Balance to Measure Quantitatively Hydrogen Generation during Electrochemical Processes

Bottini

Santamaria

Curioni³

2017

J. Electrochem. Soc.

View full text Add to dashboard Cite

A new method to measure the amount of hydrogen generated from the surface of an immersed electrode is presented in this work. The method consists of a mechanical balance with a horizontal arm attached to two hydrogen-collecting containers that are submerged in two independent electrochemical cells. One of the two cells (the test cell) contains the electrode of interest, generating an unknown amount of hydrogen, whereas the other cell (the measurement cell) contains an inert electrode that is used to evolve an amount of hydrogen equal to that generated in the test cell, such as the mechanical equilibrium between the sides of the balance is constantly maintained. Adequate electrical connections and circuitry ensures that, as hydrogen is evolved from the electrode of interest in the test cell, the displacement of the balance arms activates an electrical contact, which triggers the hydrogen evolution in the measuring cell. Once a sufficient amount of hydrogen is evolved from the measuring cell, the horizontal arm is displaced in the opposite direction and the electrical contact to the measuring cell is interrupted. The measurement of the current flowing through the measuring cell enables precise estimation of the amount of hydrogen generated in the test cell. Proton reduction, resulting in generation of hydrogen gas, is observed in many applications involving electrochemical reactions and often during corrosion of light alloys. It can be a side reaction during metal electrodeposition, 1-3 a parasitic reaction for batteries 4-6 and sacrificial anodes, 7-10 or the cathodic reaction for corrosion of metals with low electrochemical potential, such as for example magnesium 11-23 or aluminum. [24][25][26][27][28][29][30][31][32][33][34] The accurate measurement of the amount of hydrogen gas generated during an electrochemical process is important both to aid fundamental understanding and to optimize technological processes. The present work has originated from the authors' activity focusing on the measurement of the hydrogen evolved from magnesium during corrosion in aqueous environments; however the method presented here could be applied to virtually any study where quantitative measurement of gas evolving from an immersed electrode is required.The most simple and most widely applied method to measure the hydrogen generated from an immersed surface is the (volumetric) hydrogen collection method, widely used in corrosion studies on magnesium and magnesium alloys. [11][12][13][14][15][16][17][18][35][36][37] The volumetric method involves the use of a graduated cylinder that is closed at the top and open at the bottom, and initially filled with test electrolyte. The bottom of the electrolyte-filled graduated cylinder is immersed in a cell containing the same electrolyte, and a specimen evolving an unknown amount of hydrogen is then placed below the cylinder (sometimes with a funnel to aid complete bubbles collection). The hydrogen bubbles generated from the specimen float toward the top of the graduated cylinder, where the...

show abstract

Effect of Alloying Elements on Electrochemical Properties of Magnesium-Based Sacrificial Anodes

Cited by 30 publications

References 1 publication

Correlation between electrochemical impedance measurements and corrosion rate of magnesium investigated by real-time hydrogen measurement and optical imaging

Correlation between electrochemical impedance measurements and corrosion rate of magnesium investigated by real-time hydrogen measurement and optical imaging

Influence of Zr and Be on microstructure and electrochemical behavior of AZ63 anode

Development of an Electrochemical Balance to Measure Quantitatively Hydrogen Generation during Electrochemical Processes

Contact Info

Product

Resources

About