Corrosion behaviour of Terfenol-D

Sachdeva, Deepika; Balasubramaniam, R.

doi:10.1016/j.corsci.2008.01.006

Cited by 11 publications

(17 citation statements)

References 38 publications

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“…Moreover, a one order in magnitude increase in R p in comparison to Fe 62 Co 15 B 14 Si 9 alloy was also recorded. The possible anodic dissolution of Fe is shown by Equations ( 2)-( 4 For all samples, the B c was lower than B a , which suggests that the cathodic reaction connected with reducing oxygen at the interface of the electrolyte/substrate and limited the corrosion [32]. Similar results were received at [32,39] for alloys based on Fe.…”

Section: Resultssupporting

confidence: 68%

“…Observed behavior was characteristic for materials with the active dissolution of Fe [ 31 ]. However, for the Fe 62 Co 15 B 14 Si 9 sample, after 30 min in immersion, a slight increase in E OCP to –645 mV vs. SCE was observed and this resulted in an increase in the layer consisting of corrosion products on the metallic surface, which is a barrier to the corrosion agent [ 32 ]. However, the corrosion product cannot provide effective protection against chloride due to being significantly porous and their composition: Growing iron oxides and iron compounds richer in oxygen, e.g., Fe(OOH) 2 and FeOOH, creates rust instead of a passivation film [ 33 ].…”

Section: Resultsmentioning

confidence: 99%

“…For all samples, the B c was lower than B a , which suggests that the cathodic reaction connected with reducing oxygen at the interface of the electrolyte/substrate and limited the corrosion [ 32 ]. Similar results were received at [ 32 , 39 ] for alloys based on Fe.…”

Section: Resultsmentioning

confidence: 99%

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Influence of the Nb and V Addition on the Microstructure and Corrosion Resistance of the Fe-B-Co-Si Alloy

et al. 2021

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The paper presents a comparison of the results of the corrosion resistance for three Fe-B-Co-Si-based newly developed alloys with the addition of Nb and V. The corrosion performance differences and microstructure variations were systematically studied using scanning electron microscope, electric corrosion equipment, X-ray diffractometer, and differential calorimeter. It has been shown that each alloying addition increased the corrosion resistance. The highest corrosion resistance obtained by potentiodynamic polarization was found for the alloy with both Nb and V addons (Fe57Co10B20Si5Nb4V4) and lowest in the case of the basic four-element Fe62Co15B14Si9 material. This shows that the proper choice of additions is of significant influence on the final performance of the alloy and allows tailoring of the material for specific applications.

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Section: Resultssupporting

confidence: 68%

Section: Resultsmentioning

confidence: 99%

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Influence of the Nb and V Addition on the Microstructure and Corrosion Resistance of the Fe-B-Co-Si Alloy

et al. 2021

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“…Localized corrosion of Terfenol-D in a chloride environment is primarily caused by pitting and is due to preferential attack of RE-rich phase present in the structure. 4 Therefore, it was reasonably concluded that the RE content of the alloy contributes to the localized corrosion of this material. This is well supported by research work carried out on other RE magnetic alloys of Nd-Fe-B and Sm-Co, [6][7][8][9] according to which, preferential dissolution of RE-rich phase is observed in atmospheric and aqueous environments.…”

Section: Discussionmentioning

confidence: 99%

On the Mechanism of Corrosion of Terfenol-D (Tb[sub 0.3]Dy[sub 0.7]Fe[sub 1.92])

Sachdeva

Balasubramaniam

2008

J. Electrochem. Soc.

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The effect of constituent elements Tb, Dy, and Fe on corrosion of Terfenol-D ͑Tb 0.3 Dy 0.7 Fe 1.92 ͒ was studied by potentiodynamic polarization studies in freely aerated, deaerated, and fully aerated 3.5% NaCl and 0.01 N Na 2 SO 4 solutions. The corrosion products obtained from immersion and cyclic spray tests were characterized by Fourier transform infrared ͑FTIR͒ spectroscopy and scanning electron microscopy ͑SEM͒. The polarization behavior of Terfenol-D closely resembled that of pure iron in all environments. Characterization of spalled corrosion products after immersion testing revealed a higher rare earth ͑RE͒ content. An increase in iron content of the adherent corrosion products with increasing duration of exposure pointed out the significant role of iron in the general corrosion processes of Terfenol-D. The polarization and characterization results have been related to the dealloying corrosion mechanism, wherein selective dissolution of REs from the surface results in corrosion from an essentially iron-enriched surface.The corrosion of rare earth ͑RE͒ magnetic materials has been an important subject of study. The extensively studied materials in this category are materials based on Nd-Fe-B and Sm-Co alloys. A relatively new RE magnetic material is based on the Tb-Dy-Fe alloy. Detailed studies on several aspects of corrosion of commercial-grade Tb 0.3 Dy 0.7 Fe 1.92 ͑commercially called Terfenol-D͒ have recently been concluded. 1-5 Corrosion of these ͑Tb,Dy͒Fe 2 -based magnetostrictive materials is of scientific, commercial, and strategic concerns, as this material is the nextgeneration material for active sonar applications. Apart from this, Terfenol-D finds varied applications, such as in tools for well cleaning in the petroleum, oil, and gas industries, in fuel injection, and in medical appliances.The known aspects of corrosion of Terfenol-D are reviewed briefly. Terfenol-D is particularly corrosion prone in the presence of chloride ions. 3,4 Moreover, corrosion rates are higher in the absence of oxygen and with increased duration of hydrogen charging. 2 Hydrogen embrittlement accompanies the corrosion process of Terfenol-D, 2 which undermines the structural integrity of the material.The objective of the present communication is to understand the effect of constituent elements ͑Tb, Dy, and Fe͒ on the corrosion behavior of Terfenol-D. Understanding the corrosion mechanism of an alloy may be very complex when the components of the alloy differ widely in their corrosion behavior. Therefore, it may be convenient to understand the corrosion mechanisms of individual alloy components and then relate them to the alloy system under study. Characterization of corrosion products formed in different environments has been used extensively for understanding the corrosion mechanisms. The most common metallic corrosion products in atmospheric and corrosive environments include oxides ͑hydrated͒ and ͑oxy-͒ hydroxides.This study also characterizes the corrosion product on Terfenol-D and its constituents under similar t...

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“…A preliminary study on corrosion behaviour of Tb 0?3 Dy 0?7 Fe 1?92 22 suggested corrosion mechanism similar to that of Nd-Fe-B magnetic material. A detailed investigation of the corrosion behaviour of Tb 0?3 Dy 0?7 Fe 1?92 23 and hydrogen effects on corrosion behaviour 24 has recently been concluded. These studies indicate that Tb 0?3 Dy 0?7 Fe 1?92 is susceptible to localised corrosion, particularly in chloride environment.…”

Section: Introductionmentioning

confidence: 99%

Passivity of Tb_0·3Dy_0·7Fe_1·92in alkaline solution and its breakdown by chloride ions

Sachdeva

Balasubramaniam

2009

Corrosion Engineering, Science and Technology

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The passivation and pitting corrosion behaviour of stoichiometric Laves phase magnetostrictive compound Tb 0?3 Dy 0?7 Fe 1?92 , was investigated in 0?02M NaOH solution at different chloride ion concentrations (0?001-0?1M) by cyclic potentiodynamic polarisation. A systematic decrease in breakdown potential and corresponding increase in anodic current densities was observed with increasing chloride concentration. Potentiostatic currents were measured at several applied potentials in the passive range. The incubation period of pitting decreased with increasing chloride concentration. Microscopic examination of corroded surfaces after cyclic polarisation scans revealed that the attack by chloride ions was localised along arrays of active rare earth rich phase. At higher chloride levels, these phases were undermined. The number of pits and pit size increased with increasing chloride concentration. Electrochemical impedance spectroscopy conducted at open circuit potential and 50 mV above breakdown potential confirmed increasing corrosion rate with increasing chloride concentration. It has been concluded that the significant mechanistic step in the pitting corrosion of Tb 0?3 Dy 0?7 Fe 1?92 is adsorption of metal-chloride complex species.

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Corrosion behaviour of Terfenol-D

Cited by 11 publications

References 38 publications

Influence of the Nb and V Addition on the Microstructure and Corrosion Resistance of the Fe-B-Co-Si Alloy

Influence of the Nb and V Addition on the Microstructure and Corrosion Resistance of the Fe-B-Co-Si Alloy

On the Mechanism of Corrosion of Terfenol-D (Tb[sub 0.3]Dy[sub 0.7]Fe[sub 1.92])

Passivity of Tb_0·3Dy_0·7Fe_1·92in alkaline solution and its breakdown by chloride ions

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Corrosion behaviour of Terfenol-D

Cited by 11 publications

References 38 publications

Influence of the Nb and V Addition on the Microstructure and Corrosion Resistance of the Fe-B-Co-Si Alloy

Influence of the Nb and V Addition on the Microstructure and Corrosion Resistance of the Fe-B-Co-Si Alloy

On the Mechanism of Corrosion of Terfenol-D (Tb[sub 0.3]Dy[sub 0.7]Fe[sub 1.92])

Passivity of Tb0·3Dy0·7Fe1·92in alkaline solution and its breakdown by chloride ions

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Passivity of Tb_0·3Dy_0·7Fe_1·92in alkaline solution and its breakdown by chloride ions