Detection of Hidden Corrosion of Aircraft Aluminum Alloys by Magnetometry Using a Superconducting Quantum Interference Device

Li, D.; Ma, Yanxue; Flanagan, W. F.; Lichter, B. D.; Wikswo, John P.

doi:10.5006/1.3280455

Cited by 23 publications

(9 citation statements)

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“…Recently, a German group has shown that a high-temperature superconductivity SQUID can be used to detect corrosion in aluminum aircraft components (74). The Vanderbilt group has conducted a number of studies that have defined the capabilities of the SSM for quantitative measurements of corrosion (66,(75)(76)(77)(78). They have shown that an SSM can image the temporal and spatial variation of corrosion in aircraft aluminum, distinguish between the time course of corrosion in 2024 and 7075 aluminum, detect crevice and stress-corrosion cracking, detect corrosion of aluminum in salt solutions as dilute as one part per million NaCl, and map the distribution of corrosion activity from the opposite side of aluminum samples as thick as one centimeter.…”

Section: Corrosionmentioning

confidence: 99%

Scanning Squid Microscopy

Kirtley¹,

Wikswo

1999

Annu. Rev. Mater. Sci.

161

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The scanning SQUID microscope (SSM) is a powerful tool for imaging magnetic fields above sample surfaces. It has the advantage of high sensitivity and bandwidth and the disadvantages of relatively modest spatial resolution and the requirement of a cooled SQUID sensor. We describe the various implementations of this type of instrument and discuss a number of applications, including magnetic imaging of short circuits in integrated circuits, corrosion currents in aluminum, and trapped flux in superconductors.

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Section: Corrosionmentioning

confidence: 99%

Scanning Squid Microscopy

Kirtley¹,

Wikswo

1999

Annu. Rev. Mater. Sci.

161

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“…The ow of corrosion current can be well orientated and in some cases it can achieve values of 120 A cm ¡2 [9,10]. It is known [11,12], that corrosion currents can create even weak magnetic elds. The corrosion itself is determined by surface electric currents and by ion diffusion in the solution and on the surface.…”

Section: Introductionmentioning

confidence: 99%

Change of mechanical properties of Fe-Cr-Ni steel after corrosion of steel in chlorine medium without and with magnetic field

Bikulčius¹

2002

Composite Interfaces

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The in uence of weak magnetic eld (B D 0:05 T) on mechanical properties, i.e. the torsional and twisting strength, of Fe-Cr-Ni steel (18.2% Cr, 9.4% Ni, 0.08% Mn, 0.6% Ti, 0.04% Co) has been investigated. When a permanent magnetic eld is used, the steel wire, treated in acidic chloride solutions (11% FeCl 3 ¢6H 2 O or 11% FeCl 3 ¢6H 2 O C 3% NaCl), loses its mechanical properties more rapidly than if the magnetic eld is not used. It suggests that the loss of mechanical properties of the wire is connected with peculiarities of formation of pitting. When pitting is formed without magnetic eld, it penetrates preferably in depth of steel, meanwhile in the magnetic eld pitting is formed preferably on the surface area.

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“…The detection of magnetic fields associated with electron and ion transfer at the electrode−electrolyte interface provides a new method for remote sensing of electrochemical processes. Such research is part of magnetoelectrochemistry, which deals with the magnetic fields induced by electrochemical reactions − or vice versa, the influence of magnetic fields upon electrochemical reactions. − Of these two areas, the corrosion of metals has the greatest practical significance. The major advantage of the magnetometric corrosion sensing lies in its ability to detect the corrosion activity across a dielectric medium.…”

Section: Introductionmentioning

confidence: 99%

Magnetic Fields Induced by Electrochemical Reactions: Aluminum Alloy Corrosion Sensing by SQUID Magnetometry on a Macroscopic Scale

et al. 2002

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Corrosion of aluminum alloy AA 2024 at room temperature was studied in NaCl solutions by a SQUID magnetometer operating in liquid helium. Macroscopic electronic current flow along an asymmetric U-shaped sample was indicated by distinctive magnetic field images with a spatial resolution of the order of 1 mm. It was concluded that the macroscopic current originated from a corrosion potential gradient within the sample because of its asymmetric geometry; this current was negligible on an equipotential (symmetric) sample. Electrochemical quartz crystal microbalance measurement demonstrated that oxygen plays a significant part in this corrosion process, allowing control of corrosion activity of AA 2024 by changing the oxygen content in the solution. The asymmetric sample was magnetically sensitive to corrosion: the higher corrosion rate with increased oxygen concentration resulted in higher magnetic activity. By contrast, the sample that was a system of single sections did not produce a magnetic field that reflected increases in corrosion rate, and magnetic activity of this sample was much less than that of its monolithic counterpart. The obtained data demonstrated that a uniformly corroding surface could be magnetically silent on a macroscopic scale if no special measures are undertaken to distort the equipotentiality of the corroding surface.

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Detection of Hidden Corrosion of Aircraft Aluminum Alloys by Magnetometry Using a Superconducting Quantum Interference Device

Cited by 23 publications

References 1 publication

Scanning Squid Microscopy

Scanning Squid Microscopy

Change of mechanical properties of Fe-Cr-Ni steel after corrosion of steel in chlorine medium without and with magnetic field

Magnetic Fields Induced by Electrochemical Reactions: Aluminum Alloy Corrosion Sensing by SQUID Magnetometry on a Macroscopic Scale

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