Paper Title:
Scanning Kelvin Probe Studies of Cosmetic (Filiform) Corrosion on AA6016
  Abstract

Scanning Kelvin Probe (SKP) potentiometry is used to systematically investigate the effect of surface abrasion and subsequent heat-treatment on the open-circuit potential in humid air of the AA6016 surface. SKP is also used to follow the kinetics of filiform corrosion and to determine characteristic potentials associated with the electrolyte-filled filiform head and dry filiform tail. It is shown that simply abrading with 180 grit SiC produces a surface potential up to 0.5V lower than the bulk. When the abraded sample is overcoated with a 30 micron layer of PVB (polyvinyl butyral) and exposed to HCl a fast, superficial filiform corrosion (FFC) is observed in which metal loss is limited to the thickness of the surface layer. Filiform head OCP values are similar to that of the surface layer, whereas filiform tail OCP values are similar to the bulk. A mechanism is proposed in which the ultra-fine grain structure of the surface layer produces an anodic activation and the potential difference between the surface layer and the bulk provides and increased thermodynamic driving force for corrosion. For post-abrasion heat treatment temperatures up to 350°C the fast filiform process is followed by a slower, deeper form of FFC.

  Info
Periodical
Materials Science Forum (Volumes 519-521)
Edited by
W.J. Poole, M.A. Wells and D.J. Lloyd
Pages
679-686
DOI
10.4028/www.scientific.net/MSF.519-521.679
Citation
H.N. McMurray, A.J. Coleman, G. Williams, A. Afseth, G. M. Scamans, "Scanning Kelvin Probe Studies of Cosmetic (Filiform) Corrosion on AA6016", Materials Science Forum, Vols. 519-521, pp. 679-686, 2006
Online since
July 2006
Export
Price
$32.00
Share

In order to see related information, you need to Login.

In order to see related information, you need to Login.

Authors: Jakub Čížek, Ivan Procházka, Bohumil Smola, Ivana Stulíková, Radomír Kužel, Miroslav Cieslar, Z. Matěj, V. Cherkaska, Gerhard Brauer, W. Anwand, Rinat K. Islamgaliev, Olya B. Kulyasova
Abstract:In the present work, positron annihilation spectroscopy (PAS) is employed for microstructure investigations of various ultra fine grained...
207
Authors: Akio Nishimoto, Katsuya Akamatsu
Abstract:The effect of a modified layer caused by pre-deforming on the low temperature plasma nitriding of AISI 304 austenitic stainless steel was...
1811
Authors: Hong Yan Xu, Sen Chang, Xing Zhang, Zhi Min Zhang
Abstract:Aluminum (Al) coating was thermally sprayed on the surface of AZ80 magnesium (Mg) alloy. The Al-coating was deformed at 400°C with different...
319
Authors: Anna Korneva
Abstract:The article presents the results of microstructure evolution studies of the FeCr30Co8 hard magnetic alloy, subjected to deformation by...
116
Authors: B. Łosiewicz, Magdalena Popczyk, Magdalena Szklarska, Agnieszka Smołka, Patrycja Osak, A. Budniok
V. Development of Methods and Techniques for Characterization of Electrode Materials
Abstract:This paper deals with the basic theory and the usability of the scanning Kelvin probe (SKP) being a non-destructive, non-contact method for...
369