Paper Title:
Ionic Inhibition of Environental Fatigue Crack Growth in 7075-T6
  Abstract

The objective of this study is to quantify and understand the effectiveness of a hexavalent chrome replacement ion to inhibit environmentally assisted fatigue crack propagation (EFCP) in high strength aluminum alloys. Addition of molybdate (MoO4 2-) to bulk-low chloride solution effectively inhibits EFCP in peak aged 7075, comparable to that of CrO4 2-. The effectiveness of inhibition depends strongly on loading variables: .K, R, and frequency as explained qualitatively by mechanical instability of a crack tip passive film that otherwise hinders production and uptake of embrittling hydrogen. The critical loading frequency (and crack tip strain rate), below which film stability and inhibition occur, increases with increasing inhibitor concentration, but only for low stress ratio loading, perhaps due to occluded crack transport and reaction considerations. Molybdate could be a beneficial replacement for chromate and a candidate for inhibitor release from a tailored coating.

  Info
Periodical
Key Engineering Materials (Volumes 345-346)
Edited by
S.W. Nam, Y.W. Chang, S.B. Lee and N.J. Kim
Pages
989-994
DOI
10.4028/www.scientific.net/KEM.345-346.989
Citation
J. S. Warner, S. S. Kim, R. P. Gangloff, "Ionic Inhibition of Environental Fatigue Crack Growth in 7075-T6", Key Engineering Materials, Vols. 345-346, pp. 989-994, 2007
Online since
August 2007
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: Tomáš Denk, Vladislav Oliva, Aleš Materna
Abstract:A two-parameter constraint-based fracture mechanics approach is used to explain the effect of the constraint on the apparently anomalous...
307
Authors: Won Beom Kim, Jeom Kee Paik
Abstract:In this research, corrosion fatigue tests using 490MPa TMCP steel were performed in synthetic seawater condition to investigate the...
1043
Authors: Won Beom Kim, Jeom Kee Paik
Abstract:In this research, corrosion fatigue tests using tensile strength of 490MPa TMCP steel were performed in synthetic seawater condition to...
1145
Authors: Stanislav Seitl, Pavel Hutař, Zdeněk Knésl
Abstract:The formulations of fatigue crack growth prediction are still mostly based on phenomenological models. A commonly used formula in the field...
557
Authors: Wei Tang, He Xue, Dan Zhao
Abstract:Environmentally assisted cracking (EAC) or stress corrosion cracking (SCC) of key structural materials in the environments of the light water...
1128