May 29-June 3, 2016
Environment-assisted cracking (EAC) of aluminum alloys in corrosive atmospheres is an important maintenance and safety issue for aerospace structures. EAC initiation and propagation are influenced by the interaction of load, environment, and alloy properties. For atmospheric corrosion, environmental conditions are dynamic; where temperature, relative humidity, and surface contaminants interact to control thin film electrolyte properties. Recent studies have determined that stage II stress corrosion crack (SCC) propagation, under atmospheric conditions is strongly dependent on humidity. SCC propagation in AA5083 and AA7075 alloys is a maximum during drying processes at intermediate humidity levels at or below the deliquescence relative humidity (DRH) for the applied corrosive salt. An improved understanding of the dependence of cracking on atmospheric conditions is important to testing material performance, establishing durable designs, and managing structural integrity.
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Fritz Friedersdorf, Carlos Hangarter, Nate Brown, Steve Policastro, and Matt Merrill, "Relationship between electrochemical reaction processes and environment-assisted crack growth under static and dynamic atmospheric conditions" in "International Workshop on the Environmental Damage in Structural Materials Under Static Load/Cyclic Loads at Ambient Temperatures", A.K. Vasudevan, Office of Naval Research (retired), USA Ronald Latanision, Exponent, Inc., USA Henry Holroyd, Luxfer, Inc. (retired) Neville Moody, Sandia National Laboratories, USA Eds, ECI Symposium Series, (2016). http://dc.engconfintl.org/edsm/21