|About this Abstract
||Materials Science & Technology 2020
||Environmentally Assisted Cracking: Theory and Practice
||Corrosion Fatigue Testing of AA7085-T7451 in Complex Atmospheric Environments of Varied Humidity with Surface Salt Loading
||Brandon T. Free, Austin Burns, Jason Niebuhr, Sarah Galyon Dorman, Jenifer Locke
|On-Site Speaker (Planned)
||Brandon T. Free
AA7085-T7451 is used in aerospace environments with fluctuating relative humidity (RH), variable temperatures (T), ozone, UV light, and surface salt. Traditional corrosion fatigue (CF) experiments utilizing lab air, water vapor, or full immersion may not adequately model in-service environments. The aim of this study is to measure CF crack growth rates (da/dN) in environments of varied RH and T where surface salts are present. Testing is completed by monitoring crack length during intervals of fixed loading and environmental parameters. Experiments that changed loading frequency for each interval show samples loaded with 300 μg/cm2 of NaCl and exposed to 80% RH exhibit similar da/dN to samples immersed in 0.06 M NaCl. Experiments that varied RH show da/dN does not immediately rise with increasing RH or fall when RH is decreased below the efflorescent point. Effects of wet/dry cycling and da/dN changes due to changing crack tip electrolyte content are under investigation.