|About this Abstract
||2022 TMS Annual Meeting & Exhibition
||Seeing is Believing -- Understanding Environmental Degradation and Mechanical Response Using Advanced Characterization Techniques: An SMD Symposium in Honor of Ian M. Robertson
||Multi-scale Characterization of the Effects of High Altitude Environments on Crack Tip Damage Evolution during Fatigue Loading of AA7075-T651
||James Burns, Zach Harris, Adam Thompson
|On-Site Speaker (Planned)
Aerospace aluminum alloys often operate at high altitude (typified by low temperatures and water vapor pressures (PH2O)); such environments slow the fatigue crack growth behavior. Incorporating these benefits into structural life management requires an understanding of the governing damage physics.
The low temperature behavior retardation may be due to changes in dislocation structure evolution and/or on the hydrogen environment embrittlement (HEE) process. The HEE process would be influenced by temperature via a reduction in bulk PH2O, crack tip reaction kinetics producing/absorbing atomic H, H diffusion in the process zone, and/or changing the nature of the H-dislocation interactions. A novel multi-scale characterization (e.g. EBSD, FIB-TEM,ASTARS) of the damage structure in the crack wake of different samples evaluating the impact of individual variables such as driving force (ΔK), temperature and PH2O is performed with the goal of providing insights into the governing mechanisms of high altitude environment fatigue.
||Aluminum, Environmental Effects, Mechanical Properties