|About this Abstract
||Materials Science & Technology 2011
||Fatigue and Microstructure: A Symposium on Recent Advances
||In-Situ Microscale Fatigue Study to Evaluate the Role of Microstructural Neighborhoods
||Christopher Szczepanski, Sushant Jha, Paul Shade, Robert Wheeler, James Larsen
|On-Site Speaker (Planned)
A recent study of fatigue crack-initiation mechanisms and their relationship to lifetime variability in bulk samples of Ti-6Al-2Sn-4Zr-6Mo has revealed that crack initiation can occur in a variety of characteristic microstructural neighborhoods. These microstructural neighborhoods, which vary in size and frequency of occurrence, are observed at fatigue crack initiation sites through fractography. However, fractographic investigations do not allow one to identify the underlying nature of the fatigue damage accumulation and cracking mechanisms. To characterize these mechanisms under controlled conditions in a scanning electron microscope, an in-situ micro-scale tensile testing technique has been adapted to complete fatigue tests on micro-specimens extracted from representative fatigue-critical microstructural neighborhoods. The results of these experiments will be presented, with an emphasis on identifying microstructurally driven cyclic damage accumulation processes leading to fatigue crack initiation. Additionally, the potential correlation between deformation severity and specific local microstructural configurations will be investigated to validate current mechanistic models.
||Definite: A CD-only volume