|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Fatigue in Materials: Fundamentals, Multiscale Modeling and Prevention
||Understanding of Fatigue Crack Formation in Ni Superalloy with Inclusions Using HR-EBSD and HR-DIC
||Jun J Jiang, Jie Yang, Tiantian Zhang, Yu Wang, Fionn Dunne, Ben Britton
|On-Site Speaker (Planned)
||Jun J Jiang
Understanding of the mechanistic basis of crack formation remains challenging with microstructure, accumulated plastic slip, residual stress and dislocation density all playing a key role. There is significant need for mechanistically-informed crack formation criteria in order to provide effective guidance for better damage tolerance microstructure design with improved fatigue resistance.
In this study, interrupted three-point bending, low cycle fatigue tests were carried out on Ni based superalloy containing a non-metallic inclusion. We used in-house developed HR-EBSD and HR-DIC techniques to quantify the distribution and evolution of geometrically necessary dislocation density, residual stress and accumulated plastic slip at the local microstructural scale, particularly close to the non-metallic inclusion.
The relationships between these deformation parameters with respect to microstructural features such as inclusions and grain boundary are evaluated and their contributions to crack formation systematically assessed. Quantitative fatigue crack nucleation criteria are discussed in the light of these new results.
||Planned: Publication Outside of TMS (Indicate publication title and publisher if known.)