|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Fatigue in Materials: Fundamentals, Multiscale Modeling and Prevention
||Short Crack Growth in Ni-base Superalloys during Micro-bending Fatigue
||Gi-Dong Sim, Zafir Alam, Gyuseok Kim, Paul A. Shade, Chris Woodward, Kevin J. Hemker
|On-Site Speaker (Planned)
In this presentation, we will discuss experimental methods developed to study statistics of short-crack growth in 500 Ám thick Ni-base superalloy (single crystal and polycrystalline) foils. The goal is to identify intermittent, avalanche dynamics of short-crack growth and possible connections to the “avalanche oscillator” mechanism for plasticity. Using a novel resonant-based micro-bending fatigue setup, we monitor the resonance frequency (RF) change of the foil while applying cyclic loading and correlate discrete RF drops to short-crack growth. Furthermore, we employ microfabrication techniques to deposit multiple micron-scale thin metal lines on top of the foil (dielectric layer is deposited in between). These channels are designed to result in open circuits during crack propagation, and the electrical resistance of the channels is recorded using four-point resistance method. From resistance change, intermittent crack growth can be quantified and analyzed for studying self-organized criticality of short-crack growth.
||Planned: Stand-alone book in which only your symposium’s papers would appear (indicate title in comments section below)