|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Advanced Characterization Techniques for Quantifying and Modeling Deformation
||Plastic Deformation Behaviour of a 𝛾-TiAl Alloy in High Cycle Fatigue at up to 700 °C by Nano-scale Digital Image Correlation of a Remodelled Au Speckle Pattern.
||Thomas Edward James Edwards, Fabio Di Gioacchino, Nigel Martin, Mark Dixon, William John Clegg
|On-Site Speaker (Planned)
||Thomas Edward James Edwards
The limited plasticity of 𝛾-TiAl alloys is such that a threshold approach to fatigue lifing is used. In this work, the high cycle fatigue deformation behaviour up to 107 cycles of Ti-45Al-2Nb-2Mn(at.%)-0.8vol%TiB2 in different microstructural states has been studied from room temperature to 700 °C. The near-surface plastic strain field and the build-up of local strains were measured at regular intervals throughout the fatigue life using nano-scale digital image correlation (nDIC) of a remodelled gold speckle pattern, stable across the temperature range, and above. This was analysed together with the orientation maps of the same regions obtained by electron backscatter diffraction (EBSD), both before and after testing. From these results, plasticity by twin and slip mechanisms, and the flaw nucleation behaviour of the 𝛾-TiAl alloy, was investigated considering colony and lamellar-scale features, and further studies based on the lamellar plastic anisotropy are discussed.
||Planned: Supplemental Proceedings volume