|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Advanced Characterization Techniques for Quantifying and Modeling Deformation
||Novel 3D Crystallite-scale Characterization of Deformation during Cyclic Loading of Low Crystal-symmetry Phases
||Partha P Paul, Harshad M Paranjape, Darren C Pagan, L Catherine Brinson, Aaron P Stebner
|On-Site Speaker (Planned)
||Partha P Paul
Nickel-Titanium (NiTi) is the most prevalent shape memory alloy (SMA) in modern technologies. Depending on the temperature and stress state, a high crystal-symmetry austenitic and low crystal-symmetry martensitic phase coexist in NiTi. A complete understanding of the fatigue response of NiTi requires that we recognize various deformation modes active in the low-symmetry martensite phase. We report an in-situ, 3D characterization study on deformation in notched NiTi martensite samples using two techniques — high-energy X-ray diffraction microscopy and X-ray micro-Laue diffraction. We test two hypotheses.
Due to lack of slip systems, but availability of a large number of twinning systems, deformation in martensite near notch will be dominated by twinning.
At higher external loads, slip will take over as the twinning modes are saturated. The characterization data are valuable to informing and validating microstructural models of twinning, reorientation, and slip in SMA martensite phases — an area that is relatively underdeveloped.
||Planned: Supplemental Proceedings volume