Direct imaging of short-range order and its impact on deformation in Ti-6Al

Published in Science Advances, 2019

Recommended citation: Ruopeng Zhang, Shiteng Zhao (Contributed equally),Colin Ophus, Yu Deng, Shraddha Vachhani, Burak Ozdol, Rachel Traylor, Karen Bustillo, J.W. Morris Jr., Daryl C. Chrzan, Mark Asta, Andrew Minor. (2019). "Direct imaging of short-range order and its impact on deformation in Ti-6Al." Science Adcances. 5(eaax2799). http://sdlszst.github.io/files/Zhao_24_ScienceAdvances_Direct imaging of short range order and its impact on deformation in Ti-6Al.pdf

Chemical short range order(SRO) within a nominally single phase solid solution is known to affect the mechanical properties of alloys. While SRO has been indirectly related to deformation, direct observation of the SRO domain structure, and its effects on deformation mechanisms at the nanoscale, has remained elusive. Here, we report the direct observation of SRO in relatiuon to deformation using energy filtered imagin in a TEM. The diffraction contrast is enhanced by reducing the inelastically scattered electrons, revealing sub-nanometer SRO enhanced domains. The destruction of these domains by dislocation planar slip is observed after ex situ and in situ TEM mechanical testing. These results confirm the impact of SRO in Ti-Al alloys on the scale of angstroms. The direct confirmation of SRO in relationship to dislocatio plasticity in metals can provide insight into how the mechanical behavior of concentrated solid solutions by the material's thermal history.

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Recommended citation: Ruopeng Zhang, Shiteng Zhao (Contributed equally),Colin Ophus, Yu Deng, Shraddha Vachhani, Burak Ozdol, Rachel Traylor, Karen Bustillo, J.W. Morris Jr., Daryl C. Chrzan, Mark Asta, Andrew Minor. (2019). “Direct imaging of short-range order and its impact on deformation in Ti-6Al.” Science Adcances. 5(eaax2799).