About this Abstract |
Meeting |
2021 TMS Annual Meeting & Exhibition
|
Symposium
|
Accelerated Discovery and Qualification of Nuclear Materials for Energy Applications
|
Presentation Title |
Dislocation Loop Characterization Using STEM-Contrast Techniques in an Irradiated FCC Alloy |
Author(s) |
Pengyuan Xiu, Lumin Wang, Kevin G. Field |
On-Site Speaker (Planned) |
Pengyuan Xiu |
Abstract Scope |
Rel-Rod transmission-electron-microscopy (RR-TEM) has historically been used to characterize face centered cubic (FCC) materials after irradiation. In this study, we propose that scanning TEM (STEM) is a more convenient and robust method for imaging perfect and faulted types of dislocation loops in FCC materials. Three major zone axes [100], [110], [111] were used to perform on-zone STEM imaging for an irradiated model NiFe-20Cr alloy. With the aid of simulated dislocation loop morphology maps, all loop variant types were accurately identified by using the projected loop morphology on the [100] zone axis – other zone axes had ambiguous morphologies. Compared to on-zone/two-beam TEM bright-field and RR-TEM dark-field imaging, the on-zone [100] STEM imaging is the preferred method. With optimization of imaging parameters such as the collection angle, the on-zone [100] STEM is proven to robustly detect and identify dislocation loops without ambiguity and high visual contrast in irradiated FCC alloys. |
Proceedings Inclusion? |
Planned: |