| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Atom Probe Tomography for Advanced Characterization of Metals, Minerals and Materials III
|
| Presentation Title |
Atom Probe Tomography of Refractory High Entropy Alloys |
| Author(s) |
Patrick Gregory Callahan, David Beaudry, Noah Philips, Keith E Knipling |
| On-Site Speaker (Planned) |
Patrick Gregory Callahan |
| Abstract Scope |
High entropy alloys (HEAs) typically contain five or more principal elements in nearly equiatomic proportions, significantly expanding the composition space and attainable properties of novel metallic materials. Despite the potential advantages of HEAs, fundamental questions remain, particularly regarding the mechanisms of dislocation motion and diffusion in these alloys. Atom-probe tomography (APT) is a precise atom-by-atom investigation of a sample and produces 3D reconstructions with sub-nanometer resolution, chemical sensitivities near 10 ppm, and volumes approaching 250×250×1000 nm^3. This provides uniquely powerful insights into phenomena such as atomic clustering, short range order, and anti-clustering, which are not yet well understood in HEAs. However, these analyses require optimum spatial and spectral data and in this talk we present the effects of APT laser pulse energy, laser pulse frequency, and specimen tip base temperature on the analysis yield, data quality, and the propensity for generating complex ions in equiatomic MoTaTiZrW and HfNbTaTiZr refractory HEAs. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |