About this Abstract |
Meeting |
2020 TMS Annual Meeting & Exhibition
|
Symposium
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Bulk Metallic Glasses XVII
|
Presentation Title |
J-14: The Effect of Severe Plastic Deformation on the Relaxation Dynamics of a Bulk Metallic Glass Studied by X-ray Photon Correlation Spectroscopy |
Author(s) |
Hongbo Zhou, Gerhard Wilde |
On-Site Speaker (Planned) |
Hongbo Zhou |
Abstract Scope |
The relaxation dynamics of the Pd40Ni40P20 (at.%) metallic glass severely deformed by high-pressure torsion was investigated by high-resolution X-ray photon correlation spectroscopy on the atomic length scale at a series of temperatures upon heating. We found that the relaxation dynamics of the deformed sample gets accelerated compared with the undeformed sample. This indicates that rejuvenation has occurred.At temperatures below 423 K, the activation energies of both undeformed and deformed samples are approximately 21.2 kJ/mol. This indicates that the relaxation process at the low temperature is stress-dominated and the deformation could only improve the atomic mobility without changing the energy barrier. From 473 K to 533 K, a “crossover” behavior of the effective relaxation time occurs, which is due to a transition of the relaxation mechanism from a stress-dominated to a diffusion-dominated process. Upon further increase in temperature, the relaxation is accelerated dramatically and entering the glass transition process. |
Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |