| About this Abstract |
| Meeting |
Materials Science & Technology 2020
|
| Symposium
|
Micro- and Nano-Mechanical Behavior of Materials
|
| Presentation Title |
Characterization of Dislocation Avalanches by In Situ Micropillar Compression Tests with Simultaneously Detected Acoustic Emission |
| Author(s) |
Dávid Ugi, Péter Dusán Ispánovity, Michal Knapek, Kristián Máthis, Zoltán Dankházi, István Groma |
| On-Site Speaker (Planned) |
Dávid Ugi |
| Abstract Scope |
In the size regime around few µm the plastic deformation of single crystals becomes inhomogeneous and unpredictable. Therefore, it is necessary to provide an in-depth experimental investigation of these elementary deformation processes. In my talk, I will show experimental results achieved with the combination of two methods: (i) in situ nanoindentation testing used to determine the stress-strain characteristics of micrometer size Zn pillars, and (ii) acoustic emission measurement typically used to monitor plastic activities in bulk materials. The nanoindentation experiment was carried out in a SEM while a piezoelectric detector was attached to the sample. Our simultaneous measurements show real correlation between the dislocation avalanches associated with the measured stress drops and the detected acoustic signals. The statistical analysis of the sequence of acoustic signals reveals long-range temporal correlations and a complex internal structure of a single event and, thus, opens new perspectives in the interpretation of the acoustic signals. |