Temperature dependence of the plastic flow behavior of tantalum |
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| Authors: | K.V. Rajulapati† M.M. Biener J. Biener |
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| Affiliation: | 1. Aerospace and Mechanical Engineering Department , University of Southern California , Los Angeles, CA 90089, USA;2. Nanoscale Synthesis and Characterization Laboratory, Lawrence Livermore National Laboratory , Livermore, CA 94550, USA |
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| Abstract: | Nanoindention has been used to study the plastic flow behavior of bcc Ta(001) in the temperature range 25–200°C. Most notably, it is found that the shape of the load–displacement curves changes with increasing temperature. Only one large discontinuity marking the onset of plasticity is observed in room-temperature experiments, whereas multiple pop-ins separated by elastic reloading segments were observed at 200°C. Detailed analysis of the load–displacement curves indicates that the lattice resistance decreases with increasing temperature, consistent with the mobilization of screw dislocations by thermal activation. Contributions from the oxide layer and/or thermal drift can be excluded. |
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| Keywords: | nanoindentation thermal activation plastic flow BCC single crystal |
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