About this Abstract |
Meeting |
MS&T23: Materials Science & Technology
|
Symposium
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High Entropy Materials: Concentrated Solid Solutions, Intermetallics, Ceramics, Functional Materials and Beyond IV
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Presentation Title |
Dislocation Dynamics in NbMoTaW, Body Centered Cubic Multi-principal Element Alloy |
Author(s) |
Abu Anand, Chandraveer Singh |
On-Site Speaker (Planned) |
Abu Anand |
Abstract Scope |
An atomistic understanding of plasticity in Multi-Principal Element Alloys (MPEAs) is key in its compositional design for structural applications. In this work, we try to understand the mobility of ½ <111>{112} edge dislocations in NbMoTaW, a single-phase bcc MPEA using classical Molecular Dynamics. Pierels stress for the MPEA is ~600 MPa under which the dislocations are immobile (Region I). Then the velocity increases exponentially for a small stress range (Region II) and becomes linearly dependent on applied stress (Region III). The linear regime is independent of the temperature, consistent with viscous damping dynamics. The phonon spectrum broadens for the MPEA system and there is a peak shift to the lower frequency region. Nudged Elastic Band calculations reveal a ragged energy pathway for the dislocation motion. Dislocation mobility trends in MPEA could be attributed to the increased phonon drag and the solute pinning offered by the components in the MPEA. |