|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Mechanical Behavior at the Nanoscale III
||W-10: Dislocation Core Reconstruction Induced by Solute Atom Segregation in BCC Metals
||Bérengère Lüthi, Lisa Ventelon, David Rodney, François Willaime
|On-Site Speaker (Planned)
In pure Body-Centered Cubic metals, ½<111> screw dislocations adopt a symmetrical easy core configuration. Other core configurations – the asymmetric core, the hard core and the split core – are all unstable in pure BCC metals. In this work, we investigate the effect of interstitial solute atoms on ½<111> screw dislocations in BCC metals using the ab initio VASP code. First considering Fe(C), our DFT calculations show that the dislocation-solute interaction is strong enough to induce a core reconstruction to a low energy configuration, where unexpectedly, the screw dislocation adopts a hard core configuration, with the solute atoms placed at the center of regular trigonal prisms formed by the Fe core atoms, similar to the Fe3C cementite building unit. We obtain a similar reconstruction with other solutes (B, N, O) in Fe and in other metals (W, Mo). Consequences on dislocation mobility and dynamical strain ageing will also be discussed.
||Planned: A print-only volume