Dynamic strain aging caused by a new Peierls mechanism at high-temperature in iron

Daniel Caillard (1) , J. Bonneville (2)

1 CEMES - Centre d'élaboration de matériaux et d'études structurales
2 ISAE-ENSMA - École Nationale Supérieure de Mécanique et d’Aérotechnique [Poitiers]

In situ straining experiments and post-mortem observations have been carried out in pure Fe in order to investigate the dislocation mechanisms in the temperature range of dynamic strain aging. The results show that dislocations are locked in pure screw orientation at 200 °C and start to move viscously at higher temperatures, up to more than 400 °C. The unexpected reappearance of a Peierls mechanism at such a high temperature is proposed to result from the interaction between screw dislocations and solute carbon atoms. © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Mots clés: Dislocations (crystals); Dynamics; Iron; Screws; Strain; Dislocations (crystals); Dislocation mechanisms; Dynamic strain aging; High temperature; In-situ straining; Peierls; Pure screw; Solute carbon; Temperature range; Post mortem; Screw dislocations

Domaines: Physique [physics]

Daniel Caillard, J. Bonneville. Dynamic strain aging caused by a new Peierls mechanism at high-temperature in iron. Scripta Materialia, 2015, 95 (1), pp.15-18. ⟨10.1016/j.scriptamat.2014.09.019⟩. ⟨hal-01726235⟩