TEM in situ straining experiments in Fe at low temperature

Abstract

In situ TEM straining experiments were carried out in pure Fe, to investigate the origin of the discontinuity observed at 250K in the temperature variation of the deformation activation parameters. The results show that the motion of screw dislocations is steady at 300K, in agreement with a kink-pair mechanism, but jerky at 110K. This change has been attributed to a transition from a kink-pair mechanism to a locking-unlocking mechanism, similar to that observed previously in Ti. © 2010 IOP Publishing Ltd.