The influence of temperature and strain-rate, upon the reaction between the ½[111](1¯10) edge dislocation line and a periodic row of 4nm interstitial dislocation loops with a Burgers vector of b = ½[1¯11] in α-Fe, was investigated by means of molecular dynamics using a new potential for body-centred cubic Fe. In all cases, a dislocation segment with b = [010] was formed by favourable reaction. It was sessile on the (110) glide-plane and led to the formation of a screw dipole on the line under increasing stress. The mechanism which controlled line breakaway, and the corresponding critical stress, depended mainly upon temperature rather than the strain-rate. At 300 and 600K, the length of the screw dipole was less than 10b and the controlling mechanism was glide of the [010] segment over the loop surface; coupled with cross-slip of the short screws. The loop was totally absorbed on the line by the transformation of b to ½[111]. At low temperatures, where thermal effects were negligible, a long (~100b) screw dipole was drawn out and the controlling mechanism was annihilation of the dipole by screw cross-slip. This resulted in only partial absorption of the loop. By comparing these results with those obtained using an older interatomic potential, conclusions were drawn concerning the effects of interactions between edge dislocations and interstitial loops in Fe.

The Effect of Temperature and Strain Rate on the Interaction between an Edge Dislocation and an Interstitial Dislocation Loop in α-Iron. D.Terentyev, L.Malerba, D.J.Bacon, Y.N.Osetsky: Journal of Physics - Condensed Matter, 2007, 19[45], 456211 (13pp)