Molecular dynamics methods were used to investigate defect production and clustering in the α-phase, by displacement cascades produced under uniform tensile strain. Cascades of 10keV primary-recoil energy were simulated in a single crystal, under strains of up to 1% which were applied along a <111> axis. At least 4 events were modelled for each condition. The results showed that the numbers of interstitials and vacancies were smaller in strained material; particularly for a strain of 0.1%. This decrease in the number of defects was suggested to be related to the effect of strain upon self-interstitial motion; thus leading to enhanced recombination with vacancies. The numbers of interstitials in clusters were almost independent of the applied strain, but the fractions of interstitials which were aligned parallel to the strain axis increased with increasing strain. The effect was small at a strain of 0.1%, but most of the single interstitials were created in this orientation at 0.5% strain, and all of the single and clustered interstitials were aligned at 1% strain. The results were explained in terms of the effect of strain upon defect formation energy and the mobility of interstitials.

The Influence of Strain on Defect Generation by Displacement Cascades in α-Iron. F.Gao, D.J.Bacon, P.E.J.Flewitt, T.A.Lewis: Nuclear Instruments and Methods in Physics Research B, 2001, 180[1-4], 187-93