Irradiation creep due to the growth of interstitial loops

Abstract

A rate theory of the growth of irradiation-produced interstitial loops in uniaxially stressed materials which also contain voids, coherent and/or incoherent precipitates and network dislocations is derived and the resulting creep behaviour is determined. Allowance is made for the preferential nucleation of loops oriented perpendicular to the stress axis and for the subsequent enhanced growth of these same loops. It is shown that the first of these mechanisms dominates and gives a creep rate which can be correlated with the volume swelling rate. The magnitude of the effect is shown to be consistent with the limited amount of available experimental data appropriate to the void-swelling temperature regime.