An analysis of void swelling dose dependence in ion irradiated V-Fe alloys

The microstructure of V-XFe alloys (X = 0, 2, 5 and 7 at.%) irradiated as t hin foils at 625 degrees C with 50 KeV V+ ions to damage doses ranging from 2.5 to 40 dpa at averaged dose rate of 5 x 10(-3) dpa/s has been investiga ted. Data on mean void diameter, void number density, void volume fraction (Delta V/V) and total dislocation length per unit volume have been obtained . From these data the sink strengths for voids and dislocations were found and the void swelling bias factor (SBF) as a function of iron content was d etermined. Both a V/V and SBF reveal maxima at about 5 at.% Fe. For an inte rpretation of a decrease in Delta V/V and SBF at iron contents above 5 at.% , in the present work, the model developed previously is generalized to acc ount for the diffusivity dependence on alloy composition. (C) 1999 Elsevier Science B.V. All rights reserved.