VOID SWELLING BEHAVIOR IN ION-IRRADIATED VANADIUM ALLOYS

Boron doping technique has been utilized to study the helium effect on dimensional stability and mechanical property change under neutron ir radiation of the structural materials for the fusion reactor. Dual ion beam irradiation was carried out to investigate the effect of helium and the chemical effect of doped boron separately on the swelling beha vior of V and V-5wt%Fe alloy. Swelling at 873 K was estimated to be la rger than that at 793 K for both materials, Without simultaneous heliu m implantation, cavities formed near grain boundaries more than in the matrix for both V and V-5Fe. Implanted helium atoms dearly assist nuc leation of cavities in the matrix for both materials, however they sup press cavity growth at 793 K, The effect of boron addition is not so c lear as the effect of helium implantation. Boron addition enhanced swe lling of V-5Fe at 793 K, however suppressed at 873 K.