Helium Porosity Formation in Vanadium Alloys of V-Ti-Cr, V-W-Zr and V-W-Ta Systems in Comparison with Binary Alloys

Abstract

Vanadium alloys are considered candidates for use as structural materials of fusion reactors. A large amount of helium will be accumulated in such materials. The presence of helium in the materials may result in gas swelling. This paper presents the results Alloy V-4%Ti-4%Cr has a smallest helium swelling among the ternary alloys and its swelling is significantly lower than swelling of dual V-Ti and V-Cr alloys. The swelling of the ternary V-2%W-1%Zr alloy is more than 3 times less than the swelling of vanadium, several times less than that of V-W alloys and slightly lower than the swelling of VZr alloys. Swelling increases by a factor of 1.5 with increasing of Zr content to 2% in the ternary V-2%W-1%Zr alloy. Similarly, gas swelling of ternary V-2%W-1%Ta alloy is significantly lower than that for binary V-W and V-Ta alloys.Assumptions are made about the possible mechanisms of the effect of alloying elements in vanadium on helium porosity formation.