EFFECT OF ALLOYING ON ELASTIC-MODULI OF VANADIUM ALLOYS

The temperature (20 - 600 degrees C) and concentration dependences of elastic and shear moduli. Poisson's ratio and internal friction were s tudied in vanadium, binary V-Ti (10 - 30 at%), and ternary V-Ti (10 - 20 at. %)-Cr (6 - 10 at. % ) alloys which Lire considered as prospecti ve low-activation structural materials for the first wall of fusion re actor (FR). Some alloys under study were additionally alloyed with sil icon, yttrium, and zirconium. All materials exhibit virtually linear d ecrease in elastic moduli with increasing temperature. Measurements of internal friction indicated that the interstitial impurities in the a lloys V-(10 - 20 at. %) Ti are present in bound state, supposedly, as titanium oxynitrides. These alloys exhibit also nonmonotonic dependenc es of elastic and shear moduli and Poisson's ratio on titanium content in vanadium-based alloy. This is not typical of solid solutions. The vanadium alloys with 5 - 10 at. % Ti and 5 - 6 at. % Cr are considered now as the optimal low-activation alloys for FR at 600 C. these alloy s have E = (12.2 - 12.4).10(10) Pa, G = (4.5 - 4.6).10(10) Pa, and mu = 0.27 - 0.31. The elastic moduli of these alloys are lower than those of stainless steel by a factor of 1.5.