Single-crystal elastic constants of vanadium and vanadium with oxygen additions

The single-crystal elastic constants of vanadium and of vanadium with 1.07, 1.85, and 3.46 at.% oxygen have been measured ultrasonically over the temperature range 4.2--300 K. These compositions cover virtually the complete composition range of the terminal solubility at the temperatures of the experiments. Monotonic but nonlinear increases with increasing oxygen content were observed for all three of the directly measured constants, and the compositional trends were found to be relatively insensitive to temperature so the same trends should persist at elevated temperatures. A Debye temperature of 401.2 K was evaluated for 0 K. The monotonic hardening of vanadium by oxygen addition contrasts with previously published results for niobium, where oxygen additions produced a slight initial softening followed by a hardening