Low Frequency Internal Friction Study on Vanadium-Deuterium Alloys

Abstract

Low frequency internal friction measurements have been performed on vanadium-deuterium alloys over a temperature range from −190 to 300°C. The terminal solubility of deuterium in vanadium is found to increase by the addition of a small amount of oxygen. The binding energy of deuterium to oxygen has been estimated to be about 0.10 eV.It has been found that, besides the main precipitation peak, a small peak gradually develops at a lower temperature with the repetition of measurements or thermal cyclings. Since torsional deformation also introduces a peak at the same temperature, the peak is identified as due to dislocations punched out from deuteride precipitates. The main precipitation peak is found to consist of two components: the transient and the equilibrium components. The transient component increases with the increase in the cooling or heating rate, and is inversely proportional to measuring frequencies. The transient internal friction is believed to be associated with the formation or dissolution of hydride precipitates as proposed by Köster and his coworkers for a damping peak in Ti–H alloys.