Low temperature deformation characteristics of group Va metal-hydrogen single crystals

Abstract

An investigation was undertaken to determine the influence of hydrogen on the low temperature deformation characteristics of Group Va metal single crystals in a temperature range 20–473 K. High purity vanadium, niobium and tantalum containing hydrogen exhibit low-temperature perturbations in the temperature dependence of their yield stresses. On the basis of an analysis of the activation parameters, and the fact that the local perturbation in the temperature dependence of yield stress occurs at critical temperatures and below the solvus, a mechanism which could explain the results is the stressinduced reorientation of the hydride platelets due to the stress fields of the moving dislocations. Additional observations were made to demonstrate that neither precipitation hardening nor a trapping phenomenon can account for the local perturbation in the temperature dependence of yield stress.