Dislocation Dynamics in Ni3Al: Experiments and Computations

Abstract

ABSTRACTA modified electrolytic etchant has been successfully used to observe dislocation etch-pits on {100} surfaces of single crystal Ni3AI containing Hf and B additions. Four-point bending tests have been used to obtain the dependence of dislocation velocity on resolved shear stress at room temperature. A comparison with earlier studies reveal that the rate of change of dislocation velocity with resolved shear stress, to a first approximation, is independent of alloying. Atomic level simulations have been performed using the embedded atom method (EAM) to study dislocation core structures and frictional stress in Ni3Al.