Effect of symmetric and asymmetric tilt grain boundaries on the tensile behaviour of bcc-Niobium

Abstract

In this article, molecular dynamics based simulations were performed to investigate structure, energy and tensile behaviour of niobium (Nb) bi-crystals containing symmetric and asymmetric tilt grain boundaries. Six symmetric and four ∑5 asymmetric tilt grain boundaries about 〈1 0 0〉 as tilt axis were generated in molecular dynamics based environment. Minimum grain boundary (GB) energy for each configuration was predicted, and subsequently the bi-crystal was subjected to tensile loading. The strengthening of bi-crystals in conjunction with dislocation evaluation was studied with the help of atomistic simulations, and results were further fitted with Taylor’s work hardening expression. Simulations help in elucidating the effect of GBs and dislocations on the mechanical behaviour of Nb bi-crystals.