Effect of Irradiation on the Tensile Properties of Nano-sized Ti-Al Alloy Single Crystals: A Study Using Molecular Dynamics Simulations

The present work reports molecular dynamics (MD) simulation based study on the irradiation phenomena and its effect on the tensile properties of nanosized single crystals of Ti-Al alloy nanoparticles of varying compositions using Embedded Atom Method (EAM) potential. It is observed that after the alloy nano-crystals are hit by some high energy nuclear particles some atoms within the crystal are knocked out from their regular positions and subsequently give rise to displacement cascade which grows, propagate and after some instance achieves an equilibrium size. In the present study, the vacancy concentration of the irradiated crystal, which can be taken as a parameter for assessing the damage has been estimated for the crystals with varying size and initial temperature. Moreover, the damaging effect of the crystals has been assessed in terms of the temperature rise. It has been observed that the damaging effect of the crystals markedly increases with increase in the velocity of the primary knock-on atoms (PKA). The effect of radiation damage of Ti-Al alloy nanoparticles with varying compositions on their mechanical properties has been investigated by means of a subsequent tensile modelling of the irradiated particles. It was seen that the strength and ductility of the irradiated particle has decreased significantly as compared to the non-irradiated particle of same size and alloy composition. This kind of study can be extended with an objective to design and develop a new type of radiation resistant materials for the application in nuclear reactors. (c) 2018 Elsevier Ltd. All rights reserved.