Modelling radiation damage effects on a bcc iron lattice containing phosphorous impurity atoms near symmetrical tilt boundaries

Abstract

The effects of radiation on phosphorous impurity atoms present in a bcc iron lattice and their interactions with primary radiation-induced defects have been investigated by means of molecular dynamics simulations. In this work symmetrical tilt boundaries, with two different CSL relationships, have been inserted in 110,000 atom computational cells. The simulations provided information about the effects of PKA energy (between 0.5 and 6keV), PKA position, PKA direction and grain boundary on the evolution of the collision cascades. The results have shown marked difference between collisions occurring near grain boundaries and those occurring in the bulk. A large number of defects accumulate at GBs, which act as traps for defect propagation. The mobility of single P interstitial atoms and mixed dumbbells has been investigated at four different temperatures of 673, 783, 873 and 973K. The system evolution was then observed during simulation times as long as 1ns. This allowed the investigation of the effects of temperature and primary defects on the migration of the P atoms.