Heterogeneous void swelling near grain boundaries in irradiated materials

Abstract

Department of Mechanical Engineering, The Hong-Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong~Received 25 July 2002; revised manuscript received 6 November 2002; published 5 March 2003!We found that by assuming that the density of dislocations in an irradiated material varies as a function ofthe distance to grain boundaries and that mobile interstitial defect clusters perform three-dimensionaldiffu-sional motion it is possible to achieve significantly better agreement with experimental observations of profilesof heterogeneous void swelling than in the model where defects diffuse purely one-dimensionally. This ap-proach explains the origin of several distinct features characterising the effect of heterogeneous void swelling,including the variation of the shape of swelling profiles as a function of irradiation dose, the formation of peaksof swelling and void denuded zones, and the occurrence of anomalously large voids in the regions adjacent tograin boundaries.DOI: 10.1103/PhysRevB.67.094103 PACS number~s!: 61.72.Mm, 61.80.Az, 61.82.Bg, 28.52.FaI. INTRODUCTION