Edge-on dislocation loop in anisotropic hcp zirconium thin foil

Abstract

Edge-on dislocation loops with 〈a〉-type and 〈c〉-type of Burgers vectors can be formed on prismatic or basel habit planes of hexagonal close-packed (hcp) zirconium alloys during in-situ ion irradiation and neutron irradiation experiments. In this work, an anisotropic image stress method was employed to analyze the free surface effects of dislocation loops within hcp Zr thin foils. Calculation results demonstrate that image stress has a remarkable effect on the distortion fields of dislocation loops within infinite medium, and the image energy becomes remarkable when dislocation loops are situated close to the free surfaces. Moreover, image forces of the 1/2〈0001〉(0001) dislocation loop within (0001) thin foil is much stronger than that of the 1/3〈112¯0〉(112¯0) dislocation loop within (112¯0) thin foil of identical geometrical configurations. Finally, image stress effect on the physical behaviors of loops during in-situ ion irradiation experiments is discussed.