Shape of prismatic dislocation loops in anisotropic α-Fe

• Published in: Philosophical magazine letters 2009-09, Vol.89 (9), p.581-588
• Main Authors: Fitzgerald, Steven P., Yao, Zhongwen
• Format: Article
• Language: English
• Subjects: anisotropic elasticity; Condensed matter: structure, mechanical and thermal properties; Defects and impurities in crystals; microstructure; dislocations; Elasticity, elastic constants; Exact sciences and technology; Grain and twin boundaries; Mechanical and acoustical properties of condensed matter; Mechanical properties of solids; Physics; radiation damage; Structure of solids and liquids; crystallography; TEM
• ISSN: 0950-0839; 1362-3036
• DOI: 10.1080/09500830903199012

Prismatic dislocation loops are the primary manifestation of radiation damage in crystals, and contribute to the phenomenon of radiation embrittlement. This undesirable effect, most serious for materials used in high-dose environments such as next-generation fission and future fusion reactors, results from the strong interaction between gliding dislocations, the carriers of plasticity, with the population of radiation-induced prismatic loops. Ferritic-martensitic steels, the most promising candidate materials for future high-dose applications, are based on iron and are known to become highly elastically-anisotropic at the high temperatures (>500°C) at which they must operate. In this article, we develop a novel modelling approach based on anisotropic elasticity theory to predict the shapes of prismatic loops in anisotropic crystals, paying particular attention to the technologically important case of α-iron. The results are compared with transmission electron microscope observations of the damage structure sustained by ultra-high-purity iron irradiated to a dose of approximately two displacements per atom.