Sink strength and dislocation bias of three-dimensional microstructures

Journal Article · 28 May 2019 · Physical Review Materials

DOI: https://doi.org/10.1103/physrevmaterials.3.053608 · OSTI ID:1772414

Kohnert, Aaron Anthony ^[1]; Capolungo, Laurent  ^[1]

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1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

Irradiation induces significant changes in the microstructure of structural materials, many of which are driven by the preferential capture of point defects at particular sinks, such as dislocations. To quantify the kinetics of defect absorption at sinks, theoretical models of radiation damage generally rely on the concept of sink strength. However, analytical approaches to estimating the sink strength of dislocations rely, in turn, on a series of geometrical assumptions, idealizing the dislocation network as a series of infinite straight dislocations or isolated loops, often with artificial boundary conditions. In this paper, we use a recently developed technique to quantify point defect capture in three-dimensional dislocation networks. We integrate this technique with discrete dislocation dynamics to analyze the sink strengths of realistic dislocation microstructures consisting of a mixture of edge, screw, and junction segments, complete with an accurate description of the strain fields these microstructures produce and the resultant energetic interactions experienced by point defects. Furthermore, we show that the effective kinetics for absorbing point defects can vary significantly with the arrangement of the microstructure with a strong dependence on the structure and character of its dislocation content and introduce a surrogate model for sink strength which incorporates these effects.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Energy Frontier Research Centers (EFRC) (United States). Fundamental Understanding of Transport Under Reactor Extremes (FUTURE)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE National Nuclear Security Administration (NNSA); USDOE Laboratory Directed Research and Development (LDRD) Program
• Grant/Contract Number: 89233218CNA000001; AC52-06NA25396; 20170615ER
• OSTI ID: 1772414
• Alternate ID(s): OSTI ID: 1518497
• Report Number(s): LA-UR-19-20656; TRN: US2208356
• Journal Information: Physical Review Materials, Vol. 3, Issue 5; ISSN 2475-9953
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English