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Title: Statistics of dislocation pinning at localized obstacles

Pinning of dislocations at nanosized obstacles like precipitates, voids, and bubbles is a crucial mechanism in the context of phenomena like hardening and creep. The interaction between such an obstacle and a dislocation is often studied at fundamental level by means of analytical tools, atomistic simulations, and finite element methods. Nevertheless, the information extracted from such studies cannot be utilized to its maximum extent on account of insufficient information about the underlying statistics of this process comprising a large number of dislocations and obstacles in a system. Here, we propose a new statistical approach, where the statistics of pinning of dislocations by idealized spherical obstacles is explored by taking into account the generalized size-distribution of the obstacles along with the dislocation density within a three-dimensional framework. Starting with a minimal set of material parameters, the framework employs the method of geometrical statistics with a few simple assumptions compatible with the real physical scenario. The application of this approach, in combination with the knowledge of fundamental dislocation-obstacle interactions, has successfully been demonstrated for dislocation pinning at nanovoids in neutron irradiated type 316-stainless steel in regard to the non-conservative motion of dislocations. An interesting phenomenon of transition from rare pinning to multiplemore » pinning regimes with increasing irradiation temperature is revealed.« less
Authors:
 [1] ; ;  [2]
  1. S. N. Bose National Centre for Basic Sciences, Salt Lake, Kolkata 700098 (India)
  2. Variable Energy Cyclotron Centre, 1/AF Bidhannagar, Kolkata 700064 (India)
Publication Date:
OSTI Identifier:
22305787
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 14; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; DENSITY; DISLOCATION PINNING; DISLOCATIONS; DISTRIBUTION; FINITE ELEMENT METHOD; INTERACTIONS; IRRADIATION; NANOSTRUCTURES; NEUTRONS; PRECIPITATION; SIMULATION; SPHERICAL CONFIGURATION; STAINLESS STEELS