Critical Percolation Stresses of Random Frank-Read Sources in Micron-Sized Crystals of Superalloys (Preprint)
Abstract
Effective 2D dislocation dynamics simulations were used to investigate the size effect observed experimentally in the yield behavior of micron-sized crystals of 2-phase superalloys. Random Frank-Read sources were introduced on a (111) glide plane for three simulation cell sizes. The critical stresses were determined for the percolation of Frank-Read sources in such cells populated with a distribution of gamma' precipitates at approx. 73.5% vol fraction obtained from experiment. The scatter in the percolation stress at each size, as well as the weak variation in critical stress with size, were compared with experimental 0.2% yield stress values for micron-sized crystals of superalloy and found to be in good agreement. An APB energy of 250 mJ/sq m was used in the simulations. The size effect and scatter were found to be related to two factors: 1) Strength of single-arm sources as well as 2) the variation in precipitate structure at the single arm source positions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 2011
- Accession Number
- ADA553439
Entities
People
- Christopher F. Woodward
- Dennis M. Dimiduk
- M. D. Uchic
- Paul A. Shade
- S.I. Rao
- Triplicane A. Parthasarathy
Organizations
- Air Force Research Laboratory