You are not logged in Total: 7journals, 19,861articles Online
AccountAccount
Login / Register
Forgot Login?
 
Main menuMain menu
What's new
Journal list
Visiting ranking
Phrase ranking
Polls
About us
 
SearchSearch
 
Journal Site
Advanced Search
 

Home  >  Journal list  >  MATERIALS TRANSACTIONS  >  Vol.49  No.6 (2008)  >  pp.1278-1283

MATERIALS TRANSACTIONS
<<Previous article Vol.49  No.6 (2008)   pp.1278 - 1283 Next article>>

Dislocation Bow-Out Model for Yield Stress of Ultra-Fine Grained Materials

Masaharu Kato1), Toshiyuki Fujii2) and Susumu Onaka1)
1) Department of Materials Science and Engineering, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology
2) Department of Innovative and Engineered Materials, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology


A dislocation bow-out model has been developed to explain the strength of ultra-fine grained (UFG) materials with grain size roughly between 20 nm to 500 nm. In the model, perfect dislocations are assumed to be nucleated at grain-boundary sources and bow out between two pinning points on a boundary. Yielding is considered to occur when a dislocation takes a semi-circular shape under applied stress. Statistical consideration is introduced to evaluate the most probable pinning-point distance as a function of grain size. Comparison with experimental results is made for fcc UFG metals. It is found that yield stress as well as thermal activation parameters can be explained reasonably by the present theoretical model.


Keyword:
strength, ultra-fine grained materials, deformation mechanism, yield stress, grain boundaries, dislocation, modeling

Received: January 09, 2008
Accepted: March 12, 2008 , Published online: May 25, 2008
Copyright (c) 2008 The Japan Institute of Metals

PDFPDF file (J-STAGE)J-STAGEJ-STAGE


SPARC Japan

Terms of Use | Privacy Policy