Affordable Access

Publisher Website

Modelling of dislocation mobility controlled brittle-to-ductile transition

Authors
Journal
Materials Science and Engineering A
0921-5093
Publisher
Elsevier
Publication Date
Volume
176
Identifiers
DOI: 10.1016/0921-5093(94)90970-9

Abstract

Abstract The phenomenon of brittle-to-ductile transition (BDT) is known to be controlled by the competition between cleavage fracture and dislocation activity at crack tips, but the transition could be determined by one of the two successive processes, dislocation nucleation or dislocation motion. In this paper a model is developed to study the BDT controlled by dislocation mobility. The model material is assumed to undergo elastic rate-dependent plastic deformation, with the plastic strain rate scaled with dislocation velocity. An isotropic plasticity theory is used. The BDT is assumed to occur when the crack tip is shielded by the surrounding plastic zone such that it never reaches the critical stress intensity for cleavage fracture. The crack tip shielding due to plastic deformation is evaluated using the finite element method. The dimensionless groups that affect the BDT are identified, and a parametric study is performed to reveal the effects of various dimensionless parameters. Numerical results using the specific material properties of Si single crystals are compared with experimental data. Good agreements are obtained. Some interesting features of the BDT behaviour are predicted by our computer simulations which require further confirmation by experimental studies.

There are no comments yet on this publication. Be the first to share your thoughts.

Statistics

Seen <100 times
0 Comments

More articles like this

Dislocation dynamics and brittle-to-ductile transi...

on Materials Science and Engineer... Jan 01, 1993

A dislocation dynamical theory of the ductile-to-b...

on Acta Metallurgica et Materiali... Jan 01, 1995

Modelling crack tip plastic zones and brittle-duct...

on Materials Science and Engineer... Jan 01, 1997

Dislocation generation instability and the brittle...

on Materials Science and Engineer... Jan 01, 1995
More articles like this..