Fatigue fracture at bicrystal interfaces: Experiment and theory

Pedro Peralta, C. Laird

Research output: Contribution to journalArticle

33 Citations (Scopus)

Abstract

Copper bicrystals with isoaxial [149] twist boundaries and a (149)/(001) "random" boundary were notched at the interface, left or right regarding the slip geometry, and intergranular cracks were propagated under strain control, to study how dislocation structure, crystallography and strain localization affect crack growth. Forward slip at the crack surface was favored regardless of growth direction or misorientation, whereas pre-existent multiple slip around the boundary reduced the dependence of crack kinetics on the growth direction. A model is proposed for intergranular crack growth based on crack tip deformation via crystallographic slip bands and simplifying assumptions about the effects of mode I stress fields on the strain. The experimental and theoretical results, along with published data, provide evidence that an optimal slip geometry exists for fatigue crack propagation. This idea is used to explain experimental results on directional dependence of intergranular cracking of bicrystals, suggesting that the kinematics of deformation has to be considered besides the energetics of dislocation nucleation at a crack tip to explain such results.

Original languageEnglish (US)
Pages (from-to)2001-2020
Number of pages20
JournalActa Materialia
Volume46
Issue number6
StatePublished - Mar 23 1998
Externally publishedYes

Fingerprint

Bicrystals
Fatigue of materials
Cracks
Crack tips
Crack propagation
Strain control
Crystallography
Geometry
Experiments
Fatigue crack propagation
Dislocations (crystals)
Copper
Kinematics
Nucleation
Kinetics
Direction compound

ASJC Scopus subject areas

  • Materials Science(all)
  • Electronic, Optical and Magnetic Materials
  • Metals and Alloys

Cite this

Fatigue fracture at bicrystal interfaces : Experiment and theory. / Peralta, Pedro; Laird, C.

In: Acta Materialia, Vol. 46, No. 6, 23.03.1998, p. 2001-2020.

Research output: Contribution to journalArticle

@article{81c3c4702df643d3a7d080d28b07a354,
title = "Fatigue fracture at bicrystal interfaces: Experiment and theory",
abstract = "Copper bicrystals with isoaxial [149] twist boundaries and a (149)/(001) {"}random{"} boundary were notched at the interface, left or right regarding the slip geometry, and intergranular cracks were propagated under strain control, to study how dislocation structure, crystallography and strain localization affect crack growth. Forward slip at the crack surface was favored regardless of growth direction or misorientation, whereas pre-existent multiple slip around the boundary reduced the dependence of crack kinetics on the growth direction. A model is proposed for intergranular crack growth based on crack tip deformation via crystallographic slip bands and simplifying assumptions about the effects of mode I stress fields on the strain. The experimental and theoretical results, along with published data, provide evidence that an optimal slip geometry exists for fatigue crack propagation. This idea is used to explain experimental results on directional dependence of intergranular cracking of bicrystals, suggesting that the kinematics of deformation has to be considered besides the energetics of dislocation nucleation at a crack tip to explain such results.",
author = "Pedro Peralta and C. Laird",
year = "1998",
month = "3",
day = "23",
language = "English (US)",
volume = "46",
pages = "2001--2020",
journal = "Acta Materialia",
issn = "1359-6454",
publisher = "Elsevier Limited",
number = "6",

}

TY - JOUR

T1 - Fatigue fracture at bicrystal interfaces

T2 - Experiment and theory

AU - Peralta, Pedro

AU - Laird, C.

PY - 1998/3/23

Y1 - 1998/3/23

N2 - Copper bicrystals with isoaxial [149] twist boundaries and a (149)/(001) "random" boundary were notched at the interface, left or right regarding the slip geometry, and intergranular cracks were propagated under strain control, to study how dislocation structure, crystallography and strain localization affect crack growth. Forward slip at the crack surface was favored regardless of growth direction or misorientation, whereas pre-existent multiple slip around the boundary reduced the dependence of crack kinetics on the growth direction. A model is proposed for intergranular crack growth based on crack tip deformation via crystallographic slip bands and simplifying assumptions about the effects of mode I stress fields on the strain. The experimental and theoretical results, along with published data, provide evidence that an optimal slip geometry exists for fatigue crack propagation. This idea is used to explain experimental results on directional dependence of intergranular cracking of bicrystals, suggesting that the kinematics of deformation has to be considered besides the energetics of dislocation nucleation at a crack tip to explain such results.

AB - Copper bicrystals with isoaxial [149] twist boundaries and a (149)/(001) "random" boundary were notched at the interface, left or right regarding the slip geometry, and intergranular cracks were propagated under strain control, to study how dislocation structure, crystallography and strain localization affect crack growth. Forward slip at the crack surface was favored regardless of growth direction or misorientation, whereas pre-existent multiple slip around the boundary reduced the dependence of crack kinetics on the growth direction. A model is proposed for intergranular crack growth based on crack tip deformation via crystallographic slip bands and simplifying assumptions about the effects of mode I stress fields on the strain. The experimental and theoretical results, along with published data, provide evidence that an optimal slip geometry exists for fatigue crack propagation. This idea is used to explain experimental results on directional dependence of intergranular cracking of bicrystals, suggesting that the kinematics of deformation has to be considered besides the energetics of dislocation nucleation at a crack tip to explain such results.

UR - http://www.scopus.com/inward/record.url?scp=0032010456&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0032010456&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0032010456

VL - 46

SP - 2001

EP - 2020

JO - Acta Materialia

JF - Acta Materialia

SN - 1359-6454

IS - 6

ER -