Publication detail

Influence of Secondary Phase on Intrinsic Threshold and Path of Shear-Mode Fatigue Cracks in Metals

VOJTEK, T. HOHENWARTER, A. PIPPAN, R. POKLUDA, J.

Original Title

Influence of Secondary Phase on Intrinsic Threshold and Path of Shear-Mode Fatigue Cracks in Metals

English Title

Influence of Secondary Phase on Intrinsic Threshold and Path of Shear-Mode Fatigue Cracks in Metals

Type

journal article in Web of Science

Language

en

Original Abstract

particularly with the intrinsic (effective) thresholds and the crack path geometry from the point of view of the competition between the local shear and the local opening growth mode. Unlike in the case of opening mode I cracks, the microstructure can significantly influence the dominant growth mechanism of the shear-mode cracks in dependence of the type of the secondary phase. The cementite lamellae of the pearlitic steel change the local growth mode from mode II to mode I and increased the effective mode II and mode III thresholds, whereas the _-Ti lamellae of the Ti6Al4V alloy do not change the intrinsic behaviour. The difference can be explained by different ability of dislocations to cross the phase boundary. The competition between the local shear and the local opening growth modes in metals is assessed by a newly proposed mode I branching criterion based on fracture mechanics. Using this criterion, the value of the deflection angle corresponding to the transition between the dominant mode I and dominant mode II crack growth was found to be of 46_. This result agrees well with the previously published value of the transient angle based on identification of characteristic fractographical patterns on the fracture surfaces of investigated metallic materials.

English abstract

particularly with the intrinsic (effective) thresholds and the crack path geometry from the point of view of the competition between the local shear and the local opening growth mode. Unlike in the case of opening mode I cracks, the microstructure can significantly influence the dominant growth mechanism of the shear-mode cracks in dependence of the type of the secondary phase. The cementite lamellae of the pearlitic steel change the local growth mode from mode II to mode I and increased the effective mode II and mode III thresholds, whereas the _-Ti lamellae of the Ti6Al4V alloy do not change the intrinsic behaviour. The difference can be explained by different ability of dislocations to cross the phase boundary. The competition between the local shear and the local opening growth modes in metals is assessed by a newly proposed mode I branching criterion based on fracture mechanics. Using this criterion, the value of the deflection angle corresponding to the transition between the dominant mode I and dominant mode II crack growth was found to be of 46_. This result agrees well with the previously published value of the transient angle based on identification of characteristic fractographical patterns on the fracture surfaces of investigated metallic materials.

Keywords

effective crack-growth thresholds; modes II and III; growth micromechanisms; metallic materials

Released

01.09.2018

Publisher

Polish Academy of Sciences

ISBN

1898-794X

Periodical

ACTA PHYSICA POLONICA A

Year of study

134

Number

3

State

PL

Pages from

699

Pages to

702

Pages count

3

Documents

BibTex


@article{BUT152195,
  author="Tomáš {Vojtek} and Anton {Hohenwarter} and Reinhard {Pippan} and Jaroslav {Pokluda}",
  title="Influence of Secondary Phase on Intrinsic Threshold and Path of Shear-Mode Fatigue Cracks in Metals",
  annote="particularly with the intrinsic (effective) thresholds and the crack path geometry from the point of view of the competition between the local shear and the local opening growth mode. Unlike in the case of opening mode I cracks, the microstructure can significantly influence the dominant growth mechanism of the shear-mode cracks in dependence of the type of the secondary phase. The cementite lamellae of the pearlitic steel change the local growth mode from mode II to mode I and increased the effective mode II and mode III thresholds, whereas the _-Ti lamellae of the Ti6Al4V alloy do not change the intrinsic behaviour. The difference can be explained by different ability of dislocations to cross the phase boundary. The competition between the local shear and the local opening growth modes in metals is assessed by a newly proposed mode I branching criterion based on fracture mechanics. Using this criterion, the value of the deflection angle corresponding to the transition between the dominant mode I and dominant mode II crack growth was found to be of 46_. This result agrees well with the previously published value of the transient angle based on identification of characteristic fractographical patterns on the fracture surfaces of investigated metallic materials.",
  address="Polish Academy of Sciences",
  chapter="152195",
  doi="10.12693/APhysPolA.134.699",
  institution="Polish Academy of Sciences",
  number="3",
  volume="134",
  year="2018",
  month="september",
  pages="699--702",
  publisher="Polish Academy of Sciences",
  type="journal article in Web of Science"
}