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Location, location &size : Defects close to surfaces dominate fatigue crack initiation

Serrano-Munoz, Itziar; Buffiere, Jean Yves; Mokso, Rajmund LU ; Verdu, Catherine and Nadot, Yves (2017) In Scientific Reports 7.
Abstract

Metallic cast components inevitably contain defects such as shrinkage cavities which are inherent to the solidification process. Those defects are known to significantly alter the fatigue life of components. Yet very little is known, quantitatively, on the dangerosity of internal casting defects compared to surface ones. In this study, fatigue specimens containing controlled internal defects (shrinkage pores) are used to foster internal cracking. In situ fatigue tests monitored by X ray synchrotron tomography revealed that the internal nucleation and propagation of cracks was systematically overran by surface cracking initiated at castings defects up to ten times smaller than the internal ones. These findings indicate that the presence... (More)

Metallic cast components inevitably contain defects such as shrinkage cavities which are inherent to the solidification process. Those defects are known to significantly alter the fatigue life of components. Yet very little is known, quantitatively, on the dangerosity of internal casting defects compared to surface ones. In this study, fatigue specimens containing controlled internal defects (shrinkage pores) are used to foster internal cracking. In situ fatigue tests monitored by X ray synchrotron tomography revealed that the internal nucleation and propagation of cracks was systematically overran by surface cracking initiated at castings defects up to ten times smaller than the internal ones. These findings indicate that the presence of internal defects in cast components can be tolerated to a larger extent than is allowed by nowadays standards.

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Please use this url to cite or link to this publication:
author
publishing date
type
Contribution to journal
publication status
published
in
Scientific Reports
volume
7
publisher
Nature Publishing Group
external identifiers
  • scopus:85016314399
ISSN
2045-2322
DOI
10.1038/srep45239
language
English
LU publication?
no
id
67bb8b1c-c8bb-4aec-9802-286a5d897bed
date added to LUP
2017-09-19 14:34:55
date last changed
2018-08-12 04:39:24
@article{67bb8b1c-c8bb-4aec-9802-286a5d897bed,
  abstract     = {<p>Metallic cast components inevitably contain defects such as shrinkage cavities which are inherent to the solidification process. Those defects are known to significantly alter the fatigue life of components. Yet very little is known, quantitatively, on the dangerosity of internal casting defects compared to surface ones. In this study, fatigue specimens containing controlled internal defects (shrinkage pores) are used to foster internal cracking. In situ fatigue tests monitored by X ray synchrotron tomography revealed that the internal nucleation and propagation of cracks was systematically overran by surface cracking initiated at castings defects up to ten times smaller than the internal ones. These findings indicate that the presence of internal defects in cast components can be tolerated to a larger extent than is allowed by nowadays standards.</p>},
  articleno    = {45239},
  author       = {Serrano-Munoz, Itziar and Buffiere, Jean Yves and Mokso, Rajmund and Verdu, Catherine and Nadot, Yves},
  issn         = {2045-2322},
  language     = {eng},
  month        = {03},
  publisher    = {Nature Publishing Group},
  series       = {Scientific Reports},
  title        = {Location, location &size : Defects close to surfaces dominate fatigue crack initiation},
  url          = {http://dx.doi.org/10.1038/srep45239},
  volume       = {7},
  year         = {2017},
}