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Self-inflicted fracture of expanding surface precipitates

Reheman, Wureguli and Ståhle, Per LU (2018) In Fatigue and Fracture of Engineering Materials and Structures 41(12). p.2614-2628
Abstract

This work concerns spontaneous fracture of growing brittle precipitates in an elastic plastic matrix. The mass of the precipitate is increasing as more transformed matrix material is added to it. Under stress-free conditions, the new phase occupies a larger volume than the original matrix material. Just outside the expanding precipitate, the matrix undergoes stretching beyond the elastic limit. The influence of the elastic plastic material behaviour is studied. A phase field model that keeps track of the phase composition is used. Both cases with a crack and without a crack are included. The growth histories from microscopic to macroscopic precipitate sizes are followed. Growth of the precipitate is very slow and quasi-static mechanical... (More)

This work concerns spontaneous fracture of growing brittle precipitates in an elastic plastic matrix. The mass of the precipitate is increasing as more transformed matrix material is added to it. Under stress-free conditions, the new phase occupies a larger volume than the original matrix material. Just outside the expanding precipitate, the matrix undergoes stretching beyond the elastic limit. The influence of the elastic plastic material behaviour is studied. A phase field model that keeps track of the phase composition is used. Both cases with a crack and without a crack are included. The growth histories from microscopic to macroscopic precipitate sizes are followed. Growth of the precipitate is very slow and quasi-static mechanical equilibrium is assumed at all time. The result is compared with observations of hydride blisters that are formed on surfaces of zirconium alloys. The numerical model is qualified against a derived exact solution for a cylindrical precipitate without a crack. The numerical result predicts a position of the growing crack that is confirmed by the observations. Also, the predicted length of the crack is in fair agreement with the experimental observations. The depth of the blister is slightly larger than what is found at the experiments. Also, it is found that the incorporated transformed phase rejects the compression, which creates an increasing tensile stress in the inner part of the precipitate.

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type
Contribution to journal
publication status
published
subject
in
Fatigue and Fracture of Engineering Materials and Structures
volume
41
issue
12
pages
2614 - 2628
publisher
Wiley-Blackwell
external identifiers
  • scopus:85050402767
ISSN
8756-758X
DOI
10.1111/ffe.12872
language
English
LU publication?
yes
id
a8450661-2b32-42b6-a931-1e1951cf5163
date added to LUP
2018-09-26 14:30:14
date last changed
2020-10-07 06:02:25
@article{a8450661-2b32-42b6-a931-1e1951cf5163,
  abstract     = {<p>This work concerns spontaneous fracture of growing brittle precipitates in an elastic plastic matrix. The mass of the precipitate is increasing as more transformed matrix material is added to it. Under stress-free conditions, the new phase occupies a larger volume than the original matrix material. Just outside the expanding precipitate, the matrix undergoes stretching beyond the elastic limit. The influence of the elastic plastic material behaviour is studied. A phase field model that keeps track of the phase composition is used. Both cases with a crack and without a crack are included. The growth histories from microscopic to macroscopic precipitate sizes are followed. Growth of the precipitate is very slow and quasi-static mechanical equilibrium is assumed at all time. The result is compared with observations of hydride blisters that are formed on surfaces of zirconium alloys. The numerical model is qualified against a derived exact solution for a cylindrical precipitate without a crack. The numerical result predicts a position of the growing crack that is confirmed by the observations. Also, the predicted length of the crack is in fair agreement with the experimental observations. The depth of the blister is slightly larger than what is found at the experiments. Also, it is found that the incorporated transformed phase rejects the compression, which creates an increasing tensile stress in the inner part of the precipitate.</p>},
  author       = {Reheman, Wureguli and Ståhle, Per},
  issn         = {8756-758X},
  language     = {eng},
  number       = {12},
  pages        = {2614--2628},
  publisher    = {Wiley-Blackwell},
  series       = {Fatigue and Fracture of Engineering Materials and Structures},
  title        = {Self-inflicted fracture of expanding surface precipitates},
  url          = {http://dx.doi.org/10.1111/ffe.12872},
  doi          = {10.1111/ffe.12872},
  volume       = {41},
  year         = {2018},
}