Abstract
The initiation and propagation of stage-I cracks determine the magnitude of the life in copper single crystals as the transition to stage-II behavior heralds the advent of fracture. The behavior of initiation and propagation of stage-I cracks under strain control is well understood. However, the PSB behavior and consequently the behavior of the stage-I cracks under load control is significantly different and requires an understanding before a unified methodology for predicting fatigue lives of copper single crystals based on the physics of the kinetics of stage-I crack growth can be developed. Stage-I cracks are found to nucleate in PSBs under load control. However, unlike in strain control, these cracks are almost exclusively found in micro PSBs. The cracks then grow along the PSBs with the occasional crack "skipping" on a secondary slip system to an adjacent PSB. These cracks also show a tendency, similar to that in strain control, to "rob" adjacent PSBs of strain and halt the growth of cracks in those PSBs. The extent of this "strain robbing" region under load control is not known. The growth kinetics of the population of the cracks can be modeled as a function of the cumulative strain and leads to a Coffin Manson equation for predicting the fatigue life. It is seen that this Coffin Manson equation provides a lower bound for the fatigue life of the copper single crystals.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 279-286 |
| Number of pages | 8 |
| Journal | Materials Science and Engineering A |
| Volume | 342 |
| Issue number | 1-2 |
| DOIs | |
| State | Published - Feb 15 2003 |
| Externally published | Yes |
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Keywords
- Copper
- Crystals
- Load-control
- PSBs
- Single
- Stage-I
ASJC Scopus subject areas
- Materials Science(all)
Cite this
Initiation and propagation of stage-I cracks in copper single crystals under load control. / Jameel, Mohammad Ahsan; Peralta, Pedro; Laird, Campbell.
In: Materials Science and Engineering A, Vol. 342, No. 1-2, 15.02.2003, p. 279-286.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Initiation and propagation of stage-I cracks in copper single crystals under load control
AU - Jameel, Mohammad Ahsan
AU - Peralta, Pedro
AU - Laird, Campbell
PY - 2003/2/15
Y1 - 2003/2/15
N2 - The initiation and propagation of stage-I cracks determine the magnitude of the life in copper single crystals as the transition to stage-II behavior heralds the advent of fracture. The behavior of initiation and propagation of stage-I cracks under strain control is well understood. However, the PSB behavior and consequently the behavior of the stage-I cracks under load control is significantly different and requires an understanding before a unified methodology for predicting fatigue lives of copper single crystals based on the physics of the kinetics of stage-I crack growth can be developed. Stage-I cracks are found to nucleate in PSBs under load control. However, unlike in strain control, these cracks are almost exclusively found in micro PSBs. The cracks then grow along the PSBs with the occasional crack "skipping" on a secondary slip system to an adjacent PSB. These cracks also show a tendency, similar to that in strain control, to "rob" adjacent PSBs of strain and halt the growth of cracks in those PSBs. The extent of this "strain robbing" region under load control is not known. The growth kinetics of the population of the cracks can be modeled as a function of the cumulative strain and leads to a Coffin Manson equation for predicting the fatigue life. It is seen that this Coffin Manson equation provides a lower bound for the fatigue life of the copper single crystals.
AB - The initiation and propagation of stage-I cracks determine the magnitude of the life in copper single crystals as the transition to stage-II behavior heralds the advent of fracture. The behavior of initiation and propagation of stage-I cracks under strain control is well understood. However, the PSB behavior and consequently the behavior of the stage-I cracks under load control is significantly different and requires an understanding before a unified methodology for predicting fatigue lives of copper single crystals based on the physics of the kinetics of stage-I crack growth can be developed. Stage-I cracks are found to nucleate in PSBs under load control. However, unlike in strain control, these cracks are almost exclusively found in micro PSBs. The cracks then grow along the PSBs with the occasional crack "skipping" on a secondary slip system to an adjacent PSB. These cracks also show a tendency, similar to that in strain control, to "rob" adjacent PSBs of strain and halt the growth of cracks in those PSBs. The extent of this "strain robbing" region under load control is not known. The growth kinetics of the population of the cracks can be modeled as a function of the cumulative strain and leads to a Coffin Manson equation for predicting the fatigue life. It is seen that this Coffin Manson equation provides a lower bound for the fatigue life of the copper single crystals.
KW - Copper
KW - Crystals
KW - Load-control
KW - PSBs
KW - Single
KW - Stage-I
UR - http://www.scopus.com/inward/record.url?scp=0037440621&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0037440621&partnerID=8YFLogxK
U2 - 10.1016/S0921-5093(02)00321-0
DO - 10.1016/S0921-5093(02)00321-0
M3 - Article
AN - SCOPUS:0037440621
VL - 342
SP - 279
EP - 286
JO - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing
JF - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing
SN - 0921-5093
IS - 1-2
ER -