Abstract
Constitutive models for SnAgCu solder alloys are of great interest at the present. Commonly, constitutive models that have been successfully used in the past for Sn-Pb solders are used to describe the behavior of SnAgCu solder alloys. Two issues in the modeling of lead-free solders demand careful attention: (i) Lead-free solders show significantly different creep strain evolution with time, stress and temperature, and the assumption of evolution to steady state creep nearly instantaneously may not be valid in SnAgCu alloys and (ii) Models derived from bulk sample test data may not be reliable when predicting deformation behavior at the solder interconnection level for lead-free solders due to the differences in the inherent microstructures at these different scales. In addition, the building of valid constitutive models from test data derived from tests on solder joints must deconvolve the effects of joint geometry and its influence on stress heterogeneity. Such issues have often received insufficient attention in prior constitutive modeling efforts. In this study all of the above issues are addressed in developing constitutive models of Sn3.8Ag0.7Cu and Sn1.0Ag0.5Cu solder alloys, which represent the extremes of Ag composition that have been mooted at the present time. The results of monotonie testing are reported for strain rates ranging from 4.02E-6 to 2.40E-3 s-1. The creep behavior at stress levels ranging from 7.8 to 52 MPa are also described. Both types of tests were performed at temperatures of 25°C, 75°C and 125°C. The popular Anand model and the classical time-hardening creep model are fit to the data and the experimentally obtained model parameters are reported. The test data are compared against other reported data in the literature and conclusions are drawn on the plausible sources of error in the data reported in the prior literature.
| Original language | English (US) |
|---|---|
| Title of host publication | Proceedings of the ASME International Mechanical Engineering Congress and Exposition, IMECE 2007 |
| Pages | 183-196 |
| Number of pages | 14 |
| Volume | 5 |
| DOIs | |
| State | Published - May 28 2008 |
| Externally published | Yes |
| Event | ASME International Mechanical Engineering Congress and Exposition, IMECE 2007 - Seattle, WA, United States Duration: Nov 11 2007 → Nov 15 2007 |
Other
| Other | ASME International Mechanical Engineering Congress and Exposition, IMECE 2007 |
|---|---|
| Country | United States |
| City | Seattle, WA |
| Period | 11/11/07 → 11/15/07 |
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ASJC Scopus subject areas
- Engineering(all)
Cite this
Constitutive behavior of Sn3.8Ag0.7Cu and Sn1.0Ag0.5Cu alloys at creep and low strain rate regimes. / Bhate, Dhruv; Chan, D.; Subbarayan, G.; Chiu, T. C.; Edwards, D.; Gupta, V.
Proceedings of the ASME International Mechanical Engineering Congress and Exposition, IMECE 2007. Vol. 5 2008. p. 183-196.Research output: Chapter in Book/Report/Conference proceeding › Conference contribution
}
TY - GEN
T1 - Constitutive behavior of Sn3.8Ag0.7Cu and Sn1.0Ag0.5Cu alloys at creep and low strain rate regimes
AU - Bhate, Dhruv
AU - Chan, D.
AU - Subbarayan, G.
AU - Chiu, T. C.
AU - Edwards, D.
AU - Gupta, V.
PY - 2008/5/28
Y1 - 2008/5/28
N2 - Constitutive models for SnAgCu solder alloys are of great interest at the present. Commonly, constitutive models that have been successfully used in the past for Sn-Pb solders are used to describe the behavior of SnAgCu solder alloys. Two issues in the modeling of lead-free solders demand careful attention: (i) Lead-free solders show significantly different creep strain evolution with time, stress and temperature, and the assumption of evolution to steady state creep nearly instantaneously may not be valid in SnAgCu alloys and (ii) Models derived from bulk sample test data may not be reliable when predicting deformation behavior at the solder interconnection level for lead-free solders due to the differences in the inherent microstructures at these different scales. In addition, the building of valid constitutive models from test data derived from tests on solder joints must deconvolve the effects of joint geometry and its influence on stress heterogeneity. Such issues have often received insufficient attention in prior constitutive modeling efforts. In this study all of the above issues are addressed in developing constitutive models of Sn3.8Ag0.7Cu and Sn1.0Ag0.5Cu solder alloys, which represent the extremes of Ag composition that have been mooted at the present time. The results of monotonie testing are reported for strain rates ranging from 4.02E-6 to 2.40E-3 s-1. The creep behavior at stress levels ranging from 7.8 to 52 MPa are also described. Both types of tests were performed at temperatures of 25°C, 75°C and 125°C. The popular Anand model and the classical time-hardening creep model are fit to the data and the experimentally obtained model parameters are reported. The test data are compared against other reported data in the literature and conclusions are drawn on the plausible sources of error in the data reported in the prior literature.
AB - Constitutive models for SnAgCu solder alloys are of great interest at the present. Commonly, constitutive models that have been successfully used in the past for Sn-Pb solders are used to describe the behavior of SnAgCu solder alloys. Two issues in the modeling of lead-free solders demand careful attention: (i) Lead-free solders show significantly different creep strain evolution with time, stress and temperature, and the assumption of evolution to steady state creep nearly instantaneously may not be valid in SnAgCu alloys and (ii) Models derived from bulk sample test data may not be reliable when predicting deformation behavior at the solder interconnection level for lead-free solders due to the differences in the inherent microstructures at these different scales. In addition, the building of valid constitutive models from test data derived from tests on solder joints must deconvolve the effects of joint geometry and its influence on stress heterogeneity. Such issues have often received insufficient attention in prior constitutive modeling efforts. In this study all of the above issues are addressed in developing constitutive models of Sn3.8Ag0.7Cu and Sn1.0Ag0.5Cu solder alloys, which represent the extremes of Ag composition that have been mooted at the present time. The results of monotonie testing are reported for strain rates ranging from 4.02E-6 to 2.40E-3 s-1. The creep behavior at stress levels ranging from 7.8 to 52 MPa are also described. Both types of tests were performed at temperatures of 25°C, 75°C and 125°C. The popular Anand model and the classical time-hardening creep model are fit to the data and the experimentally obtained model parameters are reported. The test data are compared against other reported data in the literature and conclusions are drawn on the plausible sources of error in the data reported in the prior literature.
UR - http://www.scopus.com/inward/record.url?scp=44149101457&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=44149101457&partnerID=8YFLogxK
U2 - 10.1115/IMECE2007-44151
DO - 10.1115/IMECE2007-44151
M3 - Conference contribution
SN - 0791842991
SN - 9780791842997
VL - 5
SP - 183
EP - 196
BT - Proceedings of the ASME International Mechanical Engineering Congress and Exposition, IMECE 2007
ER -