Abstract
Severe plastic deformation (strains > 100%) has been shown to create significant grain refinement in polycrystalline materials, leading to a nanometric equiaxed crystalline structure for such metals as aluminum, copper and nickel alloys. This process, termed continuous dynamic recrystallization, is governed by evolution of the dislocation structure, which creates new grain boundaries from dislocation walls. In the proposed model, plasticity occurs which firstly involves dislocation multiplication, leading to strain hardening limited by dynamic recovery. After a critical dislocation density is reached new grain boundaries are formed by condensation of walls of dislocations, creating a new stable configuration that is favored due to a reduction of the system free energy. This evolution of the microstructure continues to develop, with a consequent progressive decrease in the average grain diameter. The proposed model provides a quantitative prediction of the evolution of the average grain size, as well as the dislocation density, during continued plastic strain. The model can be calibrated by use of results from any experiment that involves large plastic deformation of metals, subject to negligible annealing effects. In this paper, the model has been calibrated, and consequently validated, through experiments on machining of Al 6061-T6.
| Original language | English |
|---|---|
| Pages (from-to) | 148-156 |
| Number of pages | 9 |
| Journal | Mechanics of Composite Materials |
| Volume | 90 |
| Early online date | 1 Jun 2015 |
| DOIs | |
| Publication status | Published - Nov 2015 |
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Keywords
- Continuous dynamic recrystallization
- Evolution
- Machining
- Microstructure
ASJC Scopus subject areas
- Instrumentation
- Materials Science(all)
- Mechanics of Materials
Cite this
Continuous dynamic recrystallization during severe plastic deformation. / Bacca, Mattia; Hayhurst, David R.; McMeeking, Robert M.
In: Mechanics of Composite Materials, Vol. 90, 11.2015, p. 148-156.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Continuous dynamic recrystallization during severe plastic deformation
AU - Bacca, Mattia
AU - Hayhurst, David R.
AU - McMeeking, Robert M.
N1 - Acknowledgments The support by the Department of Energy Advanced Manufacturing Office with grant #DE-EE0005762 and Third Wave Systems, is greatly appreciated.
PY - 2015/11
Y1 - 2015/11
N2 - Severe plastic deformation (strains > 100%) has been shown to create significant grain refinement in polycrystalline materials, leading to a nanometric equiaxed crystalline structure for such metals as aluminum, copper and nickel alloys. This process, termed continuous dynamic recrystallization, is governed by evolution of the dislocation structure, which creates new grain boundaries from dislocation walls. In the proposed model, plasticity occurs which firstly involves dislocation multiplication, leading to strain hardening limited by dynamic recovery. After a critical dislocation density is reached new grain boundaries are formed by condensation of walls of dislocations, creating a new stable configuration that is favored due to a reduction of the system free energy. This evolution of the microstructure continues to develop, with a consequent progressive decrease in the average grain diameter. The proposed model provides a quantitative prediction of the evolution of the average grain size, as well as the dislocation density, during continued plastic strain. The model can be calibrated by use of results from any experiment that involves large plastic deformation of metals, subject to negligible annealing effects. In this paper, the model has been calibrated, and consequently validated, through experiments on machining of Al 6061-T6.
AB - Severe plastic deformation (strains > 100%) has been shown to create significant grain refinement in polycrystalline materials, leading to a nanometric equiaxed crystalline structure for such metals as aluminum, copper and nickel alloys. This process, termed continuous dynamic recrystallization, is governed by evolution of the dislocation structure, which creates new grain boundaries from dislocation walls. In the proposed model, plasticity occurs which firstly involves dislocation multiplication, leading to strain hardening limited by dynamic recovery. After a critical dislocation density is reached new grain boundaries are formed by condensation of walls of dislocations, creating a new stable configuration that is favored due to a reduction of the system free energy. This evolution of the microstructure continues to develop, with a consequent progressive decrease in the average grain diameter. The proposed model provides a quantitative prediction of the evolution of the average grain size, as well as the dislocation density, during continued plastic strain. The model can be calibrated by use of results from any experiment that involves large plastic deformation of metals, subject to negligible annealing effects. In this paper, the model has been calibrated, and consequently validated, through experiments on machining of Al 6061-T6.
KW - Continuous dynamic recrystallization
KW - Evolution
KW - Machining
KW - Microstructure
UR - http://www.scopus.com/inward/record.url?scp=84941415869&partnerID=8YFLogxK
U2 - 10.1016/j.mechmat.2015.05.008
DO - 10.1016/j.mechmat.2015.05.008
M3 - Article
AN - SCOPUS:84941415869
VL - 90
SP - 148
EP - 156
JO - Mechanics of Composite Materials
JF - Mechanics of Composite Materials
SN - 0191-5665
ER -