Abstract: For polycrystalline copper tensile deformation to a moderate strain, the microstructure after deformation and after annealing to the start of recrystallization has been studied by transmission electron microscopy. It is found that different types of deformation microstructures develop depending on the grain orientation. Quantitative measurement of misorientation and spacing of dislocation boundaries induced during deformation has allowed an estimate of the dislocation density and the stored energy for each types of structures. Upon annealing of the deformed samples, nucleation takes place at the original grain boundaries and the nuclei grow into the local region with the highest stored energy.
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DOI:10.19476/j.ysxb.1004.0609.2001.01.008
多晶铜形变显微组织及其再结晶行为
黄晓旭 蔡大勇 N.Hansen
燕山大学材料科学与化学工程学院!066004秦皇岛
Materials Research Department!Risoe National Laboratory
Deformation structure and recrystallization behaviour of tensile strained copper
Abstract:
For polycrystalline copper tensile deformation to a moderate strain, the microstructure after deformation and after annealing to the start of recrystallization has been studied by transmission electron microscopy. It is found that different types of deformation microstructures develop depending on the grain orientation. Quantitative measurement of misorientation and spacing of dislocation boundaries induced during deformation has allowed an estimate of the dislocation density and the stored energy for each types of structures. Upon annealing of the deformed samples, nucleation takes place at the original grain boundaries and the nuclei grow into the local region with the highest stored energy. [
Table 1 Characterization results of different types of microstructure
Type of microstructure
θ/ (°)
D/μm
ρb/ (1014?m·m-3)
ρ0/ (1014?m·m-3)
ρt/ (1014?m·m-3)
E/ (kJ·m-3)
TypeⅠ
0.80
0.78
2.10
1.20
3.30
486.60
TypeⅡ
0.61
0.75
1.66
0.80
2.46
363.33
Type Ⅲ
1.40
0.80
3.58
1.50
5.08
748.93
* Calculated from Eqn.1, taking G=45 GPa, b=2.56×10-10?m
图3 Ⅰ型组织与Ⅲ型组织间晶界的再结晶形核特征 (再结晶条件255 ℃×5 min)
Fig.3 Nucleation at boundary between Type Ⅰ and Type Ⅲ grains in specimen annealing for 5 min at 255 ℃ (a) —Nucleation sites and determining sites of matrix orientation (marking with 1 and 2) ; (b) —Orientation relationship between nucleus and the matrix grains
图4 Ⅱ型组织与Ⅲ型组织间晶界的再结晶形核特征 (再结晶条件255 ℃×5 min)
Fig.4 Nucleation at boundary between Type Ⅱ and Type Ⅲ grains in specimen annealing for 5 min at 255 ℃ (a) —Nucleation sites and determining sites of matrix orientation (marking with 1 to 5) ; (b) —Orientation relationship between nucleus and the matrix grains
图5 Ⅰ型组织与Ⅱ型组织间晶界的再结晶形核特征 (再结晶条件255 ℃×5 min)
Fig.5 Nucleation at boundary between Type Ⅰ and Type Ⅱ grains in specimen annealing for 5 min at 255 ℃ (a) —Nucleation sites and determining sites of matrix orientation (marking with 1 to 9) ; (b) —Orientation relationship between nucleus and the matrix grains