Jitai NIU
,
Lihong HAN
,
Chonghao WOO
材料科学技术（英）
Grain growth and grain boundary sliding are the two main superplastic deformation mechanisms. In the paper, simulation work is focused on the sliding of a Σ13 (111) symmetric twist coincidence grain boundary, a Σ13 (110) asymmetric tilt coincidence grain boundary, and a Σ3 (110) symmetric tilt coincidence grain boundary in Al, and the energies of grain boundary for each of equilibrium configurations are computed. An embedded atom method (EAM) potential was used to simulate the atomic interactions in a bicrystal containing more than 2000 atoms. At 0 K, the relationships between total potential energy and time steps for 3 (111) symmetric twist coincidence grain boundary and Σ3(110) symmetric tilt coincidence grain boundary during sliding at 2 m/s represent the periodic characteristic. However, the relationship between total potential energy and time steps for Σ13 (110) asymmetric tilt coincidence grain boundary represents the damp surge characteristic. It is found that grain boundary sliding for Σ3 (110) symmetric tilt coincidence grain boundary is coupled with apparent grain boundary migration.
关键词:
Aluminum
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null
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null
,
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Lijun HAN
,
Junjie ZHU
,
Lihong HAN
材料科学技术（英）
The hysteresis unit system was introduced to mechanical structure behavior of the TiNi SMA joint based on the structure characteristics of the martensite variants in the joints, and some functions reflecting its inner structure characteristics and micro-behavior such as density function, phase transformation function were set up from micropoints. Finally, the structure behavior relationship and corresponding mathematic model reflecting the relationship among hysteresis strain, stress and phase transformation strain were provided, which could predict the stress-strain behavior of the TiNi SMA joint to large extent.
关键词:
TiNi shape memory alloy
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null
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