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Effects of low- to medium-angle grain boundaries on creep properties of superalloy |
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| Authors: | Chengjiang Zhang Weibing Hu Chenyu Liu Yunsong Zhao Jing Shang Zhixun Wen |
| Affiliation: | 1. School of Civil Engineering, Xi’an university of Architecture and Technology, Xi’an, People’s Republic of China;2. Faculty of Engineering, Department of Mechanical Engineering, Division PMA, KU Leuven, Leuven, Belgium;3. Science and Technology on Advanced High Temperature Structural Materials laboratory, Beijing Institute of Aeronautical Materials, Beijing, People’s Republic of China;4. School of Mechanics, Civil Engineering and Architecture, Northwestern Polytechnical University, Xi’an, People’s Republic of China |
| Abstract: | The creep properties of Ni-based bicrystal specimens with low- to medium-angle grain boundaries are investigated at 1100°C and 130?MPa with two misorientation angles prepared by double-seed solidification. Experimental results show that the angle of the grain boundary with respect to the stretching direction has a strong effect on creep life. Molecular dynamics simulations show that the effect of the grain boundary on the neighbouring dislocation density is related to the grain boundary angle. A creep constitutive model with the grain boundary angle and the initial damage rate can be adopted to describe the creep damage evolution. The model is then modified according to the molecular dynamics simulation and experimental results to give more accurate predictions of creep life. |
| Keywords: | Grain boundary creep properties molecular dynamics crystal plasticity |