| Atomic-scale computer simulation for ternary alloy Ni-Cr-Al during early precipitation process |
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| 作者姓名： | CHU Zhong CHEN Zheng WANG Yongxin LU Yanli LI Yongsheng |
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| 作者单位： | State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, China,State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, China,State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, China,State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, China,State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, China |
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| 摘 要： | The aging behaviors of Ni-Cr-Al ternary alloy are studied at temperature 873 K based on the mean-field theory, and the early precipitation process is simulated at atomic-scale with microscopic phase-field model. The precipitation mechanism of the low supersaturated alloy Ni-12.2at.%Cr-7.8at.%Al is non-classical nucleation and growth, the L12 structure (Ni3Al) and D022 structure (Ni3Cr) phases precipitate simultaneously, a part of D022 phase transmits to L12 structure phase, and other part retains its previous structure. For high supersaturated alloy, congruent ordering appears first, then followed by spinodal decomposition, the nonstoicheometric ordered phases are produced in this process, which occurs before clustering. The precipitation mechanism of Ni-8at.%Cr-18at.%Al alloy is similar to Ni-10at.%Cr-12at.%Al alloy, but the ordering process of the former is ahead of the latter.
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| 关 键 词： | microscope phase-field model Ni-Cr-Al precipitation ordering parameter simulation. |
Atomic-scale computer simulation for ternary alloy Ni-Cr-Al during early precipitation process |
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| CHU Zhong,CHEN Zheng,WANG Yongxin,LU Yanli,LI Yongsheng.Atomic-scale computer simulation for ternary alloy Ni-Cr-Al during early precipitation process[J].Progress in Natural Science,2005,15(7):656-660. |
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| Authors: | CHU Zhong CHEN Zheng WANG Yongxin LU Yanli LI Yongsheng |
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| Institution: | State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi' an 710072, China |
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| Abstract: | The aging behaviors of Ni-Cr-Al ternary alloy are studied at temperature 873 K based on the mean-field theory, and the early precipitation process is simulated at atomic-scale with microscopic phase-field model. The precipitation mechanism of the low supersaturated alloy Ni-12.2at. % Cr-7.8at. % Al is non-classical nucleation and growth, the L12 structure (Ni3Al) and D022 structure (Ni3Cr)phases precipitate simultaneously, a part of D022 phase transmits to L12 structure phase, and other part retains its previous structure. For high supersaturated alloy, congruent ordering appears first, then followed by spinodal decomposition, the nonstoicheometric ordered phases are produced in this process, which occurs before clustering. The precipitation mechanism of Ni-8at. % Cr-18at. %Al alloy is similar to Ni-10at. % Cr-12at. %Al alloy, but the ordering process of the former is ahead of the latter. |
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| Keywords: | microscope phase-field model Ni-Cr-Al precipitation ordering parameter simulation |
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