| Computer simulation for the precipitation process of Ni75Al7.5V17.5 alloy |
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| 作者姓名： | LI Yongsheng CHEN Zheng LU Yanli WANG Yongxin ZHANG Jianjun |
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| 作者单位： | Department of Material Science and Engineering, Northwestern Polytechnical University, Xi'an 710072, China,Department of Material Science and Engineering, Northwestern Polytechnical University, Xi'an 710072, China,Department of Material Science and Engineering, Northwestern Polytechnical University, Xi'an 710072, China,Department of Material Science and Engineering, Northwestern Polytechnical University, Xi'an 710072, China,Department of Material Science and Engineering, Northwestern Polytechnical University, Xi'an 710072, China |
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| 基金项目： | 国家自然科学基金，国家高技术研究发展计划(863计划) |
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| 摘 要： | The precipitation mechanism of Ni75Al7.5V17.5 alloy above the L12 instability line, between the L12 and D022 instability lines and below the D022 instability line are studied using microscopic phase-field kinetic equation. This paper is aimed at investigating the effect of temperature on precipitation mechanism and morphological evolution of the alloy. Our simulations demonstrate that the precipitation is a mixed mechanism of non-classical nucleation growth and spinodal decomposition above the L12 instability line. It needs certain thermal fluctuations for nucleation and the number of θ phases is small at this temperature. The precipitation mechanism of γ'phase is congruent ordering followed by spinodal decomposition, and θ phase is a mixed mechanism of non-classical nucleation growth and spinodal decomposition between the L12 and D022 instability lines. The mechanism below the D022 instability line is similar to that between the L12 and D022 instability lines. With the decrease of the temperature, ordering and phase separation becomes fast, the dimension of γ'phase becomes small, the shape transforms from equiaxed to block, the dimension of θ phase becomes large and the shape transforms from strip to circle.
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| 关 键 词： | precipitation mechanism atomic configuration order parameter Ni75Al7.5V17.5 alloys computer simu |
Computer simulation for the precipitation process of Ni75Al7.5V17.5 alloy |
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| LI Yongsheng,CHEN Zheng,LU Yanli,WANG Yongxin,ZHANG Jianjun.Computer simulation for the precipitation process of Ni75Al7.5V17.5 alloy[J].Progress in Natural Science,2004,14(12):1099-1103. |
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| Authors: | LI Yongsheng CHEN Zheng LU Yanli WANG Yongxin ZHANG Jianjun |
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| Institution: | Department of Material Science and Engineering, Northwestern Polytechnical University, Xi'an 710072, China |
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| Abstract: | The precipitation mechanism of Ni75Al7.5V17.5 alloy above the L12 instability line, between the L12 and D022 instability lines and below the D022 instability line are studied using microscopic phase-field kinetic equation. This paper is aimed at investigating the effect of temperature on precipitation mechanism and morphological evolution of the alloy. Our simulations demonstrate that the precipitation is a mixed mechanism of non-classical nucleation growth and spinodal decomposition above the L12 instability line. It needs certain thermal fluctuations for nucleation and the number of θ phases is small at this temperature. The precipitation mechanism of γ'phase is congruent ordering followed by spinodal decomposition, and θ phase is a mixed mechanism of non-classical nucleation growth and spinodal decomposition between the L12 and D022 instability lines. The mechanism below the D022 instability line is similar to that between the L12 and D022 instability lines. With the decrease of the temperature, ordering and phase separation becomes fast, the dimension of γ'phase becomes small, the shape transforms from equiaxed to block, the dimension of θ phase becomes large and the shape transforms from strip to circle. |
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| Keywords: | precipitation mechanism atomic configuration order parameter Ni75Al7 5V17 5 alloys computer simulation |
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