Yang Kun, Wang Yanghe, Tang Jingjing, Wang Zixuan, Zhang Dechuang, Dai Yilong, Lin Jianguo
School of Materials Science and Engineering, Xiangtan University, Xiangtan 411105, China.
Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
Materials (Basel). 2023 Apr 8;16(8):2969. doi: 10.3390/ma16082969.
In this study, a phase field method based on the Cahn-Hilliard equation was used to simulate the spinodal decomposition in Zr-Nb-Ti alloys, and the effects of Ti concentration and aging temperature (800-925 K) on the spinodal structure of the alloys for 1000 min were investigated. It was found that the spinodal decomposition occurred in the Zr-40Nb-20Ti, Zr-40Nb-25Ti and Zr-33Nb-29Ti alloys aged at 900 K with the formation of the Ti-rich phases and Ti-poor phases. The spinodal phases in the Zr-40Nb-20Ti, Zr-40Nb-25Ti and Zr-33Nb-29Ti alloys aged at 900 K were in an interconnected non-oriented maze-like shape, a discrete droplet-like shape and a clustering sheet-like shape in the early aging period, respectively. With the increase in Ti concentration of the Zr-Nb-Ti alloys, the wavelength of the concentration modulation increased but amplitude decreased. The aging temperature had an important influence on the spinodal decomposition of the Zr-Nb-Ti alloy system. For the Zr-40Nb-25Ti alloy, with the increase in the aging temperature, the shape of the rich Zr phase changed from an interconnected non-oriented maze-like shape to a discrete droplet-like shape, and the wavelength of the concentration modulate increased quickly to a stable value, but the amplitude decreased in the alloy. As the aging temperature increased to 925 K, the spinodal decomposition did not occur in the Zr-40Nb-25Ti alloy.
在本研究中，基于Cahn-Hilliard方程的相场方法被用于模拟Zr-Nb-Ti合金中的调幅分解，并研究了Ti浓度和时效温度（800-925K）对合金在1000分钟时效后的调幅结构的影响。研究发现，在900K时效的Zr-40Nb-20Ti、Zr-40Nb-25Ti和Zr-33Nb-29Ti合金中发生了调幅分解，形成了富Ti相和贫Ti相。在900K时效的Zr-40Nb-20Ti、Zr-40Nb-25Ti和Zr-33Nb-29Ti合金中的调幅相在时效初期分别呈相互连接的无取向迷宫状、离散的液滴状和聚集的片状。随着Zr-Nb-Ti合金中Ti浓度的增加，浓度调制的波长增加但幅度减小。时效温度对Zr-Nb-Ti合金体系的调幅分解有重要影响。对于Zr-40Nb-25Ti合金，随着时效温度的升高，富Zr相的形状从相互连接的无取向迷宫状变为离散的液滴状，浓度调制的波长迅速增加到一个稳定值，但合金中的幅度减小。当时效温度升高到925K时，Zr-40Nb-25Ti合金中未发生调幅分解。
