Ostwald ripening under temperature gradient: A phase-field study
Ostwald ripening under temperature gradient: A phase-field study
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DOI：
10.1063/5.0055198
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发表时间：
2021-07
影响因子：
3.2
通讯作者：
R. Yamada;Haruki Inubushi;M. Ohno
中科院分区：
文献类型：
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作者：
R. Yamada;Haruki Inubushi;M. Ohno
采用定量相场模型研究了温度梯度下二元模型合金的奥斯特瓦尔德熟化过程。模拟结果表明，第二相粒子平均半径的立方与时间成正比，在稳态下，粒子尺寸分布与均匀温度场一样具有自相似性。结果表明，温度梯度下颗粒的生长速度比等温条件下快，稳态颗粒尺寸分布与温度梯度的大小有关。此外，当施加非均匀温度场时，第二相颗粒从低温区域迁移到高温区域。在整个系统上平均的颗粒的迁移速度随着温度梯度的大小而增加。另一方面，每个颗粒的速度与颗粒尺寸无关。因此，颗粒迁移完全归因于由溶质溶解度的温度依赖性引起的浓度梯度驱动的扩散通量。
Ostwald ripening under a temperature gradient in binary model alloys is investigated using a quantitative phase-field model. The simulations show that a cube of average radius of a second-phase particle is proportional to time, and the particle size distribution shows self-similarity in a steady state, as with a uniform temperature field. It is found that the growth rate of particles under a temperature gradient is faster than that in the isothermal case, and the steady-state particle size distribution depends on the magnitude of the temperature gradient. Furthermore, the second-phase particles migrate from low temperature regions to high temperature regions when a non-uniform temperature field is applied. The migration velocity of particles, averaged over the whole system, increases with the magnitude of the temperature gradient. On the other hand, the velocity of each particle is not relevant to particle size. Hence, the particle migration is entirely ascribed to the diffusion flux driven by the concentration gradient originating from the temperature dependence of solute solubility.