Multiphase-field modelling of concurrent grain growth and coarsening in complex multicomponent systems
Multiphase-field modelling of concurrent grain growth and coarsening in complex multicomponent systems
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DOI：
10.1016/j.jmst.2019.11.011
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发表时间：
2020-05
影响因子：
10.9
通讯作者：
P. Amos;Ramanathan Perumal;M. Selzer;B. Nestler
中科院分区：
文献类型：
--
作者：
P. Amos;Ramanathan Perumal;M. Selzer;B. Nestler
相场法模拟具有相关联晶粒的多晶系统中的微观结构演化，在很大程度上局限于连续场模型。在这项研究中，一个多相场的方法，规定引入晶界和相间扩散，扩展到分析并发晶粒生长和粗化的多组分多晶微结构与化学不同的晶粒。通过考虑二元和三元体系的双相和三相微观结构，沿着与单相体系的数量和组分的演变动力学的影响。人们认识到，仅仅增加相的数量最小化并发的晶粒生长和粗化的速率。然而，组件的效果基本上取决于各自的动力学系数。这项工作揭示了相和组分的影响的差异主要是由于转化机制中引入的相应变化。虽然相数的增加使扩散路径回旋，但组分数的增加影响通过相互扩散的演化速率，这在扩散化学物质中引入了相互依赖性。此外，相分数的三重组织的转变速率的作用进行了研究，并相应地，界面和扩散控制的演变的相互作用进行了阐述。比较分析了具有代表性的等相分数三维三重组织的演化与相应的二维组织的演化。
Phase-field modelling of microstructural evolution in polycrystalline systems with phase-associated grains has largely been confined to continuum-field models. In this study, a multiphase-field approach, with a provision for introducing grain boundary and interphase diffusion, is extended to analyse concurrent grain growth and coarsening in multicomponent polycrystalline microstructures with chemically-distinct grains. The effect of the number of phases and components on the kinetics of evolution is investigated by considering binary and ternary systems of duplex and triplex microstructures, along with a single phase system. It is realised that the mere increase in the number of phases minimises the rate of concurrent grain growth and coarsening. However, the effect of components is substantially dependent on the respective kinetic coefficients. This work unravels that the disparity in the influence of phases and components is primarily due to the corresponding change introduced in the transformation mechanism. While the raise in number of phases convolutes the diffusion paths, the increase in number of component effects the rate of evolution through the interdiffusion, which introduces interdependency in the diffusing chemical-species. Additionally, the role of phase-fractions on the transformation rate of triplex microstructure is studied, and correspondingly, the interplay of interface- and diffusion-governed evolution is elucidated. A representative evolution of three-dimensional triplex microstructure with equal phase-fraction is comparatively analysed with the evolution of corresponding two-dimensional setup.