Kinetics and associated microstructure for reactive phase formation
Kinetics and associated microstructure for reactive phase formation
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反应相形成的动力学和相关微观结构
DOI：
10.1016/j.actamat.2021.117456
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发表时间：
2022
期刊：
影响因子：
9.4
通讯作者：
Chan, H.M.
中科院分区：
文献类型：
--
作者：
McNamara, C.;Rickman, J.M.;Chan, H.M.
虽然固态反应被用于复杂材料的加工，但从组成不均匀的图案化结构开始的微观结构演变几乎没有受到关注。例如，最近已经认识到，可以在具有熵稳定的线化合物的系统中实现这样的结构，所述熵稳定的线化合物仅在高于某个临界温度时才是热稳定的。为了更好地了解与模板上引发的反应相关的动力学和产物微观结构，我们在这里采用反应-扩散形式主义来模拟从起始的双相模板通过固态反应产生的产物相的微观结构演变。特别是，我们连接的时空演变的产品相的几何形状和化学的起始双链结构。这里采用的形式主义是为化学系统开发的，在这种情况下，我们表明，它使与固态反应相关的微观结构演变的理解。虽然我们在这里考虑理想化的例子，突出底层的过程中，我们还讨论了如何可以使用的结果来选择明智的模板，以促进理想的微观结构的形成，并量化重要的实验动力学参数，决定观察到的模式。最后，我们描述了使用我们的模拟方法来提取重要的动力学信息，从实验产生的产物相微观结构导致固态反应。
While solid-state reactions are employed for the processing of complex materials, the microstructural evolution that initiates from a compositionally inhomogeneous patterned structure has received little to no attention. For example, it has been recognized recently that it is possible to achieve such structures in systems having entropy-stabilized line compounds that are thermodynamically stable only above a certain critical temperature. To obtain a better understanding of the kinetics and product microstructures associated with reactions that initiate on a template, we employ here a reaction-diffusion formalism to model the microstructural evolution of the product phase produced via solid-state reaction from a starting, bi-phasic template. In particular, we connect the spatio-temporal evolution of the product phase with the geometry and chemistry of the starting duplex structure. The formalism employed here was developed for chemical systems and, in this context, we show that it enables an understanding of microstructural evolution associated with solid-state reactions. While we consider here idealized examples to highlight underlying processes, we also discuss how one can use the results to select judiciously templates to promote the formation of desirable microstructures and to quantify important experimental kinetic parameters that dictate observed patterns. Finally, we describe the use of our simulation methodology to extract important kinetic information from experimentally-generated product-phase microstructures resulting from solid-state reactions.