论文标题
通过Spinodal介导的相变途径（HEAS）使用相位场建模的微结构设计
Microstructural Design via Spinodal-Mediated Phase Transformation Pathways in High-Entropy Alloys (HEAs) using Phase-Field Modelling
论文作者
论文摘要
了解多相HEAS中的相变通路（PTP）和微观结构演化将有助于合金和过程设计，以根据特定工程应用调整微观结构。在这项工作中，我们研究了两相HEAS中的微观结构进化，其中无序的父阶段分为两个阶段的混合物：一个有序阶段（$β'$） +一个无序相（$β$）在两个不同的PTPS进行冷却后：（i）一致的顺序排列，然后在有序的phases of nise $ phase nir'中均匀地分解。 \rightarrowβ_1' +β_2'\ rightarrowβ +β_2'$和（ii）在无序相中的旋转分解，然后订购其中一个无序相，即$β\rightarrowβ_1 +β_1 +β_2\rightarrowβ_2\rightarrowβ_1 +β_1 +β'$。我们系统地研究了单个相，自由能景观的平衡体积分数的影响（特别是，与最终两个平衡相的组成相对于混溶性差距的临界点的位置）以及两个平衡相之间的弹性模态不匹配在这些heas的微观结构进化上。我们关注以下形态特征：双连续微结构与沉淀 +基质微结构，有序的基质 +无序沉淀物与无序的基质 +有序的沉淀物以及沉淀相位的离散性。这项参数研究可能有助于用于所需的微观结构的多相HEA设计。
Understanding the phase transformation pathways (PTPs) and microstructural evolution in multi-phase HEAs will aid alloy and process designs to tailor the microstructures for specific engineering applications. In this work, we study microstructural evolution in two-phase HEAs where a disordered parent phase separates into a mixture of two phases: an ordered phase ($β'$) + a disordered phase ($β$) upon cooling following two different PTPs: (i) congruent ordering followed by spinodal decomposition in the ordered phase and then disordering of one of the ordered phases, i.e., $β\rightarrow β' \rightarrow β_1' + β_2' \rightarrow β+ β_2'$ and (ii) spinodal decomposition in the disordered phase followed by ordering of one of the disordered phases, i.e., $β\rightarrow β_1 + β_2 \rightarrow β_1+β'$. We systematically investigate the effects of equilibrium volume fractions of individual phases, free energy landscapes (in particular, the location of the critical point of the miscibility gap relative to the compositions of the final two equilibrium phases), and elastic modulus mismatch between the two equilibrium phases on the microstructural evolution of these HEAs. We focus on the following morphological characteristics: bi-continuous microstructures vs. precipitates + matrix microstructures, ordered matrix + disordered precipitates vs. disordered matrix + ordered precipitates, and the discreteness of the precipitate phase. This parametric study may aid in multi-phase HEA design for desired microstructures.
