标题： 通过使用相场建模，在高熵合金（HEAs）中利用旋节分解介导的相变路径进行微观结构设计 显示英文标题

标题： Microstructural Design via Spinodal-Mediated Phase Transformation Pathways in High-Entropy Alloys (HEAs) using Phase-Field Modelling

摘要： 理解多相高熵合金中的相变路径（PTPs）和微观结构演变将有助于合金和工艺设计，以定制适用于特定工程应用的微观结构。 在本工作中，我们研究了两相高熵合金中的微观结构演变，其中无序的母相在冷却过程中通过两种不同的PTPs分离成两种相的混合物：有序相（$\beta'$）+ 无序相（$\beta$），其路径为：(i) 共晶有序化后，在有序相中发生旋节分解，然后其中一个有序相发生无序化，即$\beta \rightarrow \beta' \rightarrow \beta_1' + \beta_2' \rightarrow \beta + \beta_2'$；以及(ii) 在无序相中发生旋节分解，然后其中一个无序相发生有序化，即$\beta \rightarrow \beta_1 + \beta_2 \rightarrow \beta_1+\beta'$。 我们系统地研究了各相的平衡体积分数、自由能景观（特别是混溶间隙临界点相对于最终两个平衡相组成的相对位置）以及两个平衡相之间的弹性模量失配对这些高熵合金微观结构演变的影响。 我们关注以下形态特征：双连续微观结构与析出物+基体微观结构，有序基体+无序析出物与无序基体+有序析出物，以及析出相的离散性。 这项参数研究可能有助于设计具有所需微观结构的多相高熵合金。 显示英文摘要

摘要： 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 ($\beta'$) + a disordered phase ($\beta$) 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., $\beta \rightarrow \beta' \rightarrow \beta_1' + \beta_2' \rightarrow \beta + \beta_2'$ and (ii) spinodal decomposition in the disordered phase followed by ordering of one of the disordered phases, i.e., $\beta \rightarrow \beta_1 + \beta_2 \rightarrow \beta_1+\beta'$. 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.