From simple binary to complex multicomponent eutectic alloys
From simple binary to complex multicomponent eutectic alloys
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DOI：
10.1016/j.pmatsci.2021.100779
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发表时间：
2021-02
影响因子：
37.4
通讯作者：
I. Chang;Qingwei Cai
中科院分区：
文献类型：
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作者：
I. Chang;Qingwei Cai
几乎所有的二元和大多数关键的三元合金系统的共晶凝固已经被广泛研究和模拟。三元、多元和高熵合金中共晶微结构的发展产生了潜在的工程合金，其具有优异的上级机械/磁性，由于细化的微结构和/或双硬/软相混合物的存在，其优于其传统的二元共晶对应物。目前，我们对共晶凝固的理解主要限于具有多达3种成分的合金系统（例如，三元共晶）。在对高次多元共晶合金凝固行为的认识上存在着知识空白。本文简要介绍了从二元系到六元系共晶合金的发展背景，并综述了具有五种或五种以上共晶成分的铝基多元合金的复杂微观结构的最新发展。虽然在铝基共晶合金中共存的晶相的数量随着组元数量的增加而增加。在近共晶组成的13元素合金系统的熔体的凝固导致了七个结晶相的发展，主要是非合作生长，导致无层状特征的显微组织，相比于它们的低阶成分合金对应物。最后，铝基共晶合金的硬度随着组元数的增加而显著增加。这为开发基于高阶多元共晶合金系统的高强度合金提供了新的机会。
The eutectic solidification of almost all binary and majority of key ternary alloy systems have been studied and modelled extensively. The development of eutectic microstructure in ternary, multicomponent and high entropy alloys have generated potential engineering alloys with superior mechanical/magnetic properties that outperform their traditional binary eutectic counterparts due to refined microstructure and/or the presence of dual hard/soft phase mixture. Currently, our understanding of the eutectic solidification is mainly restricted to alloy systems having upto 3 constituents (eg. ternary eutectic). There exists a knowledge gap in our understanding of the solidification behaviour of high order multicomponent eutectic alloys. This review article gives a brief background of the development of eutectic alloys from binary to senary multicomponent systems, together with an overview of recent development of complex microstructures of aluminium based multicomponent alloys with five or more constituents at/near eutectic compositions. Although the number of crystalline phases coexisted in the Al-based eutectic alloys increases with increasing number of constituents. The solidification of a melt at near eutectic composition of 13-element alloy system has led to the development of seven crystalline phases with predominantly non-cooperative growth, leading to a microstructure free of lamellar feature, as compared to their low-order constituent alloy counterparts. Finally, the hardness of Al-based eutectic alloy increases significantly as the number of constituents in excess of ten. This opens up a new opportunity to develop ultrahigh strength alloys based on high-order multicomponent eutectic alloy systems.