高熵合金中的第二相强韧化-中国材料进展

文章信息/Info

Author(s):: WEN Xiaocan; ZHANG Fan; LEI Zhifeng; WU Yuan; LIU Xiongjun; WANG Hui; LU Zhaoping; （State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China）

Keywords:: high-entropy alloys; second phase strengthening; strengthening mechanism

摘要:: 高熵合金是由多种元素以等原子比或近等原子比合金化所形成的一类新型金属材料。不同于传统的以一元或二元为主的合金设计思想，高熵合金颠覆性的合金设计理念使得其具有独特的原子结构特征，因而呈现出许多优异的力学、物理及化学性能。但其力学性能还有需继续提高之处，FCC结构的高熵合金通常塑性较好但强度偏低，而BCC结构的高熵合金强度较高但塑性较小。第二相强韧化已经被应用在高熵合金中以改善其强韧性，目前已经开发了大量高性能第二相强韧化高熵合金。然而，由于高熵合金独特的结构和性能特点，其强韧化行为特点和机制与传统合金并不完全相同。从高熵合金第二相强韧化的研究现状出发，简要介绍了高熵合金中的第二相种类及其强韧化机理，并对高熵合金第二相强韧化的研究进行了简单的展望。

Abstract:: Recently, a new alloy design strategy, i.e., high-entropy alloys (HEAs), was proposed based on the principle of equal-molar or near-equalmolar fraction for all the components. Different from traditional alloy design strategy which usually blends with one or two elements as the principal constituent, such revolutionary alloy design concept leads to the unique atomic structure, which giving rise to unique mechanical, physical and chemical properties of HEAs. However, mechanical properties of HEAs need to be further improved, e.g., FCC (face-centered cubic)-structured HEA usually has a large ductility but a low strength, BCC (body-centered cubic)-structured HEA usually has a high strength but a low ductility. Second phase strengthening has been widely applied in HEAs and was proved to be effective to strengthening or toughening HEAs. However, due to the unique atomic structure of HEAs, behavior and mechanism of second phase strengthening were different from that in traditional alloys. Here in this short review manuscript, the current research status and underlying mechanism of second phase strengthening were briefly reviewed. The future perspective of second phase strengthening in HEAs was also discussed.