A Promising New Class of High-Temperature Alloys: Eutectic High-Entropy Alloys

作者：Yiping Lu, Yong Dong, Sheng Guo, Li Jiang, Huijun Kang, Tongmin Wang, Bin Wen, Zhijun Wang, Jinchuan Jie, Zhiqiang Cao, Haihui Ruan, Tingju Li · 发表于：Scientific Reports · 年份：2014 · DOI：10.1038/srep06200 · 被引用次数：1740 · 研究领域：High Entropy Alloys Studies、High-Temperature Coating Behaviors、Advanced materials and composites

High-entropy alloys (HEAs) can have either high strength or high ductility, and a simultaneous achievement of both still constitutes a tough challenge. The inferior castability and compositional segregation of HEAs are also obstacles for their technological applications. To tackle these problems, here we proposed a novel strategy to design HEAs using the eutectic alloy concept, i.e. to achieve a microstructure composed of alternating soft fcc and hard bcc phases. As a manifestation of this concept, an AlCoCrFeNi2.1 (atomic portion) eutectic high-entropy alloy (EHEA) was designed. The as-cast EHEA possessed a fine lamellar fcc/B2 microstructure, and showed an unprecedented combination of high tensile ductility and high fracture strength at room temperature. The excellent mechanical properties could be kept up to 700°C. This new alloy design strategy can be readily adapted to large-scale industrial production of HEAs with simultaneous high fracture strength and high ductility.