Metal-carbide eutectics with multiprincipal elements make superrefractory alloys

Qinqin Wei; Xiandong Xu; Qiang Shen; Guoqiang Luo; Jian Zhang; Jia Li; Qihong Fang; Chain-Tsuan Liu; Mingwei Chen; Tai-Gang Nieh; Jianghua Chen

doi:10.1126/sciadv.abo2068

Metal-carbide eutectics with multiprincipal elements make superrefractory alloys

Sci Adv. 2022 Jul 8;8(27):eabo2068. doi: 10.1126/sciadv.abo2068. Epub 2022 Jul 8.

Authors

Qinqin Wei^{1

2}, Xiandong Xu¹, Qiang Shen², Guoqiang Luo², Jian Zhang², Jia Li³, Qihong Fang³, Chain-Tsuan Liu⁴, Mingwei Chen⁵, Tai-Gang Nieh⁶, Jianghua Chen^{1

7}

Affiliations

¹ Centre for High-Resolution Electron Microscopy, College of Materials Science and Engineering, Hunan University, Changsha 410082, China.
² State Key Lab of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China.
³ State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, College of Mechanical and Vehicle Engineering, Hunan University, Changsha 410082, China.
⁴ College of Science and Engineering, City University of Hong Kong, Hong Kong 999077, China.
⁵ Department of Materials Science and Engineering and Hopkins Extreme Materials Institute, Johns Hopkins University, Baltimore, MD 21218, USA.
⁶ Department of Materials Science and Engineering, The University of Tennessee, Knoxville, TN 37996, USA.
⁷ Pico Electron Microscopy Center, College of Materials Science and Engineering, Hainan University, Haikou, Hainan 570228, China.

Abstract

Materials with excellent high-temperature strength are now sought for applications in hypersonics, fusion reactors, and aerospace technologies. Conventional alloys and eutectic multiprincipal-element alloys (MPEAs) exhibit insufficient strengths at high temperatures due to low melting points and microstructural instabilities. Here, we report a strategy to achieve exceptional high-temperature microstructural stability and strength by introducing eutectic carbide in a refractory MPEA. The synergistic strengthening effects from the multiprincipal-element mixing and strong dislocation blocking at the interwoven metal-carbide interface make the eutectic MPEA not only have outstanding high-temperature strength (>2 GPa at 1473 K) but also alleviate the room-temperature brittleness through microcrack tip blunting by layered metallic phase. This strategy offers a paradigm for the design of the next-generation high-temperature materials to bypass the low-melting point limitation of eutectic alloys and diffusion-dominated softening in conventional superalloys.