Ultra-strong and thermally stable nanocrystalline CrCoNi alloy

Peng Gao ¹Shuo Sun ²Heng Li ³Ranming Niu ¹Shuang Han ²Hongxiang Zong ⁴Hao Wang ¹Jianshe Lian ²Xiaozhou Liao¹

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作者信息

1. School of Aerospace,Mechanical&Mechatronic Engineering,The University of Sydney,Sydney,NSW 2006,Australia
2. Key Laboratory of Automobile Materials,Ministry of Education,College of Materials Science and Engineering,Jilin University,Changchun 130025,China
3. School of Aerospace,Mechanical&Mechatronic Engineering,The University of Sydney,Sydney,NSW 2006,Australia;Key Laboratory of Automobile Materials,Ministry of Education,College of Materials Science and Engineering,Jilin University,Changchun 130025,China
4. State Key Laboratory for Mechanical Behavior of Materials,Xi'an Jiaotong University,Xi'an 710049,China
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Abstract

Grain refinement to the nanocrystalline regime is the most effective way to strengthen materials but this often deteriorates the grain-size thermal stability and plasticity.Here we manufactured a nanocrystalline face centred cubic CrCoNi medium entropy alloy with columnar grains via magnetron sputtering.Com-pression of CrCoNi pillars with diameters of～1 μm revealed a record high yield strength of～5 GPa for pillars with face centred cubic structures and engineering plastic strain of＞30％.The alloy possessed an outstanding grain-size thermal stability even at 1073 K.Both nanocrystalline grain size and a high density of nanotwins/stacking faults are critical to the exceptional yield strength.Deformation twinning,grains refinement during deformation,grain boundary sliding and random grain orientation all contribute to the large plasticity.The outstanding thermal stability is attributed to the sluggish diffusion effect and the low energy of twin boundaries.

Key words

Medium entropy alloy/CrCoNi/Nanocrystalline/In-situ microscopy/Mechanical properties/Thermal stability

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基金项目

scientific and technical input and support from the Microscopy Australia node at the University of Sydney Sydney Microscopy&()

Australian Government under the NCRIS pro-gram()

National Natural Science Foundation of China(51601067)

Science and Technol-ogy Development Program of Jilin Province(20160520007JH)

National Natural Science Foundation of China(51871177)

Australian Research Council Discovery Project(DP190102243)

出版年

2022

材料科学技术(英文版)

中国金属学会中国材料研究学会中国科学院金属研究所

材料科学技术(英文版)

CSTPCDCSCDSCI

影响因子：0.657

ISSN：1005-0302

参考文献量84

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