内容:
通过晶界析出相发生相变使得晶界析出强化高熵合金
( FeCoNiCr)90Ti5Al5 获得断裂强度超过了1.5GPa,延伸率达到38%。
本工作由本单位西安交大、南京理工大学、西北工业大学共同完成,博士生齐永良为第一作者, 西北工业大学刘峰教授、本单位孙军教授和江峰教授为共同通讯作者。
Enhanced mechanical performance of grain boundary precipitation hardened high-entropy alloys via a phase transformation at grain
boundaries
Y. L. Qi
1
, L. Zhao
1
, X. Sun
1
, H. X. Zong
1
, X. D. Ding
1
, F. Jiang
1,
*, H. L. Zhang
1
, Y.
K. Wu
1
, L. He
1
, F. Liu
2,
*, S. B. Jin
3
, G. Sha
3
, J. Sun
1,
*
1
State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong
University, Xi’an, Shanxi 710049, China
2
Analytical & Testing Center, Northwestern Polytechnical University, Xi'an, Shanxi
710072, China
3
School of Materials Science and Engineering, Nanjing University of Science and
Technology, Jiangsu, 210094, China
*Corresponding authors E-mail: jiangfeng@ mail.xjtu.edu.cn; junsun@mail.xjtu.edu.cn;
liufeng@nwpu.edu.cn
Abstract
Grain-boundary (GB) precipitation has a significant adverse effect on plasticity of
alloys, which easily leads to catastrophic intergranular failure in safety-critical
applications under high external loading. Herein, we report a novel strategy that uses
the local stress concentration induced by GB precipitates as a driving force to trigger
phase transformation of preset non-equiatomic high-entropy solid-solution phase at
GBs. This in situ deformation-induced phase transformation at GBs introduces a well
known effect: transformation-induced plasticity (TRIP), which enables an exceptional
elongation to fracture (above 38%) at a high strength (above 1.5 GPa) in a GB
precipitation-hardened high-entropy alloy (HEA). The present strategy in terms of
“local stress concentration-induced phase transformations at GBs” may provide a
fundamental approach by taking advantage of (rather than avoiding) the GB
precipitation to gain a superior combination of high strength and high ductility in HEAs.