Charge transfer effect on local lattice distortion in a HfNbTiZr high entropy alloy

SCRIPTA MATERIALIA

卷:203

Article

Meng, Fanchao¹  Zhang, Wenyan¹  Zhou, Zhukun²  Sheng, Ruixin¹  Chuang, Andrew C. -P.³  Wu, Chongchong¹  Huang, Hailiang¹  Zhang, Shangzhou¹  Zhang, Hua¹  Zhu, Lilong^1,4  Jiang, Liang¹  Liaw, Peter K.⁵  Chen, Shuying¹  Tong, Yang¹ 

[1] Yantai Univ, Inst Adv Studies Precis Mat, Yantai 264005, Shandong, Peoples R China

[2] Guangxi Univ, Sch Mech Engn, Inst Laser Intelligent Mfg & Precis Proc, Nanning 530004, Guangxi, Peoples R China

[3] Argonne Natl Lab, Lemont, IL 60439 USA

[4] Cent South Univ, State Key Lab Powder Met, Changsha 410083, Peoples R China

[5] Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA

关键词: High-entropy alloy;    Local lattice distortion;    Charge transfer;    Atomic pair distribution function;    Reverse Monte Carlo simulation;    Density functional theory;   

DOI  :  10.1016/j.scriptamat.2021.114104

来源: Elsevier

【 摘 要 】

It is often assumed that atoms are hard spheres in the estimation of local lattice distortion (LLD) in high entropy alloys (HEAs). However, our study demonstrates that the hard sphere model misses the key effect, charge transfer among atoms with different electronegativities, in the understanding of the severely distorted local structure in the body-centered cubic (BCC) HfNbTiZr HEA. Through the characterization and simulations of the local structure of the HfNbTiZr HEA, we found that the LLD regions in HfNbTiZr have larger average size compared with face-centered cubic (FCC) HEAs, but the magnitude of LLD significantly varies from one atomic site to another because of electron transfer from larger atoms, Hf and Zr, to smaller ones, Nb and Ti. Our finding may form the basis for the design of high performance HEAs through tuning their site-to-site chemical heterogeneity. (c) 2021 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

【 授权许可】

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