Effect of lattice distortion on the diffusion behavior of high-entropy alloys

Wang, Ruixin1; Tang, Yu1; Li, Shun1; Ai, Yuanlin1; Li, Yongyan1; Xiao, Bin2; Zhu, Li'an1; Liu, Xiyue1; Bai, Shuxin1

2020

10.1016/j.jallcom.2020.154099

JOURNAL OF ALLOYS AND COMPOUNDS   影响因子和分区

0925-8388

1873-4669

The presence and effect of lattice distortion have become the most concerned issue of high-entropy alloys (HEAs) recently. To address this issue, TiZrNbTa (TZNT) HEAs were presented and an in-depth analysis concerning their microstructure, elemental diffusion and oxidation behavior was conducted. The results showed that during the high-temperature oxidation process at 800–1400 °C, the metastable homogeneous microstructure of TZNT HEAs segregated, then TiZr-rich and TaNb-rich regions with different lattice distortion degrees formed. Although O has stronger affinities with Ta and Nb, the oxygen atoms are more likely to diffuse in TiZr-rich region due to the dislocation pipe effect caused by severe lattice distortion. The inhomogeneous diffusion of oxygen atoms leads to inhomogeneous distribution of internal stress. The stress concentration and the structure transformation from BCC to brittle HCP jointly facilitate the cracks to form easier and grow in TiZr-rich region, finally resulting in a catastrophic pesting of TZNT HEAs at 800 °C. By contrast, the heterogeneity of oxygen atoms diffusion rate decreases as temperature increases. Therefore, the TZNT HEAs exhibited a parabolic oxidation behavior between 1000 and 1400 °C. The lattice distortion, whose degree is below the threshold for the generation of dislocation pipe effect, slows down the oxygen atoms diffusion rate. The findings of this work deepen the understanding on HEAs and can be utilized in tailoring the diffusion and oxidation behavior of high-performance HEAs via controlling lattice distortion.
© 2020 Elsevier B.V.

High-entropy alloys Lattice distortion Diffusion Oxidation

SCI ; EI

英语

其他

[2019JJ40338] ; National Natural Science Foundation of China[11972327]

Chemistry ; Materials Science ; Metallurgy & Metallurgical Engineering

Chemistry, Physical ; Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering

WOS:000514848600019

Elsevier Ltd

20200608133709

Atoms ; Crystal structure ; Entropy ; High-entropy alloys ; Microstructure ; Niobium alloys ; Oxidation ; Oxygen ; Tantalum alloys ; Thermooxidation ; Titanium alloys ; Zircaloy

Titanium and Alloys:542.3 ; Tantalum and Alloys:543.4 ; Nonferrous Metals and Alloys excluding Alkali and Alkaline Earth Metals:549.3 ; Thermodynamics:641.1 ; Chemical Reactions:802.2 ; Chemical Products Generally:804 ; Atomic and Molecular Physics:931.3 ; Crystal Lattice:933.1.1 ; Materials Science:951

MATERIALS SCIENCE

Web of Science

1.Department of Materials Science and Engineering, College of Aerospace Science and Engineering, National University of Defense Technology, Changsha; 410073, China
2.Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen; 518055, China

Wang, Ruixin,Tang, Yu,Li, Shun,et al. Effect of lattice distortion on the diffusion behavior of high-entropy alloys[J]. JOURNAL OF ALLOYS AND COMPOUNDS,2020,825.

Wang, Ruixin.,Tang, Yu.,Li, Shun.,Ai, Yuanlin.,Li, Yongyan.,...&Bai, Shuxin.(2020).Effect of lattice distortion on the diffusion behavior of high-entropy alloys.JOURNAL OF ALLOYS AND COMPOUNDS,825.

Wang, Ruixin,et al."Effect of lattice distortion on the diffusion behavior of high-entropy alloys".JOURNAL OF ALLOYS AND COMPOUNDS 825(2020).