Observing strain glass transition in Ti33Nb15Zr25Hf25O2 high entropy alloy with Elinvar effect

• Published in: Journal of materials science & technology 2024-01, Vol.168, p.16-23
• Main Authors: Zhang, Kaichao, Wang, Kai, Wang, Bin, Lv, Chao, Zheng, Jiaxing, Li, Guanqi, Fu, Yu, Xiao, Wenlong, Cai, Qingqing, Nie, Xutao, Shao, Yingfeng, Hou, Huilong, Zhao, Xinqing
• Format: Article
• Language: English
• Subjects: Elinvar effect; High entropy alloys; Microstructural evolution; Nanodomains; Strain glass transition
• ISSN: 1005-0302; 1941-1162
• DOI: 10.1016/j.jmst.2023.06.009

•The Ti33Nb15Zr25Hf25O2 HEA has been prepared and shows the Elinvar effect.•The strain glass transition is confirmed in the Ti33Nb15Zr25Hf25O2 HEA.•Microstructural evolution in the HEA has been investigated.•Strain glass transition has been proposed to explain the Elinvar effect. Exploring the phase transition of high entropy alloys (HEAs) with multiple major elements is of great importance for understanding the underlying physical mechanisms. Macroscopic martensitic phase transition has been frequently reported in HEAs, however, nanoscale microstructural phase evolution has not been investigated to the same extent. Herein, we have prepared the Ti33Nb15Zr25Hf25O2 HEA and investigated the strain glass transition and its associated properties using dynamic mechanical analysis and microstructure characterization. We have found that the elastic modulus in Ti33Nb15Zr25Hf25O2 HEA deviates from Wachtman's equation and observed the Elinvar effect in the form of temperature-independent modulus in the temperature range from 150 K to 450 K and frequency-dependence modulus around 220 K. The strain glass transition has been evidenced in Ti33Nb15Zr25Hf25O2 HEA by the formation and growth of nano-sized domains during in-situ transmission electron microscopy (TEM) cooling, and substantiated by the broken ergodicity during zero-field-cooling/field-cooling. The strain glass transition is believed to account for the Elinvar effect, where the modulus hardening of nano-sized domains compensates dynamically with the modulus softening of the transformable matrix. [Display omitted]