Spinodal Decomposition and Mechanical Response of a TiZrNbTa High-Entropy Alloy

Tai-You Liu; Jacob C Huang; Wen-Shuo Chuang; Hung-Sheng Chou; Jui-Yu Wei; Chih-Yeh Chao; Yu-Chin Liao; Jason S C Jang

doi:10.3390/ma12213508

Spinodal Decomposition and Mechanical Response of a TiZrNbTa High-Entropy Alloy

Materials (Basel). 2019 Oct 25;12(21):3508. doi: 10.3390/ma12213508.

Authors

Tai-You Liu¹, Jacob C Huang^{1

2}, Wen-Shuo Chuang¹, Hung-Sheng Chou¹, Jui-Yu Wei¹, Chih-Yeh Chao³, Yu-Chin Liao⁴, Jason S C Jang^{4

5}

Affiliations

¹ Department of Materials and Optoelectronic Science, National Sun Yat-Sen University, Kaohsiung 804, Taiwan.
² Institute for Advanced Study, Department of Materials Science & Engineering, City University of Hong Kong, Kowloon, Hong Kong, China.
³ Department of Mechanical Engineering, National Pingtung University of Science and Technology, Pingtung 912, Taiwan.
⁴ Department of Mechanical Engineering, National Central University, Taoyuan 320, Taiwan.
⁵ Institute of Materials Science and Engineering, National Central University, Taoyuan 320, Taiwan.

Abstract

In this study, the effects of spinodal decomposition on the microstructures and mechanical properties of a TiZrNbTa alloy are investigated. The as-cast TiZrNbTa alloy possesses dual phases of TiZr-rich inter-dendrite (ID) and NbTa-rich dendrite (DR) domains, both of which have a body-centered cubic (BCC) structure. In the DRs of the as-cast alloy, the α and ω precipitates are found to be uniformly distributed. After homogenization at 1100 °C for 24 h followed by water quenching, spinodal decomposition occurs and an interconnected structure with a wavelength of 20 nm is formed. The α and ω precipitates remained in the structure. Such a fine spinodal structure strengthens the alloy effectively. Detailed strengthening calculations were conducted in order to estimate the strengthening contributions from the α and ω precipitates, as well as the spinodal decomposition microstructure.

Keywords: high entropy alloy; precipitate; spinodal decomposition; strengthening.