Formation of nanocrystalline γ-ZrH in Zr-Nb alloy: Crystal structure and twinning

Xinu Tan; Yushun Liu; Feitao Li; Risheng Qiu; Qing Liu

doi:10.1016/j.micron.2023.103414

Formation of nanocrystalline γ-ZrH in Zr-Nb alloy: Crystal structure and twinning

Micron. 2023 Apr:167:103414. doi: 10.1016/j.micron.2023.103414. Epub 2023 Jan 14.

Authors

Xinu Tan¹, Yushun Liu², Feitao Li³, Risheng Qiu⁴, Qing Liu⁵

Affiliations

¹ Electron Microscopy Center, College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China; International Joint Laboratory for Light Alloys (MOE), College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China.
² Electron Microscopy Center, College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China; Department of Mechanical Engineering, University of Manitoba, 15 Gillson Street, Winnipeg MB R3T 5V6, Canada.
³ Electron Microscopy Center, College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China; TU Ilmenau, Chair Materials for Electrical Engineering and Electronics, Institute of Materials Science and Engineering and Institute of Micro, and Nanotechnologies MacroNano, Gustav-Kirchhoff-Strasse 5, 98693 Ilmenau, Germany.
⁴ Electron Microscopy Center, College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China; International Joint Laboratory for Light Alloys (MOE), College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China. Electronic address: rsqiu@cqu.edu.cn.
⁵ Electron Microscopy Center, College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China; Key Laboratory for Light-weight Materials, Nanjing Tech University, Nanjing 210009, China.

PMID: 36706541
DOI: 10.1016/j.micron.2023.103414

Abstract

In the present work, the lattice parameter and the twins of γ-ZrH hydride in Zr-2.5Nb-1Si were characterized using high resolution electron microscopy. The lattice parameters of γ-ZrH (P4₂/mmc, Zr₂H₂ unit cell) is determined to be a = 0.336 nm, c = 0.508 nm. Twinning γ-ZrH hydride ({011}<01̅1> type) is for the first time reported in zirconium alloys, whose orientation relationship with α-Zr is [100]_γ-twins // [12̅10]_α and (011)_γ-twins // (0002)_α. The formation process of γ-ZrH twins is also discussed based on a 'grow-in' mechanism during the transformation from α-Zr to γ-ZrH hydride.

Keywords: Electron diffraction; Phase transition; The hydride; Transmission electron microscopy; Zirconium alloys.