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

• Published in: Micron (Oxford, England : 1993) Vol. 167; p. 103414
• Main Authors: Tan, Xinu, Liu, Yushun, Li, Feitao, Qiu, Risheng, Liu, Qing
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.04.2023
• Subjects: Electron diffraction; Phase transition; The hydride; Transmission electron microscopy; Zirconium alloys; The hydride; Transmission electron microscopy; Electron diffraction; Zirconium alloys; Phase transition
• ISSN: 0968-4328; 1878-4291
• DOI: 10.1016/j.micron.2023.103414

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. •The lattice parameters of γ-ZrH (P42/mmc, Zr2H2 unit cell) is determined to be a 0.336 nm, c = 0.508 nm by transmission electron microscope.•The twinning ({011}<01̅1> type) in γ-ZrH hydride is for the first time reported in zirconium alloys.•The formation process of the twining was discussed based on a ‘grow-in’ mechanism during the transformation from α-Zr to γ-ZrH hydride.