In situ transmission electron microscopy study of the thermally induced formation of δ′‐ZrO in pure Zr and Zr‐based alloy. Issue 4 (26th June 2017)

• Record Type: Journal Article
• Authors: Yu, Hongbing; Yao, Zhongwen; Long, Fei; Saidi, Peyman; Daymond, Mark R.
• Is Part Of: Journal of applied crystallography. Volume 50:Issue 4(2017)
• Page Start: 1028
• Page End: 1035
• Publication Date: 2017-06-26
• Subjects: ZrO phase -- in situ heating -- transmission electron microscopy -- TEM; Crystallography -- Periodicals; 548.05
• DOI: 10.1107/S160057671700680X
• Languages: English
• ISSNs: 0021-8898

Abstract

Abstract : The formation of δ′‐ZrO in Zr‐based samples was observed by in situ transmission electron microscopy during isothermal annealing. The nucleation sites, the crystal structure of the phase and its crystallographic correspondence to the α matrix were determined. Abstract : This study reports in situ observations of the formation of the δ′‐ZrO phase, occurring during the annealing of transmission electron microscopy (TEM) thin foils of both pure Zr and a Zr–Sn–Nb–Mo alloy at 973 K in a transmission electron microsope. The lattice parameters of δ′‐ZrO were measured and determined to be similar to those of the ω‐Zr phase. The orientation relationship between the δ′‐ZrO and α‐Zr phases has been identified as either and or and depending on the orientation of the α grain relative to the TEM thin‐foil normal. The nucleation and growth of δ′‐ZrO were dynamically observed. This study suggests a new and convenient way to study oxidation mechanisms in Zr alloys and provides a deeper understanding of the properties of the newly reported δ′‐ZrO. Since δ′‐ZrO has a Zr sublattice which is identical to that of ω‐Zr, the orientation relationships between the α and δ′‐ZrO phases may also shed light on the orientation relations existing between α‐ and ω‐Zr, and hence α‐ and ω‐Ti.