Observations of temperature stability of γ-zirconium hydride by high-resolution neutron powder diffraction
Observations of temperature stability of γ-zirconium hydride by high-resolution neutron powder diffraction
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DOI：
10.1016/j.jallcom.2015.11.187
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发表时间：
2016-03
影响因子：
6.2
通讯作者：
Zhiyang Wang;Zhiyang Wang;A. Steuwer;Nanxi Liu;T. Maimaitiyili;M. Avdeev;J. Blomqvist;C. Bjerkén;C. Curfs;J. Kimpton;J. Daniels
中科院分区：
文献类型：
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作者：
Zhiyang Wang;Zhiyang Wang;A. Steuwer;Nanxi Liu;T. Maimaitiyili;M. Avdeev;J. Blomqvist;C. Bjerkén;C. Curfs;J. Kimpton;J. Daniels
锆-50氘（Zr-50 D，at.%）用原位高分辨中子粉末衍射研究了合金体系在热循环过程中的变化。结果表明，该体系没有发生高温下发生的α-Zr + δ-ZrD → γ-ZrD包析反应。从高温（≥520 K）以5 K min−1的速率缓慢冷却到室温，促进了γ-氢化物的形成，而不是之前报道的快速冷却。与系统中存在的δ-氢化物在高达740 K的温度下保持不变的观察相反，所产生的γ相在370 K-559 K的温度范围内转变为δ-氢化物，转变在约559 K完成。结果表明，γ-氢化物的形成在缓慢冷却条件下是可重复的，并认为缓慢冷却过程中δ-氢化物向γ-氢化物的缓慢转变是γ-氢化物形成的主要原因。
The phase evolution in a zirconium–50 deuterium (Zr–50D, at.%) alloy system during thermal cycling has been investigated usingin situhigh-resolution neutron powder diffraction. The results showed that the peritectoid reaction α-Zr + δ-ZrD → γ-ZrD previously suggested to occur at high temperatures does not take place in the system. Slow cooling, from high temperatures (≥520 K) to room temperature at a rate of 5 K min−1, promoted the γ-hydride formation rather than fast cooling as reported earlier. In contrast to the observation that the δ-hydride present in the system remained at temperatures up to 740 K, the produced γ phase transformed to δ-hydride in the temperature range of 370 K–559 K, with the transformation completing at approximately 559 K. It is confirmed that the formation of the γ-hydride was reproducible with slow cooling, and a diffusion-controlled sluggish δ-to γ-hydride transformation is suggested to be responsible for the favorable development of γ-hydride during slow cooling.