TEM study on the initial oxidation of Zircaloy-4 thin foil specimens heated in a low vacuum air condition at 280–300 °C
TEM study on the initial oxidation of Zircaloy-4 thin foil specimens heated in a low vacuum air condition at 280–300 °C
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DOI：
10.1016/j.jnucmat.2017.02.019
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发表时间：
2017-04
影响因子：
3.1
通讯作者：
Zhen Wang;Bangxin Zhou;Wei Zhu;B. Wen;M. Yao;Qiang Li;Lu Wu;Jinlong Zhang;Z. Fang
中科院分区：
文献类型：
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作者：
Zhen Wang;Bangxin Zhou;Wei Zhu;B. Wen;M. Yao;Qiang Li;Lu Wu;Jinlong Zhang;Z. Fang
作为核工业中重要的结构材料之一，锆合金的耐腐蚀性限制了其在堆内的应用。因此，有必要对锆合金的腐蚀机理进行研究。O/M界面上的锆氧反应是影响氧化过程的因素之一。这方面的报道很少。理想情况下，O/M界面的反应过程与锆的引发氧化有一定的相关性，这为通过观察引发氧化行为来研究反应过程提供了一种新的途径。为了研究锆合金的初期氧化行为，本文对直径为3 mm的Zircaloy-4电子显微镜薄片在280℃、290℃和300℃的真空条件下加热30min后进行了透射电子显微镜观察。结果表明，当高Zr/O比为10.4时，ZrO2开始形核，尺寸为3~5 nm，当Zr/O比为4.6时，形成氧化层。由于Zr的P.B比产生的应力，形成了滑移带，并观察到体心立方结构的亚氧化物b-ZrOx(a=0.51 nm)与滑移带一起生长。在b-ZrOx的两侧检测到两个具有相同晶胞参数和不同晶胞参数的hcp结构的亚氧化物。
As one of the important structural materials in nuclear industry, the corrosion resistance of zirconium alloy limits their in-pile application. Therefore, it is necessary to investigate the corrosion mechanism of zirconium alloys. The zirconium-oxygen reaction at the O/M interface is one of the factors that affect the oxidation process. There are few reports in this regard. Ideally, the reaction process at the O/M interface has certain relevance with the initiation oxidation of zirconium, which provided a new way to investigate the reaction process by observing the initiation oxidation behaviours. To investigate the oxidation behaviours of zirconium alloy at the initial stage, in this paper, zircaloy-4 TEM thin foil specimens in 3 mm diameter were studied by TEM observation after heating in air condition with a vacuum of 3 Pa at 280 °C, 290 °C and 300 °C for 30 min exposures. The results show that, ZrO2begin to nucleate at a size of 3–5 nm at a high Zr/O ratio of 10.4 and oxide layer formed while Zr/O was 4.6. As a result of stress caused by the P.B ratio of Zr, slip bands formed and a bcc structure sub-oxide b-ZrOx (a = 0.51 nm) grew up along with the slip bands was observed. At both sides of b-ZrOx, two hcp structure sub-oxides having the samea-axis lattice parameter and differentc-axis lattice parameter were detected.