In Situ Measurement of the Phase Transformation Behavior of Al2O3 Scale during High-Temperature Oxidation using Synchrotron Radiation
In Situ Measurement of the Phase Transformation Behavior of Al2O3 Scale during High-Temperature Oxidation using Synchrotron Radiation
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使用同步辐射原位测量 Al2O3 氧化皮高温氧化过程中的相变行为
DOI：
10.4028/www.scientific.net/msf.696.63
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
Masayuki Segawa
中科院分区：
文献类型：
--
作者：
S. Hayashi;I. Saeki;Y. Nishiyama;T. Doi;Shoji Kyo;Masayuki Segawa
在我们以前的研究中发现，非常薄的Fe涂层，~ 50 nm，抑制亚稳Al_2 O_3形成Fe-50 Al和Ni-50 Al合金。由于α-Al_2 O_3和α-Fe_2 O_3具有类质同象结构，作者提出了α-Al_2 O_3从初始氧化过程中形成的Al饱和Fe_2 O_3中析出的机理。为了证实所提出的机制，原位测量的结构变化，在加热和随后的等温高温氧化过程中形成的FeAl与Fe涂层的氧化皮与二维X射线探测器同步辐射。Fe 2 O3的衍射峰最初在约350°C下在Fe涂覆的样品上观察到。Fe 2 O3的晶格常数最初由于热膨胀而线性增加，但随后由于形成Fe 2 O3-Al 2 O3固溶体而迅速减小。α-Al 2 O3在800 ℃左右开始出现，但没有观察到亚稳Al 2 O3的峰。Fe包覆样品上α-Al 2 O3的衍射峰由两个明显的衍射峰组成，表明α-Al 2 O3具有两个不同的晶格参数。这些结果表明，α-Al_2O_3不仅是由Al饱和的Fe_2O_3沉淀形成的，而且也是由基体中Al的氧化形成的。
Very thin Fe-coatings, ~50nm, were found to suppress metastable Al2O3 formation on Fe-50Al and Ni-50Al alloys in our previous study. The authors proposed a mechanism whereby α-Al2O3 precipitates from the Al-saturated Fe2O3, which was formed during initial oxidation, since α-Al2O3 and α-Fe2O3 have isomorphous structures. In order to confirm the proposed mechanism, in-situ measurements were made of structural changes in the oxide scales formed on FeAl with and without Fe coating during heating and subsequent isothermal high temperature oxidation by synchrotron radiation with a two-dimensional X-ray detector. Diffraction peaks from Fe2O3 were initially observed at around 350°C on Fe-coated samples. The lattice parameter of the Fe2O3 initially increased linearly due to thermal expansion, but then rapidly decreased due to the formation of a solid solution of Fe2O3-Al2O3. α-Al2O3 started to appear at around 800°C, but no peaks from metastable Al2O3 were observed. The diffraction peaks from the α-Al2O3 on Fe-coated samples consisted of two distinct peaks, indicating that the α-Al2O3 had two different lattice parameters. These results suggest that the α-Al2O3 was formed not only by precipitation from the Al-saturated Fe2O3, but also by oxidation of Al in the substrate.
900℃纯金属涂层在Fe-Al合金上快速形成α-Al203氧化皮
影响因子：
2.2
作者：
Y.Kitajima;S.Hayashi;T.Nishimoto;T.Narita;S.Ukai
通讯作者：
S.Ukai