J. Mater. Sci. Technol. ›› 2019, Vol. 35 ›› Issue (7): 1479-1484.DOI: 10.1016/j.jmst.2019.02.005

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Anomalous formation of micrometer-thick amorphous oxide surficial layers during high-temperature oxidation of ZrAl2

Zhangping Hua, Yifei Xua, Yuanyuan Chena, Peter Schützendübebb, Jiangyong Wangc*, Yuan Huanga, Yongchang Liua, Zumin Wanga()   

  1. aSchool of Materials Science and Engineering, Tianjin University, Tianjin, 300350, China
    bMax Planck Institute for Intelligent Systems, Heisenbergstrasse 3, D-70569, Stuttgart, Germany
    cDepartment of Physics, Shantou University, Shantou, 515063, China
  • Received:2018-09-26 Revised:2019-01-24 Accepted:2019-02-01 Online:2019-07-20 Published:2019-06-20
  • Contact: Wang Jiangyong
  • About author:

    1These authors contributed equally to this work.

Abstract:

The thermal oxidation of ZrAl2 in the temperature range of 550-750 °C in pure oxygen has been investigated by a combinational experimental approach using X-ray diffraction, scanning electron microscopy/energy dispersive spectrometer, Auger electron spectroscopy and cross-sectional transmission electron microscopy. The thermal oxidation leads to the growth of anomalously thick (up to 4.5 μm) amorphous (Zr0.33Al0.67)O1.66 surficial layers at temperatures as high as 750 °C. The oxidation kinetics obeys a parabolic law with an activation energy of 143 kJ/mol. The underlying mechanism for the formation of such micrometer-thick amorphous oxide surficial layers has been discussed on the basis of interface thermodynamics and the occurrence of high interface stability associated with a synchronous oxidation of Al and Zr elements.

Key words: Thermal oxidation, Zr-Al alloys, Amorphous oxides, Oxidation kinetics, Interface thermodynamics