The nanoscale oxidation mechanisms and kinetics of a model β-NiAl system were investigated using in situ closed-cell gas reaction scanning transmission electron microscopy (STEM). Here, we directly visualize the dynamic structural and chemical changes that occur during high-temperature oxidation at a high spatial resolution of 50.3Ni–49.7Al (at.%) nanoparticles under static air conditions at 730 Torr with heating up to 750 °C at 5 °C/s. A MEMS-based gas cell system, with microfabricated heater devices and a gas delivery system, was used to reveal site-specific oxidation initiation sites. Through time-resolved annular dark-field STEM imaging, we tracked the nanoscale oxidation kinetics of Al2O3. After oxidation at 750 °C, nucleation of voids at the Ni/Al2O3 interface was observed along a NiAl grain boundary, followed by the formation of faceted NiO crystals. Small faceted cubic crystals of NiO were formed at the initial stage of oxidation at high PO2 due to the outward self-diffusion of Ni2+ ions, followed by the formation of a mixture of metastable and stable α-Al2O3 at the oxide/metal interface that is attributed to a PO2 decrease with oxidation time, which agreed with thermodynamic modeling calculations. The results from these in situ oxidation experiments in the β-NiAl system are in agreement with the established oxidation mechanisms; however, with in situ closed-cell gas microscopy it is now feasible to investigate nanoscale oxidation mechanisms and kinetics in real time and at high spatial resolution and can be broadly applied to understand the basic high-temperature oxidation mechanisms for a wide range of alloy compositions.
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G. Frommeyer and R. Rablbauer, Steel Research International 79, 2008 (507–513).
P. A. Pint, Oxidation of Metals 49, 1998 (531–559).
J. Doychak, J. L. Smialek and T. E. Mitchell, Metallurgical Transactions A 20, 1989 (499).
M. W. Brumm and H. J. Grabke, Corrosion Science 33, 1992 (167–1690).
B. A. Pint, T. M. Treska and L. W. Hobbs, Oxidation of Metals 47, 1997 (1–20).
B. A. Pint, J. R. Martin and L. W. Hobbs, Oxidation of Metals 39, 1993 (167–195).
E. Schumann, J. C. Yang, M. J. Graham and M. Rühle, Materials and Corrosion 46, 1995 (218–222).
E. Schumann, J. C. Yang, M. J. Graham and M. Rühle, Materials and Corrosion 47, 1996 (631–632).
C.-M. Wang, A. Genc, H. Cheng, L. Pullan, D. R. Baer and S. M. Bruemmer, Scientific Reports 4, 2014 (1–6).
C.-M. Wang, D. K. Schreiber, M. J. Olszta, D. R. Baer and S. M. Bruemmer, Applied Materials & Interfaces 7, 2015 (17272–17277).
Q. Jeangros, T. W. Hansen, J. B. Wagner, R. E. Dunin-Borkowski, C. Hebert, J. Hessler-Wyser, et al., Acta materialia 67, 2014 (362–372).
L. F. Allard, S. H. Overbury, W. C. Bigelow, M. B. Katz, D. P. Nackashi and J. Damiano, Microscopy and Microanalysis 18, 2012 (656–666).
L. F. Allard, W. C. Bigelow, S. Zhang, X. Pan, Z. Wu, S. H. Overbury, et al., Microscopy and Microanalysis 20, 2014 (1572–1573).
L. F. Allard, W. C. Bigelow, Z. Wu, S. H. Overbury, K. A. Unocic, M. Chi, et al., Microscopy and Microanalysis 21, 2015 (97–98).
S. J. Pennycook, Ultramicroscopy 30, 1989 (59–69).
G. C. Wood and B. Chattopadhyay, Corrosion Science 10, 1970 (471–480).
J. Doychak and M. Rühle, Oxidation of Metals 31, 1989 (431–452).
H. J. Grabke, Intermetallics 7, 1999 (1153–1158).
M. W. Brumm, H. J. Grabke and B. Wagemann, Corrosion Science 36, 1994 (37–53).
B. Pint, Oxidation of Metals. 48, 1997 (303–328).
W. J. Quadakkers and M. J. Bennett, Materials Science and Technology 10, 1994 (126–131).
B. Pint and K. L. More, Journal of Materials Science 44, 2009 (1676–1686).
This research was supported by the U.S. Department of Energy, Office of Coal and Power R&D, Office of Fossil Energy (KAU, DS, LFA). Additional support was provided by the Center for Nanophase Materials Sciences, which is a U.S. Department of Energy Office of Science Scientific User Facility (RRU). The authors wish to thank K.L. More and B.A. Pint for providing comments on the manuscript.
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Unocic, K.A., Shin, D., Unocic, R.R. et al. NiAl Oxidation Reaction Processes Studied In Situ Using MEMS-Based Closed-Cell Gas Reaction Transmission Electron Microscopy. Oxid Met 88, 495–508 (2017) doi:10.1007/s11085-016-9676-2
- In situ TEM
- MEMS-based closed-cell gas