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Oxidation of a Dispersion-Strengthened Powder Metallurgical FeCrAl Alloy in the Presence of O2 at 1,100 °C: The Influence of Water Vapour

“…The predominantly inward alumina growth of the investigated alloys is in agreement with other studies of RE-containing FeCrAl alloys [12,23,[28][29][30]. The different relation between the inward-and outward-grown scale for the two alloys (Fig.…”

“…The oxidation of FeCrAl alloys [900°C has been reported to produce a protective two-layered a-Al 2 O 3 scale, the top layer being outward grown and the bottom layer being inward grown by oxygen ion diffusion [6][7][8][9][10][11][12]. In addition, the interface between the two layers has been reported to correspond to the original metal surface.…”

Comment on “Oxidation of alloys containing aluminum and diffusion in Al2O3” [J. Appl. Phys. 95, 3217 (2004)]

“…However, undoped scales have been found to grow by a combination of Al and O boundary transport. [13][14][15][16][17][18] For comparison, a value was also calculated using the extrapolated lattice diffusion value. 21 As has been found for other oxides, 20 the calculated value was much lower than the measured values; as lattice transport is too slow to account for oxidation.…”

“…In undoped ␣-Al 2 O 3 , growth occurs by the combined grain-boundary transport of Al and O ions. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] With a RE addition to the substrate ͑e.g., Y, Zr, and Hf͒, whose ions segregate to the scale grain boundaries, the transport of Al is retarded and growth occurs predominantly by the grain boundary diffusion of O ions. 31 The newly proposed mechanism is not consistent with experimental evidence and, therefore, cannot be correct.…”

Grain Boundary Chemistry and Transport Through Alumina Scales on NiAl Alloys

“…For the past 25 years, it has been generally recognized that transport through a growing a-Al 2 O 3 scale takes place predominantly by the inward diffusion of O along grain boundaries when a reactive element (RE) is present [1][2][3][4][5][6][7][8][9][10][11]. Without a RE addition, a mixed Al and O growth was observed for a-Al 2 O 3 .…”