Oxidation Behavior of the Y56Al24Co20 Bulk Amorphous Alloy Containing Crystalline Composites at 325-450°C
The oxidation behavior of Y56Al24Co20 bulk metallic glass containing ~4.2% Y-rich particles was studied over the temperature range of 325-450oC in dry air. The results showed that the oxidation kinetics of the alloy followed the parabolic rate law at T≤375oC, with rate constants generally increased with temperature. Conversely, para-linear kinetics were observed at higher temperatures (T≥400oC). The scales formed on the Y-base amorphous composite were temperature dependent, consisting of exclusively yttrium oxides (Y2O3) at T≤375oC and of mostly Y2O3 and alumina (Al2O3) at temperatures. No evidence of any cobalt-containing oxide was found in the scale.
T. Chandra, K. Tsuzaki, M. Militzer , C. Ravindran
H.H. Hsieh et al., "Oxidation Behavior of the Y56Al24Co20 Bulk Amorphous Alloy Containing Crystalline Composites at 325-450°C", Materials Science Forum, Vols. 539-543, pp. 2117-2122, 2007