The oxidation behavior of a Ni_2FeCoCrAl_(0.5) high-entropy superalloy in O_2-containing environments

摘要

The oxidation behavior of a Ni2FeCoCrAl0.5 high-entropy superalloy was studied at 900 degrees C in O-2-containing environments over the oxygen pressure range of 10 . 1.0 x 10(5) Pa. The superalloy oxidized parabolically at PO2 <= 2.1 x 10(4) Pa, having its oxidation rates increasing with increasing oxygen pressure. An exclusive alpha-Al2O3 layer formed on the alloy with its thickness increased with oxygen pressure. On the contrast, a mass-lost kinetics was observed and heterophasic scales of intermixed alpha-Al2O3, Cr2O3, and M-Cr spinels (M = Ni, Fe, or Co) were detected at PO2 = 1.0 x 10(5) Pa.