High-temperature oxidation of NiCr alloys with small amounts of rare earth elements (Y, Lu)

Abstract

High-temperature oxidation behavior of Ni-20Cr alloys with small amounts of rare earth elements (Y, Lu) was studied in oxygen for 18ks at 1473K, by mass gain measurements, observation of surface appearance,
X-ray diffraction (XRD) and scanning electron microscopy (SEM). The mass gains of the Ni-20Cr alloys with rare earth elements decreased with increasing Y and Lu up to 0.5%. The outermost continuous scale on Ni-20Cr alloy consists of NiO which is a planar morphology. On the other hand, the scale on Ni-20Cr-0.5Y (Lu) alloys consists of Cr₂O₃ which is a fine granular morphology.