Abstract
A study was conducted to investigate the effect of Y addition on the isothermal-oxidation behaviors of Ni–10Cr, Ni–10Cr–0.5Y, Ni–10Cr–5Al, and Ni–10Cr–5Al–0.5Y alloys. The alloys were oxidized in air for 50 hr at 1000°C. The oxides formed on the alloys were characterized using primarily cross-sectional transmission-electron microscopy techniques along with light microscopy, scanning-electron microscopy, and X-ray diffraction. Although the Al-containing alloys showed comparatively better oxidation behavior, all alloys exhibited “nonprotective” scaling, as suggested by the thick oxides formed. The major component of the outer oxide was NiO. However, modified Y-containing alloys formed protective layers (i.e., α-Cr2O3 for NiCrY and α-Al2O3 for NiCrAlY) at the scale–alloy interface following the nonprotective scaling. The spalling resistance of the modified Y-containing alloys was better than their counterpart unmodified Y-free alloys, while their overall oxidation mechanism remained unchanged after Y addition.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call