TEM Study of Scale Microstructures Formed on Ni–10Cr and Ni–10Cr–5Al Alloys with and Without Y Addition

摘要: A study was conducted to investigate the effect of Y addition on isothermal-oxidation behaviors 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. oxides formed characterized using primarily cross-sectional transmission-electron microscopy techniques along with light microscopy, scanning-electron X-ray diffraction. Although Al-containing showed comparatively better oxidation behavior, all exhibited “nonprotective” scaling, as suggested by thick formed. major component outer oxide NiO. However, modified Y-containing protective layers (i.e., α-Cr2O3 NiCrY α-Al2O3 NiCrAlY) scale–alloy interface following nonprotective scaling. spalling resistance than their counterpart unmodified Y-free alloys, while overall mechanism remained unchanged after addition.