Figure 6
From: Core-multishell globular oxidation in a new TiAlNbCr alloy at high temperatures
Formation and growth process of a distinctive core-multishell globular oxide in the TiAlNbCr alloy during high-temperature oxidation. Stage 1, inward diffusion of oxygen and nitrogen; Stage 2, aluminum reacted with the penetrated oxygen preferentially near the interface between Y2O3 particle and substrate to form a flower-like inner oxide; Stage 3, formation of a partial TiO2-rich shell mingled with a small amout of Al2O3; Stage 4, formation of a full TiO2-rich shell mingled with Al2O3, along with an inner aluminum-rich shell; Stage 5, formation of an Al2O3 shell; and Stage 6, formation of the innermost TiO2 shell.
