The isothermal oxidation behavior of a new developed Ni base superalloy named DM02
for high temperature dies was studied in this paper. The dynamic curve was achieved by monitoring
weight gain of the alloy as a function of time. The results showed that the alloy had fairly good
oxidation resistance at 1050°C and 1100°C. The oxidation kinetics at both 1050°C and 1100°C
followed parabolic rules in segment. It has been found that the oxidation of the alloy was controlled
by multi-oxides of (Ni, Co)O, (Ni, Co)Al2O4, and NiWO4, growth mechanism in the primary stage,
and by Al2O3, NiAl2O4 growth mechanism in the following stage. After oxidation at 1050°C for 100h,
the oxide scale of the alloy was mainly composed of two areas. Some were thin uniform (Ni，
Co)Al2O4(outer)/Al2O3 (inner) composites scale and others were multi-layer oxide scale of ( Ni,Co)O
/ multi-oxides (mainly NiWO4、NiO and NiAl2O4.) /Al2O3.
