Oxidation behavior of single crystal TMS-82+ superalloy in air
(1. Central Iron and Steel Research Institute, Beijing 100081, China;
2. Advanced Technology and Materials Co Ltd, Beijing 100081, China;
3. Research Group of Interface Control Engineering, Graduate School of Engineering,
Hokkaido University, Kita-13, Nishi-8, Kita-ku, Sapporo 060-8628, Japan;
4. Fundamentals of Advanced Materials, Delft University of Technology,
Kluyverweg 1, 2629 HS Delft, Netherlands)
2. Advanced Technology and Materials Co Ltd, Beijing 100081, China;
3. Research Group of Interface Control Engineering, Graduate School of Engineering,
Hokkaido University, Kita-13, Nishi-8, Kita-ku, Sapporo 060-8628, Japan;
4. Fundamentals of Advanced Materials, Delft University of Technology,
Kluyverweg 1, 2629 HS Delft, Netherlands)
Abstract: The oxidation behavior of the single crystal Ni-based superalloy TMS-82+ was studied under cyclic condition at 900 and 1 000 ℃ for 200 h in air. The oxidation kinetics for the superalloy at both exposure temperatures was explained by the subparabolic relationship. The results show that increasing the exposure temperature from 900 to 1 000 ℃, the amounts of α-Al2O3, (Ni, Co)Al2O4 and NiCr2O4 increase, resulting in a higher mass gain. The oxides consist of (Ni, Co)O, CrTaO4, AlTaO4, Cr2O3, θ-, α-Al2O3 and (Ni, Co)Al2O4 in the specimen at 900 ℃, but NiCr2O4 spinel forms for the specimen exposed at 1 000 ℃ except the above mentioned oxides. A continuous α-Al2O3 layer is responsible for a slow growth rate of the scale after an initial rapid oxidation of NiO.
Key words: single crystal Ni-based superalloy; oxidation behavior; microstructure; scale