Oxidation behavior of single crystal TMS-82+ superalloy in air

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.

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 temperattire 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, AITaO4, Cr2O3, θ-,_ α-Al2O3 and （Ni, Co）Al2O4 in the specimen at 900 ℃, but NiCr204 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.