Influence of the Impurity Element Sb on Oxidation Resistance and Creep Strength of the Ni-Base Single Crystal Superalloy TMS-238

The influence of impurity element Sb on the oxidation resistance and creep strength single crystal superalloy TMS-238 was studied in this work. It found that 1.1 ppm clearly degrades resistance, but not for strength. As we increased amount up to 3.8 ppm, weight loss sample increased, as expected effect resistance. To understand mechanism, oxide structure characterized by scanning electron microscope with energy dispersive X-ray spectroscopy (SEM-EDS), three-dimensional atom probe (3DAP) used visualize distribution. 3DAP analysis has revealed segregation 0.03 at％ 0.04 at oxide/substrate interfaces sample. These results indicated Sb, a low melting point metallic impurity, interface TMS-238.