Influence of Ambient–Temperature Corrosion on the Oxidation Behavior of Al-Si Coatings

The high-temperature oxidation behavior of Al-Si coatings on the Ni-base superalloy DZ125, with and without the ambient-temperature corrosion test, was investigated. The results show that the isothermal oxidation behavior of the corroded coating changes, which has the higher mass gain than that of the original coating during the initial oxidation stage. Moreover, the cyclic oxidation resistance of the corroded coating decreases severely. The oxide scale was primarily composed of Al2O3, contaminated with TiO2 that was due to the increase of Ti content after the room-temperature corrosion test.