EFFECT OF RE ADDITION ON THE OXIDATION BEHAVIOR OF NICRALY COATINGS

摘要

NiCrAlY coatings with and without Re addition were prepared by arc ion plating (AIP). The isothermal oxidation behavior of coatings was investigated at 900, 1000 and 1100°C. XRD was used to identify oxide phases formed on coatings. SEM, EDX, EPMA were used to examine the microstructural changes of coatings due to oxidation. It was found that Re addition enhanced precipitation of α phases and resulted in a high mass gain during early oxidation stage at all temperatures. After long-term exposure at 1000 and 1100°C, NiCrAlY coating with Re addition showed a lower oxidation rate than that without Re. Therefore, Re addition clearly improved the stability of NiCrAlY coatings during oxidation.