Effects of Ta on the high temperature oxidation behavior of IN617 alloy in air

Abstract

Effects of Ta on the oxidation behavior of IN617 alloy were investigated by isothermal oxidation tests in air at 900 °C and 1000 °C. The oxidation resistance was improved with Ta content increasing. The Ta addition induced the formation of TaO2 at both temperatures. Ta was found to impede the out-diffusion of Ti resulting in the formation of TiO2 at the interface between outer Cr2O3 layer and metal substrate. TiO2 and TaO2 filled the voids inside Cr2O3 layer, which was the reason for the improved density of Cr2O3 scale in Ta-added alloys. Moreover, Ta inhibited the coarsening of inner Al2O3 oxides.