Effect of Cr and Re on the Oxidation Resistance of Ni3Al-base Single Crystal Alloy IC21 at 1100°C

摘要

The oxidation kinetic curves of three Ni3Al-based single crystal alloys (IC21,IC21C and IC21CR) with different Cr and Re content were examined at 1100°C.The microstructures and element distributions of the oxide scales on these alloys were investigated by scanning electron microscopy (SEM),X-ray diffraction (XRD) and energy dispersive X-ray spectrometry (EDS).Results revealed that the oxidation resistance of these alloys was improved in the order of IC21 < IC21C < IC21CR.The oxide products of IC21 mainly consisted of NiO,α-Al2O3,NiAl2O4 and a small amount of NiMoO4 and MoO2.The volatilization of Mo oxides led to the oxide scale spallation from IC21C,thus deteriorated the oxidation properties.While for IC21C and IC21CR,the oxidation resistance was significantly improved.The Mo oxides in the oxide layer were greatly reduced and a continuous α-Al2O3 layer was formed.