Thermodynamic and Kinetic Modelling of a Bond Coat Alloy: Oxidation Induced Depletion and Its Effect on Microstructure and Material Behavior

Abstract

In this paper oxidation induced micro structural changes of a Co based bond coat alloy are discussed. Micro structure of Co32Ni21Cr(4–12)A13ReY was studied at 1000 °C and modelled using thermo-calc. The effect of varying aluminum content on precipitating phases was quantified and experimental results were compared with modelled microstructure to access modelling capabilities of thermo-calc. Dictra was used to predict microstructural changes due to Al depletion and the influence of alloy‘s microstructure on material‘s properties was also considered. Microstructural changes across oxidized alloy were related to spatially varying alloy‘s hardness. Experimental findings proved thermodynamic modelling and kinetic simulations produced excellent qualitative and quantitative phase information to represent the system under oxidation at high temperature.