Investigation of interfacial reaction mechanism between SiC and Inconel 625 superalloy using thermodynamic calculation

In this paper, the interfacial reaction is investigated by joining SiC ceramic with Inconel 625 superalloy interlayer at different temperatures. CALPHAD method is used based on a Ni-Cr-Si ternary thermodynamic database to analyze the reactions between the Inconel 625 superalloy and the SiC ceramic. It is found that when the liquid alloy reaches a specific composition, the reactions between them stop. An equilibrium is established between the liquid alloy and SiC during the joining process, regardless of the temperature change. Furthermore, thermodynamic predictions of the reaction products are proved right by EBSD and XRD analysis. This work demonstrates that CALPHAD is a suitable method for effectively investigating the complex reaction system and further promoting precise theoretical analysis.