Effect of carbon on wettability and interface reaction between melt superalloy and ceramic material

Abstract

Effect of C on wettability and interface reaction between a nickel based superalloy and ceramic material was investigated by using a sessile drop method. It was found that the content of C in the alloy is able to influence the wettability and interface reaction. Alloys with C content lower than 0.1wt.% are stable on ceramic material and no interface reaction generates at the alloy-ceramic interface. However, when C content is higher than 0.1wt.%, the interface reaction occurs and the wetting angle decreases quickly. The product of interface reaction is discontinuous and composed of 9Al2O 3.Cr2O3. Such result indicates that Cr in the alloy is impossible to react with the ceramic material and form Cr 2O3without the assistance of C. It is suggested that C in the alloy deoxidizes SiO2in the ceramic material and produces SiO and CO. SiO is unstable and it can release active O atom at the interface. Cr at the interface combines with free O atom and forms Cr2O3. Al2O3in the ceramic material and Cr2O 3finally forms 9Al2O3.Cr2O 3. © 2014 Owned by the authors, published by EDP Sciences.