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

Institute of Metal Research, Chinese Academy of Sciences, Shenyang, China

^a Corresponding author: yzzhou@imr.ac.cn

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 9Al₂O₃ ⋅Cr₂O₃. Such result indicates that Cr in the alloy is impossible to react with the ceramic material and form Cr₂O₃ without the assistance of C. It is suggested that C in the alloy deoxidizes SiO₂ in 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. Al₂O₃ in the ceramic material and Cr₂O₃ finally forms 9Al₂O₃ ⋅Cr₂O₃.