Effect of minor carbon additions on the high-temperature creep behavior of a single-crystal nickel-based superalloy

摘要

Different amounts of carbon were added to a single-crystal nickel-based superalloy. The microstructural evolution of these alloys before and after high-temperature creep tests was investigated by employing scanning electron microscopy and transmission electron microscopy. Upon increasing the carbon contents, the volume fraction and diameter of the carbides increased gradually: however, the creep lives of the alloys increased slightly at first and subsequently decreased. The formation of second-phase particles, such as the nano-sized M23C6, blocky and needle-shaped la phase, was observed in the creep samples, which was closely related to the high-temperature creep behaviors. (C) 2015 Elsevier Inc. All rights reserved.