Influence of Prolonged Exposure on the Microstructure and Stress-Rupture Property of a Single Crystal Ni-Base Superalloy

Abstract

The single crystal Ni-base superalloy possesses excellent comprehensive mechanical properties, particularly at high temperature, so it is a best candidate for the blade material in the advanced turbine engine. During high temperature long term aging, the stability of the microstructure and mechanical properties of a single crystal Ni-base superalloy is considered to be very important for the safe operation of a turbine engine. Because the single crystal superalloy is free of grain boundary, there have no problem on the weakening effect of grain boundary as well as the microcrack formation on the transverse grain boundary. It is necessary to understand the microstructural evolution and deterioration of the mechanical property of the alloy under complicated service conditions both thermally and mechanistically. For this purpose, the influence of prolonged exposure on the microstructure and stress rupture property of a single crystal Ni-base superalloy at 950°C and 1050°C has been studied in detail.