Creep resistance of single crystal superalloys CMSX-4 and CM186LC

Abstract

The high resistance of single crystals of nickel-base superalloys to plastic deformation and their superior strength properties at high temperatures are mainly due to the reinforcing γ′ precipitates. The paper deals with the properties and structures of two superalloys differing in the γ/γ′ morphology. The creep resistance of the 〈001〉, 〈011〉 and (111) oriented single crystals of superalloys CMSX-4 and CM186LC was compared on the basis of creep rupture curves, creep deformation curves and accompanying development of microstructures in the temperature interval 750 to 950 °C. Further, the effect of notches on creep behaviour and the origin of creep cracks were examined.