Creep damage of a high Mo single crystal nickel-based superalloy

By means of creep properties measurement and microstructure observation, the creep and damage behaviours of the Mo-containing single crystal Ni-based superalloys at high temperature are investigated. Results show that the 6wt%Mo single crystal Ni-based superalloy displays a better creep resistance at high temperature, wherein, the deformation feature of alloy in the later stage of creep is dislocations shearing into gamma ' phase. As the creep goes on, the alternating slipping of dislocations results in the twisted of the rafted gamma '/gamma phases to promote the initiation and propagation of cracks, along the rafted gamma/gamma ' interfaces perpendicular to the stress axis, up to creep fracture. This is thought to be the damage features of the alloy during creep.