Microstructure and Creep Features of FGH95 Powder Nickel-base Superalloy

By means of the measurement of creep curves and microstructure observation,an investigation has been made into the creep behaviors and deformation features of FGH95 powder nickel-base superalloy.Results show that,in the range of the experimental temperatures and stresses,FGH95 powder nickel-base superalloy displays an obvious sensibility of the applied temperatures and stresses.Microstructure of the alloy is made up of the various sizes γ′ phase and carbide particles,and the wider grain interfaces situated in between the powder particles.During creep,the single orientation and double orientations slipping are activated within the grains of the superalloy,and the finer carbide particles are precipitated near the regions of the slipping trace lines.The original grain interfaces with the wider size are made into the finer grains due to the effect of the bigger deformation.The deformation mechanism of the superalloy during creep is that the double orientation slipping of dislocation are activated in the alloy,including that(1/2)〈110〉 dislocation and 〈110〉 super-dislocation are activated,respectively,within the γ matrix phase and the γ′ phase.In the further,it is the reason of the stacking fault contrast appeared in the alloy that the 〈110〉 super-dislocation is decomposed into(1/3)〈112〉 super-shockleys dislocation,which results in the formation of the stacking fault.