High temperature creep behaviour of single crystal superalloy

Creep behaviour of a newly developed single crystal nickel base superalloy DMSX-1 (Ni-7.7Co-6.4Cr-8.4W-0.3Ti-5.57Al-7.6Ta-Nf-Y-Nb-Re, wt-%) with [001] orientation has been analysed and compared with the reported data of SRR99. It was concluded that the shear stress based model developed for SRR99 is also applicable for the new alloy. Although the material constants for octahedral slip for the new alloy are not exactly the same as those of SRR99, the estimated values of initial creep rate and softening coefficients are nearly of the same order. Therefore it is concluded that in the absence of a material database for cube slip for this new alloy those available for SRR99 could be used to predict the orientation dependence of its creep behaviour. (C) 1998 The Institute of Materials