Influence of cycling frequency on cyclic creep characteristics of nickel base single-crystal superalloy

The static and the cyclic creep load-controlled tests of the nickel base single-crystal superalloy, CMSX 3 have been studied. In this study, two different testing procedures of cyclic creep were carried out under specific loading schedules defined by the stress amplitude, the stress range, stress ratio, and cycling frequency. The different cycling frequencies for two cycling hold periods were investigated to influence the creep/fatigue behaviour of the alloy. The influence of these variables was evaluated through the deformation behaviour and the fracture life data. It is concluded that the additional fatigue stress component superimposed onto creep stress component is of great significance influencing the deformation process and fracture life and accelerating the creep strain rate for chosen types of testing. (C) 1997 Elsevier Science S.A.