Abstract
The creep tests of three different orientations of the single crystal superalloy DD6 were carried out at 980℃. The results indicate that the creep failure mechanism of superalloy is the initiation of micropores and the propagation of microcracks, which is caused by dislocation motion. The dislocation morphology of monocrystals in [001], [111] and [011] orientation at the initial stage of creep was analyzed by transmission electron microscopy (TEM), matching the characteristics of the octahedral sliding system activated, the hexahedral sliding system activated and the simultaneous motion of the two sliding systems, respectively. Based on the crystal plasticity theory, the creep constitutive model and creep damage model under variational stress conditions considering Orowan effect and dislocation blocking effect were established; meanwhile, the model parameters were fitted according to the creep curve obtained from the test. Moreover, the finite element simulation results of the model and creep fracture morphology of monocrystalline materials confirm each other and explain the anisotropic behavior of monocrystalline creep.
| Translated title of the contribution | Anisotropic Creep Life Prediction of Nickel-based Single Crystal Based on Dislocation Movement |
|---|---|
| Original language | Chinese (Traditional) |
| Pages (from-to) | 3930-3938 |
| Number of pages | 9 |
| Journal | Xiyou Jinshu Cailiao Yu Gongcheng/Rare Metal Materials and Engineering |
| Volume | 48 |
| Issue number | 12 |
| State | Published - 1 Dec 2019 |