Cailiao gongcheng (Oct 2018)

Stacking Fault Energies of Single Crystal Nickel-based Superalloy and Its Influence on Creep Mechanism

  • YAN Hua-jin,
  • TIAN Su-gui,
  • ZHU Xin-jie,
  • YU Hui-chen,
  • SHU De-long,
  • ZHANG Bao-shuai

DOI
https://doi.org/10.11868/j.issn.1001-4381.2016.000711
Journal volume & issue
Vol. 46, no. 10
pp. 87 – 95

Abstract

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By means of calculating stacking fault energy(SFE), measuring creep properties and contrast analysis of dislocation configuration, the influence of the temperature on the stacking fault energy and the creep mechanism of a single crystal nickel-based superalloy was investigated. Results show that there is a lower stacking fault energy(SFE) of the alloy at 760℃, and the deformed mechanism of the alloy during creep is the cubical γ' phase sheared by 〈110〉 super-dislocation which may be decomposed to form the configuration of (1/3)〈112〉 super-Shockley partials dislocation plus the super-lattice intrinsic stacking fault(SISF). But the stacking fault energy of the alloy increases with temperature, so the deformed mechanism of the alloy during creep at 1070℃ is the screw or edge super-dislocation shearing into the rafted γ' phase. The SFE of the alloy at 980℃ is in the middle value of the SFEs between 760℃ and 1070℃, the main deformed mechanism of the alloy during creep is the screw or edge super-dislocation shearing into the rafted γ' phase. And some super-dislocation shearing into γ' phase may cross-slip from {111} to {100} planes to form the K-W locks configuration of (1/2)〈110〉 partials plus the anti-phase boundary(APB). The K-W locks with non plane core structure may restrain the slipping and cross-slipping of dislocations to improve the creep resistance of alloy. Wherein, the lower strain rate during creep releases too less deformed heat to activate the dislocation in the K-W locks for re-slipping on {111} plane, which is thought to be the main reason of the K-W locks kept in the alloy during creep at 980℃.

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