3D discrete dislocation dynamics study of creep behavior in Ni-base single crystal superalloys by a combined dislocation climb and vacancy diffusion model

Gao, Siwen; Fivel, M.; Ma, Anxin; Hartmaier, Alexander

doi:10.1016/j.jmps.2017.02.010

Cited by 54 publications

(39 citation statements)

References 51 publications

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“…When stress is loaded, the dislocation in γ phase will increase and gather in the interface of γ and γ′ phases, which leads to the increase of vacancy 26,27 . The vacancies and channels formed by dislocation will enhance the diffusion of Al atoms, as illustrated by Fig.…”

Section: Discussionmentioning

confidence: 99%

Initial oxidation behavior of a single crystal superalloy during stress at 1150 °C

Jiang

Wang

et al. 2020

Sci Rep

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Revealing the initial oxidation behavior of single crystal superalloys is significant for a better understanding of the oxidation mechanism of turbine blades during service condition. the purpose of current research was to observe the initial oxidation of a single crystal superalloy. In-situ oxidation experiment during only thermal exposure and thermal-stress pattern were carried out. the mechanism of nucleation and growth of oxide scale was discussed. Results showed that the oxide on the interface of γ/γ′ phase was constituted of Al 2 o 3 precipitates and formed by external diffusion of Al atoms or ions. Loading stress enhanced the diffusion of Al atom causing high oxidation rate. A logarithmic model was proposed and fitted well with the oxidation process.

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Section: Discussionmentioning

confidence: 99%

Initial oxidation behavior of a single crystal superalloy during stress at 1150 °C

Jiang

Wang

et al. 2020

Sci Rep

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“…The recent 3D DDD simulation results on nickel-based superalloys by Gao et al [46] demonstrated that dislocation climb was capable to promote dislocation glide and multiplication, and rearrange the dislocation configuration to relax the hardening due to dislocations filling in the γ channel. 2D DDD simulations by Huang et al [47] also showed that dislocation climb decreased significantly the flow stress and hardening rate while increased the dislocation density by relieving the dislocation pile-ups against the grain boundaries (GBs).…”

Section: Limitations Of Current Workmentioning

confidence: 99%

3D DDD modelling of dislocation–precipitate interaction in a nickel-based single crystal superalloy under cyclic deformation

Lin

Huang

Zhao

et al. 2018

Philosophical Magazine

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“…The DDD model, as an outstanding tool to simulate the dislocation motion, has been used to investigate the deformation behavior in superalloys widely. The dislocation glide in γ channels, the shearing of γ precipitates, the effect of dislocation climb, and the interaction of interfacial dislocations are well discussed by using different DDD methods [33][34][35][36][37][38][39]. However, the DDD study on the influence of substitutional atoms in superalloys is rare thus far.…”

Section: Introductionmentioning

confidence: 99%

“…For the large substitutional atoms which form neither the cluster nor the cloud, we introduced the individual solute atoms in specific positions of our DDD simulation cell. In this work, the DDD model captures all the important deformation mechanisms of superalloys, including the dislocation glide and dislocation climb associated with the vacancy diffusion in the γ/γ microstructure [39]. We performed simulations at a temperature of 850 • C, at which the morphology change of γ precipitates is absent.…”

Section: Introductionmentioning

confidence: 99%

Influence of Excess Volumes Induced by Re and W on Dislocation Motion and Creep in Ni-Base Single Crystal Superalloys: A 3D Discrete Dislocation Dynamics Study

Gao

Yang

Grabowski

et al. 2019

Metals

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A comprehensive 3D discrete dislocation dynamics model for Ni-base single crystal superalloys was used to investigate the influence of excess volumes induced by solute atoms Re and W on dislocation motion and creep under different tensile loads at 850 ° C. The solute atoms were distributed homogeneously only in γ matrix channels. Their excess volumes due to the size difference from the host Ni were calculated by density functional theory. The excess volume affected dislocation glide more strongly than dislocation climb. The relative positions of dislocations and solute atoms determined the magnitude of back stresses on the dislocation motion. Without diffusion of solute atoms, it was found that W with a larger excess volume had a stronger strengthening effect than Re. With increasing concentration of solute atoms, the creep resistance increased. However, a low external stress reduced the influence of different excess volumes and different concentrations on creep.

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3D discrete dislocation dynamics study of creep behavior in Ni-base single crystal superalloys by a combined dislocation climb and vacancy diffusion model

Cited by 54 publications

References 51 publications

Initial oxidation behavior of a single crystal superalloy during stress at 1150 °C

Initial oxidation behavior of a single crystal superalloy during stress at 1150 °C

3D DDD modelling of dislocation–precipitate interaction in a nickel-based single crystal superalloy under cyclic deformation

Influence of Excess Volumes Induced by Re and W on Dislocation Motion and Creep in Ni-Base Single Crystal Superalloys: A 3D Discrete Dislocation Dynamics Study

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