Influence of misfit stresses on dislocation glide in single crystal superalloys: A three-dimensional discrete dislocation dynamics study

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

doi:10.1016/j.jmps.2014.11.015

Cited by 78 publications

(50 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Prior to the fitting process, some material constants, such as APB energy, drag coefficient and initial dislocation density, were adapted from the literature (Gao et al 2015). During the simulation, the resulting stress values were compared with the experimental data until a reasonable match was obtained.…”

Section: Parameter Calibrationmentioning

confidence: 99%

Modelling plastic deformation in a single-crystal nickel-based superalloy using discrete dislocation dynamics

Lin

Huang

Farukh

et al. 2016

Mech Adv Mater Mod Process

View full text Add to dashboard Cite

Background: Nickel-based superalloys are usually exposed to high static or cyclic loads in non-ambient environment, so a reliable prediction of their mechanical properties, especially plastic deformation, at elevated temperature is essential for improved damage-tolerance assessment of components. Methods: In this paper, plastic deformation in a single-crystal nickel-based superalloy CMSX4 at elevated temperature was modelled using discrete dislocation dynamics (DDD). The DDD approach was implemented using a representative volume element with explicitly-introduced precipitate and periodic boundary condition. The DDD model was calibrated using stress-strain response predicted by a crystal plasticity model, validated against tensile and cyclic tests at 850°C for <001 > and <111 > crystallographic orientations, at a strain rate of 1/s. Results: The DDD model was capable to capture the global stress-strain response of the material under both monotonic and cyclic loading conditions. Considerably higher dislocation density was obtained for the <111 > orientation, indicating more plastic deformation and much lower flow stress in the material, when compared to that for <001 > orientation. Dislocation lines looped around the precipitate, and most dislocations were deposited on the surface of precipitate, forming a network of dislocation lines. Simple unloading resulted in a reduction of dislocation density. Conclusions: Plastic deformation in metallic materials is closely related to dynamics of dislocations, and the DDD approach can provide a more fundamental understanding of crystal plasticity and the evolution of heterogeneous dislocation networks, which is useful when considering such issues as the onset of damage in the material during plastic deformation.

show abstract

Section: Parameter Calibrationmentioning

confidence: 99%

Modelling plastic deformation in a single-crystal nickel-based superalloy using discrete dislocation dynamics

Lin

Huang

Farukh

et al. 2016

Mech Adv Mater Mod Process

View full text Add to dashboard Cite

show abstract

“…To prevent such issues, the initial lengths of all dislocation sources were set to be 0.0875 μm (>channel width of 0.0475 μm). The initial dislocation density of nickel-based superalloy adopted in previous 3D DDD simulations [7,8,25,26] ranged from 1.4 × 10 12 to 6.7 × 10 13 m −2…”

Section: Rve Modelmentioning

confidence: 99%

“…Prior to the fitting process, some fundamental material parameters such as Poisson's ratio and modulus were directly obtained from experimental measurements. Initial values of other dislocation-dynamics related parameters were estimated based on the literature [7,26]. Following each simulation, the stress-strain responses were obtained and compared with those measured experimentally to assess the difference.…”

Section: Rve Size and Model Parameter Identificationmentioning

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

View full text Add to dashboard Cite

“…Nevertheless, all these simulations were still far away of providing parameter-free, quantitative estimations of precipitate-strengthening in metallic alloys because they did not considered very important factors such as the actual shape and crystallographic orientation of the precipitates and of the coherency or transformation stresses around the precipitates. More recent simulations [20,21,22] have demonstrated the large contribution of these factors to the CRSS but direct comparison with experimental data including all the relevant physical processes that determine the dislocation/precipitate interactions are not available.…”

Section: Introductionmentioning

confidence: 99%

Multiscale modelling of precipitation hardening in Al–Cu alloys: Dislocation dynamics simulations and experimental validation

et al. 2020

View full text Add to dashboard Cite

The mechanisms of dislocation/precipitate interactions were analyzed in an Al-Cu alloy containing a homogeneous dispersion of θ precipitates by means of discrete dislocation dynamics simulations. The simulations were carried out within the framework of the discrete-continuous method and the precipitates were assumed to be impenetrable by dislocations. The main parameters that determine the dislocation/precipitate interactions (elastic mismatch, stress-free transformation strains, dislocation mobility and cross-slip rate) were obtained from atomistic simulations, while the size, shape, spatial distribution and volume fraction of the precipitates were obtained from transmission electron microscopy. The predictions of the critical resolved shear stress (including the contribution of solid solution) were in agreement with the experimental results obtained by means of compression tests in micropillars of the Al-Cu alloy oriented for single slip. The simulations revealed that the most important contribution to the precipitation hardening of the alloy was provided by the stress-free transformation strains followed by the solution hardening and the Orowan mechanism due to the bow-out of the dislocations around the precipitates.

show abstract

Influence of misfit stresses on dislocation glide in single crystal superalloys: A three-dimensional discrete dislocation dynamics study

Cited by 78 publications

References 46 publications

Modelling plastic deformation in a single-crystal nickel-based superalloy using discrete dislocation dynamics

Modelling plastic deformation in a single-crystal nickel-based superalloy using discrete dislocation dynamics

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

Multiscale modelling of precipitation hardening in Al–Cu alloys: Dislocation dynamics simulations and experimental validation

Contact Info

Product

Resources

About