On the deformation of the 〈100〉 orientated γ′ strengthening phase of the CMSX2 superalloy

Lours, P.; Coujou, A.; Coulomb, Pierre

doi:10.1016/0956-7151(91)90147-s

Cited by 14 publications

(8 citation statements)

References 10 publications

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“…On the other hand, it is necessary to make assumptions on F and À. Since the effect of the stacking fault energy is of opposite sign for each partial [equations (2) and (3)], the difference in resulting forces necessary to keep them apart and enforce their decorrelated movement is equal then to 2À. Using the value of À measured close to 20 mJ m À2 at room temperature by Benyoucef et al [17], the decorrelation is unlikely.…”

Section: Conditions For the Decorrelated Movement Of Partial Dislocatmentioning

confidence: 97%

“…As all the parameters involved in the aforementioned analytical expressions (1), (2) and (3) are not known, reasonable assumptions have to be made in order to apply them to a specific case. Thus, it is assumed that:…”

Section: Appendix: Quantitative Analysis Of a Specific Casementioning

confidence: 99%

“…A perfect undissociated dislocation (1), a partial belonging to a perfect dissociated dislocation (2) and an isolated partial dislocation (3) are considered as a function of their character, .…”

Section: Conditions For the Decorrelated Movement Of Partial Dislocatmentioning

confidence: 99%

“…With this technique, the only one which allows direct observation of the evolution of the dislocation microstructure under stress and temperature, we have already identified such mechanisms in single-phased 0 -based monocrystals [1][2][3] as well as in single-phased monocrystals simulating the matrix of various industrial single crystal superalloys [4].…”

Section: Introductionmentioning

confidence: 96%

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Decorrelated movements of Shockley partial dislocations in the γ-phase channels of nickel-based superalloys at intermediate temperature

Raujol

Benyoucef²,

Locq

et al. 2006

Philosophical Magazine

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In nickel-based superalloys with high volume fraction of 0 precipitates, dislocations have to experience high curvatures in order to enter narrow channels by glide in the {111} planes of the fcc matrix. Observations of in situ dynamic sequences performed in a transmission electron microscope on several industrial superalloys have shown the occurrence of decorrelated movements of Shockley partial dislocations, originating from perfect dislocation dissociation. By evaluating the effective stress acting on each one of these partial dislocations, as well as their respective flexibility, the possible occurrence of such movements for some particular dislocation characters and channel widths is accounted for. These movements can play an important role in the creep behaviour of these materials in the low deformation rate regime.

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Section: Conditions For the Decorrelated Movement Of Partial Dislocatmentioning

confidence: 97%

Section: Appendix: Quantitative Analysis Of a Specific Casementioning

confidence: 99%

Section: Conditions For the Decorrelated Movement Of Partial Dislocatmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 96%

See 2 more Smart Citations

Decorrelated movements of Shockley partial dislocations in the γ-phase channels of nickel-based superalloys at intermediate temperature

Raujol

Benyoucef²,

Locq

et al. 2006

Philosophical Magazine

Self Cite

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show abstract

“…At lower temperatures, octahedral slip systems are mainly active, and slip occurs on these slip systems in both phases. According to the experimental reports, the flow stress in nickel-based superalloys increases when the temperature is elevated up to 1000 K. In this temperature range, most of the dislocations in the intermetallic γ phase become immobile screw dislocations that are locked in a Kear-Wilsdorf (or KW) configuration due to cross-slip [7]. Therefore, they act as barriers for further dislocation motions and result in increasing the flow stress.…”

Section: Introductionmentioning

confidence: 99%

Morphology Dependent Flow Stress in Nickel-Based Superalloys in the Multi-Scale Crystal Plasticity Framework

et al. 2017

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This paper develops a framework to obtain the flow stress of nickel-based superalloys as a function of γ-γ morphology. The yield strength is a major factor in the design of these alloys. This work provides additional effects of γ morphology in the design scope that has been adopted for the model developed by authors. In general, the two-phase γ-γ morphology in nickel-based superalloys can be divided into three variables including γ shape, γ volume fraction and γ size in the sub-grain microstructure. In order to obtain the flow stress, non-Schmid crystal plasticity constitutive models at two length scales are employed and bridged through a homogenized multi-scale framework. The multi-scale framework includes two sub-grain and homogenized grain scales. For the sub-grain scale, a size-dependent, dislocation-density-based finite element model (FEM) of the representative volume element (RVE) with explicit depiction of the γ-γ morphology is developed as a building block for the homogenization. For the next scale, an activation-energy-based crystal plasticity model is developed for the homogenized single crystal of Ni-based superalloys. The constitutive models address the thermo-mechanical behavior of nickel-based superalloys for a large temperature range and include orientation dependencies and tension-compression asymmetry. This homogenized model is used to obtain the morphology dependence on the flow stress in nickel-based superalloys and can significantly expedite crystal plasticity FE simulations in polycrystalline microstructures, as well as higher scale FE models in order to cast and design superalloys.

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A model for the anomalous mechanical properties of nickel-base L12 ordered alloys—I. Dislocations dynamics

Caillard

Paidar

1996

Acta Materialia

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On the deformation of the 〈100〉 orientated γ′ strengthening phase of the CMSX2 superalloy

Cited by 14 publications

References 10 publications

Decorrelated movements of Shockley partial dislocations in the γ-phase channels of nickel-based superalloys at intermediate temperature

Decorrelated movements of Shockley partial dislocations in the γ-phase channels of nickel-based superalloys at intermediate temperature

Morphology Dependent Flow Stress in Nickel-Based Superalloys in the Multi-Scale Crystal Plasticity Framework

A model for the anomalous mechanical properties of nickel-base L12 ordered alloys—I. Dislocations dynamics

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