A thermodynamic model for the stacking-fault energy

Ferreira, Paulo J.; Müllner, Peter

doi:10.1016/s1359-6454(98)00155-4

Cited by 138 publications

(45 citation statements)

References 18 publications

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“…Assuming the Burgers vector of a perfect dislocation, b 0 ϭ a/2 Ͻ110Ͼ ϭ 2.53 ϫ 10 Ϫ10 m, [13] where a is the lattice parameter of the austenite phase, the Burgers vector of a partial dislocation is b P ϭ a/6 Ͻ112Ͼ ϭ 1.46 ϫ 10 Ϫ10 m, [13] and the SFE is ␥ ϭ 0.020 J/m 2 , [14] we can plot the activation energy of nucleation (⌬G) for a perfect and for a partial dislocation loop, as a function of the loop radius. For the calculations, we will use a range of shear stresses from ϭ 1 GPa to ϭ 160 MPa.…”

Section: A Nucleation Of Defectsmentioning

confidence: 99%

Microstructure development during high-velocity deformation

Ferreira

Sande

Fortes

et al. 2004

Metall Mater Trans A

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An austenitic stainless steel was deformed at high (10 3 s Ϫ1 ) strain rates at two levels of strain by electromagnetic forces. Transmission electron microscopy (TEM) studies, X-ray diffraction analysis, and superconducting quantum-interference device (SQUID) measurements show that high strain rates induce the formation of stacking faults and twin structures, enhance the tendency for -martensite formation, and suppress the amount of ␣Ј-martensite. The increased presence of stacking faults and twin structures at high strain rates can be explained by an easy nucleation of partial dislocations at high strain rates and a superior aptitude for partial dislocations to react to high strain rates due to their jump frequency. The suppression of ␣Ј-martensite can be explained by the adiabatic heating produced during electromagnetic forming.

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Section: A Nucleation Of Defectsmentioning

confidence: 99%

Microstructure development during high-velocity deformation

Ferreira

Sande

Fortes

et al. 2004

Metall Mater Trans A

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“…The SFE dependence on Cr and Ni is well documented in the literature, and the experimental measurements are in good agreement with the thermodynamic models. [20,21] For the conventional 304 and 316 austenitic stainless steels, the SFE ranges from 9 to 30 mJ/m 2 and from 34 to 80 mJ/m 2 , respectively. [20] However, no experimental data on the SFE of the investigated steel are available in the literature.…”

mentioning

confidence: 99%

Enhanced Mechanical Properties of a Novel High-Nitrogen Cr-Mn-Ni-Si Austenitic Stainless Steel via TWIP/TRIP Effects

Pozuelo

Wittig

Jiménez³

et al. 2009

Metall Mater Trans A

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Temperature-and strain-rate-dependent mechanical properties of a high-nitrogen austenitic stainless steel containing smaller amounts of nickel than conventional austenitic nickelchromium stainless steels were investigated with special attention to the formation of martensite or mechanical twins during plastic deformation (TWIP/TRIP effect). After recrystallization treatment at 1050°C for 0.5 hour, an equiaxed fully austenitic microstructure possessing annealing twins was observed. Tensile tests were carried out at strain rates ranging from 10 À5 to 10 À2 s À1 in the temperature range from À196°C to 400°C. Deformation-induced austenite-tomartensite transformation occurred at temperatures below 0°C. From room temperature up to 200°C, plastic deformation is controlled by dislocation glide and mechanical twinning. At temperatures above 200°C, no deformation-induced structural changes were observed. The formations of bcc a¢-martensite and hcp e-martensite, or twins during plastic deformation, were analyzed by optical microscopy, transmission electron microscopy (TEM), and X-ray diffraction.

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“…Note that the dependence of APB energy has a quadratic dependence on composition as used previously by Vamsi et al [23]. Such a quadratic dependence of fault energy on composition has been also been used for modeling intrinsic stacking fault energy in a Fe-Cr-Ni solid solution [34]. The strength of the present model lies in the fact that it would potentially allow the determination of APB energy for any arbitrary composition of X, in Ni 3 Al (1−x) X x with the knowledge of only three terms, i.e., the APB energy for the terminal Ni 3 Al and Ni 3 X compounds and for one configuration of Ni 3 Al 0.5 X 0.5 .…”

Section: Nearest Neighbour Bond Modelmentioning

confidence: 90%

Modelling ternary effects on antiphase boundary energy of Ni₃Al

Vamsi

2014

MATEC Web of Conferences

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Abstract. The shearing of ordered γ precipitates by matrix dislocations results in the formation of antiphase boundaries (APB) in Ni-base superalloys. The APB energy is an important source of order-strengthening in disk and blade alloys where Ti and Ta substitute for Al in γ . While the importance of APB energy is wellacknowledged, the effect of alloying on APB energy is not fully understood. In the present study, the effect of Ti and Ta additions on the {111} and {010} APB energies was probed via electronic structure calculations. Results suggest that at low levels of Ti/Ta, APB energies on either plane increases with alloying. However, at higher Ti/Ta levels, the APB energies decrease with alloying. These trends understood by accounting for nearest neighbour violations about the APB and additionally, invoking the effect of precipitate composition on the energy penalty of the violations. We propose an Environment Dependent Nearest Neighbour Bond (EDNNB) model that predicts APB energies that are in close agreement to calculated values.

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A thermodynamic model for the stacking-fault energy

Cited by 138 publications

References 18 publications

Microstructure development during high-velocity deformation

Microstructure development during high-velocity deformation

Enhanced Mechanical Properties of a Novel High-Nitrogen Cr-Mn-Ni-Si Austenitic Stainless Steel via TWIP/TRIP Effects

Modelling ternary effects on antiphase boundary energy of Ni₃Al

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A thermodynamic model for the stacking-fault energy

Cited by 138 publications

References 18 publications

Microstructure development during high-velocity deformation

Microstructure development during high-velocity deformation

Enhanced Mechanical Properties of a Novel High-Nitrogen Cr-Mn-Ni-Si Austenitic Stainless Steel via TWIP/TRIP Effects

Modelling ternary effects on antiphase boundary energy of Ni3Al

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Modelling ternary effects on antiphase boundary energy of Ni₃Al