A strain-rate and temperature dependent constitutive model for BCC metals incorporating non-Schmid effects: Application to tantalum–tungsten alloys

Knežević, Marko; Beyerlein, Irene J.; Lovato, Manuel L.; Tomé, Carlos N.; Richards, Andrew Walter; McCabe, Rodney J.

doi:10.1016/j.ijplas.2014.07.007

Cited by 163 publications

(51 citation statements)

References 70 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…For the Nb phase, we make use of a modified hardening law that introduces non-Schmid effects into the DD model [77]. While the material parameters we use have been characterized for the particular Nb composition studied here [40], the extra parameters associated with the nonSchmid effects were not altered from those used previously for a Ta-W alloy.…”

Section: Modeling Methodologymentioning

confidence: 99%

Bulk texture evolution of nanolamellar Zr–Nb composites processed via accumulative roll bonding

et al. 2015

View full text Add to dashboard Cite

It was recently demonstrated that bulk two-phase 50/50 Zr-Nb nanolayered composites with 90 nm individual layers can be fabricated from an initial coarse-layered composite with 1 mm layers via the severe plastic deformation process of accumulative roll bonding. During the deformation, the Zr phase retained its hcp crystal structure and the Zr-Nb interface remained sharp. Here we use a combination of neutron diffraction and dislocation-based polycrystal plasticity constitutive modeling to assess the evolution of texture and deformation mechanisms over a four order-ofmagnitude range in layer thickness. The phase textures in the nanocomposite strongly deviate from that of Zr or Nb rolled in monolithic form, becoming highly peaked and intense. The model suggests that texture development in the Nb phase is associated with multiple slip and contributions from both {1 1 2}h1 1 0i slip and {1 1 0}h1 1 0i slip. In the Zr phase the model suggests that the texture develops due to a predominance of prismatic hai and basal hai slip.

show abstract

Section: Modeling Methodologymentioning

confidence: 99%

Bulk texture evolution of nanolamellar Zr–Nb composites processed via accumulative roll bonding

et al. 2015

View full text Add to dashboard Cite

show abstract

“…The barriers for twin activation and propagation within each crystal follow a different model than slip and this twinning model will be reviewed last. In several prior studies, this same basic modeling framework has been successfully applied to a variety of metals of different crystal structures: Zr [45,46], Be [47,48], and Mg [49,50], BCC Ta [51][52][53], an FCC cobalt alloy [54], and orthorhombic uranium [55,56]. However, to meet the objectives of this work, we found it necessary to extend the framework to treat multiple modes of twins per crystal, interactions between slip modes, and lattice reorientation by secondary (internal) twinning.…”

Section: Multi-scale Modeling Approachmentioning

confidence: 99%

Strain rate and temperature effects on the selection of primary and secondary slip and twinning systems in HCP Zr

et al. 2015

Self Cite

View full text Add to dashboard Cite

We investigate the temperature and rate dependence of slip, twinning, and secondary twinning in high-purity hexagonal close packed a-Zr over a wide range of temperatures and strain rates (from 76 K to 673 K and 0.001 s À1 to 4500 s À1 ). To reliably identify the dominant deformation mechanisms for each condition, we employ electron-backscattered diffraction (EBSD), dislocation theory, multi-scale polycrystal constitutive modeling, and a thermally activated dislocation density evolution based hardening law. We demonstrate with direct comparison with measurement that the constitutive model, with a single set of intrinsic material parameters, can predict the underlying texture evolution, primary and secondary slip and twin activity, and twin volume fraction associated with the different loading orientations and applied temperatures and strain rates. We find that the f1 0 1 2gh1 0 1 1i twin is the preferred tension twin, either as a primary or secondary twin depending on the sample orientation, over the broad temperature and strain rate range tested. In contrast, we show that the preferred contraction twin, whether f1 1 2 2gh1 1 2 3i or f1 0 1 1gh1 0 1 2i, is sensitive to temperature but insensitive to strain rate and whether it is a primary or secondary twin. Based on the concomitant changes in the dominant slip mode predicted by the model and revealed by the texture development, we rationalize that the temperature-induced transition in contraction twinning is due to the increased predominance of basal hai slip at high temperatures (>673 K). Last, our analysis implies that all twin modes studied are rate insensitive and so the strong influence of strain rate and temperature on twinning is due to the rate-sensitivity of slip.

show abstract

“…In general, this multi-scale method can be applied to three scales; however, in this work, we will focus on just the sub-grain and homogenized single-crystal scales. Crystal plasticity finite element models [12,13] are applied to gather the information hierarchically at each scale to build constitutive models that can be implemented for microstructure-property relations, as well as microstructure design. Meso-scale analyses of superalloys, incorporating precipitate distributions, as well as the grain structure, have been conducted using phenomenological viscoplastic constitutive laws in [14,15].…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2017

View full text Add to dashboard Cite

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.

show abstract

A strain-rate and temperature dependent constitutive model for BCC metals incorporating non-Schmid effects: Application to tantalum–tungsten alloys

Cited by 163 publications

References 70 publications

Bulk texture evolution of nanolamellar Zr–Nb composites processed via accumulative roll bonding

Bulk texture evolution of nanolamellar Zr–Nb composites processed via accumulative roll bonding

Strain rate and temperature effects on the selection of primary and secondary slip and twinning systems in HCP Zr

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

Contact Info

Product

Resources

About