Two-dimensional multi-scale dendrite needle network modeling and x-ray radiography of equiaxed alloy solidification in grain-refined Al-3.5 wt-%Ni

Sturz, Laszlo; Theofilatos, Angelos

doi:10.1016/j.actamat.2016.06.005

Cited by 8 publications

(6 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While this representation of sidebranching frequency could be improved (see e.g. [69]), it has limited influence on final selected microstructures at the scale of whole dendritic arrays, as long as sidebranches are created often enough to be in growth competition with one another [48].…”

Section: New Branch Additionmentioning

confidence: 99%

Multiscale dendritic needle network model of alloy solidification with fluid flow

Tourret

François

Clarke

2019

Computational Materials Science

View full text Add to dashboard Cite

We present a mathematical formulation of a multiscale model for solidification with convective flow in the liquid phase. The model is an extension of the dendritic needle network approach for crystal growth in a binary alloy. We propose a simple numerical implementation based on finite differences and step-wise approximations of parabolic dendritic branches of arbitrary orientation. Results of the two-dimensional model are verified against reference benchmark solutions for steady, unsteady, and buoyant flow, as well as steady-state dendritic growth in the diffusive regime. Simulations of equiaxed growth under forced flow yield dendrite tip velocities within 10% of quantitative phase-field results from the literature. Finally, we perform illustrative simulations of polycrystalline solidification using physical parameters for an aluminum-10wt% copper alloy. Resulting microstructures show notable differences when taking into account natural buoyancy in comparison to a purely diffusive transport regime. The resulting model opens new avenues for computationally and quantitatively investigating the influence of fluid flow and gravity-induced buoyancy upon the selection of dendritic microstructures. Further ongoing developments include an equivalent formulation for directional solidification conditions and the implementation of the model in three dimensions, which is critical for quantitative comparison to experimental measurements.

show abstract

Section: New Branch Additionmentioning

confidence: 99%

Multiscale dendritic needle network model of alloy solidification with fluid flow

Tourret

François

Clarke

2019

Computational Materials Science

View full text Add to dashboard Cite

show abstract

“…Mesoscopic models allow one to simulate much larger domains than microscopic models. Several mesoscopic models exist, such as the dendrite needle network (DNN) model, already applied for equiaxed [8] and columnar dendritic grain growth [9], the cellular-automaton finite-element (CAFE) model [10,11] and the dendrite envelope model. In the envelope model, the complex dendritic structure of a crystal grain is described by means of an envelope, a smooth surface that wraps the tips of the actively growing branches of the dendrite [12,13,14,15,16].…”

Section: Introductionmentioning

confidence: 99%

Quantitative 3D mesoscopic modeling of grain interactions during equiaxed dendritic solidification in a thin sample

2019

View full text Add to dashboard Cite

A 3D mesoscopic envelope model is used to numerically simulate the experimental X-ray observations of isothermal equiaxed dendritic solidification of a thin sample of Al-20 wt%Cu alloy. We show the evolution of the system composed of multiple grains growing under influence of strong solutal interactions. We emphasize the three-dimensional effects in the thin sample thickness on the growth kinetics, focusing on three aspects: (i) the impact of the third dimension on the solute diffusion, (ii) the influence of the orientation of the preferential grain growth directions 100 on the interactions with the confining sample walls, and (iii) the influence of the grain position along the sample thickness. We demonstrate the importance of considering the three-dimensional structure of the thin samples despite the small thickness. We further show that the mesoscopic envelope model can accurately describe the shape and the time-evolution of the equiaxed grains growing under influence of strong solutal interactions.

show abstract

“…The DNN model was shown to quantitatively reproduce primary dendritic spacings measured in directional solidification experiments in different Al-based alloys [27][28][29]. Implementations have been developed that include fluid flow in the liquid [30,31] and the interaction between nucleation and growth [32,33].…”

Section: Dendritic Needle Networkmentioning

confidence: 99%

Comparing mesoscopic models for dendritic growth

Tourret,

Sturz,

Viardin

et al. 2020

Preprint

Self Cite

View full text Add to dashboard Cite

We present a quantitative benchmark of multiscale models for dendritic growth simulations. We focus on approaches based on phase-field, dendritic needle network, and grain envelope dynamics. As a first step, we focus on isothermal growth of an equiaxed grain in a supersaturated liquid in three dimensions. A quantitative phase-field formulation for solidification of a dilute binary alloy is used as the reference benchmark. We study the effect of numerical and modeling parameters in both needle-based and envelope-based approaches, in terms of their capacity to quantitatively reproduce phase-field reference results. In light of this benchmark, we discuss the capabilities and limitations of each approach in quantitatively and efficiently predicting transient and steady states of dendritic growth. We identify parameters that yield a good compromise between accuracy and computational efficiency in both needle-based and envelope-based models. We expect that these results will guide further developments and utilization of these models, and ultimately pave the way to a quantitative bridging of the dendrite tip scale with that of entire experiments and solidification processes.

show abstract

Two-dimensional multi-scale dendrite needle network modeling and x-ray radiography of equiaxed alloy solidification in grain-refined Al-3.5 wt-%Ni

Cited by 8 publications

References 50 publications

Multiscale dendritic needle network model of alloy solidification with fluid flow

Multiscale dendritic needle network model of alloy solidification with fluid flow

Quantitative 3D mesoscopic modeling of grain interactions during equiaxed dendritic solidification in a thin sample

Comparing mesoscopic models for dendritic growth

Contact Info

Product

Resources

About