Physical and numerical characterization of the near-eutectic permeability of aluminum–copper alloys

Khajeh, Ehsan; Maijer, Daan M.

doi:10.1016/j.actamat.2010.07.055

Cited by 42 publications

(47 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The factor 5 is an empirical fitting factor which seems to provide good agreement with experimental data over a wide range of solid fractions g s for the case of an isotropic porous medium composed of unconsolidated material [12,13,28,29]. In order to assess the ability of the new 3-D fluid flow model to predict the bulk permeability a series of isothermal flow simulations were performed at various g s values in the interval [0, 1] with the following boundary conditions: a constant pressure p 0 , i.e.…”

Section: Permeabilitymentioning

confidence: 99%

Three-dimensional granular model of semi-solid metallic alloys undergoing solidification: Fluid flow and localization of feeding

et al. 2012

View full text Add to dashboard Cite

This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. AbstractA three-dimensional (3-D) granular model which simulates fluid flow within solidifying alloys with a globular microstructure, such as that found in grain refined Al alloys, is presented. The model geometry within a representative volume element (RVE) consists of a set of prismatic triangular elements representing the intergranular liquid channels. The pressure field within the liquid channels is calculated using a finite elements (FEs) method assuming a Poiseuille flow within each channel and flow conservation at triple lines. The fluid flow is induced by solidification shrinkage and openings at grain boundaries due to deformation of the coherent solid. The granular model predictions are validated against bulk data calculated with averaging techniques. The results show that a fluid flow simulation of globular semi-solid materials is able to reproduce both a map of the 3-D intergranular pressure and the localization of feeding within the mushy zone. A new hot cracking sensitivity coefficient is then proposed. Based on a mass balance performed over a solidifying isothermal volume element, this coefficient accounts for tensile deformation of the semi-solid domain and for the induced intergranular liquid feeding. The fluid flow model is then used to calculate the pressure drop in the mushy zone during the direct chill casting of aluminum alloy billets. The predicted pressure demonstrates that deep in the mushy zone where the permeability is low the local pressure can be significantly lower than the pressure predicted by averaging techniques.

show abstract

Section: Permeabilitymentioning

confidence: 99%

Three-dimensional granular model of semi-solid metallic alloys undergoing solidification: Fluid flow and localization of feeding

et al. 2012

View full text Add to dashboard Cite

show abstract

“…The numerically calculated permeabilities for N equal to 50 are in close agreement with the permeabilities measured on the physical models (within ±20% of those determined through measurement). The differences between the numerically calculated and experimentally measured permeabilities can be attributed to the measurement uncertainties as discussed in [8]. The comparison of results for N equal to 50 suggests that the numerical modeling techniques employed in this study provide a good representation of the physics of this problem.…”

Section: Resultsmentioning

confidence: 86%

“…A detailed description of the apparatus and testing procedure used in this study can be found in [8]. Fig.…”

Section: Physical Determination Of Permeabilitymentioning

confidence: 99%

Permeability of Dual-Structured Porous Media

Khajeh¹

2011

TOTPJ

Self Cite

View full text Add to dashboard Cite

Abstract:The effective permeability of dual-structured porous media has been determined through physical and numerical modeling. Example porous media consisting of a woven network of cylindrical bars overlaid by a network of spherical particles have been produced by a rapid prototyping technique. A glycerin-based solution, held in a pressurized reservoir, was forced through the porous samples. The resulting flow rate and pressure drop across the sample were measured and used to determine the permeability of each sample. Mathematical models, considering the continuity and momentum equations, were also developed for the geometries corresponding to the physical models. The results were compared with the analytical expressions of permeability reported by Khajeh and Maijer, Liu et al., and Carman-Kozeny

show abstract

“…A number of researchers have calculated the permeability of two-dimensional (2D) dendritic structures obtained from sections of cast alloys [16,17], while some researchers have determined the permeability of three-dimensional (3-D) microstructures [15,[18][19][20][21][22]. Early research on complex 3-D microstructures [18][19][20] employed domains discretized with uniform cubic elements.…”

Section: Introductionmentioning

confidence: 99%

“…James et al [14] passed oil through a large-scale physical model of repeating slotted plates to measure permeability. Khajeh and Maijer [15] developed a physical modeling technique to measure the permeability of dendritic structures by passing a glycerin-based solution through large-scale analogs of interdendritic structures produced by rapid prototyping. The results of these studies [13][14][15] indicate that experiments on physical models are a suitable alternative to permeameter measurements.…”

Section: Introductionmentioning

confidence: 99%