Sensitivity analysis of dendritic growth kinetics in a Bridgman furnace front tracking model

R. P. Mooney, S. McFadden

Research output: Contribution to journalConference article

Abstract

A directional solidification experiment of a Ti-Al-Nb-B-C alloy by power down method is simulated using a Bridgman furnace front tracking model. The effect of varying the dendritic growth parameters; C, the columnar dendrite growth coefficient, and n, the undercooling exponent, is investigated. A matrix of growth coefficients and undercooling exponents - at three levels each, based around a growth law for Ti-46wt.%Al - is applied in simulations, and the effect on columnar dendrite tip temperature, tip velocity, and tip temperature gradient is observed. The simulation results show that the dendrite tip velocity and temperature gradient at the tip are practically unaffected by the use of different growth parameters. However, the predicted columnar dendrite tip undercooling did vary to give the required dendrite tip velocity. This finding has implications for the analysis of microstructural transitions, such as the Columnar to Equiaxed Transition (CET). In conclusion, it is suggested that, for transient solidification conditions, a CET prediction criterion based on tip undercooling is preferable to one that uses growth velocity.

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Growth kinetics
Sensitivity analysis
Undercooling
Furnaces
Thermal gradients
Solidification
Experiments

Cite this

@article{8b9767ea2e1b4bcf8593a860d9ac8a73,
title = "Sensitivity analysis of dendritic growth kinetics in a Bridgman furnace front tracking model",
abstract = "A directional solidification experiment of a Ti-Al-Nb-B-C alloy by power down method is simulated using a Bridgman furnace front tracking model. The effect of varying the dendritic growth parameters; C, the columnar dendrite growth coefficient, and n, the undercooling exponent, is investigated. A matrix of growth coefficients and undercooling exponents - at three levels each, based around a growth law for Ti-46wt.{\%}Al - is applied in simulations, and the effect on columnar dendrite tip temperature, tip velocity, and tip temperature gradient is observed. The simulation results show that the dendrite tip velocity and temperature gradient at the tip are practically unaffected by the use of different growth parameters. However, the predicted columnar dendrite tip undercooling did vary to give the required dendrite tip velocity. This finding has implications for the analysis of microstructural transitions, such as the Columnar to Equiaxed Transition (CET). In conclusion, it is suggested that, for transient solidification conditions, a CET prediction criterion based on tip undercooling is preferable to one that uses growth velocity.",
author = "Mooney, {R. P.} and S. McFadden",
year = "2016",
month = "3",
day = "31",
doi = "10.1088/1757-899X/117/1/012012",
language = "English",
volume = "117",
journal = "IOP Conference Series : Materials Science and Engineering",
issn = "1757-8981",
number = "1",

}

Sensitivity analysis of dendritic growth kinetics in a Bridgman furnace front tracking model. / Mooney, R. P.; McFadden, S.

In: IOP Conference Series: Materials Science and Engineering, Vol. 117, No. 1, 012012, 31.03.2016.

Research output: Contribution to journalConference article

TY - JOUR

T1 - Sensitivity analysis of dendritic growth kinetics in a Bridgman furnace front tracking model

AU - Mooney, R. P.

AU - McFadden, S.

PY - 2016/3/31

Y1 - 2016/3/31

N2 - A directional solidification experiment of a Ti-Al-Nb-B-C alloy by power down method is simulated using a Bridgman furnace front tracking model. The effect of varying the dendritic growth parameters; C, the columnar dendrite growth coefficient, and n, the undercooling exponent, is investigated. A matrix of growth coefficients and undercooling exponents - at three levels each, based around a growth law for Ti-46wt.%Al - is applied in simulations, and the effect on columnar dendrite tip temperature, tip velocity, and tip temperature gradient is observed. The simulation results show that the dendrite tip velocity and temperature gradient at the tip are practically unaffected by the use of different growth parameters. However, the predicted columnar dendrite tip undercooling did vary to give the required dendrite tip velocity. This finding has implications for the analysis of microstructural transitions, such as the Columnar to Equiaxed Transition (CET). In conclusion, it is suggested that, for transient solidification conditions, a CET prediction criterion based on tip undercooling is preferable to one that uses growth velocity.

AB - A directional solidification experiment of a Ti-Al-Nb-B-C alloy by power down method is simulated using a Bridgman furnace front tracking model. The effect of varying the dendritic growth parameters; C, the columnar dendrite growth coefficient, and n, the undercooling exponent, is investigated. A matrix of growth coefficients and undercooling exponents - at three levels each, based around a growth law for Ti-46wt.%Al - is applied in simulations, and the effect on columnar dendrite tip temperature, tip velocity, and tip temperature gradient is observed. The simulation results show that the dendrite tip velocity and temperature gradient at the tip are practically unaffected by the use of different growth parameters. However, the predicted columnar dendrite tip undercooling did vary to give the required dendrite tip velocity. This finding has implications for the analysis of microstructural transitions, such as the Columnar to Equiaxed Transition (CET). In conclusion, it is suggested that, for transient solidification conditions, a CET prediction criterion based on tip undercooling is preferable to one that uses growth velocity.

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U2 - 10.1088/1757-899X/117/1/012012

DO - 10.1088/1757-899X/117/1/012012

M3 - Conference article

VL - 117

JO - IOP Conference Series : Materials Science and Engineering

T2 - IOP Conference Series : Materials Science and Engineering

JF - IOP Conference Series : Materials Science and Engineering

SN - 1757-8981

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