TY - GEN
T1 - Determination of the magnitude of interfacial air-gap and heat transfer during ingot casting into permanent metal moulds by numerical and experimental techniques
AU - Swan, Jason
AU - Ward, R. M.
AU - Reed, R. C.
PY - 2013/8/30
Y1 - 2013/8/30
N2 - Numerically and experimentally the size of the casting-mould air-gap was investigated for the aluminium alloy LM25 cast into a cylindrical H13 steel mould. The air-gap significantly affects the magnitude of heat transfer. A numerical model has been developed to predict the size of the air-gap and the temperature distribution along the metal-mould interface given an initial Interfacial Heat Transfer Coefficient (IHTC), dependent on the mould surface roughness, and sufficient knowledge of the radiative and thermomechanical properties of the casting and mould materials. The model is then able to predict the development of the air-gap and the resulting IHTC values over time. Validation was conducted experimentally by measuring the thickness of the airgap using optical techniques to measure displacements of the mould and the casting surface during solidification. Temperatures of the mould and casting were also measured and allowed the timevarying IHTC to be calculated. A fair agreement between the numerical and experimental results was found, giving confidence in the numerical model's ability to predict the magnitude of the airgap and temperature distribution. This can be extended to regions where destructive measurement techniques were not used. The air-gap width for this casting process reached 0.6 mm, for which heat transfer by conduction was found to be dominant over radiative heat transfer.
AB - Numerically and experimentally the size of the casting-mould air-gap was investigated for the aluminium alloy LM25 cast into a cylindrical H13 steel mould. The air-gap significantly affects the magnitude of heat transfer. A numerical model has been developed to predict the size of the air-gap and the temperature distribution along the metal-mould interface given an initial Interfacial Heat Transfer Coefficient (IHTC), dependent on the mould surface roughness, and sufficient knowledge of the radiative and thermomechanical properties of the casting and mould materials. The model is then able to predict the development of the air-gap and the resulting IHTC values over time. Validation was conducted experimentally by measuring the thickness of the airgap using optical techniques to measure displacements of the mould and the casting surface during solidification. Temperatures of the mould and casting were also measured and allowed the timevarying IHTC to be calculated. A fair agreement between the numerical and experimental results was found, giving confidence in the numerical model's ability to predict the magnitude of the airgap and temperature distribution. This can be extended to regions where destructive measurement techniques were not used. The air-gap width for this casting process reached 0.6 mm, for which heat transfer by conduction was found to be dominant over radiative heat transfer.
KW - Air-gap
KW - Interfacial heat transfer coefficient
KW - Numerical simulations
UR - http://www.scopus.com/inward/record.url?scp=84882987611&partnerID=8YFLogxK
U2 - 10.4028/www.scientific.net/MSF.765.276
DO - 10.4028/www.scientific.net/MSF.765.276
M3 - Conference contribution
AN - SCOPUS:84882987611
SN - 9783037857663
T3 - Materials Science Forum
SP - 276
EP - 280
BT - Light Metals Technology 2013
T2 - 6th International Light Metals Technology Conference, LMT 2013
Y2 - 24 July 2013 through 26 July 2013
ER -