TY - JOUR
T1 - Controlled undercooling of liquid iron in contact with Al 2O 3 Substrates under varying oxygen partial pressures
AU - Valdez, Martin E.
AU - Uranga, Pello
AU - Fuchigami, Katsuhiro
AU - Shibata, H.
AU - Cramb, Alan W.
N1 - Funding Information:
The authors thank the member companies of the Center for Iron and Steelmaking Research, Carnegie Mellon University, and the AISI DOE Project 0101—‘‘Inclusion Optimization for New Generation Steel Products’’—for the financial support.
PY - 2006/10
Y1 - 2006/10
N2 - The objective of this study was to determine the conditions under which alumina can act as a heterogeneous nucleant to initiate the solidification of undercooled liquid iron. The undercooling of a pure iron sessile droplet in contact with Al 2O 3 substrates was measured under controlled oxygen partial pressures by observing droplet recalescence. The experimental results indicated that the undercooling of liquid iron, in contact with an Al 2O 3 substrate, did not have a unique value, varied from 0°C to 290°C, and was significantly affected by the oxygen content of the gas phase and the degree of interaction between the oxide and the metal. Deep undercoolings are possible at low oxygen potentials, provided the oxygen potential is such that substantial substrate decomposition does not occur. The measured undercooling was a strong function of gas phase oxygen content and a maximum in undercooling of 290°C was measured at PO 2 = 10 -19 atm. The variation in undercooling was related to the wetting of the substrate by the liquid metal, where the deepest undercoolings occurred when the highest contact angle between the substrate and the liquid droplet was achieved.
AB - The objective of this study was to determine the conditions under which alumina can act as a heterogeneous nucleant to initiate the solidification of undercooled liquid iron. The undercooling of a pure iron sessile droplet in contact with Al 2O 3 substrates was measured under controlled oxygen partial pressures by observing droplet recalescence. The experimental results indicated that the undercooling of liquid iron, in contact with an Al 2O 3 substrate, did not have a unique value, varied from 0°C to 290°C, and was significantly affected by the oxygen content of the gas phase and the degree of interaction between the oxide and the metal. Deep undercoolings are possible at low oxygen potentials, provided the oxygen potential is such that substantial substrate decomposition does not occur. The measured undercooling was a strong function of gas phase oxygen content and a maximum in undercooling of 290°C was measured at PO 2 = 10 -19 atm. The variation in undercooling was related to the wetting of the substrate by the liquid metal, where the deepest undercoolings occurred when the highest contact angle between the substrate and the liquid droplet was achieved.
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U2 - 10.1007/s11663-006-0063-2
DO - 10.1007/s11663-006-0063-2
M3 - Review article
AN - SCOPUS:33749859195
VL - 37
SP - 811
EP - 821
JO - Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science
JF - Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science
SN - 1073-5615
IS - 5
ER -