TY - GEN
T1 - Thermal non-equilibrium effects on nickel solid-liquid interface
AU - Brown, Nicholas
AU - Martinez, Enrique
AU - Qu, Jianmin
N1 - Publisher Copyright:
Copyright © 2016 MS&T16®.
PY - 2016
Y1 - 2016
N2 - Rapid solidification of metallic structures results in complex microstructural changes originating from the rapid heating/cooling rates typically seen in manufacturing processes, such as additive manufacturing, cast and welding. These extreme rates cause a thermal non-equilibrium at the crystal-melt interface and affect the interfacial stiffness and energy of the system. Typical phase-field simulations of dendrite growth are limited to the assumption of thermal equilibrium, using the Gibbs-Thomson equation as a boundary condition. Under these assumptions, phase-field simulations are unable to accurately reproduce the growth patterns observed under rapid solidification. While recent advances have been made to overcome this deficiency within the phase-field simulation methodology, the work presented in this paper proposes an alternative molecular dynamics approach using a modified capillary fluctuation method. Solid-liquid interface properties are initially calculated under an equilibrium condition using the melting temperature and then compared results obtained from a range of non-equilibrium thermal conditions to quantify the effect caused by the thermal gradient. It is evident that the interfacial stiffness is no longer a function of just the normal orientation of the interface, thus requiring a change in the phase-field methodology.
AB - Rapid solidification of metallic structures results in complex microstructural changes originating from the rapid heating/cooling rates typically seen in manufacturing processes, such as additive manufacturing, cast and welding. These extreme rates cause a thermal non-equilibrium at the crystal-melt interface and affect the interfacial stiffness and energy of the system. Typical phase-field simulations of dendrite growth are limited to the assumption of thermal equilibrium, using the Gibbs-Thomson equation as a boundary condition. Under these assumptions, phase-field simulations are unable to accurately reproduce the growth patterns observed under rapid solidification. While recent advances have been made to overcome this deficiency within the phase-field simulation methodology, the work presented in this paper proposes an alternative molecular dynamics approach using a modified capillary fluctuation method. Solid-liquid interface properties are initially calculated under an equilibrium condition using the melting temperature and then compared results obtained from a range of non-equilibrium thermal conditions to quantify the effect caused by the thermal gradient. It is evident that the interfacial stiffness is no longer a function of just the normal orientation of the interface, thus requiring a change in the phase-field methodology.
KW - Additive manufacturing
KW - Interface free energy
KW - Interfacial stiffness
KW - Molecular dynamics
KW - Non-equilibrium
KW - Phase-field
KW - Rapid solidification
KW - Solid-liquid interface
UR - http://www.scopus.com/inward/record.url?scp=85017282914&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85017282914&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:85017282914
T3 - Materials Science and Technology Conference and Exhibition 2016, MS and T 2016
SP - 359
EP - 366
BT - Materials Science and Technology Conference and Exhibition 2016, MS and T 2016
T2 - Materials Science and Technology Conference and Exhibition 2016, MS and T 2016
Y2 - 23 October 2016 through 27 October 2016
ER -