Capillary-mediated solid-liquid energy fields: their detection with phase-field method

Joint 5th International Conference on Advances in Solidification Processes;5th International Symposium on Cutting Edge of Computer Simulation of Solidification, Casting and Refining

土木建筑工程;计算机科学

Glicksman, M.^1 ; Ankit, K.^2

Florida Institute of Technology, 150 West University Blvd., Melbourne

FL

32901-6975, United States^1

School for Engineering of Matter, Transport and Energy, Arizona State University, 551 E. Tyler Mall, ERC 265, Tempe

AZ

85287, United States^2

关键词: Capillary phenomena;    Energy distributions;    Grain boundary grooves;    Microstructure control;    Phase field methods;    Phase-field simulation;    Solid-liquid interfaces;    Thermodynamic fields;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/529/1/012027/pdf
DOI  :  10.1088/1757-899X/529/1/012027

来源: IOP

【 摘 要 】

Observations of melting crystallites in microgravity showed unusual shape changes as melting proceeded toward extinction. When re-analyzed in 2011, shape evolution data showed needle-like crystallites becoming spheroids as they melted toward extinction, suggesting that some type of capillary phenomenon at solid-liquid interfaces was responsible for an energy release capable of spherodising particles on melting, and stimulating pattern formation during unstable crystal growth. The presence of these previously undetected energy fields was recently uncovered using phase-field simulations that employ an entropy density functional. Simulations allow measurement of interfacial energy distributions on equilibrated solid-liquid interfaces configured as stationary grain boundary grooves (GBGs). Interfacial energy source fields - related to gradients in the Gibbs-Thomson temperature - entail persistent cooling along GBG profiles, a new result that fully confirms earlier predictions based on sharp-interface thermodynamics. This study also provides new insights to improve microstructure control at reduced scales by explaining the thermodynamic fields responsible for pattern formation in castings.