Abstract

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.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.