Microscale heat and mass transfer and non-equilibrium phase change in rapid solidification

Citation
Gx. Wang et V. Prasad, Microscale heat and mass transfer and non-equilibrium phase change in rapid solidification, MAT SCI E A, 292(2), 2000, pp. 142-148
Citations number
28
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science","Material Science & Engineering
Journal title
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
ISSN journal
0921-5093 → ACNP
Volume
292
Issue
2
Year of publication
2000
Pages
142 - 148
Database
ISI
SICI code
0921-5093(20001130)292:2<142:MHAMTA>2.0.ZU;2-C
Abstract
Many advanced materials processes such as pulsed-laser surface treatment an d thermal spray deposition involve extremely fast heat and mass transfer at very small length scales. Under such extreme conditions, the accompanying phase change processes involve complex non-equilibrium phenomena. As a resu lt, the non-equilibrium kinetics of crystalline growth becomes as important as heat and mass transfer in the determination of the materials microstruc ture and properties. Several rapid solidification processes that involve no n-equilibrium melting and solidification under the conditions of microscale heat and mass transfer are presented. Attention is focused on the processe s that can achieve either large melt undercooling prior to solidification a s in the case of electromagentic levitation process and thermal spray, or a fast rate of heat transfer and thus high-speed phase change as in pulsed l aser surface melting. Ln both cases, melting and/or solidification are char acterized by non-equilibrium behavior at the fast moving solid/liquid inter face where microscale and non-Fourier diffusion of heat and mass may take p lace. Various theoretical treatments and models for microscale heat and mas s transfer processes are discussed. Recent progress in rapid solidification modeling that takes into account both the microscale heat and mass transfe r and non-equilibrium kinetics is summarized, and some typical results are presented. (C) 2000 Elsevier Science S.A. All rights reserved.