Application of non-equilibrium dendrite growth model considering thermo-kinetic correlation in twin-roll casting
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2020年第9期
论文作者：Yubing Zhang Jinglian Du Kang Wang Huiyuan Wang Shu Li Feng Liu
文章页码：209 - 222
摘 要：Upon non-equilibrium solidifications, dendrite growth, generally as precursor of as-solidified structures,has severe effects on subsequent phase transformations. Considering synergy of thermodynamics and kinetics controlling interface migration and following conservation of heat flux in solid temperature field, a more flexible modeling for the dendrite growth is herein developed for multi-component alloys,where, two inherent problems, i.e. correlation between thermodynamics and kinetics（i.e. the thermokinetic correlation）, and theoretical connection between dendrite growth model and practical processing,have been successfully solved. Accordingly, both the thermodynamic driving force G and the effective kinetic energy barrier Qeffhave been found to control quantitatively the dendrite growth（i.e. especially the growth velocity, V）, as reflected by the thermo-kinetic trade-off. Compared with previous models, it is the thermo-kinetic correlation that guarantees quantitative connection between the practical processing parameters and the current theoretical framework, as well as more reasonable description for kinetic behaviors involved. Applied to the vertical twin-roll casting（VTC）, the present model, realizes a good prediction for kissing points, which influences significantly alloy design and processing optimization.This work deduces quantitatively the thermo-kinetic correlation controlling the dendrite growth, and by proposing the parameter-triplets(i.e. G-Qeff-V), further opens a new beginning for connecting solidification theories with industrial applications, such as the VTC.
Yubing Zhang1，Jinglian Du1，Kang Wang1，Huiyuan Wang2，Shu Li3，Feng Liu1,4
1. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University2. Key Laboratory of Automobile Materials of Ministry of Education and Department of Materials Science and Engineering, Jilin University3. School of Science, Harbin University of Science and Technology4. Analytical & Testing Center, Northwestern Polytechnical University
摘 要：Upon non-equilibrium solidifications, dendrite growth, generally as precursor of as-solidified structures,has severe effects on subsequent phase transformations. Considering synergy of thermodynamics and kinetics controlling interface migration and following conservation of heat flux in solid temperature field, a more flexible modeling for the dendrite growth is herein developed for multi-component alloys,where, two inherent problems, i.e. correlation between thermodynamics and kinetics（i.e. the thermokinetic correlation）, and theoretical connection between dendrite growth model and practical processing,have been successfully solved. Accordingly, both the thermodynamic driving force G and the effective kinetic energy barrier Qeffhave been found to control quantitatively the dendrite growth（i.e. especially the growth velocity, V）, as reflected by the thermo-kinetic trade-off. Compared with previous models, it is the thermo-kinetic correlation that guarantees quantitative connection between the practical processing parameters and the current theoretical framework, as well as more reasonable description for kinetic behaviors involved. Applied to the vertical twin-roll casting（VTC）, the present model, realizes a good prediction for kissing points, which influences significantly alloy design and processing optimization.This work deduces quantitatively the thermo-kinetic correlation controlling the dendrite growth, and by proposing the parameter-triplets(i.e. G-Qeff-V), further opens a new beginning for connecting solidification theories with industrial applications, such as the VTC.
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