Abstract This paper applies a phase field model for polycrystalline solidification in binary alloys to simulate the formation and growth of the columnar dendritic array under the isothermal and constant cooling conditions. The solidification process and microsegregation in the mushy zone are analysed in detail. It is shown that under the isothermal condition solidification will stop after the formation of the mushy zone, but dendritic coarsening will progress continuously, which results in the decrease of the total interface area. Under the constant cooling condition the mushy zone will solidify and coarsen simultaneously. For the constant cooling solidification, microsegregation predicted by a modified Brody-Flemings model is compared with the simulation results. It is found that the Fourier number which characterizes microsegregation is different for regions with different microstructures. Dendritic coarsening and the larger area of interface should account for the enhanced Fourier number in the region with well developed second dendritic arms.
Received: 23 January 2008
Revised: 24 February 2008
Accepted manuscript online:
PACS:
68.70.+w
(Whiskers and dendrites (growth, structure, and nonelectronic properties))
Fund: Project supported by the National
Natural Science Foundation of China (Grant No 50401013) and
Doctorate Foundation of Northwestern
Polytechnical University, China.
Cite this article:
Li Jun-Jie(李俊杰), Wang Jin-Cheng(王锦程), and Yang Gen-Cang(杨根仓) Phase field simulation of the columnar dendritic growth and microsegregation in a binary alloy 2008 Chin. Phys. B 17 3516
Altmetric calculates a score based on the online attention an article receives. Each coloured thread in the circle represents a different type of online attention. The number in the centre is the Altmetric score. Social media and mainstream news media are the main sources that calculate the score. Reference managers such as Mendeley are also tracked but do not contribute to the score. Older articles often score higher because they have had more time to get noticed. To account for this, Altmetric has included the context data for other articles of a similar age.
