Tip-splitting instability and transition to seaweed growth during alloy solidification in anisotropically preferred growth direction

IMR OpenIR

	Tip-splitting instability and transition to seaweed growth during alloy solidification in anisotropically preferred growth direction
	Y. Chen; B. Billia; D. Z. Li; H. Nguyen-Thi; N. M. Xiao; A. A. Bogno
	2014
发表期刊	Acta Materialia
ISSN	1359-6454
卷号	66 页码:219-231
摘要	The evolution of the solid liquid interface morphology during the initial transient of directional solidification is investigated by quantitative phase-field numerical simulation during cooling down of an Al-4 wt.% Cu alloy growing in the preferred < 100 >-direction. Simulations show that the shape of the non-planar solid liquid interface varies with the instantaneous growth parameters; in particular, above a critical value of tip velocity, cell/dendrite tips undergo Mullins-Sekerka morphological instability resulting in tip splitting and transition from cells or dendrites to seaweeds. The numerical simulations demonstrate that, despite the < 100 >-direction corresponding to high solid liquid interface energy, seaweed formation is predicted when noise, either inherent to the numerical mesh and/or intentionally added to the phase field, is strong enough to blur the solid anisotropy at the cell/dendrite tip, which confirms the analytical predictions of Brener et al. (1996). Both the tip-splitting mechanism responsible for the seaweed morphological transition as well as the seaweed growth dynamics are characterized. The numerical predictions are then compared to the seaweed transition evidenced on an Al-4 wt.% Cu alloy by in situ and real-time synchrotron X-ray radiography in the initial transient of directional solidification, and good agreement is found. (C) 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
部门归属	[chen, yun ; li, dian zhong ; xiao, na min] chinese acad sci, inst met res, shenyang natl lab mat sci, shenyang 110016, peoples r china. [billia, bernard ; nguyen-thi, henri ; bogno, abdoul-aziz] cnrs, im2np, umr 7334, f-13397 marseille 20, france. [billia, bernard ; nguyen-thi, henri ; bogno, abdoul-aziz] aix marseille univ, im2np, f-13397 marseille 20, france. ; li, dz (reprint author), chinese acad sci, inst met res, shenyang natl lab mat sci, shenyang 110016, peoples r china. ; dzli@imr.ac.cn
关键词	Seaweed Tip Splitting Noise Alloy Directional Solidification Phase-field X-ray Radiography Al-cu Alloy Diffusional Growth Morphology Diagram Initial Transient Dendritic Solidification Future-directions Crystal-growth Binary Alloy 3 Dimensions
URL	查看原文
语种	英语
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/72536
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	Y. Chen,B. Billia,D. Z. Li,et al. Tip-splitting instability and transition to seaweed growth during alloy solidification in anisotropically preferred growth direction[J]. Acta Materialia,2014,66:219-231.
APA	Y. Chen,B. Billia,D. Z. Li,H. Nguyen-Thi,N. M. Xiao,&A. A. Bogno.(2014).Tip-splitting instability and transition to seaweed growth during alloy solidification in anisotropically preferred growth direction.Acta Materialia,66,219-231.
MLA	Y. Chen,et al."Tip-splitting instability and transition to seaweed growth during alloy solidification in anisotropically preferred growth direction".Acta Materialia 66(2014):219-231.