Kinetics and morphological evolution of liquid metal dealloying
Kinetics and morphological evolution of liquid metal dealloying
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DOI：
10.1016/j.actamat.2016.05.032
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发表时间：
2016-08-15
期刊：
影响因子：
9.4
通讯作者：
Erlebacher, Jonah
中科院分区：
文献类型：
--
作者：
Mccue, Ian;Gaskey, Bernard;Erlebacher, Jonah
液态金属去合金化（LMD）是近年来出现的一种自下而上的自组织方法，用于制备大块纳米结构，但文献中缺乏对该动力学过程的基础研究。在这项工作中，我们进行了深入的研究，在LMD过程中的动力学和基本的微观组织演变机制，浸在熔融Cu作为模型系统的Ti-Ta合金。我们开发了一个LMD动力学模型的基础上，在我们的系统中，包括合金成分，脱合金时间，脱合金温度的关键参数的影响的定量表征。这项工作表明，在LMD过程中，脱合金界面处于或接近平衡，并且限速步骤是溶解原子远离脱合金界面的液态扩散（扩散限制动力学）。理论预测和测量的脱合金率之间的定量比较进一步揭示了对流运输和排斥的溶解元素在粗化的结构也影响脱合金动力学。(C)2016 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
Liquid metal dealloying (LMD) has recently emerged as a novel technique to fabricate bulk nano structures using a bottom-up self-organization method, but the literature lacks fundamental studies of this kinetic process. In this work, we conduct an in-depth study of the kinetics and fundamental microstructure evolution mechanisms during LMD using Ti-Ta alloys immersed in molten Cu as a model system. We develop a model of LMD kinetics based on a quantitative characterization of the effects of key parameters in our system including alloy composition, dealloying duration, and dealloying temperature. This work demonstrates that the dealloying interface is at or near equilibrium during LMD, and that the rate-limiting step is the liquid-state diffusion of dissolving atoms away from the dealloying interface (diffusion-limited kinetics). The quantitative comparison between theoretically predicted and measured dealloying rates further reveals that convective transport and rejection of the dissolving element during coarsening of the structure also influence the dealloying kinetics. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.