The Use of In Situ X-ray Imaging Methods in the Research and Development of Magnesium-Based Grain-Refined and Nanocomposite Materials
The Use of In Situ X-ray Imaging Methods in the Research and Development of Magnesium-Based Grain-Refined and Nanocomposite Materials
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DOI：
10.1007/s11837-016-2130-8
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发表时间：
2016-10
期刊：
影响因子：
2.6
通讯作者：
W. Sillekens;D. Casari;W. Mirihanage;S. Terzi;R. Mathiesen;L. Salvo;R. Daudin;P. Lhuissier;E. Guo;P. D. Lee
中科院分区：
文献类型：
--
作者：
W. Sillekens;D. Casari;W. Mirihanage;S. Terzi;R. Mathiesen;L. Salvo;R. Daudin;P. Lhuissier;E. Guo;P. D. Lee
冶金学家拥有越来越多的分析技术可供他们使用。这些技术中有原位方法，这些方法被设计来实际研究材料在凝固、(热)-机械加工或热处理过程中发生的事件。因此，它们是解开这些过程背后的机制的有力工具，是对非原位方法的补充，这些方法在材料加工之前和之后进行分析。本文介绍了如何将原位成像方法--更具体地说是微焦点x射线照相法和同步辐射x射线层析照相法--用于镁基细化颗粒和纳米复合材料的研究和开发。这些结果来自欧共体合作研究项目ExoMet(www.exomet-project t.eu)。第一个例子涉及添加了Zr的Mg-ND-Gd合金的凝固，以评估锆量和冷却速度在晶体形核和生长中的作用。第二个例子涉及镁锌铝合金及其含碳化硅纳米复合材料的凝固过程，以揭示颗粒添加对微观组织发展的影响。第三个例子涉及Elektron21/AlN和Elektron21/Y2O3纳米复合材料的(部分)熔融凝固，以研究重复加工过程中颗粒的推动/吞噬和团聚等效应。这样的研究首先将已知或假设的东西可视化，然后再加以确认。其次，它们通过监测和量化在过程中演化的现象来推动科学，从而有助于更好地理解所起作用的物理学。
Metallurgists have an ever-increasing suite of analytical techniques at their disposition. Among these techniques are the in situ methods, being those approaches that are designed to actually study events that occur in the material during for instance solidification, (thermo)-mechanical working or heat treatment. As such they are a powerful tool in unraveling the mechanisms behind these processes, supplementary to ex situ methods that instead analyze the materials before and after their processing. In this paper, case studies are presented of how in situ imaging methods—and more specifically micro-focus x-ray radiography and synchrotron x-ray tomography—are used in the research and development of magnesium-based grain-refined and nanocomposite materials. These results are drawn from the EC collaborative research project ExoMet ( www.exomet-project.eu ). The first example concerns the solidification of a Mg-Nd-Gd alloy with Zr addition to assess the role of zirconium content and cooling rate in crystal nucleation and growth. The second example concerns the solidification of a Mg-Zn-Al alloy and its SiC-containing nanocomposite material to reveal the influence of particle addition on microstructural development. The third example concerns the (partial) melting–solidification of Elektron21/AlN and Elektron21/Y2O3nanocomposite materials to study such effects as particle pushing/engulfment and agglomeration during repeated processing. Such studies firstly visualize and by that confirm what is known or assumed. Secondly, they advance science by monitoring and quantifying phenomena as they evolve during processing and by that contribute toward a better understanding of the physics at play.