Nucleation and growth of gas bubbles in AlSi8Mg4 foam investigated by X-ray tomoscopy
Nucleation and growth of gas bubbles in AlSi8Mg4 foam investigated by X-ray tomoscopy
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DOI：
10.1016/j.actamat.2020.116583
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发表时间：
2021-03-01
期刊：
影响因子：
9.4
通讯作者：
Banhart, John
中科院分区：
文献类型：
--
作者：
Kamm, Paul Hans;Neu, Tillmann Robert;Banhart, John
泡沫金属的形成和生长是一个复杂的动态过程，具有三维性和时间依赖性。层析成像-或时间分辨层析成像-使我们能够在发泡过程中真实的时间内跟踪AlSi 8 Mg 4合金中气泡的成核和生长。单个气泡的位置、尺寸和形状以1秒的步长确定，空间分辨率为几μ m。此外，在一系列3D图像中还识别出了导致气体析出的成分，即Al-Mg相和TiH 2颗粒。自动定量图像分析的气泡和气体产生的阶段，包括它们的空间相关性，使我们能够打破发泡过程分为两个不同的步骤，第一个均匀的驱动吸附的气体和第一熔融微观结构组件和第二归因于合金的熔化和随后的泡沫增长驱动的氢从TiH 2颗粒释放。研究结果表明，标准AlSi 8 Mg 4泡沫可以通过调整Al-Mg组分粉末的性能来改善。(C)2020 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
Initiation and growth of metal foam is a complex and dynamical process, which is intrinsically three-dimensional and time-dependent. Tomoscopy -or time-resolved tomography- allows us to follow the nucleation and growth of gas bubbles in AlSi8Mg4 alloy in real time during foaming. The location, size and shape of individual bubbles was determined in steps of 1 s with spatial resolutions of a few mu m. Moreover, the constituents responsible for gas evolution, namely Al-Mg phases and TiH2 particles, were identified in the series of 3D images. Automated quantitative image analysis of bubbles and gas-generated phases including their spatial correlations allowed us to break down the foaming process into two distinct steps, a first homogenous one driven by adsorbed gases and first melting microstructural components and a second attributed to the melting of the alloy and subsequent foam growth driven by hydrogen released from TiH2 particles. The results of the study indicate that standard AlSi8Mg4 foam can be improved by tailoring the properties of the Al-Mg constituent powder. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.