In situ observation of sublimation-enhanced magnesium oxidation at elevated temperature

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• 作者：Zijiao Zhang ; Xiaoqian Fu ; Minmin Mao ; Qian Yu ; Scott X. Mao ; Jixue Li…
• 关键词：oxidation ; magnesium ; sublimation ; nanoparticle
• 刊名：Nano Research
• 出版年：2016
• 出版时间：September 2016
• 年：2016
• 卷：9
• 期：9
• 页码：2796-2802
• 全文大小：1,526 KB
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Chinese Library of Science
  Chemistry
  Nanotechnology
  
• 出版者：Tsinghua University Press, co-published with Springer-Verlag GmbH
• ISSN：1998-0000
• 卷排序：9

文摘

Oxidation plays a tremendous role in the long-term performance of metals. As an important lightweight metal for industrial applications, magnesium suffers from its high reactivity with oxygen and increased evaporation at high temperatures. To understand the oxidation mechanism of magnesium at elevated temperatures, in situ environmental transmission electron microscopy (E-TEM) was performed on magnesium nanoparticles. At a relatively low temperature, the growth of a MgO lamellae via the outward diffusion of bulk magnesium atoms dominated the oxidation process. In contrast, a sublimation-enhanced oxidation via gas phase reaction occurred at 200 °C, leading to the growth of MgO dendrites over the particle that finally leads to the degradation of the magnesium structure. This study provides a direct observation and model of the oxidation mechanism of a direct gas–gas reaction that improves our understanding of the oxidation mechanism at elevated temperatures.