A study of the oxidation of ZrB₂ powders during high-energy ball-milling in air

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• 作者：Angel L. Ortiz ; ^{alortiz@materiales.unex.es} ; ^{alortiz@unex.es} ; Victor Zamora ; Fernando Rodrí ; guez-Rojas
• 关键词：ZrB2 ; Ultra-high-temperature ceramics ; High-energy ball-milling
• 刊名：Ceramics International
• 出版年：2012
• 期刊代码：13_02728842
• 类别：ms
• 出版时间：May, 2012
• 卷：38
• 期：4
• 页码：2857-2863
• 文件大小：1225 K

摘要

Oxide impurities in ZrB₂ powders promote coarsening, resulting in lower sinterability. Given its importance for sintering, we studied the oxidation of ZrB₂ powders during high-energy ball-milling (the form of milling able to refine ZrB₂ powders to the nanoscale) with the aid of various characterization techniques, namely fusion in inert gas, X-ray diffractometry, helium pycnometry, transmission electron microscopy, and Fourier-transform infrared, Raman, and X-ray photoemission spectroscopy. It was found that high-energy ball-milling in air introduces twice as much oxygen into the ZrB₂ powders as the more conventional attrition milling. Also, this oxygen does not form solid-solutions with ZrB₂, but amorphous oxides (i.e., ZrO₂ and B₂O₃) that locate preferentially on the surface of the ultra-fine agglomerates resulting from cold-welding of the primary nano-particles that form during the ball-milling.