A levitation instrument for containerless study of molten materials
A levitation instrument for containerless study of molten materials
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DOI：
10.1063/1.4770125
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发表时间：
2012-12-01
影响因子：
1.6
通讯作者：
Prieler, Robert
中科院分区：
文献类型：
--
作者：
Nordine, Paul C.;Merkley, Dennis;Prieler, Robert
德国亚琛的RWTH大学矿物工程研究所安装了一台新的空气声悬浮仪器（AAL）。AAL采用声稳定气体射流悬浮与激光束加热和熔化，为高温材料研究创造一个无接触的无容器环境。在超过3000摄氏度的温度下可以对液体进行无污染的研究，在远低于熔点的温度下可以对过冷液体进行无污染的研究。数字控制技术推进了无容器实验的艺术，以获得长期的悬浮稳定性，允许在极端温度材料研究中进行新的实验，并研究悬浮仪器本身的操作。本文报道了在3200 ℃以上、熔点以上1200 ℃和远低于熔点的Y3 Al 5 O 12液体中进行的实验。快速高温计和视频记录仪器产生过冷液体Al 2 O3的结晶速率作为温度的函数。证明了在2900 ℃以上的温度下稠密液体HfO 2的悬浮。描述了三轴声学定位系统中的谐振频率匹配、样品自旋的声学控制和驻波节点的位置控制的能力，以在变化的实验条件下稳定悬浮。根据实验结果和仪器操作的建模，讨论了悬浮技术的进一步发展和应用。(C)2012年美国物理学会。[http：//dx.doi.org/10.1063/1.4770125]
A new aero-acoustic levitation instrument (AAL) has been installed at the Institute for Mineral Engineering at RWTH University in Aachen, Germany. The AAL employs acoustically stabilized gas jet levitation with laser-beam heating and melting to create a contact-free containerless environment for high temperature materials research. Contamination-free study of liquids is possible at temperatures in excess of 3000 degrees C and of undercooled liquids at temperatures far below the melting point. Digital control technology advances the art of containerless experiments to obtain long-term levitation stability, allowing new experiments in extreme temperature materials research and to study operation of the levitation instrument itself. Experiments with liquid Al2O3 at temperatures more than 3200 degrees C, 1200 degrees C above the melting point, and with liquid Y3Al5O12 far below the melting point are reported. Fast pyrometry and video recording instruments yield crystallization rates in undercooled liquid Al2O3 as a function of temperature. Levitation of dense liquid HfO2 at temperatures above 2900 degrees C is demonstrated. Capabilities are described for resonant frequency matching in the three-axis acoustic positioning system, acoustic control of sample spin, and position control of standing wave nodes to stabilize levitation under changing experimental conditions. Further development and application of the levitation technology is discussed based on the results of experiments and modeling of instrument operations. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4770125]