Characterization of acoustic cavitation in water and molten aluminum alloy
Characterization of acoustic cavitation in water and molten aluminum alloy
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DOI：
10.1016/j.ultsonch.2012.10.006
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发表时间：
2013-03-01
影响因子：
8.4
通讯作者：
Dezhkunov, Nikolay
中科院分区：
文献类型：
--
作者：
Komarov, Sergey;Oda, Kazuhiro;Dezhkunov, Nikolay
高强度超声波振动已被认为是铸造技术中细化金属晶粒结构的一种有吸引力的工具。然而，超声波在该领域的实际应用仍然相当有限。原因之一是缺乏优化超声波处理条件所需的数据，特别是有关铝液空化区特征的数据。本研究的主要目的是研究超声波辐射到水和熔融铝合金时产生的空化噪声的强度和频谱特征，并建立评估空化强度的方法。测量是通过使用高温空化计来进行的，该高温空化计能够测量 0.01 至 10 MHz 五个频段内的空化噪声水平。通过对直流连铸机施加高强度超声波振动来细化模型 Al-17Si 合金的初生硅晶粒，验证了空化处理的效果。结果发现，高频噪声成分的水平是评估空化强度的最合适的参数。基于这一发现，得出结论：空化气泡的内爆对于合金结构的细化起着决定性作用。 (C) 2012 Elsevier B.V. 保留所有权利。
High-intensive ultrasonic vibrations have been recognized as an attractive tool for refining the grain structure of metals in casting technology. However, the practical application of ultrasonics in this area remains rather limited. One of the reasons is a lack of data needed to optimize the ultrasonic treatment conditions, particularly those concerning characteristics of cavitation zone in molten aluminum.The main aim of the present study was to investigate the intensity and spectral characteristics of cavitation noise generated during radiation of ultrasonic waves into water and molten aluminum alloys, and to establish a measure for evaluating the cavitation intensity. The measurements were performed by using a high temperature cavitometer capable of measuring the level of cavitation noise within five frequency bands from 0.01 to 10 MHz. The effect of cavitation treatment was verified by applying high-intense ultrasonic vibrations to a DC caster to refine the primary silicon grains of a model Al-17Si alloy. It was found that the level of high frequency noise components is the most adequate parameter for evaluating the cavitation intensity. Based on this finding, it was concluded that implosions of cavitation bubbles play a decisive role in refinement of the alloy structure. (C) 2012 Elsevier B.V. All rights reserved.