The Ideal Quenching Medium? – Characterisation of Ionic Liquids for Heat Treatment of Metallic Components
The Ideal Quenching Medium? – Characterisation of Ionic Liquids for Heat Treatment of Metallic Components
复制标题
理想的淬火介质？ - 用于金属部件热处理的离子液体的表征
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
O. Kessler
中科院分区：
文献类型：
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作者：
M. Beck;C. Schmidt;M. Ahrenberg;C. Schick;U. Kragl;O. Kessler
摘要 淬火作为热处理的一部分，是金属零部件制造链中的重要工序。最常见的工艺之一是在蒸发液体中浸没淬火。不幸的是，这个过程受到莱顿弗罗斯特现象的影响。这种效应会产生不均匀淬火，从而产生不对称的残余应力和可避免的变形。在这项工作中，离子液体被研究作为新的淬火介质，它可以用作接近室温的浴液。铝圆柱体在具有不同水含量和浴温度的不同离子液体浴中进行淬火。记录了时间-温度曲线，确定了传热系数，并与水中淬火进行了比较。在离子液体中添加百分之几的水可显着提高冷却速率。即使在较高的含水量下，气泡沸腾和对流仍占主导地位，几乎不会发生莱顿弗罗斯特效应。这为加速和均匀化浸入式淬火提供了巨大的潜力。
Abstract Quenching as a part of heat treatment is an important process in the manufacturing chain of metallic components. One of the most common processes is immersion quenching in vaporising liquids. Unfortunately, this process is affected by the Leidenfrost-phenomenon. This effect can generate inhomogeneous quenching and thus asymmetrical residual stresses and avoidable distortion. In this work, ionic liquids have been investigated as new quenching media, which can be used as baths near room temperature. Aluminium cylinders have been quenched in baths of different ionic liquids with varying water contents and bath temperatures. The time-temperature curves have been recorded and the heat transfer coefficients were determined and compared to quenching in water. Addition of a few percents water to the ionic liquids increases the cooling rate significantly. Even at higher water contents, bubble boiling and convection are predominant and almost no Leidenfrost-effect occurs. This offers a huge potential to accelerate and homogenise immersion quenching.