Prediction of Cavitation Depth in an Al-Cu Alloy Melt with Bubble Characteristics Based on Synchrotron X-ray Radiography
Prediction of Cavitation Depth in an Al-Cu Alloy Melt with Bubble Characteristics Based on Synchrotron X-ray Radiography
复制标题
基于同步辐射X射线照相的铝铜合金熔体气泡特征空化深度预测
DOI：
10.1007/s11661-018-4603-6
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发表时间：
2018-06-01
影响因子：
2.8
通讯作者：
Sun, Baode
中科院分区：
文献类型：
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作者：
Huang, Haijun;Shu, Da;Sun, Baode
空化区的大小是评价超声熔体处理对优选组织细化效果的关键参数。我们提出了一个简单的数值模型来预测金属熔体中空化区域的特征长度，称为空化深度。该模型基于空化气泡引起的声波衰减的波传播模型，空化气泡的声衰减取决于气泡的特性和超声强度。采用同步x射线成像技术，对铝铜熔体中空化区域的大小、空化气泡的体积分数和尺寸分布进行了定量测量。结果表明：空化气泡尺寸呈对数正态分布，空化气泡体积分数随超声强度的增大服从tanh函数；利用气泡特性的实验值作为输入，预测的空化深度除了在高声强处有轻微偏差外，与观测值吻合较好。进一步分析表明，随着气泡体积和气泡尺寸的增大，空化气泡的衰减会增大，因此空化深度会减小。当前的模型提供了实现UST的指导方针，特别是对于结构的细化。
The size of cavitation region is a key parameter to estimate the metallurgical effect of ultrasonic melt treatment (UST) on preferential structure refinement. We present a simple numerical model to predict the characteristic length of the cavitation region, termed cavitation depth, in a metal melt. The model is based on wave propagation with acoustic attenuation caused by cavitation bubbles which are dependent on bubble characteristics and ultrasonic intensity.In situsynchrotron X-ray imaging of cavitation bubbles has been made to quantitatively measure the size of cavitation region and volume fraction and size distribution of cavitation bubbles in an Al-Cu melt. The results show that cavitation bubbles maintain a log-normal size distribution, and the volume fraction of cavitation bubbles obeys a tanh function with the applied ultrasonic intensity. Using the experimental values of bubble characteristics as input, the predicted cavitation depth agrees well with observations except for a slight deviation at higher acoustic intensities. Further analysis shows that the increase of bubble volume and bubble size both leads to higher attenuation by cavitation bubbles, and hence, smaller cavitation depth. The current model offers a guideline to implement UST, especially for structural refinement.