High-intensity ultrasonic grain refinement of magnesium alloys: role of solute
High-intensity ultrasonic grain refinement of magnesium alloys: role of solute
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DOI：
10.1179/136404609x367894
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发表时间：
2009-08
影响因子：
1.4
通讯作者：
A. Ramirez;M. Qian;B. Davis;T. Wilks
中科院分区：
文献类型：
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作者：
A. Ramirez;M. Qian;B. Davis;T. Wilks
在高强度超声场中凝固的液态金属受到频率为20 kHz、振幅为10-50 μm的振动。此外，超声空化产生剧烈的局部扰动。这些动态因素预计将减少溶质积累的增长前沿，从而减少晶粒尺寸对溶质的依赖。研究了高强度超声处理纯镁、二元镁合金和商用镁合金，以确定溶质在这种动态条件下的作用。结果发现，通过高强度超声处理实现的平均晶粒尺寸（d）表现出强烈的溶质依赖性和依赖性可以定量地描述相同的d-1/Q的线性关系，提出了在正常的铸造条件下凝固。这些结果表明，高强度超声波并没有明显改变溶质的作用，超声波晶粒细化是溶质和超声波的共同作用。
Abstract Liquid metals that solidify in a high-intensity ultrasonic field are subjected to vibrations typically at a frequency of 20 kHz with an amplitude in the range 10–50 μm. In addition, ultrasonic cavitation produces violent local disturbances. These dynamic factors are expected to diminish solute build-up ahead of the growing fronts, thereby diminishing the dependence of grain size on solute. An investigation has been made of high-intensity ultrasonication of pure magnesium, binary, and commercial magnesium alloys to determine the role of solute under such dynamic conditions. It was found that the average grain size (d) achieved by high-intensity ultrasonication exhibited strong dependence on solute and the dependence can be described quantitatively by the same d–1/Q linear relationship proposed for solidification under normal casting conditions. These observations suggest that high-intensity ultrasonication has not obviously changed the role of solute and ultrasonic grain refinement arises from the effects of solute as well as ultrasonication.