(1. 贵州大学 机械工程学院，贵阳 550025；
2. 华南理工大学 机械与汽车工程学院，广州 510640
3. 广东省科学院 材料与加工研究所，广州 510640)
摘 要: 采用数值模拟和实验验证相结合的方法，研究了超声压力耦合场对Al-Cu合金协同作用机理及对显微组织的影响。结果表明：相比单一超声场，超声压力耦合场会使得空化效应的强度和区域增大，还可以改变熔体内部压力分布从而导致熔体内部形成更强烈的对流。通过熔体内部温度测试和宏观、微观组织定量分析的方法，对数值模拟结果进行实验验证。超声-压力耦合作用更容易促使熔体内部出现均匀的温度场，同时消除单一超声作用导致的铸锭内部晶粒细化的差异性，使微观组织分布得更均匀。
关键字: 超声振动；压力场；耦合场；数值模拟；铝铜合金
（1. School of Mechanical Engineering, Guizhou University, Guiyang 550025, China;
2. School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510640, China;
3. Institute of Materials and Processing, Guangdong Academy of Sciences, Guangzhou 510640, China）
Abstract:The effect of ultrasound vibration and pressure coupling fields on the function mechanism and microstructure of Al-Cu alloy was studied by numerical simulation and experimental validation. The results show that, compared with the single ultrasonic field, the ultrasound vibration and pressure coupling field can increase the intensity and region of cavitation effect. The distribution of inner pressure in aluminum melt can also be raised under the coupling field, which leads to the enhanced convection in the aluminum melt. By measuring the temperature in melt and analyzing the macro/microstructure of the Al-Cu alloy quantitatively, the numerical simulation result was verified. The coupling field can promote the uniform temperature distribution of Al-Cu melt. The coupling field can also eliminate the difference of grain refinement in the ingot caused by single ultrasonic field, and improve the uniformity of the microstructure obviously.
Key words: ultrasonic vibration; applied pressure; coupling fields; numerical simulation; Al-Cu alloy
