(1. 貴州大學(xué) 機(jī)械工程學(xué)院，貴陽 550025；
2. 華南理工大學(xué) 機(jī)械與汽車工程學(xué)院，廣州 510640
3. 廣東省科學(xué)院 材料與加工研究所，廣州 510640)
摘 要: 采用數(shù)值模擬和實驗驗證相結(jié)合的方法，研究了超聲壓力耦合場對Al-Cu合金協(xié)同作用機(jī)理及對顯微組織的影響。結(jié)果表明：相比單一超聲場，超聲壓力耦合場會使得空化效應(yīng)的強(qiáng)度和區(qū)域增大，還可以改變?nèi)垠w內(nèi)部壓力分布從而導(dǎo)致熔體內(nèi)部形成更強(qiáng)烈的對流。通過熔體內(nèi)部溫度測試和宏觀、微觀組織定量分析的方法，對數(shù)值模擬結(jié)果進(jìn)行實驗驗證。超聲-壓力耦合作用更容易促使熔體內(nèi)部出現(xiàn)均勻的溫度場，同時消除單一超聲作用導(dǎo)致的鑄錠內(nèi)部晶粒細(xì)化的差異性，使微觀組織分布得更均勻。
關(guān)鍵字: 超聲振動；壓力場；耦合場；數(shù)值模擬；鋁銅合金
（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
