Research progress on microstructure evolution of semi-solid aluminum alloys in ultrasonic field and their rheocasting  

作　　者：Wu Shusen Lin Chong Lü Shulin Sha Meng 

机构地区：[1]State Key Laboratory of Materials Processing and Die & Mould Technology,Huazhong University of Science and Technology

出　　处：《China Foundry》2014年第4期258-267,共10页中国铸造（英文版）

摘　　要：The effects of ultrasonic vibration(UV)treatment on microstructure of semi-solid aluminum alloys and the application of UV in rheocasting process are reviewed.Good semi-solid slurry can be produced by high-intensity UV process for aluminum alloys.The microstructures of Al-Si,Al-Mg and Al-Cu alloys produced by rheocasting assisted with UV are compact and with fine grains.The mechanical properties of the UV treated alloys are increased by about 20%-30%.Grain refinement of the alloys is generally considered because of cavitation and acoustic streaming caused by UV.Apart from these mechanisms,a hypothesis of the fuse of dendrite root caused by capillary infiltration in the ultrasonic field,as well as a mechanism of crystallites falling off from the mould-wall and crystal multiplication by mechanical vibration effect in indirect ultrasonic vibration are proposed to explain the microstructure evolution of the alloys.The effects of ultrasonic vibration（UV）treatment on microstructure of semi-solid aluminum alloys and the application of UV in rheocasting process are reviewed.Good semi-solid slurry can be produced by high-intensity UV process for aluminum alloys.The microstructures of Al-Si,Al-Mg and Al-Cu alloys produced by rheocasting assisted with UV are compact and with fine grains.The mechanical properties of the UV treated alloys are increased by about 20%-30%.Grain refinement of the alloys is generally considered because of cavitation and acoustic streaming caused by UV.Apart from these mechanisms,a hypothesis of the fuse of dendrite root caused by capillary infiltration in the ultrasonic field,as well as a mechanism of crystallites falling off from the mould-wall and crystal multiplication by mechanical vibration effect in indirect ultrasonic vibration are proposed to explain the microstructure evolution of the alloys.

关 键 词：ultrasonic vibration aluminum alloy MICROSTRUCTURE RHEOCASTING 

分 类 号：TG146.21[一般工业技术—材料科学与工程]