Development of prominent bonding strength in Al/Mg bimetal composites prepared by ultrasonic vibration-assisted compound casting:Effects of ultrasonic powers  

作　　者：Qingqing Li Wenming Jiang Yuancai Xu Linghui Yu Yanqing Niu Zitian Fan 

机构地区：[1]State Key Laboratory of Materials Processing and Die&Mould Technology,School of Materials Science and Engineering,Huazhong University of Science and Technology,Wuhan 430074,China

出　　处：《Journal of Materials Science & Technology》2024年第30期78-93,共16页材料科学技术(英文版)

基　　金：supported by the National Natural Science Foundation of China(Nos.52271102 and 52075198);the National Key Research and Development Program of China(No.2020YFB2008304),and the Analytical and Testing Center,HUST。

摘　　要：In this work,the A356/AZ91D bimetal composites were prepared by ultrasonic vibration-assisted lost foam compound casting,and the effects of ultrasonic powers on interfacial microstructures and mechan-ical properties of the Al/Mg interfaces were investigated.Results revealed that the Al/Mg bimetal com-posites without ultrasonic vibration treatment(UVT)were heterogeneous,and the Al/Mg interface was composed of Al-Mg intermetallic compounds(IMCs,i.e.,Al_(3)Mg_(2)and Al_(12)Mg_(17))area and Al-Mg eutec-tic structures(δ-Mg+Al_(12)Mg_(17))area.The Mg_(2)Si particles were gathered at the IMCs area and an oxide film that mainly composed of Al_(2)O_(3)was existed between the IMCs area and eutectic structures area.With UVT,the oxide film was eliminated and the gathered Mg_(2)Si particles were refined and dispersed by the acoustic cavitation effect,and part of the Al_(3)Mg_(2)and Al-Mg eutectic structures were transformed into the Al_(12)Mg_(17)due to the promoted solute interdiffusion,which improved the homogeneity of the Al/Mg interfaces.Besides,the grains of the Al/Mg interface with UVT under ultrasonic power of 75 W were significantly refined.The thickness of Al/Mg interface was increased with the increase of the ul-trasonic power.Due to the excessive heat induced by UVT under the further increased ultrasonic power,the cooling rates and the degree of supercooling were reduced,resulting in the coarsening of interfacial grains.The microhardness of the Al/Mg interfaces was increased and got more uniform by UVT.The shear strengths of the Al/Mg bimetal composites with UVT were enhanced to 61.4 MPa from 32.4 MPa,with an increase of 89.5%compared with that of the Al/Mg bimetal without UVT.This could be ascribed to the removal of the oxide film,the refinement of the interfacial grains and the dispersed and refined Mg_(2)Si particles achieved by UVT,which hindered the crack propagation during deformation.

关 键 词：Ultrasonic vibration treatment Al/Mg bimetal composites Compound casting Interfacial microstructure Mechanical properties 

分 类 号：TG1[金属学及工艺—金属学]