超声施振方式对消失模铸造Al/Mg双金属复合材料界面组织和力学性能的影响  

Effects of Ultrasonic Vibration Methods on the Interfacial Microstructure and Mechanical Properties of Al/Mg Bimetal Prepared by Lost Foam Casting

作　　者：李庆晴 徐远财 牛言清 樊自田[1] 蒋文明[1] LI Qingqing;XU Yuancai;NIU Yanqing;FAN Zitian;JIANG Wenming(State Key Laboratory of Materials Processing and Die&Mould Technology,Huazhong University of Science and Technology,Wuhan 430074,China)

机构地区：[1]华中科技大学材料成形与模具技术全国重点实验室,湖北武汉430074

出　　处：《铸造技术》2024年第5期411-418,共8页Foundry Technology

基　　金：国家自然科学基金(52271102,52075198);国家重点研发计划(2020YFB2008304);新金属材料国家重点实验室开放课题重点基金(2021-ZD07)。

摘　　要：研究了连续超声振动和间歇超声振动两种施振方式对消失模铸造Al/Mg双金属材料界面组织和力学性能的影响。结果表明,未施加超声振动Al/Mg双金属界面由Al-Mg金属间化合物区和共晶组织区组成,两个区域边界存在一层氧化膜,阻碍了元素扩散,Mg_(2)Si相呈网状,团聚分布于金属间化合物区。两种超声施振方式均能通过超声空化效应和声流效应破碎和消除氧化膜,并使Mg_(2)Si相细化和分散于整个界面,部分共晶组织转变为金属间化合物,提高了界面组织和显微硬度分布均匀性。连续超声振动作用下Al/Mg双金属界面剪切强度达到53.9 MPa,相比未超声处理提升63.8%。间歇超声振动作用下,界面厚度较连续超声振动减小,然而局部区域存在孔洞缺陷和Mg_(2)Si相局部聚集,削弱了对界面的强化效果,但界面剪切强度仍达到49.5 MPa。Ultrasonic vibration treatment(UVT)was applied to an Al/Mg bimetal fabricated by lost foam casting.The effects of continuous and intermittent UVT on the microstructures and mechanical properties of Al/Mg bimetal interfaces were investigated.The results reveal that the Al/Mg interface without UVT is composed of an Al-Mg intermetallic compound(IMC)area and a eutectic area,and a thin oxide film exists at the boundary between the two areas,which inhibits element diffusion.The net-shaped Mg_(2)Si gathers in the IMC area.Both continuous and intermittent UVT could remove the oxide film at the Al/Mg interface by acoustic cavitation and acoustic streaming effects.The Mg_(2)Si particles are refined and dispersed at the whole Al/Mg interface.In addition,part of the eutectic Al-Mg structure is transformed into Al-Mg IMCs due to the promotion of element diffusion by UVT,which increases the homogeneity of the interfacial microstructure and microhardness.The shear strength of the Al/Mg bimetal composite with continuous UVT reaches 53.9 MPa,which is an increase of 63.8%compared with that of the bimetal without UVT.The interface thickness of the Al/Mg bimetal composite with intermittent UVT is lower than that with continuous UVT.However,the existence of pore defects and local gathered Mg_(2)Si particles decreases the strength of the material,but the shear strength still reaches 49.5 MPa.

关 键 词：Al/Mg复合材料 消失模铸造 超声振动 界面 微观组织 力学性能 

分 类 号：TG292[金属学及工艺—铸造] TB331[一般工业技术—材料科学与工程]