Influence of rheo-diecasting processing parameters on microstructure and mechanical properties of hypereutectic Al-30%Si alloy  

流变压铸工艺参数对过共晶Al-30%Si合金显微组织和力学性能的影响（英文）

作　　者：Zhi-kai ZHENG Yong-jian JI Wei-min MAO Rui YUE Zhi-yong LIU 郑志凯;吉永健;毛卫民;岳锐;刘志勇(北京科技大学材料科学与工程学院,北京100083;清华大学机械工程系,北京100084)

机构地区：[1]Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China [2]Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China

出　　处：《Transactions of Nonferrous Metals Society of China》2017年第6期1264-1272,共9页中国有色金属学报（英文版）

基　　金：Project(5077400) supported by the National Natural Science Foundation of China

摘　　要：The effects of pouring temperature,vibration frequency,and the number of curves in a serpentine channel,on themicrostructure and mechanical properties of Al-30%Si alloy processed by rheo-diecasting(RDC)were investigated.The semisolidAl-30%Si alloy slurry was prepared by vibration serpentine channel pouring(VSCP)process in the RDC process.The results showthat the pouring temperature,the vibration frequency,and the number of the curves strongly affect the microstructure and mechanicalproperties of Al-30%Si alloy.Under experimental conditions of a pouring temperature of850°C,a twelve-curve copper channel anda vibration frequency of80Hz,the primary Si grains are refined into fine compact grains with average grain size of about24.6μm inthe RDC samples assisted with VSCP.Moreover,the ultimate tensile strength(UTS),elongation and hardness of the RDC sample are296MPa,0.87%and HB155,respectively.It is concluded that the VSCP process can effectively refine the primary Si grains.Therefinement of primary Si grains is the major cause for the improvement of the mechanical properties of the RDC sample.研究流变压铸工艺参数浇注温度、振动频率和蛇形通道弯道数量对Al-30%Si合金的显微组织和力学性能的影响。流变压铸过程中的半固态Al-30%Si合金浆料采用振动蛇形通道浇注工艺制备。实验结果表明:浇注温度、振动频率和通道数量对Al-30%Si合金显微组织和力学性能的影响较大。在浇注温度为850°C、通道弯道数量为12和振动频率为80 Hz的条件下,流变压铸工艺制备的样品组织的初生硅晶粒被细化成平均粒径约为24.6μm的块状颗粒;此外,流变压铸样品的抗拉强度、伸长率和硬度分别为296 MPa、0.87%和HB 155。因此,振动蛇形通道浇注工艺能有效地细化组织中的初生Si晶粒。初生Si晶粒的细化是流变压铸样品力学性能改善的主要原因。

关 键 词：hypereutectic Al-Si alloy primary Si vibration serpentine channel pouring process RHEO-DIECASTING microstructure mechanical properties 

分 类 号：TG146.21[一般工业技术—材料科学与工程] TG249.2[金属学及工艺—金属材料]