A356铝合金轮毂Si偏析现象及力学性能  

Study on the Si segregation and mechanical properties of A356 aluminum alloy wheel hub

作　　者：欧翅翔 汪樟锋 刘锋睿 王孟君[1] 陈柏辰 OU Chixiang;WANG Zhangfeng;LIU Fengrui;WANG Mengjun;CHEN Baichen(School of Materials Science and Engineering,Central South University,Changsha 410083,China;Research and Development Center of Kunshan Liufeng Machinery Co.,Ltd.,Suzhou 215300,China)

机构地区：[1]中南大学材料科学与工程学院,长沙410083 [2]昆山六丰机械有限公司研发中心,江苏苏州215300

出　　处：《有色金属科学与工程》2020年第1期60-66,共7页Nonferrous Metals Science and Engineering

基　　金：昆山市产学研项目计划资助(2018F0707451024)

摘　　要：采用扫描电镜、金相显微和拉伸实验等分析了低压铸造A356轮毂的组织,建立了Si偏析现象的表征方法,并探讨了铸件SDAS值和Si颗粒平均面积对其力学性能的影响。结果表明:采用共晶面积分数、Si颗粒平均面积和长径比可以很好地表征Si偏析程度;轮毂轮辐中部R角处共晶面积分数、Si颗粒平均面积、长径比和SDAS值分别为34.83%、11.33μm2、2.46和56.89μm,相应的UTS、YS和EL值分别为229.02、152.67 MPa和5.34%,轮毂Si偏析程度越高的部位,其力学性能也越差。在分析铸件拉伸性能时,应综合考虑SDAS与Si偏析的影响。并且给出了解决Si偏析问题的具体措施。The microstructure of A356 wheel casted in low pressure was analyzed by scanning electron microscopy,metallographic microscope and tensile test.The characterization method of Si segregation was established and the influence of SDAS and the average area of Si particles on the mechanical properties of the casting was analyzed.The results indicate that the degree of Si segregation can be well characterized by eutectic area fraction,the average area of Si particles and aspect ratio;eutectic area fraction,the average area of Si particles,aspect ratio and SDAS at R angle in the middle of hub spoke are 34.83%.11.33μm2,2.46 and 56.89μm,respectively,and the corresponding UTS,YS and EL values are 229.02 MPa,152.67 MPa and 5.34%,respectively;the higher the degree of Si segregation of the hub is,the worse its mechanical properties are.SDAS and Si segregation should be both taken into consideration in the analysis of the tensile properties of the casting.This paper gives some specific measures to solve the problem of Si segregation.

关 键 词：A356 铝合金轮毂 偏析 二次枝晶臂间距 共晶 

分 类 号：TG146.4[一般工业技术—材料科学与工程]