Sc含量对AlSiFeMnMg合金的组织和力学性能的影响  

Effects of Sc Content on Microstructure and Mechanical Properties of AlSiFeMnMg Alloy

作　　者：范晓明[1] 罗世旭 卢晓斌 谭俭 黄刚福 Fan Xiaoming;Luo Shixu;Lu Xiaobin;Tan Jian;Huang Gangfu(School of Material Science and Engineering,Wuhan University of Technology;Gao'an Luxe Machinery Co.,Ltd.)

机构地区：[1]武汉理工大学材料科学与工程学院 [2]高安市璐克斯机械有限公司

出　　处：《特种铸造及有色合金》2023年第8期1126-1131,共6页Special Casting & Nonferrous Alloys

摘　　要：采用金相显微镜、扫描电镜、电子探针和电子万能材料试验机等研究了不同Sc加入量[w(Sc)=0.1%,0.2%,0.3%,0.4%,0.5%]的Al-9Si-0.6Fe-0.2Mn-0.2Mg合金压铸试棒的微观组织和力学性能。结果表明,Sc能有效改善原始合金的显微组织,对初生α-Al相、共晶Si相和Fe相具有明显的细化、变质作用。随着Sc加入量增加,合金的力学性能均呈现出先上升后下降的趋势。当加入0.3%的Sc时,合金的细化变质效果和力学性能最佳。其显微组织主要为细小均匀的α-Al等轴晶,大部分为颗粒状、少量为蠕虫状的共晶Si相,以及团块状α-Al_(15)(Fe,Mn)_(3)Si_(2)+汉字状Al_(12)Si_(6)Fe_(2)(Mg,Sc)_(5)的Fe相。合金的抗拉强度、屈服强度、伸长率和硬度(HV)分别为273.0 MPa、183.6 MPa、6.4%和83.6,此时合金的断裂方式为韧性断裂。The microstructure and mechanical properties of Al-9Si-0.6Fe-0.2Mn-0.2Mg alloy die casting testing bars with different Sc content[w(Sc)=0.1%,0.2%,0.3%,0.4%,0.5%]were investigated by metallographic microscope,scanning electron microscope,electron probe and electronic universal material testing machine.The results indicate that Sc can effectively modify the microstructure of initial alloy,which has obvious refining and metamorphic effects on the primary α-Al phase,eutectic Si phase and Fe phase.With Sc content increase,the mechanical properties of the alloy present a trend of increasing firstly and then decreasing.After adding 0.3%Sc,the refining modification effect and mechanical properties of the alloy are desirable.The microstructure of the alloy is composed of fine and uniform α-Al equiaxed crystals,eutectic Si phase in which most are granular and a small amount are worm-like,and some Fe phases including massive α-Al_(15)(Fe,Mn)_(3)Si_(2) and Chinese character Al_(2)Si_(6)-Fe_(2)(Mg,Sc)_(5).The tensile strength,yield strength,elongation and microhardness of the alloy are 273.0 MPa,183.6 MPa,6.4% and 83.6,respectively,and the fracture mode is dominated by ductile fracture.

关 键 词：Al-Si压铸合金 SC 显微组织 力学性能 

分 类 号：TG146.21[一般工业技术—材料科学与工程] TG113.25[金属学及工艺—金属材料]