超声振动工艺下微量Sc对A380合金组织性能的影响  

Effect of minor Sc under ultrasonic vibration technology on microstructures and mechanical properties of A380 alloy

作　　者：雷吉平 余剑武[1] 李承波[3] 陈健美[2] 范光辉[1] 李子夫[3] LEI Jiping;YU Jianwu;LI Chengbo;CHEN Jianmei;FAN Guanghui;LI Zifu(State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body,Hunan University, Changsha 410082, China;School of Mechanical Engineering, Hunan International Economics University, Changsha 410205, China;School of Materials Science and Engineering, Central South University, Changsha 410083, China)

机构地区：[1]湖南大学汽车车身先进设计制造国家重点实验室,湖南长沙410082 [2]湖南涉外经济学院机械工程学院,湖南长沙410205 [3]中南大学材料科学与工程学院,湖南长沙410083

出　　处：《中南大学学报（自然科学版）》2017年第10期2666-2672,共7页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51275165);湖南省"十二五"重点建设学科资助项目(080204)~~

摘　　要：在超声振动工艺下加入质量分数为0~0.5%的稀土Sc对A380合金进行变质处理,以研究稀土Sc对A380合金微观组织和力学性能的影响。研究结果表明:在超声振动工艺下,加入微量Sc可以使A380合金微观组织中的初生α相显著细化,由粗大的树枝晶变为细小、无定向的枝晶,并且形态变得圆整,出现大量蔷薇状和颗粒状的α相;当Sc加入量为0.3%时,对α相的细化效果最理想;同时,超声振动工艺下微量Sc还使A380合金微观组织中的共晶Si和Al3Fe Si2相尺寸显著减小,由粗大的针状变为蠕虫状和点状;加入0.3%Sc的A380合金,其铸态下抗拉强度为314 MPa,屈服强度为223 MPa,伸长率为3.7%,勃氏硬度为109,此时,晶粒粒度最小,约为31μm,形状因子最大,为0.75。Effects of0?0.5%Sc under ultrasonic vibration technology(UVT)modification on microstructure and mechanical properties of A380alloy were investigated.The results show that the primaryαphase in A380alloy can be refined significantly,which makes coarse dendrite into fine non-directional dendrites,and a number ofαphase in form of rosette and granular can be observed.The desirable refinement ofαphase in A380alloy is obtained with0.3%Sc.Meanwhile,the sizes of eutectic silicon and Al3FeSi2phase in the alloy decrease significantly by adding minor Sc under UVT,and the shapes of the eutectic silicon and Al3FeSi2phase change from coarse acicular to vermicular and spot ones.The as-cast A380with0.3%Sc has tensile strength of314MPa,yielding strength of223MPa,elongation of3.7%and hardness of109.The grain size is the smallest(31μm),and shape factor is the largest(0.75).

关 键 词：SC 超声波振动 微观组织 

分 类 号：TG146.2[一般工业技术—材料科学与工程]