摘要
用水冷铜模激冷铸造制备Al-5.8Mg-0.4Mn-0.25Sc-0.1Zr合金。用透射电镜(TEM)、扫描电镜(SEM)和金相显微镜(OM)研究合金中Al3(Scx,M1-x)第二相粒子的存在形式和形成机制。结果表明:Al-5.8Mg-0.4Mn-0.25Sc-0.1Zr合金在急冷铸造条件下,合金中的Sc和Zr主要以固溶形式存在于α(Al)基体中,透射电镜和扫描电镜下很难观察到这些粒子存在。初生Al3(Scx,M1-x)粒子对铸态晶粒具有细化作用,晶粒尺寸可细化到10~20μm。铸态合金经550℃退火20 h后析出大量次生Al3(Scx,M1-x)粒子,这些粒子呈内部富Sc,外部富Zr的复合结构。该结构的形成一方面是由于Sc在铝合金基体中的原子扩散速率比Zr大;另一方面,通过形成这样的结构可降低界面能。
Al-5.8Mg-0.4Mn-0.25Sc-0.1Zr alloy was prepared by water-cooled copper-mold chill casting technology.Transmission electron microscopy(TEM),scanning electron microscopy(SEM)and optical microscopy(OM)were used to investigate the existence form and formation mechanism of Al3(Scx,M1-x)particles.The results show that under the condition of rapid cooling casting,Sc and Zr atoms in as-cast alloys mainly exist inα(Al)matrix as solid solution.And it is difficult to observe the presence of these particles under electron microscopy.The primary Al3(Scx,M1-x)particles have a refinement effect on the ascast grains,and the as-cast grain size can be refined to 10-20μm.After 550℃annealing for 20 h,the as-cast alloy precipitates a large number of secondary Al3(Scx,M1-x)particles.These particles exhibit a core-shell structure with Sc rich in interior and Zr rich in exterior.The structure is formed because the atomic diffusion rate of Sc in aluminum alloy matrix is much faster than that of Zr atoms in aluminum,and the interfacial energy can be reduced by forming such a structure.
作者
陈显明
潘清林
范莹莹
CHEN Xianming;PAN Qinglin;FAN Yingying(School of Electronic and Information&Mechanical Engineering,Zhaoqing University,Zhaoqing 526061,China;School of Materials Science and Engineering,Central South University,Changsha 410083,China)
出处
《兵器材料科学与工程》
CAS
CSCD
北大核心
2021年第1期18-22,共5页
Ordnance Material Science and Engineering
基金
国家自然科学基金(51402258)。
