Al−Si−Fe−Mn合金熔体保温过程中富铁相的三维形态特征和生长行为  

3D characteristics and growth behavior of Fe-rich phases in Al−Si−Fe−Mn alloys during melt holding

作　　者：宋东福 赵愈亮 贾义旺[4] 李新涛 周楠 郑开宏 张卫文[2] Dong-fu SONG;Yu-liang ZHAO;Yi-wang JIA;Xin-tao LI;Nan ZHOU;Kai-hong ZHENG;Wei-wen ZHANG(Guangdong Provincial Key Laboratory of Metal Toughening Technology and Application,Institute of New Materials,Guangdong Academy of Sciences,Guangzhou 510650,China;National Engineering Research Center of Near-net-shape Forming for Metallic Materials,South China University of Technology,Guangzhou 510641,China;School of Mechanical Engineering,Dongguan University of Technology,Dongguan 523808,China;College of Materials and Metallurgy,Guizhou University,Guiyang 550025,China;Jiangxi Universal New Material Technology Co.,Ltd.,Shangrao 334499,China)

机构地区：[1]广东省科学院新材料研究所广东省金属强韧化技术与应用重点实验室,广州510650 [2]华南理工大学金属材料近净成形国家工程技术研究中心,广州510641 [3]东莞理工大学机械工程学院,东莞523808 [4]贵州大学材料与冶金学院,贵阳550025 [5]江西寰球新材料科技有限公司,上饶334499

出　　处：《Transactions of Nonferrous Metals Society of China》2024年第6期1745-1758,共14页中国有色金属学报（英文版）

基　　金：supported by the National Natural Science Foundation,China (No.52074131);the National Key R&D Project,China (No.2022YFC3900500);the International Technology Cooperation Program of Guangdong Academy of Sciences,China (No.2020GDASYL-20200504001);the Open Competition to Select the Best Candidate of Shangrao,China (No.2021A005);the BL13HB beamline of Shanghai Synchrotron Radiation Facility (SSRF)for providing synchrotron radiation beamtime (Nos.2020-SSRF-PT-011937,2021-SSRF-PT-017645).

摘　　要：采用扫描电子显微镜、透射电子显微镜、热力学计算和同步辐射X射线成像技术研究Al−7.0Si−1.0Fe−1.2Mn合金熔体保温过程中富铁相的形态演变和生长行为。结果表明,随着保温温度的降低,富铁相的形态由粗大的星形和多边形状转变成细小的汉字状以及汉字和多边形的耦合结构。富铁相的三维形貌显示,星形富铁相由多个多分支的初生相和衍生的不规则次生相组成;耦合结构由多面体和枝晶组成;单一汉字相则由枝晶组成。随着保温温度的降低,富铁相的数量、体积分数以及最大富铁相的体积和连通性显著降低。原位同步辐射X射线结果显示,在凝固过程中形成了两类初生富铁相,其中尺寸较小的初生富铁相保留在熔体中,并成为耦合共晶结构富铁相的形核质点。The morphological evolution and growth behavior of Fe-rich phases in the Al−7.0Si−1.0Fe−1.2Mn alloy during melt holding were studied using scanning/transmission electron microscopy,thermodynamic calculations and synchrotron X-ray imaging.The results show that with a decrease in holding temperature,the Fe-rich phase underwent a morphological transformation from coarse star-like and polygonal structures to fine Chinese-script and coupled structures consisting of Chinese-script and polygonal shapes.The 3D structure of the star-like phase was composed of multibranched primary phases and irregular secondary phases;the coupled structure was composed of polyhedrons and dendrites;the Chinese-script phase was composed of dendrites.When the holding temperature was decreased,the number and volume fraction of Fe-rich phases were significantly reduced.A similar trend was also obtained for the largest volume particles and their connectivity.In situ synchrotron X-ray radiography results indicated that two types of primary Fe-rich phases were formed during the solidification process,and the smaller phase that remained in the melt could act as nucleation sites for the formation of the coupled eutectic structures.

关 键 词：保温温度 Al−Si合金 富铁相 3D形态演变 同步辐射X射线 

分 类 号：TG146.21[一般工业技术—材料科学与工程]