电解制备含钪铝合金三元相超声细化机制  

Ultrasonic refining mechanism of ternary phase in Al–Sc based alloys prepared through molten salt electrolysis

作　　者：刘轩 郭志超 薛济来[1,2] 王曾洁[3] 李想[2] 朱常伟 张鹏举 LIU Xuan;GUO Zhi-chao;XUE Ji-lai;WANG Zeng-jie;LI Xiang;ZHU Chang-wei;ZHANG Peng-ju(School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China;State Key Laboratory of Advanced Metallurgy,University of Science and Technology Beijing,Beijing 100083,China;College of Material Science and Engineering,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]北京科技大学冶金与生态工程学院,北京100083 [2]北京科技大学钢铁冶金国家重点实验室,北京100083 [3]北京工业大学材料科学与工程学院,北京100124

出　　处：《工程科学学报》2020年第11期1465-1472,共8页Chinese Journal of Engineering

基　　金：国家自然科学基金资助项目(51704020,51874035);中央高校基本科研业务费资助项目(FRF-TP-19-034A2)。

摘　　要：研究采用超声协同熔盐电解法制备Al–Si–Sc和Al–Cu–Sc合金,采用光学显微镜、扫描电镜和X射线衍射研究超声对合金中三元含钪强化相形貌与尺寸的影响,进而阐明超声细化机制.研究结果表明,协同超声促使三元AlSiSc相由粗大菱形管状转变为细小实心方棒状,其尺寸由205减小到40μm左右;超声显著细化三元AlCuSc相团簇尺寸,由约100减小至约30μm;超声协同细化机制主要是通过提高形核率细化初生Al3Sc相并促进其均匀分布,进而作为形核发育基底,最终实现三元含钪相细化;同时超声也可促进合金溶质均匀分布,避免粗大Al3Sc相析出;超声细化三元含钪相机制主要作用于电解后凝固阶段.Aluminum alloys are widely used in cutting-edge technologies and emerging strategic industries,namely aerospace,highspeed rail transportation,electric vehicles,advanced functional materials,new energy storage,and conversion devices.The processability as well as the mechanical properties of aluminum alloys can be improved via the addition of trace scandium.The ultrasonically assisted molten salt electrolysis is a promising,short technical route for large-scale preparation of low-cost,Al–Sc-based alloys characterized by uniform and fine strengthening phases.At present,it is still unclear if that is the case for the ultrasonic refining mechanism of the Sc-bearing ternary phase.This study aims at clarifying the ultrasonic refining mechanism on the strengthening phase containing scandium.Two Al–Sc based alloys were prepared using ultrasonically assisted molten salt electrolysis while the effect of ultrasound on the morphology and size of the Sc-bearing ternary phase was studied using optical microscope,scanning electron microscope,and X-ray diffraction meter.The results show that the synergetic ultrasound facilitates the transformation of the ternary AlSiSc phase from the coarse rhombic tubes(~205μm)to the short rod(40μm).The cluster size of ternary AlCuSc phase is also greatly reduced from^100μm to^30μm.The ultrasonic refining mechanism is mainly related to the increase of the nucleation rate of the primary Al3Sc particles which are greatly refined and dispersed in the alloy melt before the solidification stage.The refinement of the Scbearing ternary phase is considered to be caused by the fine and disperse Al3Sc particles serving as nuclei.Furthermore,ultrasound can also aid the uniform distribution of solute field and prevent the precipitation of coarse Al3Sc phase.The effect of ultrasonic refinement of the ternary rhenium-containing phase is mainly present at the solidification stage after electrolysis.

关 键 词：含钪铝合金 三元强化相 超声协同 熔盐电解法 细化机理 

分 类 号：TF82.1[冶金工程—有色金属冶金]