第一性原理法分析Ce对TiAl_(3)/α-Al异质形核界面的影响  

Effect of Ce on the heterogeneous nucleation interface of TiAl_(3)/α-Al by first-principles

作　　者：宋莉莉 傅高升[2,3] 王火生[4] SONG Li-li;FU Gao-sheng;WANG Huo-sheng(College of New Energy and Intelligent Manufacturing,Ningde Vocational and Technical College,Fu’an,Fujian 355000,China;School of Materials Science and Engineering,Fuzhou University,Fuzhou,Fujian 350108,Fujian,China;College of Physics and Electronic Information Engineering,Minjiang University,Fuzhou,Fujian 350108,China;School of Materials Science and Engineering,Fujian University of Technology,Fuzhou,Fujian 350118,China)

机构地区：[1]宁德职业技术学院新能源与智能制造学院,福建福安355000 [2]福州大学材料科学与工程学院,福建福州350108 [3]闽江学院物理与电子信息工程学院,福建福州350108 [4]福建理工大学材料科学与工程学院,福建福州350118

出　　处：《宁德师范学院学报(自然科学版)》2024年第4期360-366,共7页Journal of Ningde Normal University(Natural Science)

基　　金：福建省中青年教师教育科研项目(JAT210951);福建省科技计划(产学研联合创新)项目(2020Y4018)。

摘　　要：为深入了解稀土元素Ce在Al-Ti-B-Ce细化剂中对第二相TiAl_(3)的作用机理,采用第一性原理方法研究Ce在TiAl_(3)/α-Al界面的偏聚行为,Ce偏聚对界面稳定性、界面结合强度以及界面电子结构的影响。结果表明,Ce能够自发偏聚于TiAl_(3)与Al的形核界面处,使TiAl_(3)/α-Al界面稳定性提高,有效促进α-Al在TiAl_(3)表面形核。Ce对TiAl_(3)/α-Al界面不同侧影响不同。在TiAl_(3)(001)侧Ce对Al原子有较强键合力,能降低TiAl_(3)的表面能,改变TiAl_(3)的择优生长取向,提供更多的形核基底,促进α-Al在TiAl_(3)表面形核;在Al(001)侧Ce对电子结构影响较小,无法对α-Al产生直接细化作用。The effect of Ce on the refinement of Al is strongly associated with its characteristics of interface structure,electronic construction and properties of TiAl_(3)/α-Al heterogeneous nucleation interface.The firstprinciples calculation is employed to describe the occupancy tendency,segregation behavior and bond strength of Ce-doping on the TiAl_(3)/α-Al interface aiming to further our understanding of grain refining mechanism in⁃volving Al-Ti-B-Ce refiners.The results show that,the Ce-doped interfaces have negative segregation ener⁃gies which indicates that Ce is easy to segregate at the TiAl_(3)/α-Al interface to influence nucleation capacity of TiAl_(3)on Al.Compared with the clean interface of TiAl_(3)/α-Al,the Ce-doped interface shows smaller interface energy to improve the capacity of TiAl_(3)by offering more nucleation interface matches.The influence of Ce on the TiAl_(3)/α-Al interface on both sides is different.On the TiAl_(3)(001)side,Ce has a stronger bonding force with Al atoms,and can lower the surface energy of TiAl_(3),change its preferred growth orientation,and promote the nucleation ofα-Al on the surface of TiAl_(3).The influence of Ce on the Al(001)side is small and cannot directly refineα-Al.

关 键 词：CE TiAl_(3)/α-Al 异质形核 第一性原理 

分 类 号：TG146.2[一般工业技术—材料科学与工程]