TiC/Ni固液界面异质形核行为的第一性原理分子动力学模拟  

Ab initio molecular dynamics simulation of heterogeneous nucleation behavior at TiC/Ni solid-liquid interface

作　　者：王文菲 康瑶 黄盛星 黄昊[1] 王旭东[1] 姚曼[1] WANG Wenfei;KANG Yao;HUANG Shengxing;HUANG Hao;WANG Xudong;YAO Man(School of Materials Science and Engineering,Dalian University of Technology,Dalian 116024,China)

机构地区：[1]大连理工大学材料科学与工程学院,大连116024

出　　处：《中国有色金属学报》2024年第8期2673-2683,共11页The Chinese Journal of Nonferrous Metals

摘　　要：本文借助第一性原理分子动力学方法和密度泛函理论,针对四种TiC/Ni固液界面,从原子的异质形核行为与界面的电子性质两方面综合分析,进一步研究TiC促进Ni异质形核的机制。结果表明:TiC(100)、[Ti]-TiC(111)、[C]-TiC(111)基底均可诱导出Ni的预形核层(Pre-nucleation layer,PNL),且界面PNL的层间及面内有序度排序均为:[Ti]-TiC(111)/Ni>[C]-TiC(111)/Ni>TiC(100)/Ni。[Ti]-TiC(111)与PNL的Ni原子之间的强相互作用及化学键合使得其诱导出的PNL有序度最高。而TiC(110)基底无法诱导液体Ni原子形成预形核层,相较于上述三种基底,其促进Ni原子形核的能力最弱。在降温过程中,液相中剩余的Ni原子通过在TiC(100)、[Ti]-TiC(111)及[C]-TiC(111)基底诱导出的PNL作为过渡层的基础上,随温度的降低在PNL外侧聚集成簇,形成稳定的晶核。In this work,the heterogeneous nucleation behavior of atoms and the electronic structure of four TiC/Ni solid-liquid interfaces were comprehensively analyzed by using ab initio molecular dynamics(AIMD)and density functional theory(DFT)simulations.The mechanism of TiC promoting heterogeneous nucleation of Ni was then further discussed.The results show that pre-nucleation layer(PNL)of Ni can be induced by TiC(100),[Ti]-TiC(111)and[C]-TiC(111)substrates,and the arrangement of interlayer and in-plane ordering of the PNL at the interface is:[Ti]-TiC(111)/Ni>[C]-TiC(111)/Ni>TiC(100)/Ni.The strong interactions and chemical bonds between[Ti]-TiC(111)and the Ni atoms of PNL lead to the highest order degree of PNL.However,the TiC(110)substrate cannot induce the formation of pre-nucleation layer,and its ability to promote heterogeneous nucleation of Ni is the weakest compared to the above three substrates.During the cooling process,the remaining Ni atoms in the liquid phase gather into clusters on the outside of the PNL,which are induced as a transition layer on TiC(100),[Ti]-TiC(111)and[C]-TiC(111)substrates,and form a stable crystal nucleus as the temperature decreases.This provides quantitative theoretical data to explore the mechanism by which TiC particles promote heterogeneous nucleation of nickel-based superalloys.

关 键 词：TiC/Ni固液界面 预形核层 异质形核 第一性原理分子动力学模拟 

分 类 号：TG131[一般工业技术—材料科学与工程]