在TiAl合金快速凝固过程中拓扑密堆结构的演化特征  

Evolution characteristics of topologically close-packed structures during rapid solidification of Ti Al alloy

作　　者：朱挥 陈茜 罗玉玺 高廷红 田泽安 ZHU Hui;CHEN Qian;LUO YuXi;GAO TingHong;TIAN ZeAn(Institute of Advanced Optoelectronic Materials and Technology,School of Big Data and Information Engineering,Guizhou University,Guiyang 550025,China;College of Computer Science and Electronic Engineering,Hunan University,Changsha 410082,China)

机构地区：[1]贵州大学大数据与信息工程学院,新型光电子材料与技术研究所,贵阳550025 [2]湖南大学信息科学与工程学院,长沙410082

出　　处：《中国科学：物理学、力学、天文学》2022年第12期71-81,共11页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：国家自然科学基金(编号:51761004);贵州省科技计划(黔科合基础-ZK[2022]一般042)资助项目。

摘　　要：快速凝固是材料加工的手段之一.本文使用分子动力学模拟了不同组分的TiAl合金在2×10^(11)K/s冷速下的快速凝固过程.通过平均原子势能、双体分布函数(PDF)、最大标准团簇分析法(LaSCA)和可视化方法分析了体系的特性.研究发现,Al含量较高的体系发生非晶化,较低的体系发生晶化.在非晶体系中,TCP LaSC能很好地表征TiAl合金微观结构.有趣的是,在玻璃化过程中,不同的拓扑密堆(Topologically Close-Packed,TCP)结构的子集表现出不同的演变趋势.这种不同的演变特征为解释TiAl合金玻璃化特性提供了新的视角.这个发现对非晶形成能力与非晶结构之间相关性的研究具有启发意义.Rapid solidification is one of the material processing methods.In this study,the rapid solidification process of Ti Al alloys at a cooling rate of 2×10^(11)K/s was simulated using molecular dynamics.The properties of the system were analyzed using the potential energy,pair distribution function,largest standard cluster analysis(La SCA),and visualization methods.Notably,after the melt processes of supercooled liquid and solid,the system with a high Al content undergoes amorphization,and that with a low Al content undergoes crystallization.In the amorphous system,topologically closepacked(TCP)La SCA can well characterize the microstructure of Ti Al alloy.Notably,different subsets of TCP structures show different evolutionary trends during amorphization.Different evolutionary characteristics provide proof that explains the vitrification characteristics of Ti Al alloy.This finding can be the basis for the analysis of the correlation between glass-forming capability and amorphous structures.

关 键 词：MD模拟 快速凝固 TCP结构 最大标准团簇分析法 

分 类 号：TG146.23[一般工业技术—材料科学与工程]