Pd82 Si18非晶合金结构演变的分子动力学模拟研究  

Molecular Dynamics Simulation of Structure Evolution in Amorphous Pd82 Si18 Alloy

作　　者：薛博钰 Xue Boyu(School of Materials Science and Engnieering,Shaanxi University of Technology,Shaanxi Hanzhong 723001,China)

机构地区：[1]陕西理工大学材料科学与工程学院,陕西汉中723001

出　　处：《机械科学与技术》2020年第4期629-634,共6页Mechanical Science and Technology for Aerospace Engineering

摘　　要：为了研究Pd⁃Si非晶合金的结构和非晶转变过程中结构的演化规律,通过分子动力学(MD)方法模拟了Pd⁃Si体系从液态到非晶态的非晶转变过程,并利用双体分布函数、Voronoi多面体等方法表征了原子尺度结构。结果表明,通过MD模拟得到的非晶转变温度和合金液体的双体分布函数均与实验结果相一致。在非晶合金结构中,Pd与Si原子相互吸引并排列在第一近邻的位置上,而Si与Si原子之间的相互排斥作用使得它们之间的距离较大。在短程序结构(SRO)方面,在Pd原子周围并无占据主导地位的SRO,而在Si原子周围Z9和Z10为占据主导地位的SRO。此外,随着温度的降低,配位数缓慢增加,而SRO的含量和五重局部对称性的程度迅速增加,并且SRO连接得更加紧密。To investigate the structure of Pd⁃Si metallic glass and the structure evolution in the glass transition process,molecular dynamics(MD)simulation was performed to simulate the glass transition process from liquid to glassy state by adopting the pair distribution functions and Voronoi Polyhedra analysis to characterize the atomic⁃level structure.The simulated results of the glass transition temperature and pair distribution functions of the alloy liquid from the MD simulation are in a good agreement with the experimental.In the structure of metallic glass,Pd and Si atoms tend to attract each other and lie on the positions of the first neighbor,while the repulsive interaction among Si and Si atoms results in the larger distance.From the aspect of short⁃range order(SRO),there is no dominant SRO around Pd atoms,while Z9 and Z10 are the dominant SROs around Si atoms.In addition,the coordination number increases slightly with the decreasing of temperature,,the fraction of the SRO and the degree of the five⁃fold local symmetry increase significantly,and the SRO connects more firmly with each other.

关 键 词：Pd⁃Si合金 液态结构 非晶转变 计算机模拟 

分 类 号：TB303[一般工业技术—材料科学与工程]