The influence of structure evolution of metallic glass on glass forming ability by molecular dynamics study
The glass transformation processes of Ti75Al25,Ni50Zr50 and Cu50Zr50 were simulated by molecular dy-namics method.The average atomic volume and radial pair distribution function were obtained.Besides,the number of icosahedral and icosahedral-like clusters were calculated by Voronoi polyhedron index analysis.E-ventually,the dynamic evolution of amorphous atoms from short order to medium order and then to long range disorder was studied by analyzing the type and number of clusters during glass transformation.The results show that the glass forming ability is closely related to the type and number of Voronoi clusters.Besides,the clusters with high local quintuple symmetry tend to join together in order to form chains during the glass transformation process,which densely fills the whole space and reduces the dynamic behavior of the system.Furthermore,the plastic deformation tends to occur at the area with low local quintuple symmetry.It is intriguing to note that the abrupt changes of the types and number of clusters near the glass transformation temperature reflect the self-or-ganized criticality behavior of metallic glass.
万方数据
维普
