The heredity of clusters in rapidly cooled(Zr_(50)Cu_(50))_(100-x)Al_x melts and its correlation with glass-forming ability(GFA)are studied via molecular dynamics simulations.Pair distribution function and the largest...The heredity of clusters in rapidly cooled(Zr_(50)Cu_(50))_(100-x)Al_x melts and its correlation with glass-forming ability(GFA)are studied via molecular dynamics simulations.Pair distribution function and the largest standard cluster(LSC)are adopted to characterize the local atomic structures in the(Zr_(50)Cu_(50))_(100-x)Al_(x)systems.The[12/555]icosahedra and their medium-range order(IMRO)play an important role in forming(Zr_(50)Cu_(50))_(100-x)Al_(x)metallic glasses(MGs).The fraction of[12/555],the number of IMRO,and the maximum size of IMRO in MGs increase significantly with increasing x.A tracking study further reveals that the configuration heredity of icosahedral clusters starts from supercooled liquids.No direct correlation exists between the GFA and the onset temperature of continuous or stated heredity.Instead,a larger hereditary supercooled degree of icosahedra matches with better GFA of Al-doped Zr_(50)Cu_(50)alloys.展开更多
The sintering-alloying processes of nickel(Ni),iron(Fe),and magnesium(Mg) with aluminum(Al) nanoparticles were studied by molecular dynamics simulation with the analytic embedded-atom model(AEAM) potential.Potential e...The sintering-alloying processes of nickel(Ni),iron(Fe),and magnesium(Mg) with aluminum(Al) nanoparticles were studied by molecular dynamics simulation with the analytic embedded-atom model(AEAM) potential.Potential energy,mean heterogeneous coordination number NAB,and surface atomic number Nsurf-A were used to monitor the sintering-reaction processes.The effects of surface segregation,heat of formation,and melting point on the sinteringalloying processes were discussed.Results revealed that sintering proceeded in two stages.First,atoms with low surface energy diffused onto the surface of atoms with high surface energy;second,metal atoms diffused with one another with increased system temperature to a threshold value.Under the same initial conditions,the sintering reaction rate of the three systems increased in the order MgAl <FeAl <NiAl.Depending on the initial reaction temperature,the final core-shell(FeAl and MgAl) and alloyed(NiAl and FeAl) nanoconfigurations can be observed.展开更多
基金the National Natural Science Foundation of China(Grant No.51701071)the Natural Science Foundation of Hunan Province,China(Grant Nos.2018JJ3100 and 2018JJ2078)the Project of the Hunan Educational Department,China(Grant No.19B122)。
文摘The heredity of clusters in rapidly cooled(Zr_(50)Cu_(50))_(100-x)Al_x melts and its correlation with glass-forming ability(GFA)are studied via molecular dynamics simulations.Pair distribution function and the largest standard cluster(LSC)are adopted to characterize the local atomic structures in the(Zr_(50)Cu_(50))_(100-x)Al_(x)systems.The[12/555]icosahedra and their medium-range order(IMRO)play an important role in forming(Zr_(50)Cu_(50))_(100-x)Al_(x)metallic glasses(MGs).The fraction of[12/555],the number of IMRO,and the maximum size of IMRO in MGs increase significantly with increasing x.A tracking study further reveals that the configuration heredity of icosahedral clusters starts from supercooled liquids.No direct correlation exists between the GFA and the onset temperature of continuous or stated heredity.Instead,a larger hereditary supercooled degree of icosahedra matches with better GFA of Al-doped Zr_(50)Cu_(50)alloys.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11572124 and 51871096)the Natural Science Foundation of Hunan Province of China(Grant Nos.2018JJ4044 and 2018JJ3100).
文摘The sintering-alloying processes of nickel(Ni),iron(Fe),and magnesium(Mg) with aluminum(Al) nanoparticles were studied by molecular dynamics simulation with the analytic embedded-atom model(AEAM) potential.Potential energy,mean heterogeneous coordination number NAB,and surface atomic number Nsurf-A were used to monitor the sintering-reaction processes.The effects of surface segregation,heat of formation,and melting point on the sinteringalloying processes were discussed.Results revealed that sintering proceeded in two stages.First,atoms with low surface energy diffused onto the surface of atoms with high surface energy;second,metal atoms diffused with one another with increased system temperature to a threshold value.Under the same initial conditions,the sintering reaction rate of the three systems increased in the order MgAl <FeAl <NiAl.Depending on the initial reaction temperature,the final core-shell(FeAl and MgAl) and alloyed(NiAl and FeAl) nanoconfigurations can be observed.
